Association of malnutrition with functional and cognitive trajectories in people living with dementia: a five-year follow-up study

Background: In dementia, functional status depends on multiple factors in addition to cognition. Nutritional status is a potentially modifiable factor related to homeostasis and proper functioning of body systems and may contribute to cognitive and functional decline. Objective: This paper aims to analyze the association of malnutrition with the course of cognitive and functional decline in people living with dementia. Methods: This is an analysis of a longitudinal cohort study, the Dementia Study of Western Norway. Data of 202 patients diagnosed with mild dementia were analyzed; Alzheimer’s disease (AD) (n = 103), Lewy body dementia (LBD) (n = 74), and other dementias (OD) (n = 25). Cognition was assessed with the Mini-Mental State Examination and functional decline through the activities of daily living included in the Rapid Disability Rating Scale. The Global Leadership Initiative on Malnutrition Index was used to determine nutritional status. Associations of nutritional status with cognitive and functional decline were evaluated through adjusted linear mixed models. Results: At baseline, the prevalence of general malnutrition was 28.7%; 17.3% were classified as moderate malnutrition and 11.38% as severe malnutrition (there were no significant differences between AD and LBD). Malnutrition at diagnosis and over follow-up was a significant predictor of functional-decline, but not of cognitive decline. Conclusion: According to our results malnutrition was associated with faster functional loss but, not cognitive decline in older adults with dementia. A more comprehensive dementia approach including nutritional assessments could improve prognosis.