Association of the Geriatric Nutritional Risk Index with incident cognitive impairment and longitudinal cognitive trajectories in older adults

BackgroundMalnutrition is a modifiable risk factor for cognitive deterioration. The Geriatric Nutritional Risk Index (GNRI) objectively assesses nutritional status, but its longitudinal association with incident cognitive impairment and distinct cognitive trajectories remains insufficiently characterized.ObjectiveTo assess the association between baseline GNRI and incident cognitive impairment.MethodsWe analyzed data from 2596 community-dwelling adults aged ≥60 years from the Health and Retirement Study (2016-2022). Baseline nutritional status was assessed by GNRI. Incident cognitive impairment was defined using the modified Telephone Interview for Cognitive Status. Group-based trajectory modeling identified longitudinal cognitive patterns. Cox proportional hazards regression and multinomial logistic regression models examined associations, adjusting for sociodemographic, lifestyle, and clinical covariates.ResultsCompared with the high GNRI group (≥98), low GNRI (<98) was associated with a higher hazard of incident cognitive impairment (HR = 1.25; 95% CI: 1.05-1.49). This association was linear (p for nonlinearity = 0.62). Longitudinal modeling identified four trajectory groups: "High-stable" (21.7%), "High-decline" (29.6%), "Moderate-decline" (41.4%), and "Low-rapid decline" (7.3%). In multinomial analyses, low GNRI (<98) was specifically associated with higher odds of the "Low-rapid decline" trajectory (OR = 1.61; 95% CI: 1.06-2.46) versus the "High-stable" reference, whereas intermediate-pattern associations were not significant. The association was consistent across subgroups, including those defined by body mass index and alcohol consumption (p for interaction > 0.05).ConclusionsLow baseline GNRI was associated with a higher hazard of incident cognitive impairment and greater odds of membership in an adverse cognitive trajectory. The predictive and screening utility of GNRI requires further evaluation.