Inflammation is a contributory factor for cardiovascular disease (CVD), and diet can modulate inflammation. This study aimed to investigate the association between dietary inflammatory index (DII) and CVD outcomes, and the mediating roles of cardiovascular risk factors.

A prospective cohort study.

A total of 3,013 Chinese community-dwelling older adults aged ≥65 years without CVD were included between 2001 and 2003 in Hong Kong.

DII was calculated using a 280-item validated food frequency questionnaire. CVD outcomes included incident CVD, coronary heart disease (CHD), stroke, and CVD mortality, which were obtained from official records. Cox proportional hazards models examined the association between tertiles of DII and CVD outcomes. Mediation analysis explored the mediating roles of cardiovascular risk factors, including inflammatory biomarkers, impaired renal function, abnormal ankle-brachial index (ABI), obesity, central obesity, diabetes mellitus, and hypertension.

There were 263 CVD cases, 147 CHD cases, and 130 strokes during a median follow-up of 5.7 years. There were 277 CVD deaths during a median follow-up of 16.8 years. The highest tertile of DII was associated with increased risks of CVD incidence (HR: 1.43, 95% CI: 1.05–1.96) and CVD mortality (HR: 1.45, 95% CI: 1.03–2.03) compared with the lowest tertile. No significant associations were found for CHD and stroke. Impaired renal function, abnormal ABI, and hyperhomocysteinemia mediated the effects of a pro-inflammatory diet on CVD risk, with mediated proportions ranging from 3.68% to 7.78%.

A pro-inflammatory diet increased the risks of CVD incidence and mortality, mediated by impaired renal function, abnormal ABI, and hyperhomocysteinemia.