Dietary inflammatory potential and the risk of nonfatal cardiovascular diseases in the China Health and Nutrition Survey

Background No evidence exists to link dietary inflammatory potential to cardiovascular disease (CVD) in China. Furthermore, the precise mechanisms underlying the link between a pro-inflammatory diet and CVD remain incompletely understood. Objective We aimed to investigate the relationship between dietary inflammatory potential and nonfatal CVD in the Chinese population and to explore the mediating role of insulin resistance. Methods A total of 4,822 adults participated in the China Health and Nutrition Survey (CHNS) were included in this analysis. The dietary inflammatory index (DII) was used to assess dietary inflammatory potential. Cox proportional hazards models and restricted cubic spline were applied to assess the longitudinal associations. The triglyceride-glucose (TyG) index was calculated to measure insulin resistance. Mediation analysis using a two-stage regression method for survival data to explore the mediating effects of the TyG index on the association between DII score and nonfatal CVD. Results During a median follow-up of 18 years, 234 incident cases of nonfatal CVD, including 136 stroke and 114 myocardial infarction (MI), were observed. For each standard deviation of DII score, nonfatal CVD incidence increased by 15% [hazard ratio (HR): 1.15, 95% confidence interval (CI): 1.01-1.31], and stroke incidence increased by 22% (HR = 1.22, 95% CI: 1.03-1.45). DII score displayed a linear association with nonfatal CVD and stroke (P for nonlinearity = 0.250 and 0.238, respectively). No significant association was found between the DII score and MI. Mediation analyses showed that the TyG index mediated 5.90% and 9.35% of the total association between DII score and nonfatal CVD and stroke, respectively. Conclusion This study provides evidence that dietary inflammatory potential is positively associated with nonfatal CVD and stroke in Chinese adults, and the association was partly mediated by insulin resistance.