leptin and Diabetic-Nephropathies

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce the risk of serious heart failure events in patients with type 2 diabetes, but little is known about mechanisms that might mediate this benefit. The most common heart failure phenotype in type 2 diabetes is obesity-related heart failure with a preserved ejection fraction (HFpEF). It has been hypothesized that the synthesis of leptin in this disorder leads to sodium retention and plasma volume expansion as well as to cardiac and renal inflammation and fibrosis. Interestingly, leptin-mediated neurohormonal activation appears to enhance the expression of SGLT2 in the renal tubules, and SGLT2 inhibitors exert natriuretic actions at multiple renal tubular sites in a manner that can oppose the sodium retention produced by leptin. In addition, SGLT2 inhibitors reduce the accumulation and inflammation of perivisceral adipose tissue, thus minimizing the secretion of leptin and its paracrine actions on the heart and kidneys to promote fibrosis. Such fibrosis probably contributes to the impairment of cardiac distensibility and glomerular function that characterizes obesity-related HFpEF. Ongoing clinical trials with SGLT2 inhibitors in heart failure are positioned to confirm or refute the hypothesis that these drugs may favourably influence the course of obesity-related HFpEF by their ability to attenuate the secretion and actions of leptin.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Cardiomyopathies; Diabetic Nephropathies; Heart; Heart Failure; Humans; Hypoglycemic Agents; Intra-Abdominal Fat; Kidney Tubules; Leptin; Models, Biological; Myocardium; Obesity; Renal Insufficiency; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Stroke Volume

A case of Berardinelli-Seip syndrome, a congenital generalised lipodystrophy, is reported. Symptoms first appeared when the patient was 20 years old. She showed severe insulin resistance as well as micro- and macro-angiopathic complications, including chronic kidney disease, which required renal replacement therapy with peritoneal dialysis. The patient's clinical course was reviewed since paediatric age (when initial signs of the disease being already evident) to present time. Berardinelli-Seip syndrome is very uncommon, and the present case is particularly rare because it is the only case (at least as reported in the literature) in a patient receiving dialysis.

Topics: Acromegaly; Cardiomyopathy, Hypertrophic; Child; Delayed Diagnosis; Diabetic Nephropathies; Diagnosis, Differential; Exons; Female; Glomerulonephritis, Membranoproliferative; GTP-Binding Protein gamma Subunits; Humans; Insulin Resistance; Leptin; Lipodystrophy, Congenital Generalized; Peritoneal Dialysis, Continuous Ambulatory

Obesity and diabetes are major causes of CKD and ESRD, and are thus enormous health concerns worldwide. Both obesity and diabetes, along with other elements of the metabolic syndrome including hypertension, are highly interrelated and contribute to the development and progression of renal disease. Studies show that multiple factors act in concert to initially cause renal vasodilation, glomerular hyperfiltration, and albuminuria, leading to the development of glomerulopathy. The coexistence of hypertension contributes to the disease progression, which, if not treated, may lead to ESRD. Although early intervention and management of body weight, hyperglycemia, and hypertension are imperative, novel therapeutic approaches are also necessary to reduce the high morbidity and mortality associated with both obesity-related and diabetes-related renal disease.

Topics: Adiponectin; Animals; Cardiovascular Diseases; Cytokines; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Early Medical Intervention; Glomerular Filtration Rate; Humans; Kidney; Kidney Failure, Chronic; Leptin; Medication Therapy Management; Mice; Models, Animal; Obesity; Risk Reduction Behavior

Recent studies have demonstrated the role of insulin resistance in renal injury related to obesity, with hyperfiltration leading to glomerulomegaly in a pattern similar to that found in diabetic nephropathy. Similarities in the histologic patterns of damage from obesity and diabetes point to overlapping mechanisms of injury. In this review, we will examine the hormonal mechanisms, signaling pathways and injury patterns in renal injury resulting from obesity and attempt to draw conclusions on the reasons for these similarities.

Topics: Adiponectin; Diabetic Nephropathies; Female; Glomerular Filtration Rate; Hemodynamics; Humans; Insulin Resistance; Insulin-Secreting Cells; Kidney; Leptin; Male; Membrane Proteins; Obesity; Podocytes; Resistin; Signal Transduction; Sleep Apnea, Obstructive

Progress in identification of effective therapies for diabetic nephropathy continues to be limited by the lack of ideal animal models. Here we review the current status of some leading murine models of this disorder.. A consensus statement of the Animals Models of Diabetic Complications Consortium sets forth guidelines and standards for measuring renal function and structural parameters necessary for validating murine models of diabetic nephropathy. Two murine models exploiting endothelial nitric oxide synthase (eNOS) deficiency as a major susceptibility factor for development of diabetic nephropathy are among the very few options for studying features of advanced diabetic nephropathy. Akita and OVE26 mice with mutations that result in Type I diabetes are also useful models of diabetic nephropathy. The recently described BTBR ob/ob (leptin deficient) mouse with Type II diabetes demonstrates key features of early podocyte loss and mesangiolysis characteristic of human diabetic nephropathy.. While there are many murine models of mesangial matrix expansion in the setting of diabetes, few progress to develop advanced diabetic lesions. Mice with eNOS deficiency, OVE26 mice, and the recently described BTBR ob/ob mouse currently appear to be the best murine models of advanced disease. A model that allows testing of interventions that modulate podocyte loss and regeneration, such as the BTBR ob/ob mouse, may be of particular benefit in developing therapeutics for diabetic nephropathy.

Topics: Animals; Calmodulin; Diabetic Nephropathies; Disease Models, Animal; Glomerular Mesangium; Humans; Insulin Resistance; Leptin; Mice; Nitric Oxide Synthase Type III; Receptor, Insulin

Stroke is an important cause of morbidity and mortality, and is an economic burden. Diabetes and obesity are two important modifiable risk factors for stroke. Patients with diabetes have a higher incidence of stroke and a poorer prognosis after stroke. Risk-factor modification is the most important aspect of prevention of stroke in diabetes and obesity. This includes lifestyle modifications and different therapeutic modalities to control conditions, such as diabetes, hypertension, dyslipidemia and arrhythmia. Recent landmark studies have shown the beneficial effects of statins in diabetic patients even with close to normal or normal low-density lipoprotein cholesterol. Obesity, which is a risk factor for diabetes, hypertension and hyperlipidemia has been shown to be an independent risk factor for stroke. Increased leptin, dysregulation of adipocyte proteins, increased insulin resistance and C-reactive protein may be factors involved in the increased incidence of cardiovascular morbidity and mortality directly related to obesity. Visceral fat is a much bigger health risk than subcutaneous fat. Lifestyle interventions and pharmacotherapeutic agents have been used to manage obesity. In morbidly obese patients, surgical intervention seems to be the best method of treatment with a long-lasting favorable metabolic outcome. In the 21st Century, with the advanced medical knowledge and the therapeutic modalities available, it should be possible to reduce the incidence of stroke associated with diabetes and obesity.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Atrial Fibrillation; Blood Glucose; Cardiovascular Agents; Carotid Stenosis; Diabetes Mellitus; Diabetic Angiopathies; Diabetic Nephropathies; Diabetic Retinopathy; Dyslipidemias; Humans; Hypertension; Insulin Resistance; Ischemic Attack, Transient; Leptin; Life Style; Lipoproteins; Obesity; Plasminogen Activator Inhibitor 1; Risk Factors; Smoking; Stroke

Topics: Animals; Carrier Proteins; Diabetic Nephropathies; Glomerulosclerosis, Focal Segmental; Humans; Leptin; Proteins; Receptors, Cell Surface; Receptors, Leptin

Diabetic Nephropathy (DN) is one of the main complications of diabetes mellitus, mostly ending to end-stage renal disease. Leptin and C-reactive protein (CRP), as inflammatory markers implicated in the progression of DN, increase in diabetes mellitus, while transferrin and albumin, as members of anti-oxidant defense mechanism, are found to decline.. In a controlled clinical trial, 65 patients with type 2 DN were assigned to receive lovastatin or placebo, for 3 months, to assess statins' impact on serum levels of leptin, CRP, transferrin, albumin, and lipid profile.. Serum levels of CRP (3.52 +/- 4.16 mg/dL to 2.84 +/- 3.06 mg/dL, P = .02), leptin (10.78 +/- 8.30 mg/dL to 7.80 +/- 5.41 mg/dL, P = .006), low-density lipoprotein cholesterol (116.16 +/- 46.54 mg/dL to 85.46 +/- 29.22 mg/dL, P = .001), and total cholesterol (199.00 +/- 43.33 mg/dL to 164.67 +/- 35.19 mg/dL, P = .001) were lowered after lovastatin therapy. Mean serum level of high-density lipoprotein cholesterol increased (40.00 mg/dL to 42.80 mg/dL, P = .005) after the treatment. Lovastatin had no significant effect on albumin and transferrin. Placebo did not change any of the parameters after 3 months.. The effect of statins on the inflammatory markers involved in the development of DN is a new approach to evidence supporting the pleiotropic effect of this drug group.

