Prognostic nutritional index, sarcopenia, and risk of mortality: a national population-based study

The role of nutritional status in predicting prognosis in patients with sarcopenia has not been fully elucidated. This investigation sought to evaluate the link between prognostic nutritional index (PNI) and sarcopenia, as well as its influence on overall and cardiovascular death rates in adults diagnosed with sarcopenia.

This retrospective observational study utilized data from individuals aged 18 years and older extracted from the National Health and Nutrition Examination Survey (NHANES) during 1999-2004 and 2011-2018. The PNI calculation incorporated initial serum albumin measurements and complete lymphocyte numbers. To investigate the link between PNI and sarcopenia, researchers employed multiple analytical approaches, including multivariate logistic regression, stratified group evaluation, restricted cubic spline, and threshold and saturation effect analysis. The investigation utilized Cox regression modeling and Kaplan-Meier survival analysis to examine the link between PNI and both overall and cardiovascular-related mortality among subjects with sarcopenia.

Among the 24,661 patients examined, sarcopenia was detected in 2760 individuals (11.19%). Throughout a median monitoring duration of 132.01 months, all-cause mortality claimed 959 (34.75%) subjects with sarcopenia, while cardiovascular-related fatalities accounted for 321 (33.47%) cases. Subjects in the uppermost PNI quartile (Q4) exhibited markedly decreased likelihood of sarcopenia (odds ratio [OR] 0.43, 95% confidence interval [CI] 0.37-0.49) and lower risks of both all-cause and cardiovascular mortality (hazard ratio [HR] 0.64, 95% CI 0.53-0.78; and 0.60, 95% CI 0.43-0.84, respectively) versus those in the lowermost quartile (Q1). These findings were consistent across subgroup analyses, restricted cubic spline, and threshold and saturation effect analysis.

The PNI is an independent predictor of sarcopenia, all-cause mortality, and cardiovascular mortality in U.S. adults. It can be a valuable tool for identifying individuals at elevated risk of unfavorable health outcomes.