Intramuscular adipose tissue of the quadriceps is more strongly related to recovery of swallowing ability than is muscle mass in older inpatients: A prospective study

This study aimed to examine whether intramuscular adipose tissue of the quadriceps at admission is related to the recovery of swallowing ability during a hospital stay in older inpatients. This prospective study included 344 inpatients ages ≥ 65 y. Those who had stroke that was the obvious cause of dysphagia were excluded. Recovery of swallowing ability was assessed using Food Intake Level Scale (FILS) score at discharge and FILS change. Ultrasound images were acquired at admission. Intramuscular adipose tissue and muscle mass of the quadriceps were assessed based on echo intensity and muscle thickness, respectively. Multiple regression analysis was performed to examine whether quadriceps echo intensity is independently associated with FILS score at discharge and FILS change. The independent variables were quadriceps echo intensity and thickness, subcutaneous fat thickness of the thigh, Barthel Index score at admission, age, sex, number of medications, C-reactive protein, updated Charlson Comorbidity Index, FILS score at admission, Geriatric Nutritional Risk Index, days from disease onset, length of hospital stay, and units of rehabilitation therapy. Quadriceps echo intensity was independently and significantly associated with FILS score at discharge (β = −0.15, P < 0.01) and FILS change (β = −0.19, P < 0.01). Quadriceps thickness was not independently and significantly associated with FILS score at discharge or FILS change. The present study revealed that intramuscular adipose tissue of the quadriceps in older inpatients is more strongly related to recovery of swallowing ability than is muscle mass. •We examined the relationship between intramuscular adipose tissue of the quadriceps at admission and recovery of swallowing ability in older inpatients.•Increased intramuscular adipose tissue was more strongly related to worse recovery of swallowing ability than was loss of muscle mass.•Assessing intramuscular adipose tissue of the quadriceps is important for predicting recovery of swallowing ability.•Intervention for intramuscular adipose tissue may be important for improving swallowing ability in older inpatients.