dimethylarginine and Diabetes-Mellitus--Type-2

The endothelium is a thin layer of cells at the internal surface of blood vessels in continuous contact with the circulating fluids. The endothelial cells represent the primary barrier for the transport of glucose from the vascular conduits into the interstitial space. Insulin and nitric oxide have an important role in the regulation of glucose transport and metabolism. Hyperglycaemia is the main criteria for the diagnosis of diabetes and is responsible for the micro- and macro-vascular pathology seen in diabetic patients. Recent evidence suggests that post-challenge hyperglycaemia is a better predictor of cardiovascular risk than fasting glucose. Acute glucose elevations have been associated with a reduced endothelial-dependent flow mediated dilation indicating a decrease in nitric oxide production. Post-prandial hyperglycaemic peaks have been directly associated with increased intima media thickness in type 2 diabetic patients indicative of an increased atherosclerotic risk. The increase in intra-cellular glucose concentrations in the endothelial cells induces a hyper-generation of reactive oxygen species via the activation of different pathways (polyol-sorbitol, hexosamine, advanced glycated end products, activation of PKC, asymmetric dimethylarginine (ADMA)). These mechanisms influence the expression of genes and release of signalling and structural molecules involved in several functions (inflammation, angiogenesis, coagulation, vascular tone and permeability, cellular migration, nutrient metabolism). ADMA is considered as a biomarker of endothelial dysfunction and it has been associated with an increased risk of atherosclerosis and cardiovascular diseases. The increased generation of ADMA and reactive oxygen species in subjects with persistent hyperglycaemia could lead to an impairment of nitric oxide synthesis.

Topics: Animals; Arginine; Diabetes Mellitus, Type 2; Endothelium, Vascular; Glucose; Glucose Tolerance Test; Heart Diseases; Humans; Hyperglycemia; Metabolic Diseases; Nitric Oxide; Oxidative Stress

To study the effect of metformin on plasma levels of arginine, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), indicators of the nitric oxide pathway.. In this post hoc analysis of the HOME trial, we analysed plasma levels of arginine, ADMA and SDMA during the 4.3-year follow-up (comparing the effects of metformin versus placebo on top of insulin therapy). Statistical analysis was performed with a mixed model approach, in which simultaneously constant treatment effects were estimated, as well as time-dependent treatment effects.. We found that metformin compared with placebo did not affect ADMA or SDMA plasma levels but rapidly decreased arginine plasma levels and hence the arginine to ADMA ratio. The constant treatment effect on ADMA was 0.99 (95% CI 0.97, 1.00) relative to placebo and the time-dependent treatment effect was 1.00 (95% CI 1.00, 1.01). By contrast, the constant treatment effect on arginine was 0.86 (95% CI 0.84, 0.88), with only a minimal time-dependent change of 1.01 (95% CI 1.00, 1.01).. The potential benefits of metformin on endothelial function cannot be explained by a decrease in ADMA or by improved global arginine availability. The clinical significance of the decreased arginine plasma levels is not clear and can be harmful or beneficial, depending on the mechanism involved. However, a potential effect of metformin on the nitric oxide pathway is not restricted to the studied metabolites.

Topics: Arginine; Biomarkers; Diabetes Mellitus, Type 2; Humans; Metformin; Nitric Oxide

Topics: Anti-Inflammatory Agents; Antioxidants; Arginine; Ascorbic Acid; Atorvastatin; Cytokines; Diabetes Mellitus, Type 2; Endothelium, Vascular; Female; Forearm; Heptanoic Acids; Humans; Hyperemia; Male; Middle Aged; Pyrroles; Regional Blood Flow; Single-Blind Method; Vitamins

Elevated asymmetric dimethylarginine (ADMA) levels, an endogenous inhibitor of nitric oxide synthase, are an important cardiovascular risk factor. In patients with diabetes, increased ADMA levels have been reported, which may be associated with endothelial dysfunction. In this study, effect of nebivolol on serum ADMA levels in hypertensive patients with type 2 diabetes have been compared with metoprolol, an another beta-blocker.. A total of 54 patients (27 female, 27 male; mean age: 53.0+/-8.7 years) with type 2 diabetes and hypertension were included in this randomized, open-label, prospective study. Patients were randomized to receive either nebivolol 5 mg/day (n=28) or metoprolol 100 mg/day (n=26) for 12 weeks. When the patients could not reach target blood pressure levels at the end of week 4, indapamide (2.5 mg/day) was added. Enzyme Linked Immunosorbent Assay was used for serum ADMA measurements.. Similar reductions in blood pressure values were observed in both groups (p>0.05). In nebivolol group, there were no significant changes in serum ADMA levels compared to baseline (0.6+/-0.2 micromol/l vs 0.6+/-0.1 micromol/l, p>0.05), whereas in metoprolol group a 35.6% increase in serum ADMA levels was observed (0.6+/-0.1 micromol/l vs 0.7+/-0.2 micromol/l, p<0.01).. We observed a significant increase in ADMA levels, a marker of endothelial dysfunction, during metoprolol treatment, whereas nebivolol had neutral effects on ADMA levels in patients with type 2 diabetes mellitus and hypertension.

