Vigorous-Intensity Physical Activity is Associated with Metabolic Syndrome Among the Chinese Middle-Aged Population: A Cross-Sectional Study.

Objective: To examine the association and relative contribution of different levels of physical activity (PA) with metabolic syndrome (MS). Methods: The cluster sampling method was used to recruit 8,750 community-based individuals between 40 and 60 years of age. MS was defined according to the International Diabetes Federation, 2005. PA was estimated with the International Physical Activity Questionnaire, and three levels of PA (low, moderate, vigorous) were used to classify the individuals. The risk factors of MS were comprehensively collected, and logistic regression methods were used to measure the association between PA and MS. Population-attributable risks and their 95% confidence intervals (CI) were calculated based on the regression model. Results: Approximately 30.4% (2,661) of the participants were MS patients. The percentage of individuals with vigorous levels of PA was 46.2% and 43.5% and with low levels of PA was 11.3% and 11.3% in non-MS and MS group, respectively. Individuals with vigorous PA had an odds ratio (OR) of 0.78 (95% CI: 0.66, 0.91) for MS compared with those with low PA, and the OR for individuals with moderate PA was 0.85 (95% CI: 0.73, 1.01). Moderate and vigorous PA levels decreased risk of MS by 18.3%, with approximately 11% of that decrease due to vigorous PA. Conclusions: Vigorous PA levels were consistently associated with a reduced risk of MS; however, a protective role of moderate PA was not found. The population-attributable risk for vigorous PA was about 11% for all MS risk factors. [ABSTRACT FROM AUTHOR]