Insulin resistance in Brazilian adolescent girls: Association with overweight and metabolic disorders

We assessed the association between insulin resistance, overweight and metabolic disorders in a probabilistic sample of 388, 12-19-year-old girls from public schools in Niteroi, Rio de Janeiro State, Brazil. Insulin resistance was determined using Homeostatic Model Assessment-Insulin Resistance (HOMA-IR). Overweight and obesity were defined by the sex- and age-specific body mass index cut-offs recommended by the International Obesity Task Force. Metabolic syndrome (MS) was identified by the presence of at least three of the following factors: fasting glucose >= 100 mg/dL, triglycerides > 130 mg/dL, LDL-C >= 110 mg/dL, HDL-C < 35 mg/dL and overweight. The combined prevalence of obesity (2.9%) and overweight was 14.2%. The average HOMA-IR level was 2.24 (95% confidence interval = 1.40-3.10) in the overweight group and 1.91 (95% CI = 1.32-2.50) in the non-overweight one, and MS prevalence was 20 times higher in the first group (21.4 and 0.1%). MS prevalence in the overweight group was 6.3 times higher in adolescents above the 66th percentile of HOMA-lR (55.9%) than those under the 33rd percentile (8.9%). Brazilian overweight girls with higher insulin resistance had high risk of developing MS. Therefore, prevention should occur at an early age to impair the evolution of this process. (c) 2006 Elsevier Ireland Ltd. All rights reserved.