Impact of Sarcopenia on Functional Outcomes Among Patients With Mild Acute Ischemic Stroke and Transient Ischemic Attack: A Retrospective Study

Abstract

Introduction: Sarcopenia, a age-related disease characterized by loss of muscle mass accompanied by loss of function, is associated with nutrition imbalance, physical inactivity, insulin resistance, inflammation, metabolic syndrome, and atherosclerosis which are risk factors for cardiovascular disease. However, its association with outcomes after ischemic stroke has not been well-established. This study investigated whether functional outcomes of patients with acute ischemic stroke is associated with sarcopenia.

Methods: Data were collected from 568 consecutive patients with acute ischemic stroke with National Institute of Health Stroke Scale 0-5 or transient ischemic attack who underwent bioelectrical impedance analysis between March 2018 and March 2021. Sarcopenia was defined, as low muscle mass, as measured by bioelectrical impedance analysis, and low muscle strength, as indicated by the Medical Research Council score. Unfavorable functional outcome was defined as mRS score of 2-6 at 90 days after discharge. The relationship between functional outcomes and the presence of sarcopenia or its components was determined.

Results: Of the 568 patients included (mean age 65.5 ± 12.6 years, 64.6% male), sarcopenia was detected in 48 (8.5%). After adjusting for potential confounders, sarcopenia was independently and significantly associated with unfavorable functional outcome (odds ratio 2.37, 95% confidence interval 1.15-4.73 for unfavorable functional outcome, odds ratio 2.10, 95% confidence interval 1.18-3.71 for an increase in the mRS score). Each component of sarcopenia was also independently associated with unfavorable functional outcome (odds ratio 1.76, 95% confidence interval 1.05-2.95 with low muscle mass, odds ratio 2.64, 95% confidence interval 1.64-4.23 with low muscle strength). The impact of low muscle mass was larger in men than in women, and in patients with lower muscle mass of the lower extremities than in those with lower muscle mass of the upper extremities.

Conclusions: In this study, the prevalence of sarcopenia in patients with stroke was lower than most of previous studies and patients with sarcopenia showed higher likelihood for unfavorable functional outcomes at 90 days after acute ischemic stroke or TIA. Further investigation of the interventions for treating sarcopenia and its impact on the outcome of ischemic stroke patients is needed.

Keywords: aged; muscle; prognosis; sarcopenia; stroke.

Figure 1

Distribution of modified Rankin Scale scores at 90 days in patients with and without sarcopenia.

Figure 2

Subgroup analysis. Logistic regression analysis of the association between sarcopenia with unfavorable outcomes 90 days after discharge, adjusted for sex and age. *Adjusted for age only. CI, confidence interval; NIHSS, national institute of health stroke scale.

Figure 3

Restricted cubic spline models for low muscle mass, low muscle strength, and unfavorable outcomes at 90 days. Effect of low muscle mass and low muscle strength on functional outcomes in ischemic stroke or TIA patients assessed with (A,D,G) Z-transformed appendicular skeletal muscle mass index, (B,E,H) only upper extremity muscle mass (C,F,I) only lower extremity muscle mass. OR, odds ratio; ASMI, Z-transformed appendicular skeletal muscle index; MRC, Medical Research Council.