Introduction: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, may result in musculoskeletal tissue injury and is assumingly regulated through central and peripheral pathways. Muscle-specific creatinine kinase (CK-MM) is a specific biomarker used to indicate the presence of musculoskeletal tissue damage. This study aimed to investigate the correlation between the levels of CK-MM and the incidence of persistent myalgia in patients with post-COVID-19 syndromes.
Methods: A cross-sectional study was conducted among COVID-19 survivors at the Faculty of Medicine and Clinical Pathology Laboratory, Universitas Airlangga, Surabaya from June - August 2022. The degree of pain of the myalgia was assessed using a visual analog scale (VAS), while CK-MM level was measured using a sandwich enzyme-linked immunosorbent assay (ELISA). Pearson correlation test at α=0.05 was used to identify the correlation between the levels of CK-MM and the incidence of persistent myalgia in patients with post-COVID-19 syndromes.
Results: A total of 84 participants were enrolled in the study and half (50%) of them reported persistent myalgia post-COVID-19 recovery. Fatigue was the patients' most common persistent symptom (63%). Of the total 42 patients with persistent myalgia, more than half (56%) had mild pain intensity (VAS score: 1–3), and almost all of them (41 patients) experienced myalgia during the COVID-19 diagnosis. All the patients with post-COVID-19 myalgia had normal levels of CK-MM (mean: 32.7 ng/mL; range: 12–93 ng/mL), suggesting no musculoskeletal tissue damage. Anova test suggested no significant different of CK-MM levels between those with and without myalgia in patients with post-COVID-19 syndromes p=0.054).
Conclusion: There was no significant association between CK-MM levels and the incidence of persistent myalgia in patients with post-COVID-19 syndromes.