leptin and Nephrotic-Syndrome

The aim of the present study was to evaluate the serum and urinary levels of leptin and ghrelin in children with primary idiopathic nephrotic syndrome (NS), to compare these results between patients during the relapse and remission phase and to evaluate the possible role of leptin and ghrelin in the pathogenesis of NS.. Forty-nine children with primary idiopathic NS (25 children with relapse and 24 children in remission), who were followed up at the Pediatric Nephrology Unit, enrolled. Twenty-eight age- and sex-matched healthy children served as controls. Serum and urinary leptin levels were determined by immunoenzymatic ELISA, and serum and urinary ghrelin levels were determined by the RIA method.. The serum leptin levels were significantly lower in the children with NS during the relapse phase than in the children with NS during remission or in the controls (1.42±0.34 ng/dl and 3.60±0.70 ng/ml; p<0.01, 1.42±0.34 ng/ml and 5.27±4.67 ng/ml; p<0.001, respectively). The urinary leptin excretion levels were significantly higher in the relapse group than in the controls (0.40±0.11 ng/ml and 0.12±0.06 ng/ml, p<0.01, respectively). The serum ghrelin levels were similar between the study groups (p>0.05). The urinary ghrelin excretion levels were significantly higher in the relapse group than in the remission group and the controls (965.0 pg/ml [93-3711] and 679.7 pg/ml [93-3783], p<0.05; 965.0 pg/ml [93-3711] and 387.7 pg/ml [114-1214], p<0.001, respectively). The urinary ghrelin levels were also significantly higher in the remission group than in the controls (679.7 pg/ml [93-3783] and 387.7 pg/ml [114-1214]), p<0.01, respectively). The serum leptin levels were positively correlated with the serum albumin levels (r=0.440, p<0.05) and were negatively correlated with the serum triglyceride levels during the relapse phase. The urinary leptin and ghrelin levels were positively correlated with proteinuria in the relapse group.. We propose that leptin plays a role in the pathophysiology of NS and is associated with proteinuria, hypoproteinemia and hyperlipidemia. The significant urinary excretion of ghrelin in children with NS is possibly due to underlying pathophysiological changes, and normal serum ghrelin levels might be associated with an unknown compensatory mechanism.

Topics: Adolescent; Child; Child, Preschool; Female; Ghrelin; Humans; Leptin; Male; Nephrotic Syndrome

Leptin is a small peptide hormone which centrally regulates weight. Leptin receptor (OB-R) is expressed in hematopoietic cells, the central nervous, and immune systems. OB-R bears a homology similar to members of the class Iota cytokine family, and therefore, leptin appears to modulate immune responses. The aim of this study was to examine the effect of plasma leptin, soluble OB-R (sOB-R), and the free leptin index (FLI), the ratio between leptin and sOB-R levels, on the sensitivities of peripheral blood mononuclear cells (PBMCs) to prednisolone and cyclosporine in 16 healthy subjects and seven nephrotic syndrome (NS) patients. The NS patients had significantly higher serum sOB-R and lower FLI, compared with the healthy subjects (respectively, P=0.0026, P=0.0383). Whereas, the NS patients had significantly lower PBMC sensitivity to prednisolone (P=0.0049). PBMCs sensitivity to cyclosporine was not significantly different between the healthy subjects and the NS patients. In addition, when the data from all subjects were analyzed, there was a significantly positive correlation between plasma sOB-R concentrations and the IC50 values of prednisolone (P=0.0478). In contrast, plasma leptin concentrations and FLIs did not correlate significantly with the prednisolone and cyclosporine IC50 values. From these observations it can be suggested that plasma leptin has little effect on PBMC sensitivity to immunosuppressive drugs in NS patients. Molecular background(s) for the influence of sOB-R on the PBMC sensitivity to glucocorticoids remain(s) to be elucidated.

Topics: Adult; Female; Humans; Immunosuppressive Agents; Leptin; Leukocytes, Mononuclear; Male; Middle Aged; Nephrotic Syndrome; Prednisolone; Receptors, Leptin

Literature data point to the relationship between leptin concentration and certain markers of the metabolic syndrome, including cholesterol, triglycerides and apolipoproteins. A substantial lipid metabolism disturbance occurs in children with idiopathic nephrotic syndrome (NS). The aim of the study was to find out whether in NS children, serum and urine leptin levels change proportionally to lipid metabolism disturbances. The study was performed on two groups: (I) 30 children with NS (A) before, (B) during, prednisone therapy after proteinuria regression; (II) 25 healthy children. Serum and urine leptin levels were determined by the immunoenzymatic ELISA method. Serum leptin level in NS children before and after treatment was similar to that in the control group (p>0.05). Leptin urinary excretion in group A was approximately 60 times and in group B 24 times higher than in the controls (p<0.01). Before treatment, children with NS had increased concentrations of TC, TG, LDL, beta-lipoprotein, apolipoprotein B (apo B) (p<0.01) and reduced HDL and apolipoprotein A (apo A) (p<0.01). The conclusions were that: (1) in NS children leptin urinary excretion increases but its level is unchanged in serum; (2) serum leptin level is correlated with lipid parameters.

