Circulating leptin and insulin in obese patients with and without type 2 diabetes mellitus: Relation to ghrelin and oxidative stress

Aim: This case control study aimed to investigate relationship between appetite hormones (ghrelin and leptin) and body mass index (BMI), insulin and oxidative stress in simple obese and type 2 diabetes (T2DM) obese patients. Methods: Thirty healthy controls; 30 simple obese and 30 T2DM obese patients were enrolled. Demographic and clinical data of all participants were reported. Serum levels of fasting blood glucose (FBG), postprandial blood glucose (PBG), lipid peroxide (LPO) and nitric oxide (NO) were measured by chemical methods while, insulin, leptin and ghrelin by ELISA kits. Results: Serum levels of insulin, leptin, LPO were significantly higher while, ghrelin was significantly lower in simple obese and obese patients with diabetes versus controls. Insulin resistance was found in 76.67% simple obese and 93.33% obese patients with diabetes. Ghrelin showed a positive correlation with PBG in controls; but negative correlation with BMI in simple obese and with NO in obese patients with diabetes. Positive correlations were found between LPO and FBG, insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and between leptin and FBG in obese patients with diabetes. Conclusions: Our results suggested that hyperinsulinemia and hyperleptinemia may be most important mechanisms in decreasing ghrelin and inducing oxidative stress in simple obese and T2DM obese patients. © 2011 Elsevier Ireland Ltd.