Low Phase Angle and Skeletal Muscle Index Increase Hospital-Acquired Infections During Stroke Rehabilitation

Abstract

Objectives: Sarcopenia is common in patients with stroke and may increase the risk of medical complications such as infection. However, assessing sarcopenia in stroke patients with consciousness disturbance, aphasia or severe paralysis is challenging. This study aimed to investigate whether a combined assessment of phase angle (PhA) and skeletal muscle index (SMI), estimated using bioelectrical impedance analysis, was associated with 2 common nosocomial infections, hospital-acquired pneumonia (HAP) and urinary tract infection (UTI), during inpatient stroke rehabilitation.

Design: Single-center retrospective observational study.

Settings and participants: A total of 1068 patients with stroke admitted to a rehabilitation hospital between January 2016 and September 2019 were analyzed.

Methods: The study variables included demographic characteristics, comorbidities, stroke severity, blood chemistry and urine analysis, SMI, and PhA obtained using bioelectrical impedance analysis. Patients were classified as normal, low PhA only, low SMI only, and low PhA + SMI. Multivariate Cox proportional analysis was used to determine the variables associated with HAP and UTI.

Results: A combination of low PhA + SMI was observed in 429 (40.2%) patients. Over a median follow-up duration of 46 days, HAP occurred in 187 patients (17.5%) and UTI occurred in 155 patients (14.5%). The low PhA + SMI group showed a significantly higher incidence of HAP and UTI than the normal group (32.6% vs 4.6%, P < .001, for HAP; 20.7% vs 6.2%, P < .001, for UTI). In multivariate Cox analyses, low PhA and SMI were associated with significantly higher rates of HAP [hazard ratio (HR) 3.36, 95% CI 1.796-6.304, P < .001] and UTI (HR 1.71, 95% CI 1.002-2.947, P < .05) after adjusting for confounding variables.

Conclusions and implications: Combination of low PhA + SMI was independently associated with a higher risk of HAP and UTI in stroke patients who underwent inpatient rehabilitation. Measuring PhA and SMI using bioelectrical impedance analysis might be helpful in establishing care plans in these population.

Keywords: Sarcopenia; body composition; infection; phase angle; stroke.