Topics: Administration, Oral; Adrenergic beta-Antagonists; Adult; Aged; Arginine; Benzopyrans; Biomarkers; Blood Pressure; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Ethanolamines; Female; Humans; Hypertension; Male; Metoprolol; Middle Aged; Nebivolol; Prospective Studies; Treatment Outcome; Triglycerides

Asymmetric dimethylarginine (ADMA) is a recently identified potent cardiovascular risk factor. ADMA levels are increased in hyperhomocysteinaemia and the metabolism of ADMA is linked with that of homocysteine in several ways. Treatment with B vitamins effectively reduces homocysteine levels, but studies investigating the effect on ADMA levels are scarce and show conflicting results. In this study we evaluated the effect of treatment with B vitamins on ADMA levels in two high cardiovascular risk populations.. In study I, 110 siblings of patients with clinical atherosclerotic disease and postmethionine hyperhomocysteinaemia were treated with 5 mg of folic acid and 250 mg of pyridoxine or placebo, and were analysed after 1 year. In study II, 41 patients with type 2 diabetes and mild hyperhomocysteinaemia were analysed after 6 months treatment with 5 mg of folic acid or placebo.. A correlation between baseline homocysteine and ADMA levels was found, which was partly due to confounding by renal function. Homocysteine levels decreased by 43% in study I and by 28% in study II. In both studies, treatment with B vitamins had no effect at all on ADMA, arginine/ADMA ratio and SDMA levels. This result was confirmed in multiple linear regression analyses with adjustment for baseline values and gender.. Our studies indicate that B vitamins, despite causing a substantial reduction in plasma homocysteine levels, have no beneficial effect on ADMA levels.

Topics: Adolescent; Adult; Arginine; Atherosclerosis; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Administration Schedule; Female; Folic Acid; Humans; Hyperhomocysteinemia; Linear Models; Male; Middle Aged; Pyridoxine; Risk Factors; Time Factors; Treatment Failure; Vitamin B Complex

Symmetrical dimethylarginine (ADMA) endogenously inhibits nitric oxide synthase (NOS) and strongly indicates oxidant stress, whose formation primarily derived from type 1 protein arginine N-methyltransferase (PRMT1) and whose metabolism was governed by type 1 dimethylarginine dimethylaminohydrolase (DDAH1). This study aimed to evaluate participation of the PRMT1-ADMA-DDAH1 metabolism axis in the kidneys of type 2 diabetes model rats and human subjects, and the effect of probucol on this axis and renal function.. A total of 30 rats were randomly assigned to a normal group (NC, n=10), diabetic group (DM, n=10), and a diabetics under probucol treatment group (PM, n=10). Throughout 8 weeks of probucol treatment, plasma NOS, the malondialdehyde (MDA), superoxide dismutase (SOD), nitric oxide (NO), and catalase (CAT) activity were evaluated by chemical colorimetric approach. ADMA concentration was evaluated with an enzyme-linked immunosorbent assay (ELISA) and analysis of expression of PRMT1 and DDAH1 in kidneys with reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC) and western blotting were performed.. The expression of DDAH1 in the kidney, and the plasma NOS, NO, SOD, and CAT activities in diabetic group were lower, while MDA and the expression of PRMT1 and ADMA were higher in contrast to the control group. In diabetics rats receiving probucol, the expressions of DDAH1 and ADMA were downregulated, whereas that of PRMT1 was upregulated. Probucol inhibited the indexes of oxidative stress and improved the kidney function in both diabetic rats and humans.. We found that the expression of the PRMT1-ADMA-DDAH1 axis was altered in the kidneys of diabetic rats. Moreover, results indicated that probucol therapy regulates expression at both ends of this axis, which may preserve renal function by reducing oxidant stress. Therefore, probucol may partially restore expression of the PRMT1-ADMA-DDAH1 axis in diabetic kidneys, immigrate oxidant stress, and enhance renal function.

