Objective: There is growing evidence that adiponectin function is related to the pathogenesis of insulin resistance. Insulin resistance might be present even in lean subjects with a strong family history of type 2 diabetes. The aim of the study was to look for adiponectin's role in the pathogenesis of insulin resistance in offspring of type 2 diabetic patients, and its relation to the activity of the tumor necrosis factor (TNF)-alpha system.
Research design and methods: The study was carried out in 23 lean offspring of type 2 diabetic subjects and in 23 controls matched for age, sex and body mass index. The oral glucose tolerance test for glucose and insulin estimations and hyperinsulinemic, euglycemic clamp studies were performed in all patients. The plasma concentration of adiponectin, TNF-alpha, soluble TNF receptors 1 and 2 (sTNFR1, sTNFR2), HbA1c, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein-cholesterol and triglycerides were estimated.
Results: The insulin sensitivity index, normalized for fat-free mass (M(ffm)) and adiponectin concentrations were markedly decreased in offspring of type 2 diabetic subjects compared with the control group (P = 0.0046 and P = 0.00058 respectively). TNF-alpha and sTNFR1 concentrations did not differ between the studied groups; however the concentration of sTNFR2 was markedly increased in the offspring of type 2 diabetic patients (P = 0.0002). Adiponectin concentration was positively correlated to the insulin sensitivity index (r = 0.34; P = 0.020) and to HDL-cholesterol (r = 0.29, P = 0.047) and was inversely related to sTNFR2 (r = -0.33, P = 0.027).
Conclusions: The obtained results suggest that adiponectin could play a role in the pathogenesis of insulin resistance in lean offspring of type 2 diabetic subjects.