Social isolation is associated with higher leisure-time sedentary behavior and lower physical activity practice: A multi-country analysis of data from 79 countries from the Global School-Based Student Health Survey

Aim: To investigate the association of social isolation with physical activity and leisure-time sedentary behavior among adolescents.Methods: We used data from the Global School-based Health Survey, including a representative sample of 296,861 adolescents (11-18y) from 79 countries (48.9% girls, 14.5 +/- 1.6 years). Social isolation was estimated by combining the self-reported number of friends and loneliness perception. Physical activity and leisure-time sedentary behavior were assessed through questionnaires. Multinomial logistic regression models were created to analyze the associations of social isolation with physical activity and leisure-time sedentary behavior.Results: Compared with those practicing >= 60 min of physical activity during 1-4 days/week, social isolation was associated with a higher prevalence of not practicing physical activity (Prevalence ratio [PR]:1.24; 95% CI:1.19-1.29), and a lower prevalence of practicing during >= 5d/wk. (PR:0.91; 95%CI:0.88-0.94). Compared with <4 h/d of leisure-time sedentary behavior, being socially isolated was also associated with a higher prevalence of 4-7 h/d (PR: 1.08; 95%CI:1.03-1.14) and >= 8 h/d (PR: 1.24; 95%CI:1.16-1.33) of leisure-time sedentary behavior. Compared with those participants without elevated leisure-time sedentary behavior and with those practicing adequate physical activity, social isolation was independently associated with a higher prevalence of physical inactivity (PR: 1.20; 95%CI: 1.15-1.26) and elevated leisure-time sedentary behavior (PR: 1.21; 95%CI: 1.14-1.30), as well as with both risk factors simultaneously (PR: 1.36; 95%CI: 1.28-1.45).Conclusion: Reducing social isolation could be an important component of future interventions to reduce sedentary behavior and physical inactivity among adolescents.