Topics: Amidohydrolases; Animals; Arginine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Humans; Nitric Oxide; Probucol; Protein-Arginine N-Methyltransferases; Rats; Repressor Proteins

Altered circulatory asymmetric and symmetric dimethylarginines have been independently reported in patients with end-stage renal failure suggesting their potential role as mediators and early biomarkers of nephropathy. These alterations can also be reflected in urine. Herein, we aimed to evaluate urinary asymmetric to symmetric dimethylarginine ratio (ASR) for early prediction of diabetic nephropathy (DN). In this cross-sectional study, individuals with impaired glucose tolerance (IGT), newly diagnosed diabetes (NDD), diabetic microalbuminuria (MIC), macroalbuminuria (MAC), and normal glucose tolerance (NGT) were recruited from Dr. Mohans' Diabetes Specialties centre, India. Urinary ASR was measured using a validated high-throughput MALDI-MS/MS method. Significantly lower ASR was observed in MIC (0.909) and MAC (0.741) in comparison to the NGT and NDD groups. On regression models, ASR was associated with MIC [OR: 0.256; 95% CI: 0.158-0.491] and MAC [OR 0.146; 95% CI: 0.071-0.292] controlled for all the available confounding factors. ROC analysis revealed ASR cut-point of 0.95 had C-statistic of 0.691 (95% CI: 0.627-0.755) to discriminate MIC from NDD with 72% sensitivity. Whereas, an ASR cut-point of 0.82 had C-statistic of 0.846 (95% CI: 0.800 - 0.893) had 91% sensitivity for identifying MAC. Our results suggest ASR as a potential early diagnostic biomarker for DN among the Asian Indians.

Topics: Adult; Aged; Albuminuria; Arginine; Chromatography, High Pressure Liquid; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Feasibility Studies; Female; Humans; Male; Middle Aged; Predictive Value of Tests; ROC Curve; Tandem Mass Spectrometry

Asymmetric dimethylarginine (ADMA) plays a vital role in the regulation of insulin sensitivity and has been shown as a potential marker for various disease, including type 2 diabetes mellitus (DM2). However, the correlation between ADMA and impaired glucose tolerance (IGT) and obesity has not been studied. A total of 195 subjects were involved in our study. The characteristics of the subjects in the study cohort were measured and analyzed. We found that the serum ADMA and C-reactive protein levels were significantly increased in IGT and diabetic patients, whereas the levels of lipoprotein A and adiponectin were decreased, especially in diabetic patients with obesity. The serum ADMA level was positively correlated to a homeostatic model assessment for insulin resistance, and multivariate regression analysis further indicated that ADMA was an independent factor for DM patients with obesity. Our study expands the understanding of the complicated relationship between obesity, insulin resistance, IGT, and ADMA. In addition, we demonstrated that the serum ADMA level could serve as a diagnositic biomarker of the early signs for IGT patients with obesity.

Topics: Aged; Arginine; Biomarkers; Blood Glucose; C-Reactive Protein; Diabetes Mellitus, Type 2; Female; Glucose Intolerance; Glucose Tolerance Test; Humans; Insulin Resistance; Male; Middle Aged; Obesity

To evaluate symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA) as risk markers of cardiovascular disease, all-cause mortality and deterioration in renal function in a well characterised type 2 diabetic population with microalbuminuria and without symptoms of coronary artery disease.. 200 participants followed for 6.1 years. SDMA and ADMA were measured at baseline. Endpoints included (1) composite cardiovascular endpoint (n = 40); (2) all-cause mortality (n = 26); and (3) decline in eGFR of >30% (n = 42). Cox models were unadjusted and adjusted for traditional risk factors (sex, age, systolic blood pressure, LDL-cholesterol, smoking, HbA. Higher SDMA was associated with increased risk of all three endpoints (unadjusted: p ≤ 0.001; adjusted: p ≤ 0.02). Higher ADMA was associated with all-cause mortality (unadjusted: p = 0.002; adjusted: p = 0.006), but not cardiovascular disease or decline in eGFR (p ≥ 0.29).The c statistic was not significant for any of the endpoints for either SDMA or ADMA (p ≥ 0.10). The rIDI for SDMA was 15.0% (p = 0.081) for the cardiovascular endpoint, 52.5% (p = 0.025) for all-cause mortality and 48.8% (p = 0.007) for decline in eGFR; for ADMA the rIDI was 49.1% (p = 0.017) for all-cause mortality.. In persons with type 2 diabetes and microalbuminuria higher SDMA was associated with incident cardiovascular disease, all-cause mortality and deterioration in renal function. Higher ADMA was associated with all-cause mortality. SDMA and ADMA significantly improved risk prediction for all-cause mortality, and SDMA for deterioration in renal function beyond traditional risk factors.

