Decreased Skeletal Muscle Mass and Risk Factors of Sarcopenic Dysphagia: A Prospective Observational Cohort Study

Background: Dysphagia is a known risk factor for malnutrition and pneumonia. Although sarcopenia is hypothesized to cause dysphagia, its causality remains unclear. Thus, this study aimed to investigate causality and the risk factors for sarcopenic dysphagia. Methods: We enrolled 95 hospitalized patients aged 65 years or older who had restricted oral intake without dysphagia. The skeletal muscle index and Functional Oral Intake Scale were used to evaluate muscle mass and swallowing ability, respectively. Nutritional status, assessed by body mass index, the Mini Nutritional Assessment-Short Form, and energy intake; activity of daily living, assessed by the Barthel Index; hand-grip strength; duration of oral intake restriction; and cognitive status were measured. Dysphagia (Functional Oral Intake Scale <= 5) was determined after 2 months. Results: The participants' mean age was 83.2 +/- 8.0 years; 63% were women. Of the surviving 82 patients, 63 (77%) had sarcopenia and 21 (26%) developed dysphagia, all of whom had sarcopenia (p =.002). Most variables were risk factors for dysphagia on univariate analysis. Decreased skeletal muscle index (odds ratio [OR] 24.0, 95% confidence interval [CI] 3.6-159.0, p =.001), Barthel Index (OR 12.9, 95% CI 2.1-78.4, p =.005), and body mass index (OR 11.4, 95% CI 1.8-70.5, p =.009) were independent predictors of dysphagia in the multivariate analysis. Conclusion: This study provides evidence for sarcopenic dysphagia and its risk factors. Preventive and therapeutic interventions require further study.