Background and aim: Both physical activity (PA) and sedentary behaviors have demonstrated independent associations with the development of type 2 diabetes mellitus (T2DM). However, the combination of both, has been less explored. We aimed to compare the associations of PA-only versus the simultaneous effect of PA and sedentary behaviors on T2DM in a Mediterranean cohort.
Methods and results: Participants (n = 19,524) initially free of T2DM from the SUN Project were followed-up for a median of 10.4 years. Analyses were conducted in 2018. PA and sedentary parameters (TV viewing time and sitting time) were assessed through a validated questionnaire. The amount of each PA was expressed in METs-h/wk. After that, a previously developed 8-item active + sedentary lifestyle score was computed. T2DM was defined according to ADA criteria. To adjust for potential confounders, Cox regression models were adjusted. Among 19,524 participants, 175 cases of new-onset T2DM were observed during follow-up. After multivariable adjustment, higher PA was strongly inversely associated with T2DM, showing highly significant differences between extreme quartiles (HR = 0.51; 95% CI 0.32-0.79 p for trend<0.001). When considering not only PA, but also the more comprehensive active + sedentary lifestyle combined score, even stronger differences were found between the lowest and the highest categories (HR = 0.40; 95%CI 0.20-0.80; p for trend<0.001).
Conclusion: Sedentary lifestyles, in addition to PA patterns, should be included in the assessment of T2DM risk. Promoting PA should be coupled with the avoidance of a sedentary lifestyle to lower the risk of T2DM.