Topics: Adult; C-Reactive Protein; Cholesterol, HDL; Cholesterol, LDL; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Kidney Failure, Chronic; Leptin; Lovastatin; Male; Middle Aged

Diabetic kidney disease (DKD) is a major health burden closely related to lipid metabolism disorders. Leptin has lipid-lowering efficacy, but the specific mechanism of its local effects on kidney is still unclear. This study aims to investigate the role of ectopic lipid deposition (ELD) in DKD and evaluate the lipid-lowering efficacy of leptin in the palmitic acid (PA)-induced renal tubular epithelial cells (NRK-52E). DKD model was established in Sprague-Dawley (SD) rats by giving single intraperitoneal injection of streptozotocin (STZ, 30 mg/kg) after high-fat diet for 8 weeks. Then, the expression changes of lipid metabolism-related markers were observed. At week 12, the protein expression level of lipid-deposited marker adipose differentiation-related protein (ADRP) was significantly increased. Besides, the lipid synthesis marker sterol regulatory element-binding protein 1c (SREBP 1c) was highly expressed while the expression of insulin-induced gene 1 (Insig-1), a key molecular of inhibiting SREBP 1c, was decreased. Leptin and compound c were incubated with the PA-induced NRK-52E cells to investigate the lipid-lowering effects and whether this effect was mediated by the AMPK/Insig-1/SREBP 1c signaling pathways. mRNA and protein of ADRP and SREBP 1c were reduced after leptin treatment, while Insig-1 and phosphorylated AMP-activated protein kinase (AMPK) were increased. Conversely, inhibition of AMPK phosphorylation by compound c mostly eliminated lipid-lowering efficacy of leptin in PA-induced cells. Collectively, these results suggested that there was ELD of renal tubular epithelial cells in DKD rats. Leptin upregulated the expression level of Insig-1 by activating AMPK to attenuate ELD in PA-induced NRK-52E cells.

Topics: AMP-Activated Protein Kinases; Animals; Diabetes Mellitus; Diabetic Nephropathies; Leptin; Lipid Metabolism; Palmitic Acid; Rats; Rats, Sprague-Dawley; Sterol Regulatory Element Binding Protein 1; Streptozocin

The etiology of diabetic nephropathy in type 2 diabetes is multifactorial. Sustained hyperglycemia is a major contributor, but additional contributions come from the hypertension, obesity, and hyperlipidemia that are also commonly present in patients with type 2 diabetes and nephropathy. The leptin deficient BTBR ob/ob mouse is a model of type 2 diabetic nephropathy in which hyperglycemia, obesity, and hyperlipidemia, but not hypertension, are present. We have shown that reversal of the constellation of these metabolic abnormalities with leptin replacement can reverse the morphologic and functional manifestations of diabetic nephropathy. Here we tested the hypothesis that reversal specifically of the hypertriglyceridemia, using an antisense oligonucleotide directed against ApoC-III, an apolipoprotein that regulates the interactions of VLDL (very low density lipoproteins) with the LDL receptor, is sufficient to ameliorate the nephropathy of Type 2 diabetes. Antisense treatment resulted in reduction of circulating ApoC-III protein levels and resulted in substantial lowering of triglycerides to near-normal levels in diabetic mice versus controls. Antisense treatment did not ameliorate proteinuria or pathologic manifestations of diabetic nephropathy, including podocyte loss. These studies indicate that pathologic manifestations of diabetic nephropathy are unlikely to be reduced by lipid-lowering therapeutics alone, but does not preclude a role for such interventions to be used in conjunction with other therapeutics commonly employed in the treatment of diabetes and its complications.

Topics: Animals; Apolipoprotein C-III; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Hypertriglyceridemia; Leptin; Male; Mice; Mice, Obese; Oligonucleotides, Antisense; Podocytes

Topics: Albuminuria; Animals; Antibodies, Neutralizing; Diabetic Nephropathies; Disease Progression; Humans; Interleukin-17; Kidney; Leptin; Male; Mice; Mice, Transgenic; Th17 Cells

Metabolic abnormalities in congenital generalized lipodystrophy (CGL) are associated with microvascular complications. However, the evaluation of different types of neuropathy in these patients, including the commitment of cardiovascular autonomic modulation, is scarce. The objective of the present study was to determine the prevalence of cardiovascular autonomic neuropathy (CAN) in patients with CGL compared with individuals with type 1 diabetes and healthy subjects.. Ten patients with CGL, 20 patients with type 1 diabetes and 20 healthy subjects were included in the study. Controls were paired 1:2 for age, gender, BMI and pubertal stage. Heart rate variability (HRV) was analyzed using cardiovascular autonomic reflex tests, including postural hypotension test, Valsalva (VAL), respiratory (E/I) and orthostatic (30/15) coefficients, and spectral analysis of the HRV, determining very low (VLF), low (LF) and high (HF) frequencies components. The diagnosis of CAN was defined as the presence of at least two altered tests.. CAN was detected in 40% of the CGL patients, 5% in type 1 diabetes patients and was absent in healthy individuals (p < 0.05). We observed a significant reduction in the E/I, VLF, LF and HF in CGL cases vs. type 1 diabetes and healthy individuals and lower levels of 30/15 and VAL in CGL vs. healthy individuals. A significant positive correlation was observed between leptin and 30/15 coefficient (r = 0.396; p = 0.036) after adjusting for insulin resistance and triglycerides. Autonomic cardiovascular tests were associated with HbA1c, HOMA-IR, triglycerides and albumin/creatinine ratio in CGL cases.. We observed a high prevalence of CAN in young patients with CGL, suggesting that insulin resistance, hypertriglyceridemia and hypoleptinemia, may have been involved in early CAN development. Additional studies are needed to evaluate the role of leptinemia in the physiopathogenesis of the condition.

Topics: Adolescent; Adult; Autonomic Nervous System; Autonomic Nervous System Diseases; Biomarkers; Blood Glucose; Brazil; Cardiovascular Diseases; Cardiovascular System; Case-Control Studies; Child; Creatinine; Cross-Sectional Studies; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Female; Glycated Hemoglobin; Heart Rate; Humans; Insulin; Insulin Resistance; Leptin; Lipodystrophy, Congenital Generalized; Male; Prevalence; Serum Albumin, Human; Triglycerides

Topics: Diabetes Mellitus, Type 2; Diabetic Nephropathies; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Kidney Failure, Chronic; Leptin; Lovastatin; Male

The intercellular adhesion molecule-1 (ICAM-1) and leptin are important inflammatory biomarkers. We investigated whether plasma-soluble ICAM-1 levels were related to the diabetic nephropathy and systemic inflammation. One hundred forty-seven type 2 diabetic patients and 46 healthy control subjects were studied. Plasma sICAM-1 concentrations were significantly higher in the diabetic groups than controls and increased significantly as diabetic nephropathy advanced. Plasma sICAM-1 levels were positively correlated with body mass index, fasting and postprandial blood glucose, urinary albumin excretion, and negatively correlated with creatinine clearance. Multiple regression analysis showed that plasma leptin levels were associated with a significant increase in plasma sICAM-1 levels. In cultured HUVECs, leptin increased ICAM-1 production in a dose-dependent manner, and this stimulating effect of leptin on ICAM-1 expression was reversed by MEK inhibitor, PD98059. Overall, these findings suggest that activation of leptin synthesis in a diabetic environment promotes ICAM-1 activation via mitogen-activated protein kinase pathway in type 2 diabetic patients.

Topics: Albuminuria; Blood Glucose; Body Mass Index; Cells, Cultured; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Enzyme Activation; Fasting; Female; Flavonoids; Humans; Inflammation; Intercellular Adhesion Molecule-1; Leptin; Male; MAP Kinase Signaling System; Middle Aged; Mitogen-Activated Protein Kinases; Protein Kinase Inhibitors

The reversibility of diabetic nephropathy remains controversial. Here, we tested whether replacing leptin could reverse the advanced diabetic nephropathy modeled by the leptin-deficient BTBR ob/ob mouse. Leptin replacement, but not inhibition of the renin-angiotensin-aldosterone system (RAAS), resulted in near-complete reversal of both structural (mesangial matrix expansion, mesangiolysis, basement membrane thickening, podocyte loss) and functional (proteinuria, accumulation of reactive oxygen species) measures of advanced diabetic nephropathy. Immunohistochemical labeling with the podocyte markers Wilms tumor 1 and p57 identified parietal epithelial cells as a possible source of regenerating podocytes. Thus, the leptin-deficient BTBR ob/ob mouse provides a model of advanced but reversible diabetic nephropathy for further study. These results also suggest that restoration of lost podocytes is possible but is not induced by RAAS inhibition, possibly explaining the limited efficacy of RAAS inhibitors in promoting repair of diabetic nephropathy.

