PURPOSE: This study investigated the clinical significance of AN in children and adolescents with obesity induced metabolic complications. METHODS: Forty-nine patients who had obesity induced metabolic complications were participated in this cross-sectional study. Obesity induced metabolic complications are as follows: hypertension, dyslipidemia, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), nonalcoholic steatohepatitis (NASH), homeostasis model assessment of insulin resistance (HOMA-IR)>3.16. Clinical characteristics, such as, age, percentage-weight-for-height (PWH), pubertal status, blood pressure (BP), fasting plasma insulin level, fasting and post-oral glucose tolerance test 2-hour glucose levels, liver function test, lipid profile, HOMA-IR were compared according to the presence of AN. RESULTS: Sixty-five percent of patients had AN, 57.1% NASH, 57.1% dyslipidemia, 55.1% hypertension, 46.9% IFG, 24.5% HOMA-IR>3.16 and 16.2% IGT. The patients who were moderately to severely obese with AN had higher incidence of IGT and HOMA-IR>3.16. The patients with AN had significantly higher diastolic BP (79.4+/-6.9 vs 75.4+/-5.6 mmHg), fasting levels of plasma insulin (10.6+/-6.0 vs 6.2+/-5.4 microIU/mL), HOMA-IR index (2.6+/-1.4 vs 1.4+/-1.3) and PWH (42.4+/-13.0 vs 34.3+/-1.8%). The increasing tendency for the presence of AN was significantly related to the cumulative number of obesity induced metabolic complications. Binary logistic regression analysis revealed that the presence of AN was significantly associated with fasting plasma insulin level, PWH and IFG. CONCLUSION: AN could be useful as a clinical surrogate of obesity induced metabolic complications.