Associations between mental distress and physical activity in US adults: a dose-response analysis BRFSS 2011

Background To examine the associations between levels of severity of mental distress (MD) and meeting the 2008 physical activity (PA) recommendations using the MD Severity Index (MDSI). Methods Participants (n = 431 313) were adults (>= 18 years of age) who responded to the 2011 Behavioral Risk Factor Surveillance System (BRFSS). MD was categorized into five levels of severity: 0-4, 5-10, 11-16, 17-22 and >= 23 days/month. The dependent variable was self-reported PA volume of at least 150 min/wk (or vigorous equivalent, 75 min/wk). Results Following adjustment for age, gender, race/ethnicity, education and body mass index, the odds of reporting meeting the PA recommendations were significantly lower among those reporting the following days per month of MD: 5-10 (odds ratio [OR] = 0.92, 95% confidence interval [CI]: 0.87-0.96), 11-16 (OR = 0.76, 95% CI: 0.71-0.82), 17-22 (OR = 0.69, 95% CI: 0.62-0.76) and >= 23 (OR = 0.64, 95% CI: 0.60-0.67). An inverse dose-response (P < 0.01) was observed between the severity of MD and meeting the current PA recommendations. Conclusions An inverse dose-response relationship was found between the severity of MD and volumes of PA meeting the 2008 recommendation. These findings lend support for the epidemiological utility of the MDSI when examining the relationship between MD and PA.