Abstract P034: Association between Obesity Indices and Insulin Resistance among Healthy Korean Adolescents

Abstract

OBJECTIVE: To investigate whether five indices of obesity are associated with insulin resistance in a cohort of healthy Korean adolescents. METHODS: This is a cross-sectional analysis for 821 healthy adolescents who were aged 14-17 years and free of diabetes. Percentile values of weight-for-height, body mass index (BMI)-for-age, waist circumference (WC)-for-age, and skin fold thickness (SFT)-for-age were calculated comparing to the 2007 Korean National Growth Charts. Waist-to-hip ratio (WHR) percentile value was based on the distribution of study population, because the growth chart did not include WHR values. Insulin resistance was estimated by homeostatic model assessment (HOMA-IR) based on fasting glucose and insulin levels. Logistic regression models were used to estimate odds ratio for insulin resistance according to five different obesity indices. Generalized linear models were used to assess the associations between obesity indices and continuous HOMA-IR levels. RESULTS: Mean ± standard deviation of BMI was 22.2 ± 3.3 kg/m 2 for male and 21.2 ± 2.6 kg/m 2 for female adolescents. Sex and age-adjusted odds ratio (95% CI) for insulin resistance, defined as HOMA-IR>2.50, of 50-74th, 75-94th, and ≥95th percentiles of weight-for-height was 1.53 (0.88–2.63), 4.35 (2.63–7.20) and 14.95 (7.50–29.80), respectively, when compared to <50th percentiles. Corresponding odds ratios (95% CI) were 1.28 (0.74-2.22), 3.70 (2.25-6.08) and 14.78 (7.41-29.47) for BMI-for-age percentiles, 1.98 (1.15-3.43), 5.53 (3.24-9.44) and 16.34 (7.70-34.70) for WC-for-age percentiles, 1.90 (1.13-3.18), 4.46 (2.61-7.60) and 15.98 (7.55-33.81) for SFT-for-age percentiles, 1.57 (0.94-2.65), 3.57 (2.19-5.81) and 12.43 (6.08-25.38) for WHR percentiles. Similar findings were observed when insulin resistance was defined as HOMA-IR>3.16. Continuous measure of HOMA-IR was significantly associated with all five obesity indices both in males and females. The associations between obesity indices and insulin resistance were stronger in males than in females. Continuous measure of HOMA-IR was significantly associated with all five obesity indices both in males and females. CONCLUSION: Our findings suggest that obesity indices are strongly and progressively associated with insulin resistance even in apparently healthy adolescents.