Background: Little is known about the relationship of depression with incident cardiovascular disease (CVD) among American Indians (AIs), a population with a high burden of depressive symptoms and CVD. In this study, we examined the association of depressive symptoms with CVD risk among AIs and assessed whether an objective marker of ambulatory activity influenced the relationship.
Methods: The study comprised participants from the Strong Heart Family Study, a longitudinal study of CVD risk among AIs free of CVD at baseline (2001-2003) and who participated in a follow-up examination (n = 2209). The Center for Epidemiologic Studies of Depression Scale (CES-D) was used to assess depressive symptoms and depressive affect. Ambulatory activity was measured using Accusplit AE120 pedometers. Incident CVD was defined as new myocardial infarction, coronary heart disease, or stroke (through 2017). Generalized estimating equations were used to examine the association of depressive symptoms with incident CVD.
Results: 27.5% of participants reported moderate or severe depressive symptoms at baseline and 262 participants developed CVD during follow-up. Compared to participants who reported no depressive symptoms, the odds ratios for developing CVD among those who reported mild, moderate, or severe symptoms were: 1.19 (95% CI: 0.76, 1.85), 1.61 (95% CI: 1.09, 2.37), and 1.71 (95% CI: 1.01, 2.91), respectively. Adjustment for activity did not alter findings.
Limitations: CES-D is a tool used to identify individuals with depressive symptoms and not a measure of clinical depression.
Conclusion: Higher levels of reported depressive symptoms were positively associated with CVD risk in a large cohort of AIs.
Keywords: American Indians; Cardiovascular disease; Cohort study; Depression; Physical activity.