A case-control study and meta-analysis reveal the association between COX-2 G-765C polymorphism and primary end-stage hip and knee osteoarthritis.

Background: Osteoarthritis (OA) is a popular arthrosis featured as pain, limited joint activity, and deformity. Cyclooxygenase-2 (COX-2) has been reported to be up-regulated in arthritic tissues and is integral to the progression of osteoarthritis (OA). Previous studies showed the COX-2 promoter G-765C polymorphism could influence COX-2 expression. However, the relationship between the variant and OA risk is contrasting.

Methods: We conducted a case-control study with 196 primary end-stage hip and knee OA cases and 196 controls in a Chinese Han population. Subsequently, we integrated this case-control study in a meta-analysis to acquire greater statistical power. The results from our case-control study using MassARRAY genotyping technology and binary logistic regression statistical methods.

Results: The variant carriers in the Chinese Han population had a lower primary end-stage hip and knee OA susceptibility (C vs G: OR = 0.350, 95%CI: 0.154-0.797, P = .012; GC vs GG: adjusted OR = 0.282, 95%CI: 0.118-0.676, P = .005). Stratification studies indicated that a higher GC frequency in women decreased not only knee OA susceptibility but also unilateral knee OA risk. The meta-analysis showed that the variant exhibited a significantly decreased OA risk through comparisons involving allelic, homozygous, heterozygous, and dominant models.

Conclusion: Our findings suggest that the COX-2 G-765C polymorphism exerts a protective effect against primary end-stage knee osteoarthritis in a female Chinese Han population.