Obesity has become a pandemic and especially the prevalence of childhood obesity has increased remarkably over the past years. Childhood obesity is often accompanied by the expected morbidities such as hyperlipidemia, fatty liver and glucose intolerance. We evaluated the pattern of alteration in the body mass index (BMI), serum adiponectin concentration, insulin resistance (HOMA-IR), and complication rates after one year follow-up.

Forty two obese children (age: 8-15 years, 95th percentile of BMI for age and sex) were examined twice annually on June, 2004 and July, 2005. The body mass index (BMI) and sexual maturity rating (SMR) were determined annually by the same examiner and serum fasting glucose, liver enzyme, lipid profiles, adiponectin, insulin and HOMA-IR were measured and annual results were compared. Upper abdominal sonography was performed to detect fatty liver.

BMI (25.3±2.9 kg/m² vs. 26.0±2.9 kg/m²) and HOMA-IR (3.6±1.8 vs. 4.7±1.9) have increased significantly after one-year follow-up. The serum adiponectin concentration (17.2±5.2 g/mL vs. 12.6±5.2 g/mL) has decreased after one year. The prevalence of hyperlipidemia and fatty liver were not changed significantly but that of hyperinsulinemia increased after one-year. HOMA-IR showed a positive correlation with BMI and SMR, but was negatively correlated with serum adiponectin concentration.

Obese children in our study showed significant increment of insulin resistance during one year. These results suggest that well-organized and continuous obesity control is required especially for obese adolescent to prevent complication of obesity.