Associations of Trunk Muscle Mass and Muscle Quality Indicators with Self-Reported Dysphagia in Older Inpatients

Recent studies have correlated dysphagia with ultrasound-measured quadriceps muscle mass and quality. Computed tomography (CT) is more precise than ultrasound for estimating muscle mass and quality. We aimed to investigate the possible associations of chest CT-determined trunk muscle mass and quality with dysphagia. A cross-sectional study. Older inpatients in a geriatric department of a university hospital. Self-reported dysphagia was determined by the Dysphagia Handicap Index. Unenhanced chest CT images were segmented to calculate skeletal muscle area (SMA) and intermuscular adipose tissue (IMAT). Skeletal muscle index (SMI) was calculated via SMA/ height squared. The percentage of IMAT (IMAT%) was calculated by IMAT% = IMAT/ (SMA + IMAT) x 100%. Mimics software was applied to calculate the mean skeletal muscle radio density (SMD).The semiquantitative food frequency method, the Barthel Index (BI), and the Mini Nutritional Assessment Short-Form (MNA-SF) were used to evaluate energy intake, activities of daily living, and nutrition status, respectively. Among the 212 participants (mean age: 84 years), 89 (42%) had self-reported dysphagia. After adjustment for age, nutrition status, energy intake, and other confounders, the SMI (adjusted OR 0.91, 95% CI 0.86, 0.96) was negatively associated with dysphagia, whereas the IMAT (adjusted OR 1.08, 95% CI 1.01, 1.16) and the IMAT% (adjusted OR 1.10, 95% CI 1.04,1.17) were positively associated with dysphagia. However, the SMD (adjusted OR 0.99, 95% CI 0.94, 1.05) was not significantly associated with dysphagia. The subgroup analyses indicated that only the SMI (adjusted OR 0.92, 95% CI 0.86, 0.97) and the IMAT% (adjusted OR 1.08, 95% CI 1.01, 1.17) were significantly associated with dysphagia in men. None of these indicators was significantly associated with dysphagia in women. Trunk muscle mass and quality (estimated by chest CT-derived SMI and IMAT%, respectively) were significantly associated with self-reported dysphagia in older inpatients, especially in men. IMAT% might be a more sensitive muscle quality indicator than IMAT (or SMD). These results merit further investigation in prospective studies.