Association between the dietary inflammatory index and all-cause and cardiovascular mortality in patients with atherosclerotic cardiovascular disease

Abstract

Background and aims: Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death worldwide. Inflammation is pivotal in atherosclerosis development. The dietary inflammatory index (DII) is a tool to quantify the overall inflammatory potential of diet. The association between DII and all-cause and cardiovascular mortality in ASCVD patients remains undetermined.

Methods and results: Participants included individuals with ASCVD from the National Health and Nutrition Examination Survey from 1999 to 2018. A total of 5006 participants were included, during a median of 6.6 years of follow-up, of which 2220 (44.4 %) were dead. The Cox proportional hazard model evaluated the association between DII and all-cause and cardiovascular mortality. Participants in the higher DII quartile exhibited a higher mortality of ASCVD. Compared with the patients in quartile 1, those in quartile 4 had a 34 % increased risk for all-cause mortality (HR = 1.34, 95 % CI = 1.21-1.61, p = 0.001). Cardiovascular mortality showed a similar trend, however the correlation is not significant. The restricted cubic spline (RCS) showed that the relationship between DII and all-cause and cardiovascular mortality was linear. Subgroup analysis revealed a persistently positive association between DII and all-causemortality across population subgroups. However, an interaction was detected between DII and alcohol history in relation to cardiovascular mortality.

Conclusion: DII was positively correlated with the all-cause mortality of ASCVD patients. The intake of a pro-inflammatory diet may increase mortality in ASCVD patients.

Keywords: ASCVD; Dietary inflammatory index; Mortality; NHANES.