Relationship between serum sclerostin, bone metabolism markers, and bone mineral density in maintenance hemodialysis patients.

BACKGROUND: Sclerostin, which is secreted exclusively by osteocytes, is a negative regulator of bone formation. The role of sclerostin in chronic kidney disease-mineral and bone disorder is not well known. In the present study, we examined the relationship between serum sclerostin levels, bone turnover markers, and bone mineral density (BMD) of the radius in maintenance hemodialysis patients.

METHODS: This was a cross-sectional study that analyzed sclerostin, bone alkaline phosphatase (a bone formation marker), and tartrate-resistant acid phosphatase 5b (a bone resorption marker) in stored serum samples from 181 hemodialysis patients (age, 68 ± 11 y; 105 males and 76 females; hemodialysis duration, 6.9 ± 5.9 y). The BMD in the distal one-third of the radius and in the ultradistal radius, which are enriched with cortical and cancellous bone, respectively, was examined by dual-energy x-ray absorptiometry.

RESULTS: Serum sclerostin was 125 ± 53 pmol/L (mean ± SD). Serum sclerostin correlated significantly and negatively with serum bone alkaline phosphatase and tartrate-resistant acid phosphatase 5b (r = -0.265, P < .001; r = -0.218, P < .01, respectively). The BMD in the distal one-third of the radius and in the ultradistal radius both correlated significantly and positively with serum sclerostin levels (r = 0.454, P < .0001; r = 0.329, P < .0001, respectively). In multiple regression analysis, serum sclerostin was associated significantly and independently with BMD of both parts of the radius (β = 0.200, P < .001; β = 0.218, P < .05), after adjustment for age, hemodialysis duration, and bone metabolism markers.

CONCLUSION: Serum sclerostin was associated significantly, independently, and positively with BMD of both cortical and cancellous bone. Sclerostin is considered to be one of the factors associated with chronic kidney disease-mineral and bone disorder in hemodialysis patients.