Risks of Muscle Atrophy in Patients with Severe COVID-19 during Hospitalization for the Acute Phase

Abstract

Objective: This study aimed to investigate changes in skeletal muscle mass and risk profiles for muscle atrophy during hospitalization in patients with COVID-19.

Methods: We enrolled 15 patients with COVID-19. Skeletal muscle mass was evaluated according to the skeletal muscle index (SMI) using computed tomography on admission and during hospitalization. The patients were classified into the severe muscle atrophy group or mild muscle atrophy group based on the rate of change in the SMI. Background factors and biochemical tests on admission were also compared. Profiles associated with severe muscle atrophy were evaluated by decision tree analysis.

Results: The SMI was significantly decreased during hospitalization (P=0.001); its rate of change was –8.1%. According to the decision tree analysis, BMI was selected as the initial split and, in patients with a BMI of ≥23.4 kg/m², 50% showed a severe muscle atrophy group. For patients with a BMI of ≥23.4 kg/m², the second version of the acute physiology and chronic health evaluation score (APACHE II score) was selected as the second split. Seventy-five percent of patients with an APACHE II score ≥17 were categorized into the severe muscle atrophy group.

Conclusions: We demonstrated that skeletal muscle mass had decreased during hospitalization in patients with COVID-19. Patients with a BMI of 23.4 kg/m² or higher and an APACHE II score of 17 or higher upon admission were at risk for decreased skeletal muscle mass.