title: Evaluation of bone microarchitecture by high-resolution peripheral quantitative computed tomography (HR-pQCT) in hemodialysis patients.
abstract: Hemodialyzed patients have decreased bone strength not completely characterized. We evaluated bone microarchitecture in hemodialysis patients and compared it to that of subjects without renal disease by high-resolution peripheral quantitative computed tomography (HR-pQCT). Hemodialysis patients have a marked decreased in cortical density, thickness, and area with significant reduction in trabecular parameters that correlated with the severity of secondary hyperparathyroidism only in women.
  
  
  BACKGROUND
  Although fracture risk is greatly increased in dialysis patients, the corresponding decreased in bone strength has not been completely characterized.
  
  
  METHODS
  We evaluated volumetric bone mineral density (vBMD) and bone microstructure by HR-pQCT at the distal radius and tibia in 50 hemodialyzed (HD) patients (30 females, mean age 53.2 ± 6 years and 20 males, mean age 59.1 ± 11 years) and 50 sex- and age-matched controls.
  
  
  RESULTS
  At the distal radius HD, women showed a 29% reduction in total and trabecular density and trabecular bone volume fraction (p < 0.0001) compared to controls. Trabecular number was reduced by 25% (p < 0.0001), while trabecular separation was increased by 51%. Cortical thickness (-40%, p < 0.0001) and cortical area (-42%, p < 0.0001) were the parameters most reduced, while compact density was the parameter least reduced (-15%, p < 0.0001). Similar findings were found at the tibia. In HD men, HR-pQCT at the distal radius and tibia showed a reduction in volumetric density and microstructure parameters to a lesser extent than in women. In the hemodialyzed group, cortical thickness at the radius was negatively correlated with age both in women and men. At the distal radius and tibia, we found significant negative correlations between Log iPTH and total alkaline phosphatase with cortical vBMD(r = -0.48, p < 0.01; r = -0.69, p < 0.001), thickness (-0.37, p < 0.05; r = -0.60, p < 0.001), and area ((r = -0.43, p = 0.02; r = -0.65, p < 0.001) but only in women.
  
  
  CONCLUSIONS
  We conclude that hemodialysis patients have a marked decreased in cortical density, thickness, and area with significant reduction in trabecular parameters that correlated with the severity of secondary hyperparathyroidism only in women.
authors.affiliation: Instituto de Investigaciones Metabólicas, Universidad del Salvador, Libertad 836 1 piso, Buenos Aires 1012, Argentina. negri@casasco.com.ar
authors.forename: A L
authors.initials: AL
authors.lastname: Negri
authors.forename: E E
authors.initials: EE
authors.lastname: Del Valle
authors.forename: M B
authors.initials: MB
authors.lastname: Zanchetta
authors.forename: M
authors.initials: M
authors.lastname: Nobaru
authors.forename: F
authors.initials: F
authors.lastname: Silveira
authors.forename: M
authors.initials: M
authors.lastname: Puddu
authors.forename: R
authors.initials: R
authors.lastname: Barone
authors.forename: C E
authors.initials: CE
authors.lastname: Bogado
authors.forename: J R
authors.initials: JR
authors.lastname: Zanchetta
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000886:Anthropometry / Q000379:methods; D015519:Bone Density / Q000502:physiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000150:complications; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D011884:Radius / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006435:Renal Dialysis; D012737:Sex Factors; D013977:Tibia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000379:methods*