[A cohort study on the association of healthy lifestyle with co-morbidity of overweight/obesity and myopia in adolescents].

Objective: To explore the association between healthy lifestyle and co-morbidity of overweight/obesity and myopia in adolescents. Methods: Based on the Shanghai Municipal Dynamic Cohort of Student Common Diseases, we used the group-based trajectory model (GBTM) to establish a model for the development of adolescents' healthy lifestyle trajectories aged 11-14 years and the Cox proportional hazard regression model to assess the effects of different healthy lifestyles on the co-morbidity of overweight/obesity and myopia in adolescents. Results: A total of 2 331 adolescents were included in the analysis. The average follow-up time was 1.87 years, with age of (11.44±0.45) years at the initial follow-up, among 1 106 boys and 1 225 girls. During the 2-year follow-up period, the incidence rates of overweight/obesity, myopia, and co-occurrence of overweight/obesity and myopia were 25.9%, 77.0%, and 13.7%, respectively. GBTM identified 3 healthy lifestyles: the unhealthy group (7.3%), the relatively healthy group (50.2%), and the healthy group (42.5%). The risk of overweight/obesity was lower in the relatively healthy group than in the unhealthy group (HR=0.694, 95%CI: 0.508-0.947). There was no statistically significant association between the GBTM lifestyle subgroups and myopia (P>0.05). The risk of co-occurrence of overweight/obesity and myopia was lower in both relatively healthy group and healthy group than in the unhealthy group (relatively healthy group: HR=0.515, 95%CI: 0.348-0.763; healthy group: HR=0.571, 95%CI: 0.384-0.849). Sensitivity analyses showed this result to be stable for myopia, overweight/obesity and myopia co-morbidities. Conclusion: Persistent unhealthy lifestyle increases the risk of overweight/obesity and myopia co-occurrence in adolescents.