The Relationship of Depressive Symptoms and Vitamin D Intake to Cardiac Event-Free Survival in Patients With Heart Failure.
Low vitamin D and depressive symptoms are associated with inflammation activation that predicts cardiovascular disease. Little is known about the relationships among vitamin D intake, depressive symptoms, and cardiac events in heart failure (HF). The aim of this study is to determine the relationships among vitamin D deficiency, depressive symptoms, and cardiac events. A total of 204 HF patients completed a 3-day food diary to determine average daily intake of vitamin D. Patients completed the Patient Health Questionnaire-9 to assess somatic and cognitive depressive symptoms and were split into 2 groups using the Patient Health Questionnaire-9 cut-point score of 10 (< 10, no depressive symptoms; ≥ 10, depressive symptoms). Data on cardiac events during 1 year were obtained through medical record review. Hierarchical Cox and logistic regressions were used for data analyses. Sixty patients (29.4%) had depressive symptoms and 106 (52.0%) had vitamin D deficiency. Depressive symptoms (hazard ratio [HR], 1.93; P = .031) and vitamin D deficiency (HR, 1.84, P = .036) predicted shorter cardiac event-free survival in Cox regression. Depressive symptoms predicted shorter cardiac event-free survival in patients with vitamin D deficiency (HR, 2.16; P = .038), but not those with vitamin D adequacy. Somatic depressive symptoms were associated with vitamin D deficiency (odds ratio, 1.12; P = .028) in logistic regression, whereas cognitive depressive symptoms were not. Vitamin D deficiency and depressive symptoms predicted shorter cardiac event-free survival. Depressive symptoms did not predict cardiac events in HF patients with vitamin D adequacy. Somatic depressive symptoms predicted vitamin D deficiency, but cognitive depressive symptoms did not. Additional research is necessary to determine the protective role of vitamin D in the link between somatic depressive symptoms and cardiac events.