Discrepancies in self-report and accelerometer-measured moderate-to-vigorous physical activity (MVPA) may influence relationships with obesity-related biomarkers in youth.
Data came from 2003–2006 National Health and Nutrition Examination Surveys (NHANES) for 2174 youth ages 12 to 19. Biomarkers were: body mass index (BMI, kg/m2), BMI percentile, height and waist circumference (WC, cm), triceps and subscapular skinfolds (mm), systolic & diastolic blood pressure (BP, mmHg), high-density lipoprotein (HDL, mg/dL), total cholesterol (mg/dL), triglycerides (mg/dL), insulin (μU/ml), C-reactive protein (mg/dL), and glycohemoglobin (%). In separate sex-stratified models, each biomarker was regressed on accelerometer variables [mean MVPA (min/day), nonsedentary counts, and MVPA bouts (mean min/day)] and self-reported MVPA. Covariates were age, race/ethnicity, SES, physical limitations, and asthma.
In boys, correlations between self-report and accelerometer MVPA were stronger (boys: r = 0.14−0.21; girls: r = 0.07−0.11; P < .010) and there were significant associations with BMI, WC, triceps skinfold, and SBP and accelerometer MVPA (P < .01). In girls, there were no significant associations between biomarkers and any measures of physical activity.
Physical activity measures should be selected based on the outcome of interest and study population; however, associations between PA and these biomarkers appear to be weak regardless of the measure used.
Belcher (email@example.com) is with the Cancer Prevention Fellowship Program, Division of Cancer Prevention, Health Behaviors Research Branch, Behavioral Research Program, National Cancer Institute, Bethesda, MD. Moser is with the Science of Research and Technology Branch, Behavioral Research Program, National Cancer Institute, Bethesda, MD. Dodd is with the Biometry Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD. Atienza is with the Science of Technology and Research Branch, Behavioral Research Program, National Cancer Institute, Bethesda, MD. Rachel Ballard-Barbash is with the Office of Disease Prevention, National Institutes of Health, Bethesda, MD. Berrigan is with the Health Behaviors Research Branch, Behavioral Research Program, National Cancer Institute, Bethesda, MD.