Association between inflammatory burden index and all-cause mortality in the general population aged over 45 years: Data from NHANES 2005-2017.

Background And Aim: The objective of this study was to investigate the association between inflammatory burden index (IBI) and all-cause mortality in the general population aged over 45 years.

Methods And Results: The study included 8827 participants from the National Health and Examination Nutrition Survey (NHANES) who were aged over 45 years. The IBI was calculated using three markers: C-reaction protein × neutrophil/lymphocyte, and all the participants were classified into four groups (Quartile 1: IBI ≤0.178, N = 2206; Quartile 2: 0.178 1.099, 2207). Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95 % confidence interval (CI) for the association between IBI and all-cause mortality. During a median follow-up of 129 month, 2431 deaths occurred. The all-cause mortality rate in Quartile 1, Quartile 2, Quartile 3 and Quartile 4 was 14.76 %, 17.67 %, 23.18 % and 29.69 %, respectively (p < 0.001). After adjustment for demographic, and potential clinical factors, higher IBI was significantly associated with an increased risk of all-cause mortality (Quartile 3 vs. Quartile 1: HR = 1.26, 95 % CI: 1.08 to 1.46, p = 0.003; Quartile 4 vs. Quartile 1: HR = 1.59, 95 % CI: 1.40 to 1.80, p < 0.001). Furthermore, the results of the restricted cubic spline analysis suggested that the association between IBI and all-cause mortality was nonlinear and positive, without specific threshold value.

Conclusions: This study supports that higher IBI is associated with an increased risk of all-cause mortality in the general population aged over 45 years.