The relationship between the prognostic nutritional index (PNI) and mortality in patients with hypertension remains unclear. This study aimed to investigate the specific shape of the dose-response relationship and to identify a clinically meaningful risk threshold for PNI in this population. This retrospective cohort study included 6,165 adults with hypertension from the National Health and Nutrition Examination Survey (NHANES) 2003-2018. Weighted Cox proportional hazards models and restricted cubic splines were used to evaluate the associations between PNI and all-cause and cardiovascular disease (CVD) mortality. During a median follow-up of 7.9 years, 1,733 all-cause and 516 CVD deaths occurred. We identified a non-linear, L-shaped association between PNI and mortality. The risk of mortality was significantly lower with increasing PNI up to an inflection point of 51.55, beyond which the association plateaued. Each unit increase in PNI below this threshold was associated with a 9% reduction in all-cause mortality risk (Fully adjusted HR = 0.91, 95% CI: 0.87-0.95). The association was stronger in hypertensive individuals younger than 60 years and those with comorbid diabetes (P for interaction < 0.05). In a hypertensive population, PNI demonstrates an L-shaped association with all-cause and CVD mortality, with a distinct threshold at 51.55. This pattern suggests that PNI serves as a robust biomarker of immunonutritional status, and it ≥ 51.55 is associated with reduced mortality risk, supporting its utility as a prognostic biomarker for risk stratification in hypertensive patients.
Liu et al. (2026) studied this question.