The association of circulating systemic inflammation with premature death and the protective role of the Mediterranean diet: a large prospective cohort study of UK biobank.

BACKGROUND

Although previous studies have identified specific circulating inflammatory markers associated with the risk of mortality, they have often overlooked the broader impact of a comprehensive inflammatory response on health outcomes. This study aims to assess the association between circulating systemic inflammation and age-related hospitalization and premature death, as well as explore the potential mediating effects of various dietary patterns on these associations.

METHODS

A total of 448,574 participants enrolled in the UK Biobank study were included. Circulating C-reactive protein(CRP), white blood cell count(WBC), platelet count(Plt), and neutrophil/lymphocyte ratio(NLR) were measured, which were used to establish a weighted systemic inflammatory index of inflammation index(INFLA-Score). Dietary intake information was documented through 24-hour dietary recalls, and dietary pattern scores including Dietary Approaches to Stop Hypertension(DASH), Mediterranean(MED), and Healthy Eating Index-2020(HEI-2020) were calculated. Cox proportional hazards regression models were performed to assess the associations between INFLA-Score and age-related disease hospitalization, cause-specific and all-cause premature death.

RESULTS

During a median follow-up of 12.65 years, 23,784 premature deaths were documented. After adjusting for multiple covariates, higher levels of CRP, WBC, NLR, and INFLA-Score were significantly associated with increased risks of age-related disease hospitalization(HR=1.19; 95%:1.17-1.21; HR=1.17; 95%:1.15-1.19; HR=1.18; 95%:1.16-1.20; HR=1.19; 95%:1.17-1.21) and premature death(HR=1.68; 95%:1.61-1.75; HR=1.23; 95%:1.18-1.27; HR=1.45; 95%:1.40-1.50; HR=1.58; 95%:1.52-1.64). Compared to the lowest INFLA-Score group, the highest INFLA-Score group was associated with increased values of whole-body and organ-specific biological age, and had a shortened life expectancy of 2.96 (95% CI 2.53-3.41) and 4.14 (95% CI 3.75-4.56) years at the age of 60 years in women and men, respectively. Additionally, we observed no significant association of the INFLA-Score with aging-related hospitalization and premature death among participants who were more adhering to the Mediterranean (MED) dietary pattern(HR=1.07; 95%:0.99-1.16;HR=1.19; 95%:0.96-1.47).

CONCLUSION

A higher INFLA-Score was correlated with an increased risk of age-related hospitalization and premature death. Nevertheless, adherence to a Mediterranean (MED) diet may mitigate these associations.