High serum leptin levels in children with type 1 diabetes mellitus: contribution of age, BMI, pubertal development and metabolic status

OBJECTIVE Children with diabetes mellitus are prone to develop obesity and to experience a delay in onset of the pubertal process. In order to understand the role of leptin in these abnormalities, serum leptin levels were analysed in children with type 1 diabetes mellitus. SUBJECTS Twenty diabetic girls, 23 diabetic boys and 66 healthy children (selected from a reference population of 706 normal children), age-, sex- and BMI-matched with diabetic patients, were studied. MEASURMENTS Standing height, weight and BMI were determined in each child. Serum testosterone, oestradiol and leptin were measured by specific radioimmunoassays, and HBA1c by high performance liquid chromatography. RESULTS Both diabetic girls and boys showed higher leptin levels than the normative healthy population and a group of age-, sex- and BMI-matched normal children. In an age-related analysis, leptin levels in diabetic girls rose from 7.4 ± 1.2 and 8.1 ± 2.1 μg/l for the 5–7.99 and 8–10.99 year groups, to 12.6 ± 2.4 μg/l for the 11–13.99 year group, and to 15.6 ± 4.0 μg/l in the 14–15.99 year group in parallel with body weight. Leptin concentrations were parallel but higher (P