Topics: Adult; Aged; Albuminuria; Arginine; Cardiovascular Diseases; Coronary Disease; Creatinine; Diabetes Mellitus, Type 2; Female; Glomerular Filtration Rate; Humans; Kidney; Male; Middle Aged; Risk Factors

Elevated levels of circulating asymmetric and symmetric dimethylarginines (ADMA and SDMA) predict and potentially contribute to end organ damage in cardiovascular diseases. Alanine-glyoxylate aminotransferase 2 (AGXT2) regulates systemic levels of ADMA and SDMA, and also of beta-aminoisobutyric acid (BAIB)-a modulator of lipid metabolism. We identified a putative binding site for hepatic nuclear factor 4 α (HNF4α) in AGXT2 promoter sequence. In a luciferase reporter assay we found a 75% decrease in activity of Agxt2 core promoter after disruption of the HNF4α binding site. Direct binding of HNF4α to Agxt2 promoter was confirmed by chromatin immunoprecipitation assay. siRNA-mediated knockdown of Hnf4a led to an almost 50% reduction in Agxt2 mRNA levels in Hepa 1-6 cells. Liver-specific Hnf4a knockout mice exhibited a 90% decrease in liver Agxt2 expression and activity, and elevated plasma levels of ADMA, SDMA and BAIB, compared to wild-type littermates. Thus we identified HNF4α as a major regulator of Agxt2 expression. Considering a strong association between human HNF4A polymorphisms and increased risk of type 2 diabetes our current findings suggest that downregulation of AGXT2 and subsequent impairment in metabolism of dimethylarginines and BAIB caused by HNF4α deficiency might contribute to development of cardiovascular complications in diabetic patients.

Topics: Aminoisobutyric Acids; Animals; Arginine; Cardiovascular Diseases; Cell Line; Diabetes Mellitus, Type 2; Gene Expression Regulation; Hepatocyte Nuclear Factor 4; Humans; Liver; Mice; Mice, Inbred C57BL; Mice, Knockout; Polymorphism, Single Nucleotide; Promoter Regions, Genetic; Risk; RNA, Small Interfering; Transaminases

To investigate determinants of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), including single nucleotide polymorphisms (SNPs), in the DDAH1, DDAH2, and AGXT2 genes and their associations with prevalent and incident cardiovascular disease (CVD) in older adults with type 2 diabetes mellitus.. Prevalent CVD was assessed in men and women aged 60-75 years with type 2 diabetes as part of the Edinburgh Type 2 Diabetes Study (ET2DS), and the participants were prospectively followed up for 4 years for incident CVD. Dimethylarginines were measured in 783 of these subjects, and genotyping for tag SNPs in the DDAH1, DDAH2, and AGXT2 genes was performed in 935 subjects.. Plasma ADMA levels were significantly associated with SNPs in DDAH1 (top SNP rs1554597; P = 9.0E-09), while SDMA levels were associated with SNPs in AGXT2 (top SNP rs28305; P = 1.3E-04). Significant, independent determinants of plasma ADMA were sex, L-arginine, creatinine, fasting glucose, and rs1554597 (all P < 0.05; combined R(2) = 0.213). Determinants of SDMA were age, sex, creatinine, L-arginine, diabetes duration, prevalent CVD, and rs28305 (all P < 0.05; combined R(2) = 0.425). Neither dimethylarginine was associated with incident CVD. None of the investigated SNPs were associated with overall CVD, although subgroup analysis revealed a significant association of AGXT2 rs28305 with intermittent claudication.. Our study in a well-characterized population with type 2 diabetes does not support reported associations or causal relationship between ADMA and features of diabetes or CVD.

