Relative hypoleptinemia in patients with type 1 and type 2 diabetes mellitus

OBJECTIVE: To determine the relation between plasma leptin concentrations a nd metabolic control in human diabetes mellitus. DESIGN AND SUBJECTS: Cross sectional study consisting of 156 patients with diabetes mellitus type 1 (n = 42), type 2 (n = 114), and non-diabetic subje cts (n = 74). RESULTS: Plasma leptin concentrations were lower (P < 0.05) in type 1 (8.3 +/- 1.7 ng/ml) and type 2 diabetic (14.9 +/- 1.8 ng/ml) than in non-diabeti c humans (18.3 +/- 1.9 ng/ml). Only female type 1 and type 2 diabetic subje cts also had decreased leptin/BMI ratios (P < 0.05 vs non-diabetic females) . The log rank test identified age-adjusted correlation of plasma leptin co ncentration with sex (P < 0.0004) and body mass index (P < 0.0218), but not with glycosylated haemoglobin A(1c) (P > 0.5) in all groups. Plasma leptin was correlated with age (P < 0.0058) and serum triglycerides (P < 0.0199) in type 1 diabetic patients, and with serum cholesterol (P < 0.0059) and LD L (P < 0.0013) in type 2 diabetic patients. CONCLUSIONS: Defective leptin production and/or secretion might be present independently of metabolic control in female patients with type 1 or type 2 diabetes mellitus.