Device-based physical activity and late-life depressive symptoms: An analysis of influential factors using share data

Background: Regular physical activity is effective for preventing and managing depression; however, only a few studies have assessed physical activity using device-based measures. We aimed to examine the association be-tween device-based total physical activity and late-life depressive symptoms and explore which factors may explain this relationship.Methods: Data from 10 European countries who participated in wave 8 of the Survey of Health, Ageing and Retirement in Europe (SHARE) were analyzed. Triaxial accelerometers (Axivity AX3; Axivity, Newcastle UK) were used to assess total physical activity. Depressive symptoms were assessed through the EURO-D scale. Possion regression models and mediation analysis were performed.Results: The final sample included 785 older adults (70 participants had missing data in one or more variables and were excluded from the analysis) [mean (SD): age 68.6 (8.8) years; 59.2 % female]. After adjusting for several confounders, a 10 % increase in the mean acceleration was associated with lower depressive symptoms (B =-0.0228; 95%CI =-0.0395,-0.0061). This association was partly explained by limitations in activities of daily living and quality of life.Limitations: Cross-sectional design, convenience sample, bi-directionality, lack of cutoff points for classification of the Axivity AX3 placed in the thigh, into intensities.Conclusions: Higher device-based total physical activity was linked with lower depressive symptoms in older European adults. Future studies employing device-based measures that allow to better capture important physical activity dimensions (i.e., intensity) will better inform about dose-response relationships.