The predictive value of malnutrition for functional and cognitive status in elderly hemodialysis patients

The study aims to objectively and precisely describe, in elderly dialysis patients from a single center, the prevalence of malnutrition and severe cognitive/functional impairment and to establish the prognostic role of malnutrition assessment for patient's severe cognitive/functional status.

Cross-sectional study.

A single dialysis center from north-eastern Romania.

Eighty-one elderly ambulatory hemodialysis patients.

The aim of the study was to establish in hemodialysis elderly patients a correlation between two malnutrition scores [Mini Nutritional Assessment (MNA) and Subjective Global Assessment (SGA)] and geriatric tests (Geriatric Depression Scale-GDS), daily activities (Activities of Daily Living-ADL, Instrumental Activities of Daily Living-IADL), and cognitive impairment scores (Mini Mental State Examination-MMSE). A correlation between objective malnutrition parameters (bioimpedance lean tissue index (LTI) and fat tissue index (FTI) by bioimpedance) was also assessed.

Using area under the curve analysis, two malnutrition scores and bioimpedance assessed nutritional status were explored as possible predictors for the most severe category of functional and cognitive status.

All patients had mild/moderate malnutrition by SGA, while the MNA test reported malnutrition in 14.5%, and 58% of cases. There was no correlation between subjective scores and objective biomarkers of malnutrition (albumin levels, bioimpedance-derived LTI, FTI). ROC curve analysis showed that MNA and SGA predict the most severe category of depression and functional impairment with relatively good accuracy (specificity, sensibility).

The study confirms the important correlation between malnutrition and cognitive/functional impairment and confirms that malnutrition scores could be useful in predicting depression and physical dependance in elderly dialysis patients.