Inflammatory properties of diet mediate the effect of depressive symptoms on Framingham risk score in men and women: Results from the National Health and Nutrition Examination Survey (2007-2014)

Depression is common in patients with cardiovascular disease (CVD) and associated with inflammation. Inflammation contributes to the development of CVD and can be modulated by diet. However, the role of inflammatory properties of diet in the relationship between depressive symptoms and CVD risk is not well understood. We hypothesized that the inflammatory properties of diet mediate the relationship between depressive symptoms and CVD risk in men and women. Cross-sectional data collected by the National Health and Nutrition Examination Survey (2007–2014) were used for the study. Depressive symptoms scores, inflammatory properties of diet, and CVD risk were measured by the Patient Health Questionnaire-9 (PHQ-9), the Dietary Inflammatory Index (DII), and the Framingham risk score (FRS), respectively. Generalized linear models were used for the mediation analysis. There were significant differences in the proportions of men and women in the depressed group (PHQ-9 ≥ 10; 5.24 ± 0.65% vs 9.36 ± 0.87%, P <. 001) and high CVD risk group (FRS >20%; 16.47 ± 0.79% vs 6.03 ± 0.32%, P <. 001). The DII partially mediated the relationship between depressive symptoms and CVD risk in men (indirect effect: 0.06, P =. 010) but fully mediated the relationship between depressive symptoms and CVD risk in women (indirect effect: 0.10, P <. 001). These findings confirmed our hypothesis that inflammatory properties of diet at least partially mediate the relationship between depressive symptoms and CVD risk in men and women. Our findings suggest that interventions designed to reduce depressive symptoms should contain strategies to reduce pro-inflammatory and increase anti-inflammatory properties of diet to decrease CVD risk.