The Nutritional Metabolic Risk Index As a Predictor of All-cause and Cardiovascular Mortality: A National Cohort Study

Background: Recent studies show that malnutrition increases all-cause mortality by 1.11 times and cardiovascular mortality by 2.60 times. Similarly, metabolic syndrome raises overall mortality by 40% and cardiovascular mortality by 37%. This research assesses the Nutritional Metabolic Risk Index (NMRI) for predicting these mortality risks.

Methods: We analyzed data from 14,209 participants in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018, where the NMRI was calculated based on the ratio of GNRI to TyG-WHtR. The relationship between NMRI and mortality was investigated using Kaplan-Meier methods and Cox regression models, with restricted cubic splines (RCS) employed to examine non-linear associations. The predictive capabilities of NMRI, GNRI, and TyG-WHtR for mortality were assessed using receiver operating characteristic curve (ROC) curve analysis.

Results: Over a median follow-up period of 89 months, there were 1358 all-cause deaths and 345 cardiovascular deaths recorded. Cox regression analysis indicated that each unit increase in NMRI was associated with an 8% reduction in all-cause mortality risk and a 15% reduction in cardiovascular mortality risk. RCS analysis found a nonlinear negative correlation between NMRI and both all-cause and cardiovascular mortality. NMRI demonstrated superior predictive accuracy for all-cause mortality (AUC: 0.696, 95% CI: 0.682-0.710) and cardiovascular mortality (AUC: 0.713, 95% CI: 0.689-0.737) compared to GNRI and TyG-WHtR (P < 0.05).

Conclusions: The NMRI is inversely associated with the risk of all-cause and cardiovascular mortality in American adults.