Serum advanced glycation end products are associated with insulin resistance in male nondiabetic patients with obstructive sleep apnea.

PURPOSE: Advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic vascular complications. Recently, growing evidence has shown that AGEs could be involved in the pathogenesis of insulin resistance. It has also been suggested that circulating AGE are associated with insulin resistance in nondiabetic patients. This study investigated whether serum AGEs levels are associated with insulin resistance in nondiabetic patients with obstructive sleep apnea (OSA). METHODS: A total of 139 male nondiabetic patients with OSA were recruited for participation in the study. Serum AGE levels were examined using an enzyme-linked immunosorbent assay. Insulin resistance was determined using the homeostasis model assessment index (HOMA-IR). RESULTS: There was a significant correlation between serum AGEs and the apnea-hypopnea index (AHI) (r = 0.281, p = 0.014), duration of SaO2 < 90% (r = 0.267, p = 0.018), minimum SaO2 (r = -0.188, p = 0.046), high-sensitivity C-reactive protein (hsCRP) (r = 0.274, p = 0.012), and HOMA-IR (r = 0.303, p < 0.001). Multiple regression analysis showed that serum AGEs (p = 0.011), AHI (p = 0.024), waist circumference (p = 0.040), and hsCRP (p = 0.046) were independently associated with HOMA-IR (R(2) = 0.392). In addition, the strength of the correlation between serum AGEs and HOMA-IR was related to the severity of OSA. CONCLUSIONS: The present study indicated that serum AGE levels were associated with insulin resistance in male nondiabetic patients with OSA. These findings suggest that AGEs may play a role in insulin resistance in OSA and may also be a biomarker for patients with OSA with high risk of developing type 2 diabetes.

Polymorphism 2184A/G in the AGER gene is not associated with diabetic retinopathy in Han Chinese patients with type 2 diabetes.

OBJECTIVE: To assess the association between the 2184A/G polymorphism in the advanced glycosylation end product-specific receptor (AGER) gene and the susceptibility to diabetic retinopathy (DR) in Han Chinese patients with type 2 diabetes mellitus (T2DM). METHODS: This cross-sectional genotyping study included patients with T2DM with and without DR. Genotype and allele frequencies of the 2184A/G polymorphism were detected using polymerase chain reaction-restriction fragment-length polymorphism analysis. RESULTS: This study included 943 patients with T2DM (285 with DR [DR group] and 658 without DR [NDR group]). There were no significant differences in age, sex, body mass index, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, diastolic blood pressure, glycosylated haemoglobin, fasting blood glucose, postprandial 2-hour blood glucose, and triglycerides between the two groups. The duration of T2DM and systolic blood pressure were significantly increased in the DR group compared with the NDR group. No significant differences were found in allele (A and G) and genotype (AA, AG and GG) frequencies of the 2184A/G polymorphism between the two groups. CONCLUSION: The 2184A/G polymorphism in the AGER gene is not associated with DR in Han Chinese patients with T2DM.

Association of 2184AG Polymorphism in the RAGE Gene with Diabetic Nephropathy in Chinese Patients with Type 2 Diabetes.

OBJECTIVE: The interaction between advanced glycation end products and their cellular receptor (RAGE) has an important role in the pathogenesis of diabetic microvascular complications. The aim of this study was to investigate the relationship between the 2184A/G polymorphism in the RAGE gene and diabetic nephropathy in Chinese Han patients with type 2 diabetes mellitus. METHODS: A total of 868 patients with type 2 diabetes mellitus (486 without and 382 with diabetic nephropathy) were enrolled in this study. The genotype and allele frequencies of the 2184A/G polymorphism were detected using the polymerase chain reaction-restriction fragment-length polymorphism method. RESULTS: The G allele and AG + GG genotype frequencies in patients with diabetic nephropathy were significantly lower than those in patients without diabetic nephropathy (P = 0.001 and P = 0.005, resp.). After adjustments for possible confounders, multivariate logistic regression analyses showed that the 2184A/G polymorphism was independently associated with diabetic nephropathy (OR = 0.46, 95% CI: 0.22-0.92, P = 0.028). CONCLUSIONS: Our study indicated that the 2184A/G polymorphism in the RAGE gene was significantly associated with diabetic nephropathy in Chinese Han patients with type 2 diabetes.