Abstract
The association between Neutrophil-Percentage-to-Albumin Ratio (NPAR) and mortality in cardiovascular disease (CVD) patients with diabetes or pre-diabetes is not well understood. This study investigates the relationship between baseline NPAR levels and all-cause and cardiovascular mortality among American adults with CVD and diabetes or pre-diabetes. This study enrolled 6,080 patients with diabetes or prediabetes from the National Health and Nutrition Examination Survey (2001-2018). Mortality outcomes were determined by linkage to the National Death Index (NDI) records through December 31, 2019. Multivariate Cox proportional hazards models were used to explore associations between NPAR and mortality. Non-linear correlations were assessed with restricted cubic splines, and segmented Cox proportional hazards models were used to evaluate threshold effects. Receiver operating characteristic (ROC) curves were used to evaluate NPAR's predictive ability for all-cause mortality. Weighted Kaplan-Meier curves with log-rank tests assessed cumulative survival differences across NPAR levels. In this cohort study, with a total follow-up of 53,217 person-years, 1,378 deaths from all causes and 476 deaths from CVD were recorded. Restricted cubic spline analysis revealed a J-shaped association between NPAR and both all-cause and cardiovascular mortality. Threshold effect analysis identified inflection points for NPAR in relation to all-cause mortality at 15.1 and cardiovascular mortality at 14.2. When baseline NPAR exceeded these inflection points, a positive correlation was observed with all-cause mortality (HR: 1.55, 95% CI: 1.08-2.16) and cardiovascular mortality (HR: 1.25, 95% CI: 1.09-1.86). ROC curves for 3-year, 5-year, and 10-year survival rates for all-cause mortality had areas under the curve (AUC) of 0.83, 0.83, and 0.81, respectively. For cardiovascular mortality, the AUC values were 0.86, 0.87, and 0.84. Increased NPAR is significantly associated with increased all-cause and cardiovascular mortality in individuals with diabetes or prediabetes, suggesting its potential role as a prognostic marker.