BURDEN ATTRIBUTABLE TO PHYSICAL INACTIVITY

Abstract

Physical inactivity is recognized as an important risk factor for the leading causes of death and is included as one of 26 risk factors in the World Health Organization's (WHO) ‘Risk to Health’ Report in 2002. PURPOSE To estimate the current and avoidable burden of disease due to participation in physical activity at less than recommended levels worldwide. METHODS Using estimates of current and projected prevalence of physical activity (PA) for 14 WHO regions and new summary estimates of relative risk associated with five health outcomes (CHD), ischemic stroke, breast cancer, colon cancer, and type 2 diabetes) estimates of current and avoidable burden (mortality and disability life years (DALY's)) were calculated for 2000, 2010, 2020 and 2030. Two levels of exposure (inactive and insufficiently active based on occupational, transportation, and leisure-time PA) and corresponding levels of risk were assessed using definitions consistent with public health recommendations for regular, moderate and vigorous PA. Current and projected estimates of burden were computed and a sensitivity analysis was conducted. RESULTS Estimates of global burden revealed physical inactivity accounted for 22% of ischemic heart disease, 11% of ischemic stroke, 14% of diabetes, 16% of colon cancer and 10% of breast cancer. Taking into account all diseases, inactive lifestyles accounted for 3.4% of worldwide morbidity and mortality. There were small differences in attributal risk between males and females, due in part to differences in level of types of PA performed, different distributions of chronic disease events, and similar PA patterns between men and women in different regions of the world. CONCLUSION The risk estimates are likely to underestimate the true magnitude of the burden of disease due to sedentary lifestyles and could be of the order 20% higher. Nevertheless, successful promotion of more active lifestyles would prevent at least 2 million premature deaths worldwide.