Topics: Animals; Diabetic Nephropathies; Disease Models, Animal; Immunohistochemistry; Leptin; Mice; Mice, Inbred Strains; Podocytes; Renin-Angiotensin System

Obesity is prevalent worldwide and is a major risk factor for many diseases including renal complications. Thrombospondin 1 (TSP1), a multifunctional extracellular matrix protein, plays an important role in diabetic kidney diseases. However, whether TSP1 plays a role in obesity-related kidney disease is unknown. In the present studies, the role of TSP1 in obesity-induced renal dysfunction was determined by using a diet-induced obese mouse model. The results demonstrated that TSP1 was significantly upregulated in the kidney from obese mice. The increased TSP1 was localized in the glomerular mesangium as well as in the tubular system from obese wild-type mice. Obese wild-type mice developed renal hypertrophy and albuminuria, which was associated with increased kidney macrophage infiltration, augmented kidney inflammation, and activated transforming growth factor (TGF)-β signaling and renal fibrosis. In contrast, obese TSP1-deficient mice did not develop these kidney damages. Furthermore, in vitro studies demonstrated that leptin treatment stimulated the expression of TSP1, TGF-β1, fibronectin, and collagen type IV in mesangial cells isolated from wild-type mice. These leptin-stimulated effects were abolished in TSP1-deficient mesangial cells. Taken together, these data suggest that TSP1 is an important mediator for obesity- or hyperleptinemia-induced kidney dysfunction.

Topics: Animals; Cells, Cultured; Collagen Type IV; Diabetic Nephropathies; Diet, High-Fat; Disease Models, Animal; Fibronectins; Fibrosis; Kidney; Leptin; Male; Mice; Nephritis; Obesity; Thrombospondin 1; Transforming Growth Factor beta

In our previous study to evaluate the effects of soluble silicon (Si) on bone metabolism, Si and coral sand (CS) as a natural Si-containing material suppressed peroxisome proliferator-activated receptor γ (PPARγ), which regulates both glucose and bone metabolism and increases adipogenesis at the expense of osteogenesis, leading to bone loss. In this study, we investigated the anti-diabetic effects of bone-seeking elements, Si and stable strontium (Sr), and CS as a natural material containing these elements using obese diabetic KKAy mice.. Weanling male mice were fed diets containing 1% Ca supplemented with CaCO(3) as the control and CS, and diets supplemented with 50 ppm Si or 750 ppm Sr to control diet for 56 d. The mRNA expressions related to energy expenditure in the pancreas and kidney were quantified by real-time polymerase chain reaction.. At the end of feeding, plasma glucose, insulin, leptin, and adiponectin levels decreased significantly in three test groups, while pancreatic PPARγ and adiponectin mRNA expression levels increased significantly toward the normal level, improving the glucose sensitivity of β-cells and inducing a significant decrease in insulin expression. The renal PPARγ, PPARα, and adiponectin expression levels, histologic indices of diabetic glomerulopathy, and plasma indices of renal function were also improved significantly in the test groups.. Taken together, anti-osteoporotic trace minerals, Si and Sr, and CS containing them showed novel anti-diabetic effects of lowering blood glucose level, improving the tolerance to insulin, leptin, and adiponectin, and reducing the risk of glomerulopathy through modulation of related gene expression in the pancreas and kidney.

Topics: Adiponectin; Animals; Biomarkers; Blood Glucose; Bone Density Conservation Agents; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Dietary Supplements; Hypoglycemic Agents; Insulin; Kidney; Kidney Diseases; Kidney Glomerulus; Leptin; Male; Mice; Mice, Inbred Strains; Osteoporosis; Pancrelipase; PPAR gamma; Silicon; Silicon Compounds; Soil; Trace Elements

Several researches attempt to protect diabetic patients from the development of nephropathy. Involvement of leptin and renal Na+,K+-ATPase enzyme in diabetic nephropathy (DN) development is a recent field for researches. Vanadium, as a trace element with insulin mimetic effect, may act synergistically with insulin to protect against the development of DN. Sixty male Sprague Dawley rats were divided into six groups: control group (C), vanadium control group (CV), streptozotocin-induced diabetic group (D), insulin-treated diabetic group (DI), vanadium-treated diabetic group (DV), and combined insulin and vanadium-treated diabetic group. Six weeks later, systolic blood pressure (SBP) was measured and retro-orbital blood samples were collected to estimate glycosylated hemoglobin (HbA(₁c)), serum sodium (Na+) and creatinine, blood urea nitrogen (BUN) and plasma leptin levels. Preparation of microsomal fraction of renal tissue homogenate for estimation of Na+,K+-ATPase activity was done. The D group showed a significant increase in SBP, HbA(₁c), serum Na+, creatinine, and BUN levels and Na+,K+-ATPase activity in microsomal fraction of renal tissue homogenate while plasma leptin level decreased significantly compared with C and CV groups. Both DI and DV groups showed a significant improvement in all the above measured parameters compared with D group while there were no significant changes between the DI and DV groups. Concomitant treatment with insulin and vanadium resulted in a significant improvement in all the measured parameters compared to each alone. Vanadium in combination with insulin ameliorates DN markers and reduces renal Na+,K+-ATPase overactivity in diabetic rats. An effect that may be partially mediated through correction of hypoleptinemia observed in these animals.

Topics: Animals; Blood Urea Nitrogen; Creatinine; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Glycated Hemoglobin; Insulin; Kidney; Leptin; Male; Rats; Rats, Sprague-Dawley; Sodium Chloride; Sodium-Potassium-Exchanging ATPase; Vanadium

To clarify the association of serum leptin levels with progression of diabetic kidney disease in patients with type 2 diabetes (T2D).. This was an observational cohort study of 668 patients with T2D. Patients were classified into three groups by sex-specific tertile of leptin levels. Outcome measurements were the rate of change in estimated glomerular filtration rate (eGFR) and progression to a more advanced stage of albuminuria.. Patients with low or high leptin levels had a steeper eGFR decline (-2.07 and -2.14 mL/min/1.73 m(2)/year) than those with midrange leptin levels (-0.82 mL/min/1.73 m(2)/year; P < 0.01), whereas patients with low leptin levels had an elevated risk of progression of albuminuria as compared with those with high leptin levels (hazard ratio 3.125 [95% CI 1.302-7.499]).. Both low and high serum leptin levels were risk factors for kidney function decline. Meanwhile, lower serum leptin levels were associated with progression of albuminuria.

Topics: Aged; Albuminuria; Asian People; Cohort Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Progression; Female; Glomerular Filtration Rate; Humans; Leptin; Male; Middle Aged; Risk Factors

Adipokines play an important role in metabolic regulations. Obesity, diabetes, and renal disturbances affect adipokine profile by influencing their complex effects on metabolism. Our objective was to assess the effect of low-energy diet intervention on serum adiponectin, leptin, and resistin levels in diabetic nephropathy.. Seventeen subjects with diabetes type 2 and nephropathy participated in the study. After estimation of individual resting metabolic rates by indirect calorimetry, diets introducing 20% energy deficit were applied. At baseline and after 2 months of dieting, the following parameters were measured: body composition by dual x-ray spectrometry and serum adiponectin (Adp), leptin (Lep), resistin (Res), insulin, urea, creatinine, glucose, glycosylated hemoglobin, C-reactive protein, and tumor necrosis factor-alpha concentrations. Homeostatic model assessment (HOMA) was used to quantify insulin resistance.. Total energy, protein, and fat intakes diminished significantly with intentional dieting. Significant decreases in total body fat mass (FM) and its percentage in body mass (FM%) and trunk and gynoid fat mass, as well as in serum resistin and tumor necrosis factor-alpha levels, were also observed. Responses of adipokines to dietary treatment varied individually. Generally, they were affected by FM. Alterations in Lep concentrations correlated negatively with baseline FM, FM%, and android and gynoid fat mass and positively with changes in intake of protein, carbohydrates, and total energy of the consumed diet. Changes in Adp were inversely related to FM after therapy. Alterations in Res concentrations correlated positively with android fat mass before therapy and initial Lep levels. Adiponectin was inversely related to HOMA index before and after treatment.. Low-energy diet applied in diabetic nephropathy may decrease serum resistin levels and inflammation. In addition, responses of all adipokines to dieting appear to be affected by body fat mass, especially android fat mass.

