U-shaped association between neutrophil-percentage-to-albumin ratio and all-cause mortality in adults with hyperlipidemia: A prospective cohort study of NHANES 1999 to 2018

Hyperlipidemia impacts global mortality, and the neutrophil-percentage-to-albumin ratio (NPAR) is a novel inflammatory marker, but its association with mortality in hyperlipidemic adults is unknown. Using National Health and Nutrition Examination Survey data (1999–2018), this study examined NPAR’s association with all-cause and cardiovascular disease (CVD) mortality in hyperlipidemic adults via multivariate Cox models and restricted cubic splines, with threshold effects and subgroup analyses also evaluated. Among 35,356 participants, NPAR showed a U-shaped link with all-cause mortality (inflection = 11.7; hazard ratio (HR) = 0.94, 95% confidence interval (CI) 0.91–0.98 below; HR = 1.14, 95% CI, 1.12–1.15 above) and a positive linear association with CVD mortality (HR = 1.12, 95% CI, 1.10–1.15). The all-cause mortality risk from higher NPAR was greater in physically inactive individuals. Among US adults with hyperlipidemia, a U-shaped association was identified between NPAR and all-cause mortality, while a linear positive correlation was noted with CVD mortality. An NPAR of 11.7 may be optimal, and physical activity might reduce risks from higher NPAR levels. NPAR may help identify high-risk patients for closer monitoring and targeted prevention strategies.