Background: Emerging evidence indicates that the association between depression and subsequent cardiovascular events is largely mediated by health behaviors. However, it is unclear whether depression is the cause or the consequence of poor health behaviors.
Purpose: The purpose of the present study is to examine prospective, bidirectional relationships of depressive symptoms with behavioral and lifestyle factors among patients with coronary heart disease.
Methods: Depressive symptoms and lifestyle behaviors (physical activity, medication adherence, body mass index, waist to hip ratio, sleep quality, and smoking status) were assessed at baseline and 5 years later among a prospective cohort of 667 patients with stable coronary heart disease.
Results: Greater depressive symptoms at baseline predicted poorer lifestyle behaviors 5 years later (less physical activity, lower medication adherence, higher body mass index, higher waist to hip ratio, worse sleep quality, and smoking). After adjustment for demographics, cardiac disease severity, comorbidity, and baseline lifestyle behaviors, depressive symptom severity remained predictive of subsequent worsening of physical activity (beta = -0.08; 95 % confidence interval (CI) = -0.16, -0.01; p = 0.03), medication adherence (beta = -0.16; 95 % CI = -0.24, -0.08; p < 0.001), and sleep quality (beta = -0.19; 95 % CI = -0.27, -0.11; p < 0.001). Baseline lifestyle behaviors also predicted 5-year change in depressive symptoms, although the associations were attenuated after adjustment for baseline depressive symptoms and covariates.
Conclusions: Among patients with coronary heart disease, depressive symptoms were linked to a range of lifestyle risk factors and predicted further declines in physical activity, medication adherence, and sleep quality.
Keywords: Coronary heart disease; Depression; Health behaviors; Medication adherence; Physical activity; Sleep quality.