Topics: Aged; Arginine; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Environment; Female; Genotype; Humans; Intermittent Claudication; Male; Middle Aged; Polymorphism, Single Nucleotide; Risk Factors

We investigated the association of serum asymmetric dimethylarginine (ADMA) with metabolic syndrome (MetS), type-2 diabetes and coronary heart disease (CHD) in the general population.. Cross-sectional and, at 2000 person-years' follow-up, prospective analysis. Adults with measured serum ADMA level (n=848) were analyzed using tertiles or dichotomized values. ADMA concentrations were measured by a validated commercial ELISA kit.. Dichotomized subjects of combined sexes with low (≤0.68 µmol/L) ADMA values had significantly higher fasting glucose, total cholesterol, apolipoprotein B and lower diastolic blood pressure. In linear regression analyses comprising age, smoking, triglyceride, HDL-cholesterol, C-reactive protein and waist circumference as well, creatinine was significantly and independently associated with ADMA, further in women glucose (inversely). In logistic regression analyses uniformly adjusted for age, smoking status and waist girth, prevalent MetS tended to positive independent association with ADMA tertiles only in men. Combined prevalent and incident diabetes weakly tended to be associated with the lowest (vs mid- and highest) ADMA tertiles in combined gender; and prevalent and incident CHD was not associated with ADMA tertiles in either sex.. Apparently "low" circulating ADMA is independently associated with fasting glucose and tends to be so with type-2 diabetes. The lack of anticipated positive associations of ADMA with cardiometabolic disorders is likely due to autoimmune responses operating against serum ADMA under oxidative stress, rendering partial failure in immunoassay.

Topics: Adult; Anthropometry; Arginine; Biomarkers; Coronary Disease; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Glucose Tolerance Test; Humans; Male; Metabolic Syndrome; Prospective Studies

Type 2 diabetes mellitus (T2DM) has become a major public health issue and is considered a risk factor for erectile dysfunction (ED). T2DM is also associated with androgen deficiency. However, there have been few basic studies on androgen replacement therapy (ART) for ED treatment in T2DM animal models, and the mechanism underlying the effect of ART on T2DM-induced ED is unclear.. To investigate the effect of ART on ED in T2DM rats by examining inflammatory and nitric oxide (NO)-related factors.. Otsuka Long-Evans Tokushima Fatty (OLETF) rats and their controls, Long-Evans Tokushima Otsuka (LETO) rats, were distributed into three groups: LETO, OLETF, and ART. In the ART group, OLETF rats were treated daily with testosterone (3 mg/kg/day, subcutaneously) from 20 to 25 weeks of age; LETO and OLETF rats received vehicle only.. We measured erectile function by using measurements of the ratio between intracavernosal pressure (ICP) and mean arterial pressure (MAP) following electrical stimulation of the cavernous nerve and by evaluating the endothelial function of the corpus cavernosum in an isometric tension study. Expression of endothelial NO synthase (eNOS), inducible NO synthase (iNOS), sirtuin-1 (Sirt1), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) mRNA was detected using polymerase chain reaction.. The ICP/MAP ratio in the OLETF group was significantly decreased and that in the ART group was significantly improved (P < 0.01). The response to acetylcholine was significantly decreased in the OLETF group and improved in the ART group (P < 0.01). Although expression of eNOS and Sirt1 mRNA was decreased and that of iNOS, IL-6, and TNF-α mRNA was increased in the OLETF group, ART improved mRNA expression.. ART suppressed inflammation in rats with T2DM and metabolic disorders and improved their endothelial and erectile functions. ART could be effective for T2DM-induced ED and may be considered a potential ED treatment method.

Topics: Androgens; Animals; Arginine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Electric Stimulation; Erectile Dysfunction; Hormone Replacement Therapy; Interleukin-6; Male; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Penile Erection; Penis; Rats, Long-Evans; Testosterone; Tumor Necrosis Factor-alpha

