C-terminal cross-linking telopeptide levels in COVID-19 patients: A prospective case-control study.

BACKGROUND: Coronavirus disease 19 (COVID-19) is a viral infection mediated by coronavirus-2 that causes severe acute respiratory syndrome (SARS-CoV-2). The disease may affect biochemical parameters and electrolytes. C-terminal cross-linking telopeptide (CTX-I) is released during mature bone resorption and is a biomarker for predicting bone resorption.

OBJECTIVES: As the pandemic progressed, understanding the effects of COVID-19 disease remained critical. Inflammatory responses triggered by the virus can result in a bone metabolism regulation imbalance. As such, this study aimed to analyze serum levels of CTX-I, calcium (CA), phosphorus (P), magnesium (Mg), C-reactive protein (CRP), and alkaline phosphatase (ALP) in COVID-19 patients to investigate the relationship between bone resorption and the disease.

MATERIAL AND METHODS: The study included 56 individuals with COVID-19 (divided into mild, moderate and severe subgroups depending on disease severity) and 25 healthy adults as a control group. Serum CTX-I concentrations were measured with enzyme-linked immunosorbent assay (ELISA). In addition, CRP, Ca, Mg, P, and ALP levels were measured using an automated clinical chemistry analyzer.

RESULTS: Serum CTX-I levels were significantly higher in COVID-19 patients than in the control group (p < 0.05). Furthermore, a positive weak relationship was detected between CRP and CTX-I (r = 0.303, p < 0.05).

CONCLUSIONS: Increased serum CTX-I levels in the patient group caused COVID-19-driven bone degradation, though serum CTX-I levels did not differ according to disease severity.