Loss of bone mineral density in renal transplantation recipients

Transplant Proc. 2010 Nov;42(9):3550-3. doi: 10.1016/j.transproceed.2010.07.106.

Abstract

Aim: This study investigated the prevalence and contributing factors of loss of bone mineral density after renal transplantation among Turkish patients.

Patients and methods: The study included 70 subjects, namely 50 males and 20 females of overall mean age of 36.94 ± 10.09 years. We measured femoral neck mineral density by dual-energy X-ray absorptiometry (DEXA). A T score above -1 was defined as a normal bone mineral density compared with T scores of -1.0 to -2.5 or below -2.5 which were defined as either osteopenia or osteoporosis, respectively.

Results: At a median duration of 23 months after renal transplantation, osteopenia or osteoporosis was observed among 30 (42.9%) or 30 (42.9%) of the 70 patients, respectively. The mean body mass index (BMI) value was significantly higher among the normal than the osteoporotic group: 27.59 ± 4.66 kg/m(2) vs 24.18 ± 3.57 kg/m(2), respectively. However, no significant differences occurred in terms of BMI among the other groups. The amount of proteinuria was significantly lower in the normal than the osteopenic or osteoporotic group: (12.5 (range, 10.0-20.0); 105.0 (10.0-2800.0) or 215.5 (10.0-1880.0) mg/d (P = .001 and .004, respectively). In contrast, there was no significant difference between the amounts of proteinuria displayed by the osteopenic group and the osteoporotic group (P < .05)]. These patient groups showed no difference in age, gender, donor source, cause of end-stage renal disease (ESRD), pretransplant dialysis modality, duration of dialysis, use of a vitamin D preparation, immunosuppressive regimen, posttransplantation period, levels of iPTH or 25 hydroxy vitamin D3 (25OH vit D), exposure to tacrolimus or cyclosporine (CyA), calcium × phosphate product, serum albumin and hemoglobin content, creatinine clearance, or serum bicarbonate concentrations (P > .05). The T scores of the femoral neck correlated with BMI (r: 0.415; P = .001), 25OH vit D level (r: 0.268, P = .026), creatinine clearance (r: 0.273, P = .022), and serum glucose level (r: 0.349, P = .003). It inversely correlated with the amount of proteinuria (r: -0.263, P = .028), serum alkaline phosphatase level (r: -0.329, P = .005), and serum magnesium concentration (r: -0.252, P = .035). Upon multivariate analysis, BMI and 25OH vit D level were observed to be independent risk factors for loss of femoral mineral density.

Conclusion: Loss of bone mineral density is a common complication that correlates with low BMI values and decreased 25OH vit D levels as major risk factors for this problem.

MeSH terms

  • Absorptiometry, Photon
  • Adult
  • Biomarkers / blood
  • Body Mass Index
  • Bone Density*
  • Bone Diseases, Metabolic / blood
  • Bone Diseases, Metabolic / diagnostic imaging
  • Bone Diseases, Metabolic / etiology*
  • Calcifediol / blood
  • Chi-Square Distribution
  • Cross-Sectional Studies
  • Female
  • Femur Neck / diagnostic imaging*
  • Humans
  • Kidney Failure, Chronic / surgery*
  • Kidney Transplantation / adverse effects*
  • Linear Models
  • Male
  • Middle Aged
  • Osteoporosis / blood
  • Osteoporosis / diagnostic imaging
  • Osteoporosis / etiology*
  • Prevalence
  • Risk Assessment
  • Risk Factors
  • Time Factors
  • Treatment Outcome
  • Turkey
  • Vitamin D Deficiency / complications

Substances

  • Biomarkers
  • Calcifediol