Background and aim: Insulin resistance and hypo-insulinemia are the major problems in Type 2 Diabetes Mellitus (T2DM). Epidemiological evidences suggest that obesity is linked with insulin resistance. Inflammatory cytokines such as TNF-α has also been associated with obesity and insulin resistance. The present study aims to evaluate fasting serum TNF-α in newly diagnosed type 2 diabetic subjects in different BMI group to observe its association with insulin sensitivity and obesity.
Methods: A total number of 145 newly diagnosed T2DM subjects were recruited in this study. On a prescheduled morning fasting and postprandial (2hrs after 75g glucose load) blood was drawn. Serum glucose was measured by glucose-oxidase method, lipid profile by enzymatic end-point method, insulin and TNF-α by ELISA methods. Insulin secretory capacity (HOMA%B) and insulin sensitivity (HOMA%S) were calculated using fasting glucose and insulin by HOMA-CIGMA software. SPSS for Windows was used for statistical analysis.
Results and conclusion: The subjects were divided into three groups on the basis of BMI cut-off points suggested by WHO for the Asian population (Gr1: BMI < 23, Gr2: BMI 23.1-27.5, Gr3: BMI>27.5). The fasting serum insulin and TNF-α levels were significantly (p<0.005) higher in group 3 than the other groups. HOMA%B was significantly higher in Gr 3 and HOMA%S was significantly lower in group 3 compared to group 1 and group 2. From multiple linear regression analysis it can be concluded that both BMI and postprandial serum glucose had potential effects on serum TNF-α level but the later one had stronger.