Abstract
BACKGROUND: Accumulated evidence confirmed depression was positively associated with coronary heart disease (CHD). But evidence of the association between depression and premature CHD is still unknown.</p>
OBJECTIVES: To explore the association between depression and premature CHD, and to investigate whether and to what extent the association is mediated by metabolic factors and systemic immune-inflammation index (SII).</p>
METHODS: In this large population-based cohort study based on the UK Biobank, 176,428 CHD-free (mean age: 52.70) adults were followed up for 15 years to detect incident premature CHD. Depression and premature CHD (mean age: female, 54.53; male, 48.13) were ascertained from self-report data and linked hospital-based clinical diagnosis. Metabolic factors included central obesity, hypertension, dyslipidemia, hypertriglyceridemia, hyperglycemia, and hyperuricemia. Systemic inflammation was evaluated by calculating SII, which equals platelet count (/L) × neutrophil count (/L) / lymphocyte count (/L). Data were analyzed using Cox proportional hazards models and generalized structural equation model (GSEM).</p>
RESULTS: During follow-up (median: 8.0 years, interquartile range: 4.0 to 14.0 years), 2990 participants developed premature CHD (1.7 %). The adjusted hazard ratio (HR) and 95 % confidence interval (CI) of premature CHD related to depression were 1.72 (1.44-2.05). The association between depression and premature CHD was 32.9 % mediated by comprehensive metabolic factors (β = 0.24, 95 % CI: 0.17-0.32) and 2.7 % by SII (β = 0.02, 95 % CI = 0.01-0.04), respectively. Concerning metabolic factors, the strongest indirect association was for central obesity, accounting for 11.0 % of the association between depression and premature CHD (β = 0.08, 95 % CI: 0.05-0.11).</p>
CONCLUSIONS: Depression was associated with an increased risk of premature CHD. Our study provided evidence that metabolic and inflammatory factors might play a mediating role in the association between depression and premature CHD, especially central obesity.</p>