Serum Leptin Level Is Reduced in Non-Obese Subjects with Type 2 Diabetes

Background: leptin, a protein released from adipose tissue, could have significant role in pathogenesis of obesity and type 2 diabetes mellitus. objectives: this study aimed to evaluate variations in serum leptin levels in non-obese subjects with type 2 diabetes mellitus (t2dm). patients and methods: we studied forty-one patients with type 2 diabetes. fasting lipid profile, hemoglobin a1c (hba1c), serum leptin, insulin, and glucose levels were measured by standard methods. results: the serum leptin level in type 2 diabetic patients (19.32 ± 11.43 ng/ml) was significantly lower than that in non-diabetic subjects (32.16 ± 11.02 ng/ml). serum leptin level was strongly and positively correlated with body mass index (bmi) (r = 0.658, p < 0.0001) and calculated body fat percentage (r = 0.431, p < 0.0001) in all the study subjects with a better corrlation in the control subjcts compared to control cases (r = 0.661 for bmi and r = 0.466 for body fat). on the other hand, leptin showed a positive and significant correlation with insulin and homa- β (homeostasis model assessment for β-cell function) in both groups. furthermore, leptin related to homeostasis model assessment for insulin resistance (homa-ir) (r = 0.422, p = 0.006) was observed only in t2dm subjects. leptin showed negative correlation with waist to hip ratio in diabetic (r = -0.407, p =0.008) and non-diabetic subjects (r = -0.318, p =0.049). in the regression model, bmi, homa-β, and gender were independent predictors of leptin in all subjects. however, in non-diabetic and diabetic subjects, β-cell function and insulin were independent predictors, respectively (p =0.01).conclusions: it is speculated that lower serum leptin levels in diabetic patients may be a consequence of male gender. moreover, results suggest that serum leptin level in women is influenced differently than that in men.