Topics: Adiponectin; Adipose Tissue; Aged; Blood Glucose; Body Composition; C-Reactive Protein; Calorimetry, Indirect; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diet, Reducing; Dietary Carbohydrates; Dietary Fats; Energy Intake; Female; Humans; Inflammation; Leptin; Male; Resistin

Heart and coronary calcifications in hemodialysis patients are of very common occurrence and linked to cardiovascular events and mortality. Several studies have been published with similar results. Most of them were mainly cross-sectional and some of the prospective protocols were aimed to evaluate the results of the control of altered biochemical parameters of mineral disturbances with special regard to serum calcium, phosphate and CaxP with the use of calcium containing and calcium free phosphate chelating agents. The aim of the present study was to evaluate in hemodialysis patients classic and some non classic risk factors as predictors of calcification changes after one year and to evaluate the impact of progression on survival.. 81 patients on hemodialysis were studied, with a wide age range and HD vintage. Several classic parameters and some less classic risk factors were studied like fetuin-A, CRP, 25-OHD and leptin. Calcifications, as Agatston scores, were evaluated with Multislice CT basally and after 12-18 months.. Coronary artery calcifications were observed in 71 of 81 patients. Non parametric correlations between Agatston scores and Age, HD Age, PTH and CRP were significant. Delta increments of Agatston scores correlated also with serum calcium, CaxP, Fetuin-A, triglycerides and serum albumin. Logistic regression analysis showed Age, PTH and serum calcium as important predictors of Delta Agatston scores. LN transformation of the not normally distributed variables restricted the significant correlations to Age, BMI and CRP. Considering the Delta Agatston scores as dependent, significant predictors were Age, PTH and HDL. A strong association was found between basal calcification scores and Delta increment at one year. By logistic analysis, the one year increments in Agatston scores were found to be predictors of mortality. Diabetic and hypertensive patients have significantly higher Delta scores.. Progression of calcification is of common occurrence, with special regard to elevated basal scores, and is predictive of survival. Higher predictive value of survival is linked to the one year increment of calcification scores. Some classic and non classic risk factors play an important role in progression. Some of them could be controlled with appropriate management with possible improvement of mortality.

Topics: Adult; Aged; alpha-2-HS-Glycoprotein; Biomarkers; Blood Proteins; C-Reactive Protein; Calcifediol; Calcinosis; Comorbidity; Coronary Disease; Diabetic Nephropathies; Disease Progression; Follow-Up Studies; Humans; Kidney Failure, Chronic; Leptin; Male; Middle Aged; Renal Dialysis; Risk Factors; Rome; Severity of Illness Index; Survival Analysis; Tomography, Spiral Computed

To study of the contribution of obesity to renal lesion in patients with type 2 diabetes mellitus (T2DM).. One hundred and fifty-four patients (62 males and 92 females) with T2DM (mean age 58 +/- 8 years) were examined. The study excluded patients with significant stages of diabetic nephropathy (glomerular filtration rate (GFR) < 60 ml/min; proteinuria more than 2 g/day). Anthropometric indicators, such as body mass index (BMI), were estimated. The serum levels of creatinine, uric acid (UA), lipid composition, and the adipose tissue hormones leptin and adiponectin were measured. Renal lesion was evaluated from GFR and urine albumin excretion level. Groups of patients with a less and more than 5-year history and subgroups of a MBI of less and more than 30 kg/mi were identified.. In patients with a more than 5-year history of T2DM, the detection rate of microalbuminuria and proteinuria increased as obesity progressed. This regularity was not found in those with a less than 5-year history of T2DM. Diabetic patients with a BMI of > 30 kg/m2 were more frequently found to have intrarenal hemodynamic disorders (hyperfiltration) elevated blood pressure, increased UA, and decreased high-density lipoproteins, as compared with those with a BMI of < 30 kg/m2. With a higher BMI, leptin levels increased; its highest values were found in a group of patients with proteinuria. Hypoadiponectinemia was detected in most patients with T2DM. Adiponectin was decreased in early-stage nephropathy; its increase was further increased.. There was a greater prevalence of renal lesion in obese (BMI > 30 kg/m2) patients with a more than 5-year history of T2DM than in non-obese patients. Obesity has an impact on renal function due to its hemodynamic, metabolic, and hormonal effects.

Topics: Adiponectin; Adult; Aged; Anthropometry; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Hemodynamics; Humans; Hypertension; Kidney Function Tests; Leptin; Male; Middle Aged; Obesity; Risk Factors; Severity of Illness Index

The aim of this study was to investigate the relationship between plasma leptin levels and the chronic complications in type 2 diabetic (T2DM) patients.. There were 157 T2DM patients (age, 56.7 ± 11.4 years; mean diabetes duration, 8.9 ± 3.6 years; mean body mass index, 28.1 ± 4.3 kg/m(2)) included to the study. Microvascular and macrovascular complications of diabetes were evaluated in all patients. There were 46 healthy subjects as control group. Plasma leptin levels were measured in both diabetic and healthy subjects.. Plasma leptin levels of the diabetic patients were not significantly different from the healthy subjects (26.4 ± 18.2 vs. 29.1 ± 13.1 ng/mL, P > 0.05). Plasma leptin levels in obese diabetic patients were higher than in nonobese (37.6 ± 20.9 vs. 20.0 ± 17.2 ng/mL, P = 0.001); in hypertensive diabetic patients than normotensive (35.2 ± 19.3 vs. 19.4 ± 13.9 ng/mL, P < 0.001); dyslipidemic diabetic patients than normolipidemic diabetic subjects (38.5 ± 18.3 vs. 31.3 ± 19.5 ng/mL, P = 0.038); diabetic patients with metabolic syndrome than diabetic patients without metabolic syndrome (37.9 ± 20.1 vs. 23.2 ± 15.3 ng/mL, P = 0.001). Plasma leptin levels were lower in diabetic patients who were smokers than nonsmokers (20.0 ± 15.5 vs. 24.7 ± 17.4 ng/mL, P = 0.023). There was no significant difference between patients with and without diabetic nephropathy, retinopathy, neuropathy, coronary artery disease or peripheral vascular disease (P > 0.05).. Our data suggest that obesity, hypertension, dyslipidemia, and metabolic syndrome in T2DM were associated with increased plasma leptin levels. We conclude that plasma leptin levels may not be strongly associated with microangiopathy and macroangiopathy in T2DM individuals.

Topics: Adult; Aged; Body Mass Index; Case-Control Studies; Chronic Disease; Diabetes Complications; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Retinopathy; Female; Glycated Hemoglobin; Humans; Leptin; Male; Middle Aged; Obesity

Macrophage-mediated renal injury plays an important role in the development of diabetic nephropathy. Colony-stimulating factor (CSF)-1 is a cytokine that is produced in diabetic kidneys and promotes macrophage accumulation, activation and survival. CSF-1 acts exclusively through the c-fms receptor, which is only expressed on cells of the monocyte-macrophage lineage. Therefore, we used c-fms blockade as a strategy to selectively target macrophage-mediated injury during the progression of diabetic nephropathy.. Obese, type 2 diabetic db/db BL/KS mice with established albuminuria were treated with a neutralising anti-c-fms monoclonal antibody (AFS98) or isotype matched control IgG from 12 to 18 weeks of age and examined for renal injury.. Treatment with AFS98 did not affect obesity, hyperglycaemia, circulating monocyte levels or established albuminuria in db/db mice. However, AFS98 did prevent glomerular hyperfiltration and suppressed variables of inflammation in the diabetic kidney, including kidney macrophages (accumulation, activation and proliferation), chemokine CC motif ligand 2 levels (mRNA and urine protein), kidney activation of proinflammatory pathways (c-Jun amino-terminal kinase and activating transcription factor 2) and Tnf-alpha (also known as Tnf) mRNA levels. In addition, AFS98 decreased the tissue damage caused by macrophages including tubular injury (apoptosis and hypertrophy), interstitial damage (cell proliferation and myofibroblast accrual) and renal fibrosis (Tgf-beta1 [also known as Tgfb1] and Col4a1 mRNA).. Blockade of c-fms can suppress the progression of established diabetic nephropathy in db/db mice by targeting macrophage-mediated injury.

Topics: Animals; Antibodies, Monoclonal; Cell Division; Diabetic Nephropathies; Genotype; Inflammation; Kidney Tubules; Leptin; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; Polymerase Chain Reaction; Receptor, Macrophage Colony-Stimulating Factor

Malnutrition-inflammation-atherosclerosis syndrome (MIA) in haemodialysis (HD) patients is a common clinical condition characterized by increased mortality rate. The aim of this study was to analyze the frequency of MIA components in a selected population of HD patients with and without diabetic nephropathy.. The frequency of MIA components was analysed in 49 patients with an over 10-year history of diabetes before initiation of HD (DM group) and 49 non-diabetic HD patients (non-DM group).. The chance for occurrence of atherosclerosis (odds ratio = 3.26) was markedly higher in DM than non-DM subjects. The most frequent MIA component in DM and non-DM subjects was atherosclerosis (67.3% and 40.8%, respectively). Atherosclerosis frequently coexisted with inflammation in both groups (51.5% in DM and 20.0% in non-DM) and less frequently with malnutrition. The frequency of inflammation was only slightly higher in DM, while of malnutrition was similar. Patients with atherosclerosis in the DM group had significantly higher serum concentrations of interleukin-6 than the ones in the non-DM group: 11 (6-24) versus 5 (2-9) pg/mL, respectively (P = 0.002).. We can conclude that: (i) atherosclerosis is more common in HD patients with diabetic nephropathy; and (ii) this fact may explain the poor outcome of these patients and indicates the challenge in diagnostic and therapeutic management.

