Muscle involvement in SARS‐CoV‐2 infection

Pitscheider, Lea; Karolyi, Mario; Burkert, Francesco R.; Helbok, Raimund; Wanschitz, Julia V.; Horlings, Corinne; Pawelka, Erich; Omid, Sara; Traugott, Marianna; Seitz, Tamara; Zoufaly, Alexander; Lindeck‐Pozza, Elisabeth; Wöll, Ewald; Beer, Ronny; Seiwald, Stefanie; Bellmann‐Weiler, Rosa; Hegen, Harald; Löscher, Wolfgang N.

BACKGROUND: Since the outbreak of the SARS‐CoV‐2 pandemic several reports indicated neurological involvement in COVID‐19 disease. Muscle involvement has also been reported as evidenced by creatine kinase (CK) elevations and reports of myalgia. METHODS: CK, markers of inflammation, pre‐existing diseases and statin use were extracted from records of Austrian hospitalized COVID‐19 patients. Disease severity was classified as severe in case of intensive care unit (ICU) admission or mortality. COVID‐19 patients were additionally compared to a historical group of hospitalized influenza patients. RESULTS: 351 patients with SARS‐CoV‐2 and 258 with influenza were included in the final analysis. CK was elevated in 27% of COVID‐19 and in 28% of influenza patients. CK was higher in severe COVID‐19 as were markers of inflammation. CK correlated significantly with inflammation markers, which had an independent impact on CK when adjusted for demographic variables and disease severity. Compared to influenza patients, COVID‐19 patients were older, more frequent male, had more comorbidities and more frequently a severe disease course. Nevertheless, influenza patients had higher baseline CK than COVID‐19, and 35.7% of ICU admitted patients had CK levels > 1000 U/l compared to only 4.7% of ICU‐admitted COVID‐19 patients. CONCLUSIONS: HyperCKemia occurs in a similar frequency in COVID‐19 and influenza infection. CK levels were lower in COVID‐19 than in influenza in mild and severe disease. CK levels strongly correlate with disease severity and markers of inflammation. To date it remains unclear whether hyperCKemia is due to a virus‐triggered inflammatory response or direct muscle toxicity.