Abstract

BACKGROUND
Insulin resistance, which implies impairment of insulin signaling in target tissues, is a common cause of type 2 diabetes. Adipose tissue plays an important role in insulin resistance through the dysregulated production and secretion of adipose-derived proteins, including tumor necrosis factor- , plas- minogen activator inhibitor-1, leptin, resistin, angiotensinogen and adiponectin. Adiponectin has been estimated to be a protective adipocytokine against atherosclerosis and to have an anti-inflammatory effect. In this study, the relationship between the fasting plasma adiponectin concentration and the adiposity, body composition, insulin sensitivity (ITT, HOMA(IR), QUICK), lipid profile, fasting insulin concentration were examined in type 2 diabetes. The difference in the adiponectin concentrations of diabetic and non-diabetic subjects were also examined, with adjustment for sex, age and body mass index. METHODS: One hundred ans two type 2 diabetes and 50 controls were the subjects of this study. After a 12-h overnight fast, all subjects underwent a 75g oral glucose tolerance test. Baseline blood samples were drawn to determine the fasting plasma glucose, insulin, adiponectin, total cholesterol, triglyceride and the LDL- and HDL- cholesterol levels. The body composition was estimated by a bioelectric impedance analyzer (Inbody 2.0(r)) and the insulin sensitivity by an insulin tolerance test (ITT), HOMA(IR) and QUICKI method. RESULTS: In the diabetic group, the fasting adiponectin concentrations were higher in the women than the men. The fasting adiponectin concentrations were negatively correlated with the BMI (r=-0.453), hip circumference (r=-0.341), fasting glucose concentrations (r=-0.277) and HOMA(IR) (r=-0.233). In addition, they were positively correlated with the systolic blood pressure (r=0.321) and HDL-cholesterol (r=0.291). From a multiple logistic regression analysis the systolic blood pressure and HDL-cholesterol were found to be independent variables that influenced the adiponectin concentration. The adiponectin concentrations were significantly lowered in the diabetic than the non-diabetic group, with the exception of the obese male subjects. CONCLUSION: The plasma adiponectin concentrations were closely related to the insulin resistance parameters in type 2 diabetic patients.

• Keywords: Diabetes Mellitus;Insulin Resistance;Adiponectin