Topics: Aged; Atherosclerosis; Diabetic Nephropathies; Female; Humans; Inflammation; Leptin; Male; Malnutrition; Middle Aged; Renal Dialysis; Serum Albumin

Adiponectin (ADPN) has been shown to protect against cardiovascular disease for the general population with problematic metabolic syndrome. However, it remains unclear whether ADPN is associated with mortality in patients on maintenance hemodialysis (HD). METHODS, PATIENTS OR MATERIALS: We selected 85 HD patients [51 men/34 women; mean age, 64+/-2 years; underlying kidney diseases, diabetic nephropathy in 36 patients (42.3%), chronic glomerulonephritis in 29 (34.1%), hypertensive nephrosclerosis in 10 (11.8%), and others in 10 (11.8%)] who survived for more than 3 months after the start of HD. We first measured serum ADPN levels and prospectively followed patients for the next 3 years.. We were able to follow 74 of 85 patients; 59 survived, and 15 died. Serum log-transformed ADPN levels were negatively correlated with BMI (r=-0.43, p<0.01). Despite a similar BMI (20.7+/-0.8 vs. 20.3+/-0.4 kg/m(2)), the expired patients had significantly higher ADPN compared with the surviving patients (20.5 microg/ml [14.0-23.5] vs. 14.2 microg/ml [9.7-21.3], p<0.05). Cox-hazards multivariate regression analysis adjusted for conventional case-mix features (age, sex, and underlying kidney disease) revealed that serum ADPN became a significant determinant of all-cause mortality. There was a 10.3% risk increment for each 1-microg/ml increase in ADPN during the follow-up. Kaplan-Meier analysis revealed that patients with higher ADPN levels (> or =15 microg/ml) had a significantly lower survival rate compared with those with lower ADPN levels (<15 microg/ml) (76 vs. 92%, p<0.05).. These results indicated that high rather than low ADPN independently predict total mortality in HD patients.

Topics: Adiponectin; Blood Urea Nitrogen; Body Mass Index; C-Reactive Protein; Creatinine; Diabetic Nephropathies; Female; Follow-Up Studies; Glomerulonephritis; Humans; Kaplan-Meier Estimate; Leptin; Longitudinal Studies; Male; Middle Aged; Multivariate Analysis; Nephrosclerosis; Predictive Value of Tests; Prospective Studies; Regression Analysis; Renal Dialysis; Survival Rate

Nitrosative stress contributes to nerve conduction slowing, thermal hypoalgesia, and impaired nitrergic innervation in animal models of Type 1 diabetes. The role for reactive nitrogen species in Type 2 diabetes-associated neuropathy remains unexplored. This study evaluated the role for nitrosative stress in functional and structural neuropathic changes in ob/ob mice, a model of Type 2 diabetes with mild hyperglycemia and obesity. Two structurally diverse peroxynitrite decomposition catalysts, Fe(III) tetrakis-2-(N-triethylene glycol monomethyl ether)-pyridyl porphyrin (FP15) and Fe(III) tetra-mesitylporphyrin octasulfonate (FeTMPS), were administered to control and 8-week-old ob/ob mice for 3 weeks at the doses of 5 mg kg(-1) day(-1) (FP15) and 5 and 10 mg kg(-1) day(-1) (FeTMPS). The 11-week-old ob/ob mice developed motor nerve conduction velocity (MNCV) and hind-limb digital sensory nerve conduction velocity (SNCV) deficits, thermal hypoalgesia, tactile allodynia, and a remarkable ( approximately 78%) loss of intraepidermal nerve fibers. They also had increased nitrotyrosine and poly(ADP-ribose) immunofluorescence in the sciatic nerve, spinal cord, and dorsal root ganglion neurons. Treatment with two structurally diverse peroxynitrite decomposition catalysts was associated with restoration of normal MNCV and SNCV, and alleviation of thermal hypoalgesia. Tactile response thresholds increased in response to peroxynitrite decomposition catalyst treatment, but still remained approximately 2.7- to 3.2-fold lower compared with non-diabetic controls. Intraepidermal nerve fiber loss was not alleviated by either FP15 or FeTMPS. Nitrotyrosine and poly(ADP-ribose) immunofluorescence in sciatic nerve, spinal cord, and dorsal root ganglia of peroxynitrite decomposition catalyst-treated ob/ob mice were essentially normal. In conclusion, nitrosative stress plays an important role in functional abnormalities associated with large motor, large sensory, and small sensory fiber neuropathy, but not in small sensory nerve fiber degeneration, in this animal model. Peroxynitrite decomposition catalysts alleviate Type 2 diabetes-associated sensory nerve dysfunction, likely by mechanism(s) not involving arrest of degenerative changes or enhanced regeneration of small sensory nerve fibers.

Topics: Anesthesia; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Immunohistochemistry; Leptin; Mice; Mice, Inbred C57BL; Mice, Obese; Motor Neurons; Nerve Fibers; Neural Conduction; Neurons, Afferent; Nitrites; Pain; Pain Measurement; Peroxynitrous Acid; Poly Adenosine Diphosphate Ribose; Touch

Topics: Adiponectin; Adult; Biomarkers; Diabetic Nephropathies; Diabetic Neuropathies; Diabetic Retinopathy; Diet, Diabetic; Female; Humans; Insulin; Leptin; Lipodystrophy, Congenital Generalized

Connective tissue growth factor (CTGF) is overexpressed in diabetic nephropathy (DN) and has therefore been implicated in its pathogenesis. The objective of the present study was to determine the tissue distribution of increased CTGF expression and the relationship of plasma, urinary, and renal CTGF levels to the development and severity of DN. We studied the relationship between CTGF and renal pathology in streptozotocin (STZ)-induced diabetes in C57BL/6J mice. Diabetic and age-matched control mice were killed after 1, 2, 4, and 9 wk of diabetes. In addition, key parameters of diabetes and DN were analyzed in 10-mo-old diabetic ob/ob mice and their ob/+ littermates. STZ-induced diabetic mice showed a significantly increased urinary albumin excretion after 1 wk and increased mesangial matrix score after 2 wk. Increased renal fibronectin, fibronectin ED-A, and collagen IValpha1 expression, as well as elevated plasma creatinine levels, were observed after 9 wk. After 2 wk, CTGF mRNA was upregulated threefold in the renal cortex. By 9 wk, CTGF mRNA was also increased in the heart and liver. In contrast, transforming growth factor-beta1 mRNA content was significantly increased only in the kidney by 9 wk. Renal CTGF expression was mainly localized in podocytes and parietal glomerular epithelial cells, and less prominent in mesangial cells. In addition, plasma CTGF levels and urinary CTGF excretion were increased in diabetic mice. Moreover, albuminuria strongly correlated with urinary CTGF excretion (R = 0.83, P < 0.0001). Increased CTGF expression was also demonstrated in type 2 diabetic ob/ob mice, which points to a causal relationship between diabetes and CTGF and thus argues against a role of STZ in this process. The observed relationship of podocyte and urinary CTGF to markers of DN suggests a pathogenic role of CTGF in the development of DN.

Topics: Amyloid; Animals; Connective Tissue Growth Factor; Crosses, Genetic; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Enzyme-Linked Immunosorbent Assay; Female; Gene Expression; Humans; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; Kidney; Leptin; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

To evaluate the relationship between hyperleptinemia and anemia in hemodialysis patients, we investigated the reverse epidemiological role of leptin in 36 patients (males: 21, diabetics: 11) under regular chronic hemodialysis. The patients had complete blood counts, iron profile, serum leptin, and adequacy of hemodialysis measured. We found a significant positive correlation of serum leptin with hemoglobin level and body mass index (BMI). A trend between serum leptin and total iron binding capacity was observed, however, no correlation was observed with serum ferritin. No differences in these correlations were observed in any subgroup related to gender or diabetes. Our data support previous findings showing that greater serum leptin levels are associated with greater hemoglobin levels.