Topics: Apolipoproteins A; Apolipoproteins B; Child; Child, Preschool; Cholesterol, HDL; Cholesterol, LDL; Female; Humans; Infant; Leptin; Male; Nephrotic Syndrome

Reactive oxygen species and cytokines are reported to play a role in the proteinuria of nephrotic syndrome. The aim of this study was to investigate indirect evidence of oxidant activity together with leptin, lipoproteins and pro-inflammatory cytokines in children with steroid-sensitive nephrotic syndrome.. A total of 40 children with steroid-sensitive nephrotic syndrome (20 with newly onset or relapse comprised group I and 20 in remission while receiving steroids comprised group II) and 20 sex and age matched healthy control children were included. The following indirect parameters of oxidant activity were determined: serum malondialdehyde, erythrocyte superoxide dismutase, catalase and whole-blood-reduced glutathione. Serum leptin, lipids and lipoproteins were also determined.. Similar glutathione, increased malondialdehyde levels and decreased superoxide dismutase and catalase activity were observed in group I patients compared with controls. There was no significant difference in these variables between group I and group II (P >0.05). Tumour necrosis factor-alpha and interleukin-6 concentrations were similar in patients and controls. Concentrations of interleukin-1beta and interleukin-8 were higher in the active phase of nephrotics compared with controls (P <0.05). Significant positive correlations were found between malondialdehyde and interleukin-1beta, interleukin-6, leptin and lipoprotein (a) (P <0.05). There were significant negative correlations between anti-oxidants and leptin, lipoprotein (a) and several cytokines (P <0.05).. Changes in the concentrations of malondialdehyde, superoxide dismutase, catalase and glutathione are compatible with increased amounts of oxidation in steroid-sensitive nephrotic syndrome. Leptin and pro-inflammatory cytokines may be related to excessive protein permeability in nephrotic syndrome.

Topics: Antioxidants; Catalase; Child; Cytokines; Erythrocytes; Female; Glucocorticoids; Glutathione; Humans; Inflammation Mediators; Interleukins; Leptin; Lipid Peroxidation; Lipoproteins; Male; Malondialdehyde; Nephrotic Syndrome; Prednisone; Superoxide Dismutase; Tumor Necrosis Factor-alpha

In patients with nephrotic syndrome, severe proteinuria is related to significant leptinuria; serum leptin levels remain unchanged. The goal of this study was to elucidate the role of the soluble leptin receptor (sOB-R) in maintaining serum leptin levels in nephrotic patients. Patients with proteinuria were compared with patients in remission of nephrotic syndrome. In this group proteinuria did not exceed 100 mg/m(2) of body surface area per day. The period of remission was at least 6 months and was equal in all patients included. The sOB-R level (mean +/- SD) in serum of patients with nephrotic syndrome was significantly higher during proteinuria (61.0 +/- 17.8 ng/ml) than those in remission or in control patients (36.7 +/- 7.0 ng/ml, 36.6 +/- 12.0 ng/ml, respectively, P < 0.0001). The ratio between serum leptin levels and the sOB-R (free leptin index) was significantly lower in the proteinuric group (0.012 +/- 0.005 vs. 0.06 +/- 0.03 and 0.07 +/- 0.03 in remission and control group, respectively) (P < 0.001). Urinary sOB-R excretion was similar in all groups. Our data suggest that the counteracting pathway in case of leptin loss in parallel to severe proteinuria in nephrotic syndrome is the up-regulation of its soluble binding protein in serum, which can keep total serum leptin levels constant.

Topics: Adolescent; Child; Female; Humans; Leptin; Male; Nephrotic Syndrome; Proteinuria; Receptors, Cell Surface; Receptors, Leptin; Solubility; Up-Regulation

Nephrotic syndrome (NS) remains a serious clinical setting characterized by marked proteinuria, hypoproteinemia and hypercholesterolemia, usually accompanied by the presence of oedemas. It could be presumed, that the newly discovered hormone leptin plays an important role in the complex metabolic processes occurring in patients with NS, in which apart from the changes in the hydratation, and the protein and lipid spectre profile changes, the alteration of the metabolism of glycides elicited by the treatment with corticosteroids (CS) is often observed. The aim of the study was to investigate the plasma levels of leptin and its plasma soluble receptor (sLe-R) before and after the treatment with CS and to evaluate their relationship with albuminemia and/or proteinuria. The study group consisted of 15 men and 15 women (mean age 49 +/- 13.7 years) with newly diagnosed NS, verified by renal biopsy, in which subsequently CS treatment was started. Before the treatment (period 1) and further one month (period 2) and six months (period 3) after the start of the treatment the following parameters were measured: body mass index (BMI), serum levels of creatinine, albumin, cholesterol, triglyceride, cholinesterase, proteinuria/24 hour and plasma levels of leptin and sLe-R. In comparison to the relatively high values of BMI in the period 1 a decrease of BMI towards the physiologic range was observed during the treatment periods. Statistically significant changes were also observed in proteinuria (decrease) and in serum cholesterol and albumin levels of whereas in other biochemical parameters, including plasma leptin and sLe-R levels, statistically significant changes were not found. A trend to negative correlation with borderline statistical significance could be observed between leptin and sLe-R. The results of our relatively unique study on leptin--dealing with long-term follow-up of the patients with NS suggest that regardless prominent metabolic alterations present in NS the plasma levels of leptin and sLe-R remain relatively stable, and that of regulation of leptin in this setting is probably complex and multifactorial.

