Abstract P261: Performing Recommended Physical Activity and Insulin Sensitivity by Body Mass Index, among US Adolescents: NHANES 1999–2006

Abstract

Introduction: Physical activity may enhance insulin sensitivity in youth, thereby reducing future risk of type 2 diabetes. However, no studies report the association between performing aerobic- or muscle-strengthening (MS) activities recommended in the 2008 Physical Activity Guidelines for Americans and insulin sensitivity, especially by body mass index (BMI) levels. Objective: To assess the association between meeting aerobic or muscle-strengthening guidelines and insulin sensitivity overall, and by BMI levels, in a nationally representative sample of US adolescents. Methods: We analyzed National Health and Nutrition Examination Survey (1999–2006) data for 2251 adolescents aged 12–17 years who answered 10 interviewer-administered physical activity questions. Adolescents met the aerobic guideline with ≥60 minutes/day of moderate- or vigorous- intensity level aerobic activities, and the MS guideline with ≥3 days/week of activities such as weight lifting or push-ups. We estimated insulin sensitivity via the Quantitative Insulin Sensitivity Check Index (QUICKI) calculated as 100/[log fasting insulin (μ U/mL) + log fasting plasma glucose (mg/dl)]. We used multivariable linear regression to assess the association between meeting the aerobic or MS guideline and insulin sensitivity overall, and by BMI levels (<85, 85–94, and ≥95 percentile), adjusting for demographics (age, sex, race/ethnicity, and family poverty income ratio). Significance was set at p < 0.05. Results: For these US adolescents, 40.6% [95% confidence interval (CI), 37.2, 44.1] met the aerobic guideline, 37.5% [34.2, 40.9] met the MS guideline, and their mean QUICKI value was 35.0 [34.7, 35.3]. With no adjustments, we found significantly higher insulin sensitivity values for meeting the aerobic guideline (ß=0.43 [0.04, 0.83]) and the MS guideline (ß=0.70 [0.24, 1.16]). After adjusting for demographics and meeting the aerobic guideline, adolescents meeting the MS guideline still had significantly higher levels of insulin sensitivity (ß=0.58 [0.08, 1.08]) which remained significant only for obese adolescents (BMI ≥95 percentile) (ß=0.87 [0.30, 1.45]) when stratified on weight status. With similar adjustments including meeting the MS guideline, those meeting the aerobic guideline did not have significantly higher QUICKI values. Conclusions: We found a significant positive association between meeting the MS guideline and insulin sensitivity among US adolescents who are obese. Increasing participation in MS activities might viably enhance insulin sensitivity among obese US adolescents to reduce future diabetes risk.