Topics: Adult; Anemia; Cross-Sectional Studies; Diabetic Nephropathies; Female; Ferritins; Hemoglobins; Humans; Leptin; Male; Middle Aged; Renal Dialysis

Diabetic nephropathy is the leading cause of end-stage renal disease, for which effective therapy to prevent the progression at advanced stages remains to be established. There is also a long debate whether diabetic glomerular injury is reversible or not. Lipoatrophic diabetes, a syndrome caused by paucity of adipose tissue, is characterized by severe insulin resistance, dyslipidemia, and fatty liver. Here, we show that a genetic model of lipoatrophic diabetes (A-ZIP/F-1 mice) manifests a typical renal injury observed in human diabetic nephropathy that is associated with glomerular hypertrophy, diffuse and pronounced mesangial widening, accumulation of extracellular matrix proteins, podocyte damage, and overt proteinuria. By crossing A-ZIP/F-1 mice with transgenic mice overexpressing an adipocyte-derived hormone leptin, we also reveal that leptin completely prevents the development of hyperglycemia and nephropathy in A-ZIP/F-1 mice. Furthermore, continuous leptin administration to A-ZIP/F-1 mice by minipump beginning at 40 weeks of age significantly alleviates the glomerular injury and proteinuria. These findings demonstrate the therapeutic usefulness of leptin at least for a certain type of diabetic nephropathy. The model presented here will serve as a novel tool to analyze the molecular mechanism underlying not only the progression but also the regression of diabetic nephropathy.

Topics: Animals; Biomarkers; Cells, Cultured; Crosses, Genetic; Diabetic Nephropathies; Disease Models, Animal; Drug Administration Routes; Extracellular Matrix Proteins; Female; Kidney Diseases; Kidney Glomerulus; Leptin; Male; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Mice, Transgenic; Transgenes

Because of increasing evidence that white blood cells (WBCs) play a role in the development and progression of diabetes complications, this study aimed to investigate the relation of circulating total and differential leukocyte counts to nephropathy in patients with type 2 diabetes. Plasma leptin levels were also measured to investigate their role in peripheral leukocytosis.. For this study, 1,480 subjects with type 2 diabetes who were enrolled in a disease management program were stratified according to urinary microalbumin and serum creatinine measurements. The total and differential leukocyte profiles of peripheral blood were measured and plasma leptin was examined by enzyme-linked immunosorbent assay. Demographic and potential metabolic confounding factors were analyzed with linear and logistic regression to calculate the effects of leukocyte count on diabetic nephropathy.. The peripheral total WBC, monocyte, and neutrophil counts increased in parallel with the advancement of diabetic nephropathy. In contrast, the lymphocyte count decreased. When WBC counts were analyzed per quartile and as continuous variables after adjusting for age, sex, and other known risk factors with multiple regression analysis, peripheral total WBC, monocyte, neutrophil, and lymphocyte counts were independently and significantly associated with diabetic nephropathy. Plasma leptin levels increased in patients with nephropathy and correlated significantly with total WBC count (r = 0.194, P = 0.014).. Because leukocytes are activated and secrete cytokines in the diabetic state and leptin stimulates leukocyte proliferation and differentiation, our results suggest that circulating leukocytes contribute to the development and progression of nephropathy, partially through the effects of leptin, in patients with type 2 diabetes.

Topics: Albuminuria; Biomarkers; Creatinine; Diabetic Nephropathies; Female; Humans; Leptin; Leukocyte Count; Leukocytosis; Lymphocyte Count; Male; Middle Aged; Regression Analysis; Risk Factors

The pathological significance of advanced glycation end product (AGE)-modified proteins deposited in several lesions is generally accounted for by their cellular interaction via the AGE receptors and subsequent acceleration of the inflammatory process. In this study, we focused on two AGE receptors-specifically, the role of SR-A in pathogenesis of diabetic nephropathy and the role of CD36 in AGE-induced downregulation of leptin by adipocytes. In terms of SR-A, diabetic wild-type mice exhibited increased urinary albumin excretion, glomerular hypertrophy, and mesangial matrix expansion, whereas SR-A-knockout mice showed reduced glomerular size and mesangial matrix area. In these diabetic SR-A-knockout mice, the number of macrophages that infiltrated into glomeruli was remarkably reduced (P < 0.05), suggesting that SR-A-dependent glomerular migration of macrophages plays an important role in the pathogenesis of diabetic nephropathy. In terms of CD36, incubation of glycolaldehyde-modified bovine serum albumin (GA-BSA) with 3T3-L1 adipocytes reduced leptin secretion by these cells. The binding of GA-BSA to these cells and subsequent endocytic degradation were effectively inhibited by a neutralizing anti-CD36 antibody. AGE-induced downregulation of leptin was protected by N-acetyl-cysteine, an antioxidant. These results indicate that the interaction of AGE ligands with 3T3-L1 adipocytes via CD36 induces oxidative stress and leads to inhibition of leptin expression by these cells, suggesting a potential link of this phenomenon to exacerbation of the insulin sensitivity in metabolic syndrome.

Topics: 3T3 Cells; Adipocytes; Animals; CD36 Antigens; Diabetic Nephropathies; Glycation End Products, Advanced; Leptin; Mice; Mice, Knockout; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Receptors, Leukotriene

Leptin plays an important role in the regulation of body weight and energy balance. Women have higher circulating leptin level than men. In this study, we examined serum leptin concentrations in Type 2 diabetic men and women with or without nephropathy. Fasting plasma glucose (FPG), lipid profile, and serum leptin concentrations were measured in 34 Type 2 diabetic patients with nephropathy (DMN), 12 normoalbuminuric Type 2 diabetic subjects (DM) and 34 non-diabetic control subjects, all matched for age and body mass index (BMI).. Patients with diabetic nephropathy had lower high-density lipoprotein cholesterol and higher triglyceride, FPG, urinary albumin/creatinine ratio (ACR) and serum creatinine than the other two groups. There was a significant trend in serum leptin concentrations (P<0.001, analysis of variance ANOVA) across the three groups with the main difference being detected between DMN and control subjects (DMN: 17.5 +/- 16.8 ng/ml, DM: 14.6 +/- 10.5 ng/ml and control: 9.1 +/- 7.1 ng/ml). Women had higher serum leptin concentration than men in the control group (12.5 +/- 7.3 ng/ml versus 4.2 +/- 2.0 ng/ml, P=0.001) and in the DM group (18.9 +/- 11 ng/ml versus 8.6 +/- 5.9 ng/ml, P=0.07) whereas this gender difference was not observed in the DMN group (18.6 +/- 17.0 ng/ml versus 16.8 +/- 17.0 ng/ml, P=0.754). On multivariate analysis, ACR (=0.411, P<0.001) and BMI (=0.240, P=0.002) were independently associated with serum leptin concentrations (R2=0.194, F=22.1, P<0.001) in the whole group. In the DMN group, ACR (=0.370, P=0.016) was the only independent determinant of serum leptin concentrations (R2=0.159, F=11.4, P=0.016). Serum leptin concentrations were higher in Type 2 diabetic patients with nephropathy than normoalbuminuric diabetic patients and controls. Diabetic men with nephropathy had proportionally higher serum leptin such that the gender difference in leptin observed in non-nephropathic individuals was abolished.

Topics: Adult; Albuminuria; Analysis of Variance; Body Mass Index; Case-Control Studies; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Humans; Leptin; Male; Middle Aged; Osmolar Concentration; Sex Characteristics

Generalized lipodystrophy is characterized by adipose tissue absence, hypoleptinemia, hypertriglyceridemia, insulin resistance, diabetes, hepatomegaly, and nonalcoholic steatohepatitis. In the course of recruiting patients for treatment with recombinant leptin, we were struck by the frequency and severity of proteinuria. We evaluated 25 patients with generalized lipodystrophy. Eighteen were treated with recombinant leptin, and we have followed 15 on leptin for 4-36 months. We followed renal parameters at baseline and during follow-up visits. Renal biopsies were performed as clinically indicated. At baseline, 22 of 25 patients (88%) had elevated urine albumin excretion (>30 mg/24 h), 15 (60%) had macroalbuminuria (>300 mg/24 h), and five (20%) had nephrotic-range proteinuria (>3500 mg/24 h). Twenty-three (92%) had elevated creatinine clearance (>125 ml/min.1.73 m(2)). Eleven of 15 patients (73%) treated with recombinant leptin exhibited reduction in proteinuria, associated with reduction of hyperfiltration. Four patients who did not improve are discussed individually. Renal biopsy findings were remarkable for focal segmental glomerulosclerosis in four patients, membranoproliferative glomerulonephritis in two patients, and diabetic nephropathy in one patient. In conclusion, generalized lipodystrophy is associated with proteinuria and unique renal pathologies, including focal segmental glomerulosclerosis and membranoproliferative glomerulonephritis. The majority treated with recombinant leptin demonstrated reduction in proteinuria and hyperfiltration.

