Does Daily Moderate-to-Vigorous Physical Activity Affect Glycemic Control Equally Across Populations? Insights From NHANES 2005-2006.
Current physical activity (PA) guidelines for chronic disease management (e.g., diabetes) are based on population averages and may not reflect physiological differences across racial/ethnic groups. This study investigates whether the association between PA and glycemic control varies among Non-Hispanic White (NHW), Non-Hispanic Black (NHB), and Mexican American (MA) adults. We analyzed weighted NHANES 2005-2006 data in adults aged ≥20 (n = 2354 unweighted). PA was measured via accelerometer (≥10 hours/day, 4-7 days) and glycemic control was assessed using HbA1c, categorized as normal (<5.7%), prediabetes (5.7%-<6.5%), and diabetes (≥6.5%). Questionnaire-reported sleep time was integrated with accelerometer-derived sedentary behavior (SB), light-intensity physical activity (LIPA), and moderate/vigorous physical activity (MVPA) to represent a 24-hour time-use composition. Weighted multivariate isotemporal compositional regression models were then conducted to estimate HbA1c across activity categories adjusting for confounders and stratified by race/ethnicity. Mean HbA1c differed by racial/ethnic groups: NHW (5.41%), NHB (5.78%), and MA (5.61%) (P < .01). At 30 min/day of MVPA, HbA1c was lower in NHW (5.28%) compared to NHB (5.62%) and MA (5.56%) (P < .01). Similar trends were observed at 20 and 0 min/day (P < .01). MVPA is associated with improved glycemic control, but the benefits vary by race/ethnicity. Findings suggest that PA benefits differ by race/ethnicity, indicating a need for more tailored guidelines incorporating additional lifestyle and contextual factors.