Abstract
BACKGROUND: The prognostic nutritional index (PNI) has shown prognostic value in various diseases, but its association with mortality in the general population remains unclear. METHODS: We analyzed data from 30,741 adults in the National Health and Nutrition Examination Survey (NHANES) 2007-2018. Cox proportional hazard models examined the association between PNI and mortality outcomes. Restricted cubic spline analyses were performed to assess non-linear relationships. Subgroup analyses were conducted to evaluate effect modifications. RESULTS: During follow-up, higher PNI values were associated with lower all-cause mortality (HR: 0.95, 95% CI: 0.94-0.96) and cardiovascular mortality (HR: 0.94, 95% CI: 0.93-0.96). Non-linear relationships were identified with threshold effects at PNI = 50.24 for all-cause mortality and PNI = 51.50 for cardiovascular mortality. The protective associations were particularly strong among participants with liver disease (P for interaction < 0.001). CONCLUSION: Prognostic nutritional index demonstrates significant predictive value for mortality outcomes in the general U.S. adult population, with identified threshold effects. These findings suggest PNI's potential utility as a valuable risk stratification tool in clinical practice.