title: Alterations of bone microstructure and strength in end-stage renal failure.
abstract: End-stage renal disease (ESRD) patients have a high risk of fractures. We evaluated bone microstructure and finite-element analysis-estimated strength and stiffness in patients with ESRD by high-resolution peripheral computed tomography. We observed an alteration of cortical and trabecular bone microstructure and of bone strength and stiffness in ESRD patients.
  
  
  BACKGROUND
  Fragility fractures are common in ESRD patients on dialysis. Alterations of bone microstructure contribute to skeletal fragility, independently of areal bone mineral density.
  
  
  METHODS
  We compared microstructure and finite-element analysis estimates of strength and stiffness by high-resolution peripheral quantitative computed tomography (HR-pQCT) in 33 ESRD patients on dialysis (17 females and 16 males; mean age, 47.0 ± 12.6 years) and 33 age-matched healthy controls.
  
  
  RESULTS
  Dialyzed women had lower radius and tibia cortical density with higher radius cortical porosity and lower tibia cortical thickness, compared to controls. Radius trabecular number was lower with higher heterogeneity of the trabecular network. Male patients displayed only a lower radius cortical density. Radius and tibia cortical thickness correlated negatively with bone-specific alkaline phosphatase (BALP). Microstructure did not correlate with parathyroid hormone (PTH) levels. Cortical porosity correlated positively with "Kidney Disease: Improving Global Outcomes" working group PTH level categories (r = 0.36, p < 0.04). BMI correlated positively with trabecular number (r = 0.4, p < 0.02) and negatively with trabecular spacing (r = -0.37, p < 0.03) and trabecular network heterogeneity (r = -0.4, p < 0.02). Biomechanics positively correlated with BMI and negatively with BALP.
  
  
  CONCLUSIONS
  Cortical and trabecular bone microstructure and calculated bone strength are altered in ESRD patients, predominantly in women. Bone microstructure and biomechanical assessment by HR-pQCT may be of major clinical relevance in the evaluation of bone fragility in ESRD patients.
authors.affiliation: Bone Diseases Service, Department of Internal Medicine Specialties, Geneva University Hospitals and Faculty of Medicine, Rue Gabrielle-Perret-Gentil 4, 1211, Geneva 14, Switzerland. andrea.trombetti@unige.ch
authors.forename: A
authors.initials: A
authors.lastname: Trombetti
authors.forename: C
authors.initials: C
authors.lastname: Stoermann
authors.forename: T
authors.initials: T
authors.lastname: Chevalley
authors.forename: B
authors.initials: B
authors.lastname: Van Rietbergen
authors.forename: F R
authors.initials: FR
authors.lastname: Herrmann
authors.forename: P-Y
authors.initials: PY
authors.lastname: Martin
authors.forename: R
authors.initials: R
authors.lastname: Rizzoli
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D005272:Femur Neck / Q000503:physiopathology; D020342:Finite Element Analysis; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016062:Porosity; D011884:Radius / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D006435:Renal Dialysis; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D000469:Alkaline Phosphatase