Topics: Adolescent; Adult; Aged; Biopsy; Child; Creatinine; Diabetic Nephropathies; Female; Glomerulonephritis, Membranoproliferative; Glomerulosclerosis, Focal Segmental; Humans; Kidney; Kidney Diseases; Leptin; Lipodystrophy; Male; Middle Aged; Proteinuria; Recombinant Proteins; Syndrome

(1) To evaluate the impact of body composition and gender on serum leptin concentration in hemodialysis patients. (2) To study which marker of adiposity is most appropriate in Taiwanese hemodialysis patients without diabetes. (3) To compare the nutrition status between nonlean and lean subjects.. Serum leptin concentrations were measured by radioimmunoassay collected in 88 hemodialysis patients without diabetes. Bioimpedance analysis was performed to determine percent fat mass (%FM), lean body mass (LM), and total body water (TBW). Body mass index (BMI) was calculated as weight/height2. Albumin and transferrin were measured by standard laboratory methods.. Serum leptin levels were more correlated with percent fat mass (r = 0.697; P < 0.001) than with body fat mass (r = 0.672; P < 0.001) or with BMI (r = 0.594; P < 0.001) in the group as a whole and in each subgroup when analyzed separately by gender. The mean (+/- SD) serum leptin levels were 32.5 +/- 34.3 ng mL(-1) in women subjects and 13.6 +/- 15.5 ng mL(-1) in men subjects (P < 0.001). Multiple regression analysis in all subjects revealed that serum leptin levels were independently affected by percent fat mass and gender. Adiposity corrected serum leptin, such as leptin/BMI, leptin/percent fat mass, and leptin/body fat mass was significantly different between sexes (P < 0.001). The significantly higher serum leptin concentrations in women than in men were observed in obese subjects with BMI > 25 kg/m2 (P < 0.001) as well as nonobese subjects with BMI < 25 kg/m2 (P < 0.05). There were no differences in lean mass and albumin between nonlean and lean subjects.. Gender and adiposity had impact on serum leptin levels in hemodialysis patients without diabetes. In terms of adiposity, serum leptin levels had stronger correlation with percent fat mass than with body fat mass (FM) or BMI in Taiwanese hemodialysis patients. Steady-state serum leptin levels could serve as valuable clinical markers for the body adiposity in stable hemodialysis patients without diabetes. Protein malnutrition markers and lean mass should be checked in lean subjects for the evaluation of the protein stores of hemodialysis patients.

Topics: Adult; Aged; Biomarkers; Body Composition; Body Mass Index; Case-Control Studies; Cohort Studies; Diabetic Nephropathies; Female; Follow-Up Studies; Humans; Kidney Failure, Chronic; Leptin; Male; Middle Aged; Probability; Radioimmunoassay; Reference Values; Renal Dialysis; Risk Assessment; Severity of Illness Index; Sex Factors; Taiwan; Treatment Outcome

To evaluate the changes of serum leptin levels after weight reduction in diabetic subjects with and without microalbuminuria, we studied 10 obese healthy subjects, 12 obese diabetics with persistent microalbuminuria and 10 obese diabetic subjects without microalbuminuria. Obese diabetic patients with microalbuminuria showed serum leptin levels significantly higher than normoalbuminuric diabetics, while no difference was found between obese diabetics without microalbuminuria and healthy controls. All obese subjects followed a 12-month intensive weight reduction program during which the mean change in body mass index was similar between obese diabetic and obese healthy subjects (obese diabetics without microalbuminuria: 35.2+/-4.3 vs 29.9+/-4.1, p<0.05; obese diabetics with microalbuminuria: 35.7+/-3.9 vs 30.3+/-4.0, p<0.05; obese healthy subjects: 35.5+/-4.0 vs 30.1+/-3.9, p<0.05). The mean changes in serum leptin levels tended to be similar in two groups of subjects studied (obese diabetics without microalbuminuria: 37.6+/-4.1 vs 19.7+/-4.9, p<0.001; obese healthy subjects: 37.1+/-4.3 vs 20.1+/-5.1, p<0.001); obese microalbuminuric subjects showed higher leptin levels (42.4+/-4.0 vs 30.3+/-4.2, p<0.001) than normoalbuminuric diabetic and obese healthy subjects. In conclusion, during weight loss, independently from the quality of metabolic control, serum leptin concentrations declined in both groups of obese diabetics. The changes of leptin in diabetics seem to be similar to those observed in healthy obese subjects.

Topics: Adolescent; Albuminuria; Body Mass Index; Body Weight; Diabetes Complications; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Female; Follow-Up Studies; Humans; Leptin; Obesity; Weight Loss

Leptin, secreted from fat cells, functions as a lipostat mechanism through modulation of satiety signals. Markedly elevated leptin levels have been documented in uremic patients, especially in those who are treated by peritoneal dialysis (PD). However, the role of hyperleptinemia in uremic patients is not clear, and it is not known whether elevated leptin levels contribute to uremic anorexia and changes in body composition. In this prospective study, serum leptin, C-reactive protein (CRP), plasma insulin, and body composition (dual-energy x-ray absorptiometry) were measured in 36 patients (53 +/- 1 yr) close to start and after about 1 yr of PD. In addition, markers of dialysis adequacy and urea kinetics were followed during treatment with PD. During PD, the total body fat mass (20.5 +/- 1.0 to 22.9 +/- 1.3 kg; P < 0.01), truncal fat mass (11.5 +/- 0.7 to 13. 2 +/- 0.9 kg; P < 0.001), and serum leptin levels (20.1 +/- 3.8 to 35.6 +/- 6.8 ng/ml; P < 0.01) increased markedly, especially in patients with diabetes mellitus. Twenty-five PD patients that lost lean body mass during PD had significantly (P < 0.05) elevated initial CRP levels (14 +/- 2 mg/L) compared to 11 patients (<10 mg/L) who gained lean body mass during PD. A significant increase in serum leptin levels (20.9 +/- 4.2 to 42.7 +/- 4.0 ng/ml; P < 0.001) was observed in those patients who lost lean body mass, whereas no such change (18.4 +/- 8.4 to 19.2 +/- 6.4 ng/ml) was observed in the patients that gained lean body mass during PD treatment. The present longitudinal results demonstrate that serum leptin level and body fat content increase markedly during PD, especially in diabetic patients. Patients that lost lean body mass during PD had higher initial CRP levels and increased their serum leptin levels significantly during PD compared to those patients that gained lean body mass. Additional studies are therefore needed to elucidate the role of hyperleptinemia and inflammation in causing anorexia, protein-malnutrition, and changes in body composition during treatment with PD.

Topics: Absorptiometry, Photon; Body Composition; C-Reactive Protein; Diabetic Nephropathies; Female; Glomerulonephritis; Humans; Insulin; Kidney Failure, Chronic; Leptin; Male; Middle Aged; Nephritis; Peritoneal Dialysis; Prospective Studies

Leptin is a protein hormone produced predominantly by adipocytes that affects food intake and energy expenditure. Its serum levels are significantly higher in patients with chronic renal failure compared to healthy subjects. The aim of this study was to compare serum leptin levels in hemodialyzed patients with type II diabetes mellitus (n=26) with body content-matched hemodialyzed patients without diabetes (n=26) and to explore the relationship between parameters of the long term diabetes metabolic control and serum leptin levels. Serum leptin levels in diabetic patients did not significantly differ from those of non-diabetic patients (25.3+/-8.8 vs 25.7+/-8.7 ng/ml). Serum leptin levels in diabetic patients positively correlated with body fat content, body mass index and predialysis serum insulin levels. No significant relationship were observed between serum leptin levels and blood glucose, glycated hemoglobin, glycated protein, serum urea, creatinine, leukocyte count and total hemoglobin respectively. The multiple stepwise regression analysis revealed that body fat content together with body mass index accounted for 77.8% of variations in predialysis serum leptin levels, while insulin levels and the parameters of diabetes metabolic control had only slight prediction value for leptin concentrations. We conclude that serum leptin levels in hemodialysed patients with type III diabetes mellitus do not significantly differ from those of hemodialysed non-diabetic patients. The body fat content and body mass index are the strongest predictors of serum leptin levels, while parameters of long term diabetes metabolic control play probably only minor direct role in its regulation.

Topics: Blood Glucose; Body Mass Index; C-Peptide; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Glycated Hemoglobin; Humans; Insulin; Kidney Failure, Chronic; Leptin; Male; Reference Values; Regression Analysis; Renal Dialysis; Urea

This was the first Korean-Polish seminar on renal replacement therapies which provided a survey of current research being carried out in both countries, delivered by leading experts in this field. The topics included malnutrition in uremia, biocompatibility, risk factors and complications in renal replacement therapy, diabetic nephropathy, new solutions for peritoneal dialysis, and peritoneal transport. The organizers strove to select the topics which are currently of interest to researchers from both countries with the purpose to compare results and stimulate discussion concerning possible collaboration in the future.

