Association between DII and all-cause mortality among older adults with coronary heart disease

Systemic inflammation critically drives coronary heart disease (CHD) pathogenesis. The Dietary Inflammatory Index (DII) measures the overall inflammatory impact of human diets. Here, we explored the prognostic link between DII scores and all-cause mortality in geriatric CHD patients. We included 1012 older patients (aged 65 and above) diagnosed with CHD from 6 consecutive National Health and Nutrition Examination Survey cycles (2007–2018). The inflammatory potential of participant diets was evaluated using DII scores calculated from initial 24-hour dietary interviews. To determine the independent relationship between DII and all-cause death, we applied complex survey-weighted Cox regression to generate hazard ratio alongside 95% confidence intervals. We further explored dose-response patterns and potential modifying effects via survey-weighted restricted cubic splines and stratification analyses. Over the follow-up period, 460 mortality events were recorded. Elevated DII levels significantly correlated with a greater risk of all-cause death (hazard ratio per 1-unit increment = 1.11, 95% confidence interval: 1.05–1.18, P  < .001). Furthermore, individuals in the top DII quartile faced a 14% higher mortality hazard relative to those in the bottom quartile ( P for trend < .001). The restricted cubic splines analysis showed a linear positive relationship between DII and mortality ( P for nonlinearity = .627). Associations remained consistent across gender, body mass index, and metabolic subgroups (all P for interaction > .05). Elevated dietary inflammation independently predicts poorer long-term survival in older CHD cohorts. Transitioning toward anti-inflammatory nutritional patterns might mitigate mortality risks, although prospective clinical trials are required to validate this therapeutic potential.