Dehydration and Malnutrition-Similar Yet Different: Data from a Prospective Observational Study in Older Hospitalized...

Dehydration and malnutrition are common conditions in older adults. Although both are regulated by different pathways, they seem to share common risk factors, such as dysphagia and dementia. Only scarce data on their co-occurrence are published. An exploratory analysis of a multicenter prospective trial on the determinants of malnutrition to evaluate the potential association between malnutrition and dehydration in older hospitalized patients was performed.

Patients underwent a comprehensive geriatric assessment, their nutritional status was evaluated using the Global Leadership Initiative on Malnutrition (GLIM) criteria, and routine laboratory tests were performed, including calculated serum osmolality.

A total of 454 patients were included in the analysis. Of those, 45% were classified as malnourished based on MNA-SF, and 42% according to GLIM criteria. Dehydration as determined by calculated serum osmolality was present in 32%. Multivariate binomial regression analysis revealed elevated serum creatinine (p < 0.001) and higher body mass index (BMI) (p = 0.020) as predictive factors for dehydration. Overlap between dehydration and malnutrition was present in 13% of patients; malnourished patients had no higher risk for dehydration and vice versa (p = 0.903).

Malnutrition and dehydration are common in hospitalized older adults but do not frequently occur together. We identified that BMI and creatinine levels are significant predictors of dehydration risk among this population. Consequently, the implementation of separate screening assessments for malnutrition and dehydration is recommended to better identify and address these conditions individually.