Kidney Week

Abstract: SA-PO665

Bone Loss in Kidney Transplant Recipients and Patients on Dialysis Treated with Nocturnal Hemodialysis, Conventional Hemodialysis, and Peritoneal Dialysis

Session Information

• Bone and Mineral Metabolism: Clinical - II
  October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Bone and Mineral Metabolism

• 402 Bone and Mineral Metabolism: Clinical

Authors

• Jansz, Thijs Thomas, University Medical Center Utrecht, Utrecht, Netherlands

Thijs Thomas Jansz,

• Willems, Hanna C., Academic Medical Center Amsterdam, Amsterdam, Netherlands

Hanna C. Willems,

• De jong, Pim A., University Medical Center Utrecht, Utrecht, Netherlands

Pim A. De jong,

• Verhaar, Marianne C., University Medical Center Utrecht, Utrecht, Netherlands

Marianne C. Verhaar,

• van Jaarsveld, Brigit C., VU University Medical Center, Amsterdam, Netherlands

Brigit C. van Jaarsveld,

Background

Patients on dialysis have an increased risk of fractures due to mineral bone disorder. This disturbed mineral metabolism is improved by nocturnal hemodialysis, an intensified hemodialysis regimen, and completely normalized by kidney transplantation. This study therefore had two aims: to compare bone loss and its determinants in kidney transplant recipients and patients on dialysis, and to compare bone loss between patients on nocturnal hemodialysis, conventional hemodialysis, and peritoneal dialysis.

Methods

In this prospective observational study, we measured trabecular bone mineral density at the thoracic spine with computed tomography annually for up to 3 years in 45 incident kidney transplant recipients and 78 patients on dialysis (30 on nocturnal hemodialysis, 28 on conventional hemodialysis, and 20 on peritoneal dialysis), who were all transplantation candidates. We used mixed models to compare bone loss between treatment groups and used logistic regression to assess determinants of significant bone loss.

Results

Overall, mean age was 51 ±13 years, and 80 (65%) were male. Bone mineral density remained stable in kidney transplant recipients (change 1.9, 95% confidence interval -1.4; 5.2 mg/cm³ per year), while it decreased in patients on dialysis at a rate of -6.4, 95% confidence interval -9.2; -3.7 mg/cm³ per year (P<0.001 for difference). In kidney transplant recipients, determinants of significant bone loss were female sex and over 50 years old (P=0.01), higher baseline bone mineral density (P=0.01), and no calcium supplementation (P=0.03). In patients on dialysis, determinants were female sex (P=0.01) and low parathyroid hormone levels (P=0.03). In patients on dialysis, bone loss was similar in patients on nocturnal hemodialysis, conventional hemodialysis, and peritoneal dialysis (P=0.92 for differences).

Conclusion

After kidney transplantation patients have stable trabecular bone mineral density, while patients who remain on dialysis lose substantial amounts of trabecular bone. This loss is similar in treatment with nocturnal hemodialysis, conventional hemodialysis, and peritoneal dialysis. Whether this is due to oversuppression of parathyroid hormone needs further study.

Funding

• Commercial Support – Amgen, Baxter, Fresenius Medical Care, Novartis, Roche, Shire.