Prevalence and Predictive Factors of Rhabdomyolysis in COVID-19 Patients: A Cross-sectional Study

The aim of the present prospective observational study was to demonstrate the prevalence and predictive factors of rhabdomyolysis in coronavirus disease 2019 (COVID-19) patients.

The study was performed on reverse transcriptase-polymerase chain reaction (RT-PCR)-confirmed COVID-19 patients admitted to the emergency department between March 2020 and March 2021. Peak creatinine phosphokinase (CPK) levels were used to define rhabdomyolysis. A CPK level equal to or more than 1000 IU/L was defined as the presence of moderate to severe rhabdomyolysis. We developed a COVID-19-related Rhabdomyolysis Prognostic rule (CORP rule) using the independent predictors of rhabdomyolysis in COVID-19 patients.

Five hundred and six confirmed COVID-19 patients (mean age 58.36 ± 17.83 years, 56.32% male) were studied. Rhabdomyolysis occurred in 44 (8.69%) cases throughout their hospitalization. Male gender (odds ratio [OR] = 2.78, 95% confidence interval [CI]: 1.28, 6.00), hyponatremia (OR = 2.46, 95% CI: 1.08, 5.59), myalgia (OR = 3.04, 95% CI: 1.41, 6.61), D-dimer >1000 (OR = 2.84, 95% CI: 1.27, 6.37), and elevated aspartate aminotransferase level (three times higher than normal range) (OR = 3.14, 95% CI: 1.52, 6.47) were the significant preliminary predictors of rhabdomyolysis. The area under the curve of the CORP rule was 0.75 (95% CI: 0.69, 0.81), indicating the fair performance of it in the prognosis of rhabdomyolysis following COVID-19 infection. The best cutoff of the CORP rule was 3, which had a sensitivity of 72.9% and a specificity of 72.7%.

This prospective study showed that 8.69% of patients developed rhabdomyolysis following COVID-19 infection. The CORP rule with optimal cutoff can correctly classify 72.8% of COVID-19 patients at risk of developing rhabdomyolysis.