Device-assessed total and prolonged sitting time: associations with anxiety, depression, and health-related quality of life in adults

Objective: Assessment of sitting has been challenging and nuances in the length of sitting are often missed. Methods: The present study assessed total, short and prolonged sitting time, and number of breaks from sitting, and their association with anxiety, depression, and health-related quality of life (HRQoL). Adults (M=59.1 years) in three studies (n=1,574) wore the activPAL accelerometer (thigh) to obtain a measure of sitting, and the Actigraph accelerometer (hip) for estimating moderate-to-vigorous physical activity (MVPA). Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale, and HRQoL using the EQ-5D-5L (for health state and utility scores). Generalised linear modelling tested associations. Results: Total and prolonged sitting were associated with higher depression [total: β = 0.132 (0.010, 0.254); prolonged: β = 0.178 (0.053, 0.304)] and worse HRQoL health state scores [(total: β = -0.985 (-1.471, -0.499); prolonged: β = -0.834 (-1.301, -0.367)] and utility scores [(total: β = -0.008 (-0.012, -0.003); prolonged: β = -0.008 (-0.012, -0.004)], after controlling for covariates. MVPA was associated with better HRQoL health state and utility scores [health state: β =0.554 (0.187, 0.922); utility: β = 0.001 (0.001, 0.002)]. Total and prolonged sitting were associated with a 14% increased odds of being in the borderline/abnormal category for depression. No interactions were observed between MVPA status (active vs. inactive) and total or prolonged sitting. Anxiety was unrelated to any sitting variable. Conclusion: Device-based measures of both total and prolonged sitting time were associated with depression and health-related quality of life, but not anxiety.