Abstract Body (Do not enter title and authors here): Background: The relationship between dietary inflammatory potential and mortality risk in individuals with hyperlipidemia remains underexplored. This study investigated the association between the Dietary Inflammatory Index (DII) and all-cause and cardiovascular mortality in adults with hyperlipidemia using data from the National Health and Nutrition Examination Survey (NHANES).
Methods: We analyzed 20,750 adults (aged ≥18 years) with hyperlipidemia from NHANES (1999–2018). Participants were categorized into DII tertiles (T1: least inflammatory; T3: most inflammatory). Cox proportional hazards models estimated hazard ratios (HRs) for mortality, adjusting for sociodemographic, lifestyle, and clinical factors.
Results: Higher DII (pro-inflammatory diet) was associated with increased all-cause mortality (T3 vs. T1: HR = 1.23, 95% CI: 1.03–1.47, P-trend = 0.024). Each unit increase in DII raised mortality risk by 6% (HR = 1.06, 95% CI: 1.01–1.11). As for cardiovascular mortality, participants in T3 showed a 44% higher risk compared with participants in T1 (HR = 1.44, 95% CI: 0.99–2.10, P-trend = 0.066), and per-unit DII increase was linked to 12% higher risk (HR = 1.12, 95% CI: 1.03–1.22). Our subgroup analyses indicated that the associations between DII and mortality risk were much stronger in adults aged ≥60 years (P-interaction = 0.002) and those married/living with a partner (P-interaction = 0.01).
Conclusions: A pro-inflammatory diet is associated with higher all-cause and cardiovascular mortality in hyperlipidemic adults, particularly older individuals and those with specific sociodemographic profiles. These findings underscore the importance of anti-inflammatory dietary interventions in this high-risk population.