Serum β-Catenin Levels Associated with the Ratio of RANKL/OPG in Patients with Postmenopausal Osteoporosis

Objective. To demonstrate the role of Wnt/β-catenin canonical pathway in postmenopausal osteoporosis by evaluating serum β-catenin levels in patients with postmenopausal osteoporosis and analyzing their possible relationship with serum OPG, RANKL, the ratio of RANKL/OPG, sclerostin, and bone turnover markers. Methods. 480 patients with postmenopausal osteoporosis and 170 healthy postmenopausal women were enrolled in the study. Serum β-catenin, OPG, RANKL, and sclerostin levels were measured by enzyme-linked immunosorbent assay. Bone status was assessed by measuring bone mineral density and bone turnover markers. Estradiol levels were also detected. Results. Serum β-catenin levels were lower in postmenopausal osteoporotic women compared to nonosteoporotic postmenopausal women (26.26 ± 14.81 versus 39.33 ± 5.47 pg/mL, P < 0.001). Serum β-catenin was positively correlated with osteoprotegerin (r = 0.232, P < 0.001) and negatively correlated with the ratio of RANKL/OPG, body mass index, and sclerostin (r = −0.128, P = 0.005; r = −0.117, P = 0.010; r = −0.400, P < 0.001, resp.) in patients with postmenopausal osteoporosis. Conclusion. The results indicate that lower serum β-catenin and concomitantly higher ratio of RANKL/OPG may be involved in the pathogenesis of postmenopausal osteoporosis. Functional communication between RANKL/RANK/OPG system and Wnt pathways plays an important role in postmenopausal osteoporosis.