The role of sclerostin in knee osteoarthritis and its relation to disease progression

Abstract

Abstract Background Osteoarthritis (OA) is a common joint disease especially in aging population and is characterized by progressive degeneration of articular cartilage, osteophyte formation, and subsequent joint space narrowing. Sclerostin, a protein product of the SOST gene, secreted mainly by osteocytes causes inhibition of Wnt/ β-catenin signaling pathway and bone morphogenetic protein, therefore may affect bone formation and bone remodeling in OA. Aim The aim was to assess serum sclerostin level in patients with knee osteoarthritis (KOA) and its relation to disease severity. Patients and methods A total of 80 participants (50 KOA patients and 30 healthy controls) were recruited in the present study. Sclerostin level in plasma was assessed using an enzyme-linked immunosorbent assay. OA grading was performed using the Kellgren–Lawrence classification. Assessment of physical disability was done by Western Ontario and McMaster universities Arthritis index score and health assessment questionnaire score. Results Plasma sclerostin levels were significantly lower in patients with OA than in healthy controls (P<0.001). Moreover, serum sclerostin level demonstrated a significant inverse correlation with the physical disability score (r=−0.506, P<0.01), age (r=−0.295, P<0.01), disease duration (P<0.05), and radiographic severity of KOA (P<0.001). By univariate regression analysis, sclerostin was one of the strong negative predictors for severity of OA. Conclusion Sclerostin was significantly lower in OA plasma samples when compared with healthy controls. Serum sclerostin level was inversely associated with the physical disability and radiographic severity of KOA. Therefore, sclerostin may be used as a biochemical marker for reflecting disease severity in primary KOA.