Skeletal Muscle Injury during COVID-19: A Cohort of 873 Patients

Objective: The aim of the present study was to determine the prevalence of skeletal muscle injury in the clinical course of coronavirus disease-2019 (COVID-19) using creatine kinase (CK) levels.
Materials and Methods: The medical records of all patients with COVID-19 cases were retrospectively retrieved. These comprised two groups: patients with high CK levels and patients with normal CK levels. The CK level and its relationship with other clinical features and outcome were analyzed.
Results: In the study period, 994 patients who were hospitalized with COVID-19 were identified. Of them, CK was measured in 873 patients. There were 74 patients with CK >500 IU/l and 33 patients with CK >1,000 IU/l. Seventeen patients had weakness and CK >500 IU/l. Use of favipiravir and hospitalization in the intensive care unit were the risk factors for high CK levels. The CK levels positively correlated with age, duration of hospitalization, duration in intensive care, and levels of liver function tests, serum urea, D-dimer, and ferritin levels, and negatively correlated with oxygen saturation and thrombocyte levels.
Conclusion: This study showed that the use of favipiravir is a potential risk factor for elevated CK levels. Severe systemic inflammation, disseminated intravascular coagulation, and thrombosis may facilitate skeletal muscle damage. Prolonged intensive care is probably related to more severe inflammatory and coagulation response.