Long-term bone loss in kidney transplant recipients: a cross-sectional and longitudinal study

Am J Kidney Dis. 1996 Jul;28(1):105-14. doi: 10.1016/s0272-6386(96)90138-9.

Abstract

Organ transplantation is associated with an early bone loss that subsequently increases the risk of osteopenia and bone fractures. It is not known whether bone loss continues in long-term survivors, but persistent bone demineralization could further jeopardize an already diminished bone mass. To better define long-term bone status of kidney transplant recipients (KTR), we conducted cross-sectional and longitudinal evaluations of bone mineral density (BMD) in 70 KTR with a mean posttransplantation time of 8.1 years. BMD was determined by dual-energy X-ray absorptiometry and was repeated in 55 of the patients after a mean follow-up period of 22 +/- 5 months. Lumbar and femoral osteopenia, defined as a BMD lower than 2 standard deviations from mean value of sex- and age-matched controls, was present in 28.6% and 10.5% of patients, respectively. There was a significant negative correlation between cumulative prednisone dose and adjusted lumbar as well as femoral BMD (R = 0.45, P < 0.001 and R = 0.29, P < 0.05, respectively). Five patients had a vertebral BMD below a fracture threshold of 0.777 g/cm2. Vertebral fractures (VF) were found in four men and were associated with higher prednisone dosage (P < 0.05), larger cumulative prednisone dose (P < 0.05), and significantly lower BMD values. According to World Health Organization recent criteria for women, prevalences of lumbar and femoral osteopenia and lumbar and femoral osteoporosis in female patients reach 75%, 65%, 33%, and 10%, respectively. The longitudinal part of the study showed a persistent pathological lumbar demineralization process. Over the study period, BMD, expressed as a percentage of that of controls, decreased from 89 +/- 14% to 86 +/- 14% (P < 0.001). Annual change of bone mass was -1.7 +/- 2.8% per year. Accelerated vertebral bone loss (defined as a decrease of BMD, expressed as a percentage of that of controls, of more than 1% per year) was present in 56% of patients and was associated with higher prednisone dosage (P < 0.01). In conclusion, although VF are relatively infrequent in long-term survivors of renal transplantation, osteopenia is a frequent finding, and a substantial proportion of women present lumbar osteoporosis. An ongoing demineralization process of the spine is also demonstrated and probably contributes to long-term spinal osteoporosis incidence. Prednisone dosage remains the most constantly isolated risk factor.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Bone Density*
  • Bone Diseases, Metabolic / diagnosis
  • Bone Diseases, Metabolic / epidemiology*
  • Bone Diseases, Metabolic / etiology
  • Cross-Sectional Studies
  • Female
  • Follow-Up Studies
  • Glucocorticoids / administration & dosage
  • Glucocorticoids / adverse effects*
  • Humans
  • Kidney Transplantation*
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Osteoporosis / diagnosis
  • Osteoporosis / epidemiology*
  • Osteoporosis / etiology
  • Prednisone / administration & dosage
  • Prednisone / adverse effects*
  • Prevalence
  • Risk Factors
  • Spinal Fractures / diagnosis
  • Spinal Fractures / epidemiology*
  • Spinal Fractures / etiology
  • Time Factors

Substances

  • Glucocorticoids
  • Prednisone