Topics: Adolescent; Adult; Aged; Female; Glucocorticoids; Humans; Leptin; Male; Middle Aged; Nephrotic Syndrome; Proteinuria; Receptors, Cell Surface; Receptors, Leptin; Serum Albumin

Acylation-stimulating protein (ASP) is an adipocyte-derived protein that has recently been suggested to play an important role in the regulation of lipoprotein metabolism and triglyceride (TG) storage. ASP also appears to have a role in the regulation of energy balance. In addition to its role as a hormonal regulator of body weight and energy expenditure, leptin is now implicated as a regulatory molecule in lipid metabolism. However, little is known about the alterations in fasting plasma ASP and leptin concentrations in the nephrotic syndrome. As hyperlipidemia is one of the most striking manifestations of the nephrotic syndrome, we have investigated fasting plasma ASP and leptin levels and their relation to lipid levels in this syndrome. Twenty-five patients with untreated nephrotic syndrome and 25 age-, sex-, and body mass index-matched healthy controls were included in the study. Fasting plasma lipoproteins, TG, total cholesterol, lipoprotein(a), apolipoprotein AI (apoAI), apoB, urinary protein, plasma albumin, third component of complement (C3), ASP, and leptin levels were measured in both groups. Total cholesterol, TG, low and very low density lipoproteins, lipoprotein(a), apoB, and urinary protein levels were increased in the patient group, whereas plasma albumin, high density lipoprotein cholesterol, and apoAI levels were decreased compared with those in the control group (P < 0.001). Plasma ASP levels were significantly higher in the patient group compared with the control subjects (133.72 +/- 65.14 vs. 29.93 +/- 12.68 nmol/liter; P < 0.001), whereas leptin (2.69 +/- 2.06 vs. 3.99 +/- 2.99 ng/ml; P = 0.118) and C3 (1.01 +/- 0.25 vs. 1.06 +/- 0.23 g/liter; P = 0.662) levels were not significantly different between the two groups. Plasma leptin levels were correlated with body mass index in both nephrotic patients (r(s) = 0.86; P < 0.001) and controls (r(s) = 0.98; P < 0.001), but were not correlated with the other parameters. Fasting ASP concentrations showed no correlation with body mass index, proteinuria, plasma albumin, leptin, or any lipid parameter in either group, but C3 levels (in patient group: r(s) = 0.92; P < 0.001; in control group: r(s) = 0.68; P < 0.001). Our findings showed that plasma ASP levels were significantly elevated, whereas leptin levels were normal in the nephrotic syndrome. Increased ASP levels in the setting of dyslipidemia in the nephrotic syndrome raise the possibility of an ASP receptor defect in adipocytes, which als

Topics: Adolescent; Adult; Blood Proteins; Body Mass Index; Complement C3a; Fasting; Humans; Leptin; Lipids; Nephrotic Syndrome; Osmolar Concentration

In humans, short term changes of serum leptin lead to alterations in food intake and energy expenditure. The objective of the present study was to relate urine leptin concentrations with the extent of proteinuria in patients with nephrotic syndrome (NS). A second goal was to investigate the impact of potential urinary leptin losses on serum leptin concentrations and body composition.. Seventeen patients with proteinuria were compared with twenty patients with remission of NS and ten healthy children. Leptin was measured by radioimmunoassay.. Urinary leptin excretion in proteinuric patients was significantly higher than in non-proteinuric patients with and without NS and in healthy controls (2.64+/-0.034 microg/g creatinine, 0.026+/-0.05 microg/g creatinine, and 0.073+/-0.11 microg/g creatinine respectively; P<0.001 and P<0.01 respectively compared with controls). Urine leptin positively correlated with urine IgG concentration (P=0.013, r2=0.36) in the proteinuric group. No difference in serum leptin values could be demonstrated between the three groups.. In summary, our data demonstrate a significant leptin excretion in children with severe proteinuria. Proteinuria, however, does not lead to changes in serum leptin, suggesting that the significant loss of leptin is compensated for by sustained up-regulation of leptin production.

Topics: Adolescent; Body Mass Index; Child; Female; Humans; Leptin; Male; Nephrotic Syndrome; Proteinuria; Skinfold Thickness

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