The relationship between oropharyngeal dysphagia and dehydration in older adults.

Background: Relationship between dysphagia and dehydration has not been studied widely. The aim of this study is to determine the frequency of dysphagia and dehydration in geriatric outpatient clinic, to evaluate the relationship between these two conditions.

Methods: The cross-sectional study included 1345 patients. Plasma osmolarity (Posm) was calculated using the following formula: [1.86 x (Na + K) + 1.15 x glucose + urea + 14]. Overt dehydration was defined as a calculated Posm of > 300 mmol/L. Eating Assessment Tool (EAT-10) score of ≥ 3 was accepted as dysphagia. Associations between dehydration and dysphagia was evaluated.

Results: Mean age was 78 ± 8 years, and 71% were females. Dysphagia was observed in 27% of patients. Dysphagia was associated with a higher number of drug exposure, dependency on basic activities of daily living and geriatric depression (p < 0.05). Overt dehydration was found in 29% of patients with dysphagia, and 21% of patients with no dysphagia (p = 0.002); and dysphagia was significantly associated with overt dehydration mmol/L (OR 1.49, 95% CI 1.13-1.96, p = 0.005) after adjustments for age and sex. In another model, EAT-10 score was found as one of the independent predictors of overt dehydration (OR1.03, 95% CI 1.00-1.06, p = 0.38), along with diabetes mellitus (OR 2.32, 95% CI 1.72-3.15, p < 0.001), chronic kidney disease (OR 3.05, 95% CI 2.24-4.15, p < 0.001), and MNA score (OR 0.97, 95% CI 0.94-1.00, p = 0.031).

Conclusion: EAT-10 scale was independently associated with overt dehydration among older adults, as MNA score was. Correction of both dysphagia and malnutrition might improve overt dehydration to a better extent than correction either of these factors alone. Future studies are needed to test cause and effect relationships.