Abstract
BACKGROUND: The neutrophil percentage-to-albumin ratio (NPAR) has been identified as a prognostic indicator of mortality in various diseases; however, its association with all-cause and cardiovascular mortality in the general population remains insufficiently studied. METHODS: This retrospective cohort study analyzed data from 36,428 individuals who participated in the National Health and Nutrition Examination Survey between 1999 and 2018. Participants were divided into tertiles based on NPAR levels, with follow-up data collected through December 31, 2019. Weighted multivariable Cox regression models were employed to assess the associations between NPAR and both all-cause and cardiovascular mortality. Kaplan-Meier survival analyses were used to compare survival rates across NPAR tertiles. Additionally, restricted cubic spline analyses and subgroup and sensitivity analyses were conducted to further investigate these associations. RESULTS: During the follow-up period of up to 20 years, 4,716 deaths occurred among the 36,428 participants, including 1,260 deaths attributed to cardiovascular disease. At baseline, the mean NPAR was 13.66 (SD 2.42), the average age was 45.75 years (SD 16.20), and 50.33% of participants were female. Multivariable analyses showed that individuals in the highest NPAR tertile had a significantly increased risk of both all-cause mortality (HR, 95% CI: 1.45, 1.33-1.57) and cardiovascular mortality (HR, 95% CI: 1.69, 1.39-2.06). Kaplan-Meier survival curves demonstrated significant differences in both all-cause and cardiovascular mortality across NPAR groups. A nonlinear association was observed between NPAR and the risk of both all-cause and cardiovascular mortality. Sensitivity analyses confirmed the robustness of these associations. Additionally, a significant interaction between NPAR and hypertension was identified in relation to all-cause mortality (relative excess risk due to interaction, 95% CI: 0.20, 0.07-0.34; multiplicative interaction, P = 0.04). CONCLUSIONS: An elevated baseline NPAR is independently associated with an increased risk of all-cause and cardiovascular mortality.