Leptin is the ob gene product, a 16-kDa peptide hormone secreted by adipocyte and thought to contribute to body weight regulation through modulating feeding behavior and/or energy expenditures. In human, the majority of obese subjects have elevated plasms leptin concentrations, suggesting the presence of leptin resistance. Increasing evidences suggest that insulin may play a role in the regulation of leptin concentrations. The aim of this study was to assess whether the regulation of leptin levels might be altered in Korean NIDDM patients.
We measured the height, weight, waist-hip ratio(WHR), blood pressure, fasting blood glucose(FBG), insulin, lipid profile and leptin in 87 patients with NIDDM and 87 nondiabetic subjects matched with age, sex and body mass index.
The serum leptin concentrations were not different in patients with NIDDM and nondiabetic subjects and the association of leptin with BMI was also similar in diabetic and nondiabetic subjects. The leptin concentrations were higher in women than in men. There were significant correlations of leptin with BMI, insulin and glucose/insulin(G/I) ratio in patients with NIDDM. In multiple regression analysis for leptin concentrations, BMI and gender were significantly associated with serum leptin concentrations, but age, FBG, insulin, WHR, diabetic status and other variables were not significantly associated.
In conclusion, the leptin concentrations were not different in diabetic and nondiabetic subjects and association of leptin with BMI was also similar in diabetic and nondiabetic subjects.

Keywords: Leptin, Body mass index, Obesity, NIDDM, Insulin