title: Sclerostin serum levels correlate positively with bone mineral density and microarchitecture in haemodialysis patients.
abstract: BACKGROUND
  Sclerostin is a soluble inhibitor of osteoblast function. Sclerostin is downregulated by the parathyroid hormone (PTH). Here, it was investigated whether sclerostin levels are influenced by intact (i) PTH and whether sclerostin is associated with bone turnover, microarchitecture and mass in dialysis patients.
  
  
  METHODS
  Seventy-six haemodialysis patients and 45 healthy controls were included in this cross-sectional study. Sclerostin, Dickkopf-1 (DKK-1), intact parathyroid hormone (iPTH), vitamin D and markers of bone turnover were analysed. A subset of 37 dialysis patients had measurements of bone mineral density (BMD) using dual-energy X-ray absorptiometry and bone microarchitecture using high-resolution peripheral quantitative computed tomography.
  
  
  RESULTS
  Dialysis patients had significantly higher sclerostin levels than controls (1257 pg/mL versus 415 pg/mL, P < 0.001). Significant correlations were found between sclerostin and gender (R = 0.41), iPTH (R = -0.28), 25-hydroxy-cholecalciferol (R = 0.27) and calcium (R = 0.25). Gender and iPTH remained significantly associated with sclerostin in a multivariate analysis. Sclerostin serum levels were positively associated with BMD at the lumbar spine (R = 0.46), femoral neck (R = 0.36) and distal radius (R = 0.42) and correlated positively mainly with trabecular structures such as trabecular density and number at the radius and tibia in dialysis patients. DKK-1 was related neither to bone measures nor to serologic parameters.
  
  
  CONCLUSIONS
  Considering that sclerostin is an inhibitor of bone formation, the observed positive correlations of serum sclerostin with BMD and bone volume were unexpected. Whether its increase in dialysis patients has direct pathogenetic relevance or is only a secondary phenomenon remains to be seen.
authors: Division of Nephrology & Dialysis, Department of Internal Medicine III, Medical University Vienna, Vienna, Austria.
authors: Daniel
authors: D
authors: Cejka
authors: Agnes
authors: A
authors: Jäger-Lansky
authors: Heidi
authors: H
authors: Kieweg
authors: Michael
authors: M
authors: Weber
authors: Christian
authors: C
authors: Bieglmayer
authors: Dominik G
authors: DG
authors: Haider
authors: Danielle
authors: D
authors: Diarra
authors: Janina M
authors: JM
authors: Patsch
authors: Franz
authors: F
authors: Kainberger
authors: Barbara
authors: B
authors: Bohle
authors: Martin
authors: M
authors: Haas