Role of Sclerostin in the Bone Loss of Postmenopausal Chinese Women with Type 2 Diabetes

Objective To evaluate the role of sclerostin in bone loss of postmenopausal Chinese women with type 2 diabetes mellitus.Methods The postmenopausal patients suffering from type 2 diabetes mellitus and age,body mass index,and duration of menopause matched healthy controls were enrolled into this cross-sectional study according to criteria of inclusion and exclusion.The serum sclerostin level and bone mineral density of the anterior-posterior lumbar spine(L1-L4),femoral neck,and total hip were determined by using a quantitative sandwich ELISA kit and dual X-ray absorptiometry,respectively.Meanwhile,the clinical and laboratory indexes of bone mineral metabolism were analyzed.Associations between serum sclerostin level and bone mineral density as well as bone turnover markers were evaluated by linear regression analysis.Results Finally,265 postmenopausal women with type 2 diabetes and 225 non-diabetic women were recruited in the diabetic group and control group,respectively.Serum sclerostin level of the diabetic group was significantly higher than that of the control group(48.2±19.4 vs.37.2±18.6 pmol/L,P<0.001)and was increased with age in both groups(diabetic group,r=0.374,P<0.001;control group,r=0.312,P<0.001).In type 2 diabetes patients,serum sclerostin concentration was positively correlated with hemoglobin A1c level(r=0.237;P=0.021).Biochemical bone turnover markers,intact parathyroid hormone and bone-specific alkaline phosphatase,were negatively associated with serum sclerostin level(r=0.138,P=0.078 and r=0.265,P<0.001).Conversely,the positive correlation between sclerostin and C-terminal cross-linking telopeptide of type I collagen was found in diabetic patients(r=0.354,P<0.001).Serum sclerostin levels of the diabetic group were positively correlated with bone mineral density of the lumbar spine,femoral neck,and total hip(r=0.324,0.367,and 0.416,respectively;all P<0.001).Conclusions Sclerostin might participate in the pathogenesis of bone loss of type 2 diabetes.The high sclerostin level might serve as a marker of increased osteocyte activity in postmenopausal patients with type 2 diabetes mellitus.