Associations of physical activity with risk of cardiovascular diseases using mediation analysis

BACKGROUND: The prevalence of cardiovascular disease (CVD) has been, and continues to be, one of the most pressing issues worldwide, and the most important risk factors for CVD are physical inactivity, tobacco consumption and metabolic syndrome (MS). The psychological well-being (PWB) of the population is also important, as optimism is associated with a lower risk of CVDs. AIM: To evaluate the association of PA with risk of CVD. METHODS: In the baseline survey (2006-2008), 7100 men and women ages 45-72 were examined within the framework of the international study HAPIEE. 6770 participants were available for statistical analysis (after excluding 330 respondents due to missing information on study variables). PA was determined by the mean length of time spent per week during leisure time for walking, moderate and hard work like gardening and other PA. The respondents were categorized into three tertiles according to their PA in leisure time. MS is diagnosed according to the NCEP-ATP III criteria. PWB was assessed with the CASP-12 scale. When assessing the associations between direct variables, statistical significance is defined by the P-value. For indirect associations, significance is defined in terms of CI. RESULTS: The results for PA and incidence of CVDs show that PA is statistically significantly negatively associated with MS and smoking, and statistically significantly positively associated with PWB assessment (P < 0.001). There were also statistically significant positive associations found between MS and the incidence of CVDs, and statistically significant negative associations between PWB assessment and the incidence of CVDs (P < 0.001). A direct and indirect statistical relationship was found between PA and morbidity CVDs (P < 0.05). CONCLUSIONS: PA is an important factor that directly and indirect predicts statistically significantly lower incidence of CVDs. PA has benefits in protecting against CVD, therefore it is important to encourage people to participate in PA. KEY MESSAGES: • PA directly predicts statistically significantly lower incidence of CVDs. • Indirect associations between PA and the incidence of CVDs have been found.