Elevated plasma asymmetric dimethylarginine (ADMA) levels have been observed in patients with insulin resistance and diabetes, and have been reported to predict adverse cardiovascular events in type 2 diabetic patients. However, the relationship between ADMA and glycemic control in patients with type 2 diabetes remained controversial.. We evaluated 270 patients with type 2 diabetes and measured their plasma ADMA and hemoglobin A1c (HbA1c) levels by high performance liquid chromatography. The mean age was 67 ± 12 years. The mean plasma ADMA and HbA1c level were 0.46 ± 0.09 μmol/l and 7.8 ± 1.6%, respectively. There was no significant correlation between plasma ADMA level and HbA1c level (r = -0.09, p = 0.13). During the median follow-up period of 5.7 years (inter-quartile range: 5.0 - 7.3 years), major adverse cardiovascular event (MACE, including cardiovascular death, myocardial infarction and stroke) was observed in 55 patients (20.4%). Multivariate Cox regression analysis revealed that the ADMA tertile was an independent risk factor for MACE (ADMA tertile III versus ADMA tertile I: p = 0.026, HR: 2.31, 95% CI: 1.10 - 4.81). The prognosis predictive power of ADMA disappeared in patients with well glycemic control (HbA1c ≤6.5%), and the ADMA-HbA1c interaction p value was 0.01.. In patients with type 2 diabetes, ADMA might be an independent risk factor for long-term adverse cardiovascular events. However, ADMA was not correlated with serum HbA1c level, and in diabetic patients with HbA1c ≤6.5%, elevated ADMA level was no longer associated with increased risk of long-term prognosis. Our findings suggested that the prognosis predictive value of ADMA in type 2 diabetes might be modified by the glycemic control.

Topics: Aged; Aged, 80 and over; Arginine; Biomarkers; Blood Glucose; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Glycated Hemoglobin; Humans; Middle Aged; Prognosis; Prospective Studies; Risk Assessment; Risk Factors

We tested the relationship between plasma levels of dimethylarginines (ADMA and SDMA) and glycaemic control in 43 type 2 diabetic patients. Type 2 diabetics with poor glycaemic control (HbA1c>6.5) had significantly lower SDMA and higher ADMA concentrations than those with well-controlled glycaemia (HbA1c<6.5).

Topics: Arginine; Blood Glucose; Case-Control Studies; Diabetes Complications; Diabetes Mellitus, Type 2; Female; Glycated Hemoglobin; Glycemic Index; Humans; Male; Prognosis

Oxidative stress is thought to be one of the underlying mechanisms of diabetic microvascular complications such as diabetic nephropathy and diabetic retinopathy (DRP). Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide (NO) synthase inhibitor and increased by oxidative stress. Apelin is an endogenous ligand for human orphan G-protein-coupled receptor, APJ and increases NO generation. In this study, our aim was to evaluate ADMA and apelin levels in diabetic patients with or without retinopathy and their relationships between retinopathy stages and metabolic parameters. Seventy-nine diabetic patients were included into the study and classified into three groups. Group 1 consisted of 41 patients with no DRP (NDRP), group 2 consisted of 23 patients with nonproliferative DRP (NPDRP), and group 3 consisted of 15 patients with proliferative DRP (PDRP). Plasma ADMA and apelin levels were found to be similar in all groups. But, there was a positive correlation between apelin levels and urinary albumin/creatinine ratio. Further studies involving larger patients populations and healthy controls should be done to clarify the pathogenetic significance of ADMA and apelin in diabetic microvascular complications.

Topics: Aged; Albuminuria; Apelin; Arginine; Blood Glucose; Blood Pressure; Creatinine; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Retinopathy; Fasting; Female; Humans; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; Oxidative Stress; Waist-Hip Ratio

Topics: Apelin; Arginine; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Retinopathy; Endothelium, Vascular; Humans; Intercellular Signaling Peptides and Proteins; Life Style; Neovascularization, Pathologic

To evaluate biomarkers of endothelial dysfunction and oxidative stress in glucose intolerance (GI) compared to overt diabetes (DM2).. 140 volunteers including 96 with DM2, 32 with GI and 12 controls (C) were studied. (*)NO metabolites, (*)NO synthase inhibitors, thiols and N-acetyl-beta-glucosaminidase (NAGase) activity were analyzed by chemiluminescence, capillary electrophoresis, ELISA and colorimetric assay, respectively.. (*)NO metabolites were higher in GI (NOx: p=0.03; S-nitrosothiols: p=0.001) and DM2 (p=0.006; p=0.0006) groups in relation to group C, while nitrotyrosine was higher only in the DM2 group in comparison to the other groups. NAGase activity was elevated in GI (p=0.003) and DM2 (p=0.0004) groups in relation to group C, as well as, ADMA (p=0.01; p=0.003) and GSSG (p=0.01; p=0.002).. (*)NO metabolites, (*)NO synthase inhibitors, thiols and NAGase are biomarkers suitable to indicate endothelial dysfunction and oxidative stress in the early stages of impaired response to insulin.

