Determination of the Interday and Intraday Reliability of Serum Cartilage Oligomeric Matrix Protein in a Physically Active Population

OBJECTIVE: To determine the intraday and interday reliability of serum cartilage oligomeric matrix protein (sCOMP) in a physically active population with no history of lower extremity surgery. DESIGN: A repeated-measures reliability study was employed to determine the intraday and interday reliability of sCOMP in a physically active cohort. A total of 23 subjects were recruited to the laboratory on 3 separate occasions for nonfasting serum collection. Subjects had no history of lower extremity surgery and were free from acute injury within the last 3 months. RESULTS: Our results indicate strong reliability for both intraday intraclass correlation coefficient (ICC) (0.76) and interday ICC (0.74) sCOMP values. CONCLUSION: Our results demonstrate that following 30 minutes of inactivity, nonfasting serum samples remain stable over the course of 1 day and between 2 consecutive days in a healthy population with no history of lower extremity surgery. Future research studies are needed to further investigate the magnitude of change in this biomarker for patients with acute articular cartilage damage to determine its appropriateness for use in this population and for varying degrees of articular cartilage severity.