Relationship between swallowing function and the skeletal muscle mass of older adults requiring long-term care

The present study investigated the risk factors for dysphagia among older adults who require long-term care, and also examined their systemic decrease in skeletal muscle mass.

We evaluated 399 people who required long-term care and who were residing in Omori town, Yokote city, Akita prefecture, Japan. We then analyzed data from 255 participants who had complete information available regarding their sex, age, case history (stroke, Parkinson's disease and dementia), Barthel Index, Skeletal Muscle Mass Index, oral function test and modified water swallowing test results. Participants' water swallowing test results were used to create groups with good or poor swallowing function, and a univariate analysis was carried out for each parameter. Parameters with a P-value of <0.25 in the univariate analysis were subsequently included in a multiple logistic regression model as explanatory variables, and good or poor swallowing function were defined as the dependent variables.

After adjusting for age and sex, our analysis showed that poor tongue motility (odds ratio 17.23, 95% confidence interval 5.90-50.31, P < 0.001) and decreased Skeletal Muscle Mass Index (odds ratio 3.36, 95% confidence interval 1.41-7.99, P = 0.006) were significantly correlated with decreased swallowing function.

Decreased swallowing function was closely correlated with poor tongue motility, and this finding is similar to those of previous studies. However, the present results also show that decreased Skeletal Muscle Mass Index is a novel risk factor for dysphagia among older adults who require long-term care.