Association between osteoarthritis-related serum biochemical markers over 10-13 years and knee symptoms in middle-aged adults.

Objectives: To describe the associations between OA-related biochemical markers and knee symptoms in middle-aged adults followed up over 10-13 years.

Methods: Blood samples were collected during the Childhood Determinants of Adult Health (CDAH)-1 study (year: 2004-06) and 10-13 year follow-up at CDAH-3. Serum samples from baseline (n=156) and follow-up (n=167) were analyzed for three OA-related biomarkers [cartilage oligomeric matrix protein (COMP), matrix metalloproteinase (MMP)-3, and hyaluronan (HA)] using non-isotopic enzyme-linked immunosorbent assay (ELISA). Knee symptoms were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale at follow-up. Univariable and multivariable (adjusted for age, sex, and body mass index (BMI)) zero-inflated Poisson (ZIP) regression models were used for analysis.

Results: In cross-sectional multivariable models, significant positive associations between COMP [ratio of means (RoM): 1.156; 95%CI: 0.989, 1.324], MMP-3 [RoM: 1.013; 95%CI: 1.001, 1.025], and HA [RoM: 1.008; 95%CI: 1.002, 1.015] with knee pain and WOMAC-total score were observed in middle-aged adults. Baseline serum MMP-3 [RoM: 1.013; 95%CI: 1.006, 1.020], sum of serum COMP [RoM: 1.022; 95%CI: 1.011, 1.033], and an increase in the serum HA [RoM: 1.014; 95%CI:1.007, 1.020] were significantly positively associated with knee pain assessed after 10-13 years.

Conclusion: The cumulative COMP levels in young adulthood (baseline) and mid-adulthood (follow-up), MMP-3 levels in young adulthood (baseline), and change in HA levels over the follow-up period were positively associated with knee pain assessed after 10-13 years. These biochemical markers measured in middle-aged adults may be explored further as a predictor of future knee symptoms.