Topics: Arginine; Biomarkers; Body Mass Index; Diabetes Mellitus, Type 2; Endothelium; Female; Glucose Intolerance; Glutathione; Hexosaminidases; Humans; Lipids; Male; Middle Aged; Nitrates; Nitric Oxide; Nitrites; Oxidative Stress

Topics: Adrenergic beta-Antagonists; Arginine; Benzopyrans; Confounding Factors, Epidemiologic; Diabetes Mellitus, Type 2; Ethanolamines; Humans; Hypertension; Metoprolol; Nebivolol

Patients with Type 2 diabetes mellitus (T2DM) and micro- and macroalbuminuria are at increased cardiovascular risk. The endogenous nitric oxide synthase inhibitor asymmetrical dimethylarginine (ADMA) is increased in renal failure and could promote atherosclerosis. To determine the relationship between ADMA, renal albumin excretion rate (AER) and cardiovascular risk, we studied 103 T2DM patients.. ADMA, symmetrical dimethylarginine (SDMA) and L-arginine were determined by high-performance liquid chromatography in plasma from 36 normo-, 40 micro- and 27 macroalbuminuric patients with T2DM (age 64 +/- 11 years; 38 women) who had comparable age, sex and metabolic parameters. Forty-six patients had macrovascular disease (MVD).. ADMA was significantly increased in patients with micro- and macroalbuminuria [median 0.61 (interquartile range 0.55-0.70) micromol/l and 0.62 (0.50-0.79) micromol/l, respectively] compared with those with normoalbuminuria [0.55 (0.48-0.63) micromol/l; both P < 0.05]. SDMA was elevated in micro- and macroalbuminuria [0.57 (0.42-0.80) micromol/l and 0.64 (0.50-0.96) micromol/l] compared with normoalbuminuric subjects [0.44 (0.37-0.53) micromol/l; both P < 0.01]. Patients with increased AER and MVD had higher ADMA and SDMA compared with those without MVD (both P < 0.001). L-arginine was comparable between all groups. ADMA correlated significantly with high-sensitivity C-reactive protein (hsCRP) and glomerular filtration rate (GFR) but not with the extent of albumin excretion, body mass index, fasting glucose, HbA(1c) or plasma lipids.. Increased ADMA in T2DM patients with albuminuria is linked to cardiovascular disease and is associated with renal dysfunction and subclinical inflammation.

Topics: Aged; Albuminuria; Arginine; Atherosclerosis; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Nephropathies; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged

Functional changes of the vessel wall--specifically dysfunction of endothelial cells--may precede the formation of frank plaques at the initiation of atherosclerosis. Clinically endothelial function and dysfunction can be measured by angiography or ultrasound techniques. Another possibility is the measurement of circulating markers of endothelial dysfunction in human plasma, such as the endogenous NOS inhibitor ADMA (asymmetric dimethylarginine). In our recent studies we were able to show that ADMA accumulates in the presence of metabolic changes such as hyperhomocysteinemia, insulin resistance and type-2 diabetes, and that these elevations of plasma ADMA correlate well with the amount of endothelial dysfunction and with NO bioavailability. Furthermore ADMA was shown to be dynamically regulated and to play an important patho-physiologic role in myocardial ischemia and reperfusion. Thus, measurements of plasma ADMA in patients could help to screen for manifestations of atherosclerosis. Moreover attempts to reduce plasma and tissue ADMA could potentially play an important role in the treatment of endothelial dysfunction, atherosclerosis, but also of ischemia reperfusion injury.

Topics: Arginine; Coronary Artery Disease; Diabetes Mellitus, Type 2; Endothelium, Vascular; Homocysteine; Humans; Insulin Resistance; Myocardial Reperfusion Injury; Nitric Oxide; Nitric Oxide Synthase; Statistics as Topic

Topics: Aged; Arginine; Biomarkers; Chromatography, High Pressure Liquid; Creatinine; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Humans; Middle Aged; Multivariate Analysis; Nitric Oxide; Nitric Oxide Synthase; Regression Analysis

Topics: Albuminuria; Arginine; Cholesterol, HDL; Creatinine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Female; Foot; Hot Temperature; Humans; Male; Metabolic Syndrome; Middle Aged; Multivariate Analysis; Thrombomodulin; Vasodilation

Topics: Aged; Arginine; Catalase; Diabetes Mellitus, Type 2; Female; Glutathione Peroxidase; Humans; Hungary; Male; Middle Aged; Polymorphism, Genetic