Increased intramuscular adipose tissue of the quadriceps at admission is more strongly related to activities of daily living recovery at discharge compared to muscle mass loss in older patients with aspiration pneumonia.

BACKGROUND: Recent studies reported that an increase in intramuscular adipose tissue of the quadriceps in older patients negatively affects the recovery of activities of daily living (ADL) more than the loss of muscle mass. However, whether intramuscular adipose tissue of the quadriceps in older patients with aspiration pneumonia is related to ADL recovery remains unclear. This study aimed to determine the relationship between intramuscular adipose tissue of the quadriceps and ADL recovery in older patients with aspiration pneumonia. METHODS: Thirty-nine older inpatients who were diagnosed with aspiration pneumonia participated in this prospective study. The main outcome of this study was ADL at discharge. ADL were assessed using the Barthel Index (BI). The intramuscular adipose tissue and muscle mass of the quadriceps were evaluated at admission using echo intensity and muscle thickness observed on ultrasound images. A multiple linear regression analysis was performed to confirm whether the quadriceps echo intensity was related to the BI score at discharge, even after adjusting for confounding factors. RESULTS: The medians [interquartile range] of the BI score at admission and discharge were 15.0 [0.0-35.0] and 20.0 [5.0-55.0], respectively. The BI score at discharge was significantly higher than that at admission (p = 0.002). The quadriceps echo intensity (ß = - 0.374; p = 0.036) and BI score at admission (ß = 0.601; p < 0.001) were independently and significantly related to the BI score at discharge (R2 = 0.718; f2 = 2.546; statistical power = 1.000). In contrast, the quadriceps thickness (ß = - 0.216; p = 0.318) was not independently and significantly related to the BI score at discharge. CONCLUSIONS: Increased intramuscular adipose tissue of the quadriceps at admission is more strongly and negatively related to ADL recovery at discharge than the loss of muscle mass among older patients with aspiration pneumonia. Interventions targeting the intramuscular adipose tissue of the quadriceps may improve ADL among these patients.

Increase in protein intake is related to decreasing intramuscular adipose tissue of the quadriceps in older inpatients: A longitudinal study.

BACKGROUND & AIM: Several randomized controlled trials indicated that an increase in protein intake decreases intramuscular adipose tissue of the thigh in mobility-limited or pre-frail older persons and stroke patients. However, whether the increase in protein intake in older inpatients is related to decreasing intramuscular adipose tissue remains unclear. The aim of this study was to examine the longitudinal relationship between intramuscular adipose tissue of the quadriceps and protein intake in older inpatients. METHODS: This longitudinal study included 193 older inpatients (aged ≥65 years) (median [IQR] age: 83.0 [77.0-88.0]). The primary outcomes were changes in intramuscular adipose tissue of the quadriceps and protein intake. Intramuscular adipose tissue and muscle mass of the quadriceps were examined using ultrasound images (i.e., quadriceps echo intensity and thickness). The changes in quadriceps echo intensity and protein intake were calculated by subtracting the quadriceps echo intensity and protein intake at admission from those values at discharge. Multiple linear regression analysis adjusting for confounding factors was used to determine whether the change in protein intake was independently and significantly related to changes in quadriceps echo intensity and thickness. RESULTS: Quadriceps echo intensity at discharge (81.3 ± 20.6 [a.u.]) was significantly lower than at admission (84.0 ± 20.5 [a.u.]). Protein intake at discharge (1.2 [1.0-1.4] g/kg/day) was significantly higher than at admission (1.2 [0.9-1.4] g/kg/day). Change in protein intake was negatively and significantly related to the change in quadriceps echo intensity. In contrast, change in protein intake was not independently and significantly related to change in quadriceps thickness. CONCLUSIONS: Our results indicate that an increase in protein intake is related to a decrease in intramuscular adipose tissue of the quadriceps in older inpatients. Nutritional intervention for increasing protein intake in older inpatients may be essential for decreasing intramuscular adipose tissue of the quadriceps.

Greater intramuscular adipose tissue of the quadriceps in older inpatients at post-acute hospital admission is more strongly related to a low rate of home discharge than a loss of muscle mass.

This study aimed to examine the relationships between intramuscular adipose tissue and muscle mass of the quadriceps at post-acute hospital admission and the low rate of home discharge. This prospective study included 389 inpatients aged ≥ 65 years. Patients were divided into two groups according to the destination: home discharge (n = 279) and no-home discharge (n = 110) groups. The primary outcome was hospital discharge destination (home discharge or not). Intramuscular adipose tissue and muscle mass of the quadriceps were assessed at post-acute hospital admission using echo intensity and muscle thickness on ultrasound images, respectively. Logistic regression analysis was used for determining whether quadriceps echo intensity is related to home discharge. Quadriceps echo intensity was significantly and independently associated with home discharge (odds ratio [per 1 SD increase] = 1.43, p = 0.045). Quadriceps thickness was not associated with home discharge (odds ratio [per 1 SD increase] = 1.00, p = 0.998). Our study indicates that greater intramuscular adipose tissue of the quadriceps in older inpatients at post-acute hospital admission is more strongly related to a low rate of home discharge than a loss of muscle mass.