COVID-19–Associated Rhabdomyolysis in Hospitalized Patients: Retrospective Cohort Study

Objectives: To determine the frequency of rhabdomyolysis in patients hospitalized with COVID-19 and to characterize their clinical features and outcomes. Methods: All adults admitted to the hospital were included in this single-center retrospective cohort study with COVID-19 at a tertiary care institution in Alicante, Spain, between March 2020 and March 2024. A creatine kinase (CK) threshold of 1000 U/L or higher was used to define rhabdomyolysis. Demographic, clinical, laboratory, treatment, and outcome data were collected. Patients with and without rhabdomyolysis were compared, and factors associated with in-hospital mortality (IHM) were analyzed. Results: Among 7,590 hospitalized COVID-19 patients, 20 developed rhabdomyolyses (cumulative incidence 0.26%; 95% CI 0.170.41). Most affected patients were male (85%), and male sex demonstrated an independent relationship with rhabdomyolysis (adjusted OR 4.35; 95% CI 1.2714.94). Acute kidney injury was observed in 60% of patients, and 15% required hemodialysis. IHM was markedly higher among patients with rhabdomyolysis than in those without (35% vs. 11.5%) (adjusted OR 4.24; 95% CI 1.4812.10). Conclusion: Rhabdomyolysis was an uncommon but severe complication of COVID-19, predominantly affecting men and frequently inked to acute kidney failure and high IHM.