Topics: Cardiovascular Diseases; Diabetic Nephropathies; Humans; Kidney Failure, Chronic; Leptin; Nutrition Disorders; Peritoneal Dialysis, Continuous Ambulatory; Risk Factors; Uremia

Leptin levels are elevated in end-stage renal disease, suggesting an impairment of renal leptin degradation. The present study aimed to determine whether leptin levels are also elevated in patients with earlier stages of renal disease, ie, microalbuminuric and macroalbuminuric nephropathy. A total of 60 subjects were assigned to two study groups. Group A contained 10 type 2 diabetics with macroalbuminuria, 10 type 2 diabetics with normoalbuminuria, and 10 healthy control subjects. Group B contained 10 type 2 diabetics with microalbuminuria, 10 type 2 diabetics with normoalbuminuria, and 10 healthy controls. The subgroups of both study groups were matched for sex and body fatness. In group A, macroalbuminuric diabetic patients had higher serum leptin levels than the normoalbuminuric diabetics (11.90 +/- 2.98 v 4.13 +/- 0.92 ng/mL, P < .002) and control subjects (4.78 +/- 1.37 ng/mL, P < .006). In group B, microalbuminuric diabetics had higher serum leptin levels than the normoalbuminuric diabetics (21.16 +/- 5.80 v8.74 +/- 1.89 ng/mL, P < .04) and control subjects (10.06 + 3.00 ng/mL, P < .06). In both groups A and B, creatinine clearance was inversely correlated with the serum leptin level after adjusting for body fat. In conclusion, serum leptin levels are elevated in type 2 diabetic patients with microalbuminuria and macroalbuminuria, suggesting that renal leptin degradation is already impaired in the early stages of renal disease.

Topics: Adipose Tissue; Aged; Albuminuria; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Neuropathies; Diabetic Retinopathy; Female; Humans; Hypertension; Leptin; Male; Middle Aged; Reference Values; Triglycerides

Leptin is a new hormone influencing food intake, energy expenditure and body weight. This protein is produced by adipocytes, exerts its effects on brain, endocrine pancreas and other organs by activating transmembrane receptors and is cleared from plasma mainly by the kidneys. The aim of our study was to compare plasma concentrations of leptin in our nephrological out-patients and controls.. We examined 36 diabetic patients with various stages of nephropathy, 12 males with nephrotic syndrome due to membranous nephropathy, 15 dialysis patients and 11 controls. Leptin was assessed in plasma by ELISA. There was a significant difference between plasma levels of leptin in males and females (7.7 +/- 11.4 vs 17.6 +/- 17.3, p < 0.001) and in dialysis and non-dialysis patients (19.6 +/- 16.5 vs 10.7 +/- 14.5, p < 0.05). There was also a difference between dialysed and non-dialysed men (15.1 +/- 16.2 vs 5.9 +/- 9.2, p < 0.05). We found no difference between men with and without nephrotic syndrome and between BMI or age. There was a positive correlation of leptin with diabetic and non-diabetic women. There was positive correlation of P-leptin with serum creatinine in non-dialysed women (r = 0.68, p < 0.001) and a negative correlation with S-albumin in nephrotic men (r = -0.65, p < 0.05).. Women have higher plasma leptin concentrations than men and dialysis patients have higher concentrations than non-dialysed patients. Apart from the positive correlation with S-creatinine in non-dialysed women. There was positive correlation with S-albumin in nephrotic men there were no correlations with renal function, BMI, age, S-cholesterol, S-triglycerides and S-albumin.

Topics: Adult; Diabetic Nephropathies; Female; Humans; Kidney Diseases; Leptin; Male; Middle Aged; Nephrotic Syndrome; Renal Dialysis

Topics: Albuminuria; Arizona; Confidence Intervals; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Fasting; Glomerular Filtration Rate; Humans; Indians, North American; Leptin; Proteins

Serum leptin concentrations in normal humans have been reported to correlate with the body mass index (BMI) as well as with the body fat mass. In this study, we measured serum leptin concentrations in 107 patients on hemodialysis, 30 of whom had diabetes mellitus as the cause, and examined the clinical significance. Furthermore, we evaluated the effects of high-flux dialysis membranes on serum leptin levels. Serum leptin concentrations had a linear correlation with BMI as well as with the percentage of body fat in patients on hemodialysis. The serum leptin concentrations showed a positive correlation with the serum concentrations of total cholesterol, low-density lipoprotein cholesterol, and triglyceride, the body weight, the BMI, and the percentage of body fat. The serum leptin levels were not different between the diabetic and the nondiabetic groups. The serum leptin levels in the nondiabetic group were nearly fourfold higher in women than in men. We investigated the differences in the rate of reduction in serum leptin after dialysis with polysulfone membrane dialyzers (PS-N and PS-UW) in comparison with a cellulose membrane dialyzer (AM-SD), and as a result, we found that the polysulfone membrane dialyzers removed serum leptin, while the cellulose membrane dialyzer did not. We conclude that in patients on hemodialysis, the serum leptin concentration is a valuable clinical marker of the body fat content and may also contribute to the evaluation of hyperlipidemia.

Topics: Adipose Tissue; Aged; Body Mass Index; Body Weight; Diabetic Nephropathies; Female; Humans; Kidney Failure, Chronic; Leptin; Male; Middle Aged; Proteins; Regression Analysis; Renal Dialysis; Sex Characteristics

To investigate the relationship between leptin levels and IDDM with and without microalbuminuria, fasting serum levels of leptin, insulin, insulin-like growth factor-1 (IGF-1), sex hormone-binding globulin (SHBG), testosterone (SHBG) ratio, blood pressure and body mass index (BMI) were measured in 18 normo- and 11 microalbuminuric females with >5 years of IDDM, and 24 healthy controls in late puberty. Leptin levels were higher in micro- than normoalbuminuric IDDM patients, and lower in healthy controls than in both IDDM groups (p < 0.05, respectively). In multiple regression analysis, presence of IDDM and BMI independently contributed to increased leptin values (R2 = 0.34, p < 0.001). Including IDDM females only, solely low IGF-1 and high testosterone/SHBG were associated with leptin (R2 = 0.39, p = 0.009). Albumin excretion rate (AER) was correlated to leptin (r = 0.48, p = 0.01). With AER as the dependent variable only serum leptin and diastolic blood pressure added to the regression (R2 = 0.59, p < 0.001). In conclusion, serum leptin, independently of BMI, is: (1) increased in IDDM females of late puberty; (2) associated with low IGF-1 and hyperandrogenemia, and (3) related to increased albumin excretion rate in IDDM females.

Topics: 3-Hydroxybutyric Acid; Adolescent; Adult; Albuminuria; Blood Pressure; Body Mass Index; Chromatography, High Pressure Liquid; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Female; Fluoroimmunoassay; Glomerular Filtration Rate; Glycated Hemoglobin; Humans; Hyperandrogenism; Insulin; Insulin-Like Growth Factor I; Leptin; Proteins; Puberty; Radioimmunoassay; Regression Analysis; Sex Hormone-Binding Globulin; Testosterone

The beta 3-Adrenergic receptor (beta 3AR) and leptin are molecules involved in the regulation of energy balance. Recently, a mutation in the beta 3AR gene (Trp64Arg) has been reported to be associated with features of insulin resistance, weight gain and early onset of Type 2 Diabetes Mellitus. The aim of this study was to determine the frequency and clinical characteristics of the Trp64Arg mutation in the beta 3AR gene in Type 2 diabetic patients, its relationship with leptin levels, and its role in microangiopathic complications.. 187 Type 2 diabetic patients and 100 unrelated non-diabetic subjects were studied. There was no difference between the diabetic and nondiabetic subjects in the frequency of the Trp64 and Arg64 alleles (92.5% vs. 92.3% and 7.5% vs. 7.7%, respectively). Type 2 diabetic patients were divided into two groups according to the presence (n = 27) or absence of the mutation (n = 160).. Mutation of the beta 3AR gene was not associated with any differences either in the clinical and metabolic parameters or microangiopathic complications. Type 2 diabetic patients carrying the Arg64 allele tended to have a lower diabetes duration, but this was not statistically significant. Plasma leptin levels were not different according to the beta 3AR genotype.. The Trp64Arg mutation is not a major determinant of Type 2 diabetes and its microangiopathic complications. Moreover, this mutation was not clinically relevant in leptin regulation.

Topics: Aged; Alleles; Blood Pressure; Body Mass Index; Case-Control Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Retinopathy; Female; Humans; Leptin; Male; Middle Aged; Polymorphism, Genetic; Proteins; Receptors, Adrenergic, beta; Receptors, Adrenergic, beta-3; Receptors, Leptin; Statistics, Nonparametric

Topics: Adipocytes; Animals; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Glycation End Products, Advanced; Glycosylation; Humans; Hypoglycemic Agents; Kidney Failure, Chronic; Leptin; Metformin; Mice; Mice, Mutant Strains; Mice, Obese; Obesity; Protein Biosynthesis; Proteins