Domain-specific physical activity and insomnia among individuals 15 years and older in South Africa
High levels of exercise or physical activity may decrease risk of developing insomnia. This evaluated the relationship between domain-specific physical activity and insomnia in a national population sample in South Africa. Data were examined from the cross-sectional “South African National Health and Nutrition Examination Survey (SANHANES-1)” 2012, using a sample of 14,817 persons (mean age=36.9, SD=16.5). Measures included self-reported information on domain-specific physical activity (work, transportation and leisure), insomnia, socio-demographic, health risk behaviour and mental health. Results indicated that the overall prevalence of insomnia symptoms was 7.1%, 5.4% among men and 8.6% among women (p<0.001). In adjusted logistic regression analysis among women, high level of overall physical activity and high level of work domain physical activity increased the odds of having insomnia (Odds Ratio-OR: 1.46, Confidence Interval-CI: 1.02, 2.08, and OR: 1.57, CI: 1.12, 2.19, respectively). Overall, high levels of physical activity and among men, high levels of transportation domain physical activity were associated with decreased odds of having insomnia (OR: 0.77, CI: 0.60, 0.99, and OR: 0.66, CI: 0.45, 0.97, respectively). In bivariate analysis, high levels of leisure time physical activity reduced the risks for insomnia (OR: 0.64, CI: 0.44, 0.93). In conclusion, among women, high work related physical activity increased the odds of insomnia, and among men, a high transportation related physical activity decreased the odds of insomnia.
Keywords: Physical activity domain, insomnia, adults, South Africa.