title: High prevalence of low bone mineral density in pre-dialysis chronic kidney disease patients: bone histomorphometric analysis.
abstract: Chronic kidney disease (CKD) leads to reduced bone mineral density (BMD) in pre-dialysis and dialysis patients. A few studies have used dual-energy x-ray absorptiometry (DEXA) to assess BMD in pre-dialysis CKD patients and have shown low BMD to be highly prevalent. Until now there have been no studies reporting the histological features of low BMD in pre-dialysis CKD patients.
  
  
  OBJECTIVE
  To determine the prevalence and histological features of low BMD in pre-dialysis CKD patients.
  
  
  METHODS
  Pre-dialysis CKD patients (n = 103, 46 females/57 males), median creatinine clearance of 29 (10 - 78) ml/min/ 1.73 m2, were evaluated using biochemical analysis and DEXA. Bone biopsies were obtained from those with low BMD.
  
  
  RESULTS
  Fifty (48.5%) out of the 103 patients had low BMD (LBD group) and 53 (51.5%) had normal BMD (NBD group). The risk for low BMD was increased in those patients with alkaline phosphatase levels above 190 U/l and intact-PTH (iPTH) below 70 pg/ml (p < 0.05). Demographic and biochemical parameters from both groups were comparable, except for lower body mass index (BMI) in LBD subjects (p = 0.04). Women who had been post-menopausal for at least 1 year comprised 65% (13/20) and 50% (13/26) of the LBD and NBD groups, respectively (p = NS). In 40 LBD patients, bone histomorphometry revealed adynamic bone disease (ABD, 52.5%), osteomalacia (OM, 42.5%) and mixed bone disease (MBD, 5%). Trabecular bone volume (BV/TV) was lower in ABD and OM patients. A nearly significant association was found between ABD and iPTH < or = 150 pg/ml (p = 0.056), whereas higher values of iPTH were associated with OM. Total alkaline phosphatase < or = 190 U/l was significantly associated with ABD, whereas higher values were associated with OM. No correlation was observed between BV/TV and BMD.
  
  
  CONCLUSIONS
  Low BMD is frequent in pre-dialysis CKD patients, and low turnover bone disease, manifesting as ABD and OM, was the hallmark of this bone loss.
authors.affiliation: Federal University of São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Lobão
authors.forename: A B
authors.initials: AB
authors.lastname: Carvalho
authors.forename: L
authors.initials: L
authors.lastname: Cuppari
authors.forename: R
authors.initials: R
authors.lastname: Ventura
authors.forename: M
authors.initials: M
authors.lastname: Lazaretti-Castro
authors.forename: V
authors.initials: V
authors.lastname: Jorgetti
authors.forename: J G
authors.initials: JG
authors.lastname: Vieira
authors.forename: M
authors.initials: M
authors.lastname: Cendoroglo
authors.forename: S A
authors.initials: SA
authors.lastname: Draibe
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D015992:Body Mass Index; D015519:Bone Density; D001847:Bone Diseases / Q000378:metabolism / Q000473:pathology; D003404:Creatinine / Q000378:metabolism; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology*; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010018:Osteomalacia / Q000378:metabolism / Q000473:pathology; D015995:Prevalence
chemical_list: D003404:Creatinine; D000469:Alkaline Phosphatase