Associations of malnutrition factors with dysphagia mediated by ADL among nursing home residents

Objective: The potential link between malnutrition and dysphagia along with its underlying mechanisms remains unknown. This study aimed to investigate the association between malnutrition factors and dysphagia mediated by a decline in activities of daily living (ADL) among nursing home residents. Methods: This cross-sectional study used data from 705 nursing home residents. The primary factors were risk of malnutrition and dysphagia. A body mass index (BMI) of < 18.5 and insufficient energy and protein intakes were also collected as factors related to malnutrition. The causal mediation analysis was used with malnutrition factors as the exposure, dysphagia as the outcome, and ADL as the mediation factor. Results: In total, 391 residents (55.5%) were at risk of malnutrition and 451 residents (64.0%) had dysphagia. The average causal mediation effect (ACME) of risk of malnutrition on dysphagia was 0.07 (95% confidence interval, C, 0.07-0.08), and the ACME of BMI < 18.5 was 0.05 (95% CI 0.04-0.05, P < 0.001 for both). For insufficient nutritional intake, the ACME of low energy intake was 0.07 (95% CI 0.07-0.07), and the ACME of low protein intake was 0.03 (95% CI 0.02-0.04, P < 0.001 for both). The total effects of all these exposures on dysphagia were significant (P = 0.002 for low protein intake and P < 0.001 for the others). Conclusion: Malnutrition factors were associated with dysphagia, mediated by a decline in ADL among nursing home residents. The results of this study suggest the importance of nutritional management along with approaches to ADL to prevent dysphagia.