Sedentariness and overweight in relation to mortality in sub-Saharan Africa. A mediation analysis based on the World Health Organization-Global Health Observatory data repository.

Abstract

Globally, noncommunicable diseases (NCDs) have been continuously reported to be the number one leading cause of reduced life expectancy and poor life quality and have thus become a major public health concern. This study aimed to investigate the complex mediation analysis between physical inactivity and overweight in relation to mortality. The study is based on public data collected by the Global Health Observatory of the World Health Organization. We showed that the median early mortality attributable to NCDs during the period 2016-2019 in both men and women was 23.2% (5th to 95th range=17.2, 35.6) while that in men alone was 25.1% (16.5, 45.7) and that of women alone was 22.0% (17.0, 27.9). When considering regional early NCDs mortality for both men and women, a systematically high median was observed in Southern Africa [28.7% (22.2, 43.8)] and a low median in Eastern Africa [21.1% (17.15, 27.3)]. The analysis of the overall relation between physical inactivity, overweight and early mortality due to NCDs revealed a statistical significance of the direct association between physical inactivity and early mortality due to NCDs. Our findings revealed three main epidemiological and public health concerns. First, early mortality attributable to NCDs in a range of about 20 to 30% across the sub-Saharan African regions for both sexes was observed. Second, there was a direct effect between physical inactivity and early NCDs mortality as well as the indirect effect mediated by overweight. Finally, a percentage point decrease in physical inactivity prevalence and overweight could effectively generate a reduction in mortality due to NCDs. Future studies are needed to confirm the scientific evidence observed in this study. Such studies should be based on observation of individual subjects, adopt a longitudinal design, and collect information that evaluates the complex relationship between physical inactivity and early NCDs mortality, along with the role of overweight as a possible mediator.