RESUMO
OBJECTIVE: Insulin resistance (IR) increases during puberty in normal children. IR is the first adverse metabolic event of obesity, and the marker of the metabolic syndrome. We aimed to study the effect of puberty on IR in obese and normal-weight children. DESIGN: Cross-sectional evaluation of fasting glucose, insulin concentrations, and homeostasis model assessment of IR (HOMA-IR) in obese and control children throughout puberty. PATIENTS AND METHODS: We recruited 424 obese children (207 pre-pubertal and 217 pubertal divided in Tanner stages 2-3, 4, and 5) and estimated IR using the HOMA-IR index. Data were compared to those obtained in 123 healthy normal-weight children (40 pre-pubertal and 83 pubertal divided in Tanner stages 2-3, 4, and 5). RESULTS: In the obese children mean HOMA-IR increased progressively across Tanner stages, and was significantly higher in all groups (pre-pubertal and Tanner stages 2-3, 4, and 5) of obese than in control children. HOMA-IR was significantly correlated with BMI. CONCLUSIONS: HOMA-IR in obese children increases at puberty more than in normal-weight children and does not return to pre-pubertal values at the end of puberty.