title: Reduced bone mineral density and increased bone turnover in Prader-Willi syndrome compared with controls matched for sex and body mass index--a cross-sectional study.
abstract: OBJECTIVE
  To study bone mineral status, body composition, and biochemical markers of bone turnover in Prader-Willi syndrome (PWS).
  
  
  METHODS
  Eight subjects with PWS (three males, five females; mean age, 24 years [range 16-41]) were included. Each subject was compared with an age-, sex- and body mass index-matched control randomly drawn from the background population. Bone mineral density (BMD), lean body mass, and fat mass were measured. Plasma PINP, PIIINP, osteocalcin, total alkaline phosphatase, bone-specific alkaline phosphatase, C-terminal telopeptide of type I collagen, and urine cross-linked N-terminal telopeptide of type I collagen were measured as biochemical markers of bone and collagen turnover.
  
  
  RESULTS
  The PWS patients had significantly lower whole-body BMD (mean +/- SD, 1.020 +/- 0.041 vs 1.237 +/- 0.118 g/cm(2); 2p <.01) than controls due to lower bone mineral content (BMC: 2291 +/- 607 vs 2825 +/- 409 g; 2p=.02). Resorptive and formative bone markers were significantly elevated in patients compared with controls. Plasma testosterone was low in male patients (3.50 +/- 4.97 vs 19.2 +/- 8.78 nmol/L, 2p=.05), whereas no difference in plasma estradiol was present.
  
  
  CONCLUSIONS
  The patients had a low BMD due to a high bone turnover. This high turnover was probably linked to sex steroid deficiency.
authors.affiliation: Department of Endocrinology and Metabolism C, Aarhus Amtssygehus, Aarhus University Hospital and Faculty of Health Sciences, Aarhus University, Aarhus, Denmark. p-vest@post4.tele.dk
authors.forename: Peter
authors.initials: P
authors.lastname: Vestergaard
authors.forename: Kurt
authors.initials: K
authors.lastname: Kristensen
authors.forename: Jens M
authors.initials: JM
authors.lastname: Bruun
authors.forename: John R
authors.initials: JR
authors.lastname: Østergaard
authors.forename: Lene
authors.initials: L
authors.lastname: Heickendorff
authors.forename: Leif
authors.initials: L
authors.lastname: Mosekilde
authors.forename: Bjørn
authors.initials: B
authors.lastname: Richelsen
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers; D001823:Body Composition; D015519:Bone Density; D016723:Bone Remodeling / Q000502:physiology*; D001862:Bone Resorption / Q000378:metabolism*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D011218:Prader-Willi Syndrome / Q000503:physiopathology*; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers