Insulin resistance and impaired glucose tolerance in obese children and adolescents from southern Italy

Background and aim: Obesity in children may lead to insulin resistance and impaired glucose regulation over time. The aim of this study was to investigate the insulin resistance status and the frequency of impaired glucose regulation in obese children and adolescents from the Campania region (Southern Italy), where the prevalence of obesity is among the highest in Europe. Methods and results: We studied 100 (62 mate) Italian obese children and adolescents (mean age 10.1 +/- 2.7 years) and 50 (27 mate) normal weight healthy subjects (mean age 10.2 +/- 2.7 years). Anthropometric measures and biochemical tests were performed in all subjects. In obese patients an oral glucose tolerance test was also performed. The estimate of insulin resistance was calculated by a homeostasis model. assessment (HOMA) index. A cut-off HOMA level of > 2.5 in children and > 4.0 in adolescents was used to identify an insulin-resistance status. Insulin resistance was found in 40.8% of obese children and 41.2% of obese adolescents, whereas it was found in 3.0% of normal children and none of the 17 normal adolescents (p < 0.0001 and p < 0.002, respectively). None of the subjects had impaired fasting glucose or diabetes, white 4 obese patients had impaired glucose tolerance (4%). Conclusions: Impaired glucose tolerance is still rare whereas insulin-resistance is already detectable in more than 40% of obese children and adolescents in Southern Italy. Our observations confirm that metabolic risk factors can be found at a very early age and strengthen the case for implementing programmes for prevention and treatment of childhood obesity.