Inflammation and Coronary Heart Disease Risk in Patients with Depression in China Mainland: A Cross-Sectional Study

Objective: The risk of coronary heart disease (CHD) in patients with major depressive disorder (MDD) is higher than that in the general population. However, the mechanisms underlying the increased CHD risk in patients with MDD remain unclear. Inflammation plays an important role in the pathogenesis of MDD and CHD. Therefore, we explored the relationship between inflammatory biomarkers and CHD risk in patients with MDD. Methods: We included 454 patients with acute MDD and 458 controls that matched the sample in age and gender. A readily available complete blood count was used to reflect inflammation, and the risk of CHD was assessed using the Framingham risk score. Results: The results showed that patients with MDD showed low-grade inflammation with an elevated platelet (p<0.001) and monocyte count (p<0.001), high platelet/lymphocyte (p=0.003) and monocyte/lymphocyte ratios (p<0.001), and a raised systemic immune-inflammation index (p=0.002). In addition, monocyte count was the only factor significantly associated with CHD risk in patients with MDD (B=7.521, 95% CI: 3.409-11.633, t=3.594, p<0.001). Conclusion: Collectively, the results of this study support the hypothesis that MDD is systemic inflammation, and suggest that monocyte count predicts the risk of CHD in patients with MDD.