The relationship between leisure-time physical activity and the metabolic syndrome among United States adults: 1999--2004 NHANES

The purpose of this study was to evaluate the current prevalence of the metabolic syndrome with an emphasis on examining the relationship between leisure-time physical activity (LTPA) and the metabolic syndrome in a nationally representative sample of the United States (U.S.) adult population. The sample for this study included adults (N=5,620), 20 years and older, who attended a mobile examination center (MEC) examination in the 1999-2004 National Health and Nutrition Examination Survey (NHANES). The American Heart Association and National Heart, Lung, and Blood Institute (AHA/NHLBI) definition was used to define the metabolic syndrome. A metabolic syndrome risk score (MSRS), ranging from 0 to 5 was created to sum cardiovascular (CV) risk factors. Accumulating a MSRS ≥3 designated a metabolic syndrome diagnosis, a dependent variable within this study. Physical activity (PA) was measured in two ways; a six-level measure of MET-minutes per week and a three-level variable associated with the current Centers for Disease Control and Prevention/American College of Sports Medicine public health PA recommendation. SUDAAN statistical software was used for all analysis.;The overall age-adjusted prevalence of the metabolic syndrome among the U.S. adult population was 36.3%. Adults who acquired between 736.55 and 1360.15 MET-min.wk-1 of LTPA were found to be 35% (OR 0.65; 95% CI 0.48-0.88) less likely to have the metabolic syndrome compared to those reporting no LTPA. A similar inverse association was found for an increasing the MSRS (OR 0.69; 95% CI 0.56-0.85). The strength of this inverse association increased (OR 0.55; 95% CI 0.42-0.71) when weekly LTPA MET-minutes reached >1360.15 MET-min.wk-1. This inverse association was also found for a MSRS (OR 0.58; 95% CI 0.48-0.70) at this level of LTPA. Furthermore, a significant difference was found for metabolic syndrome prevalence between those meeting the current public health PA recommendation (29.0%) and those reporting no LTPA (40.0%).;These findings estimate one in three U.S. adults have the metabolic syndrome. This study consistently showed an inverse association between LTPA and metabolic syndrome risk. While this study is cross-sectional and causality cannot be inferred, our findings do illustrate a strong inverse association for LTPA and the metabolic syndrome.