Associations between depressive symptoms, cigarette smoking, and cardiovascular health: Longitudinal results from CARDIA

INTRODUCTION: Depression is associated with increased risk of incident and recurrent cardiovascular disease, while the association between depression and cardiovascular health (CVH) remains unknown. Because the natural course of depression varies widely, different patterns of depression, as well as co-occurring factors such as cigarette smoking, may influence this relationship. We examined potential interactions between longitudinal patterns of depression and smoking with CVH. METHODS: Using data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, we modeled trajectories of depression (Center for Epidemiologic Studies Depression scale scores; Years 5, 10, 15, 20) and smoking (cigarettes/day; Years 0, 2, 5, 7, 10, 15, 20). We calculated a modified American Heart Association (AHA) CVH Score (weight, blood glucose, cholesterol, blood pressure, physical activity, and diet; Year 20); higher scores indicate better CVH. Generalized linear models evaluated associations between depression trajectories, smoking trajectories, and their interaction with CVH Score. RESULTS: The depression trajectory x smoking trajectory interaction was not associated with CVH Score, but main effects of depression trajectory (p \u3c .001) and smoking trajectory (p \u3c .001) were observed. Participants with patterns of subthreshold depression (beta = -0.26, SE=0.08), increasing depression (beta=-0.51 SE=0.14), and high depression (beta=-0.65, SE=0.32) had lower CVH Scores than those without depression. Compared to never smokers, participants who quit smoking had higher CVH Scores (beta=0.38, SE=0.11), while participants with the greatest smoking exposure had lower CVH Scores (beta=-0.49, SE=0.22). LIMITATIONS: CVH Scores were adapted from the AHA guidelines based on the available CARDIA data. CONCLUSIONS: Deleterious depression and smoking trajectories are independently but not synergistically associated with worse CVH