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Abstract: TH-PO155

Bone Disease in Kidney Transplantation: How Are the Bones of Long-Term Kidney Transplant Recipients?

Session Information

Category: Bone and Mineral Metabolism

  • 502 Bone and Mineral Metabolism: Clinical

Authors

  • Alves, Italo Rafael Correia, Hospital das Clinicas, Recife, Pernambuco, Brazil
  • Gueiros, Ana Paula, Hospital das Clinicas, Recife, Pernambuco, Brazil
  • Gueiros, Jose Edevanilson, Hospital das Clinicas, Recife, Pernambuco, Brazil
Background

Kidney transplant (KT) recipients may present persistent chronic kidney disease mineral and bone metabolism disorder (CKD-MBD), changes in bone turnover secondary to immunosuppression, de-novo MBD, and age-related bone loss. The aim of this study was to assess the osteometabolic profile and factors associated with loss of bone mass in long-term transplant patients.

Methods

This was a cross-sectional, retrospective study. Clinical parameters assessed were: age, sex, CKD etiology, dialysis time, KT time, donor type, and immunosuppression. Laboratory tests: intact parathyroid hormone (iPTH pg/dL), calcium, phosphorus, total alkaline phosphatase, 25OH vit D, creatinine and glomerular filtration rate (GFR). Bone mineral density was assessed using densitometry. According to the T-score, patients were divided into two groups: osteoporosis (T-score ≤ -2.5) and non-osteoporosis (T-score > -2.5). A comparative analysis between groups was performed; univariate and multivariate analyzes were undertaken to determine the risk factors for osteoporosis.

Results

We studied 38 patients (60.5% female), with a median age of 57 years, 74% with CKD of undetermined etiology, the median time of dialysis 71 months. Seventy-one percent of KT were from deceased donors and the median time of KT was 181 months. The median GFR was 54 mL/min. The median T-score in the femoral neck and lumbar spine were -1.9 and -2.5, respectively. Twenty patients (52.6%) presented osteoporosis. Patients with and without osteoporosis were distinguished by: age (62 x 50; p=0.002), KT time (252 x 95; p=0.009), iPTH (131 x 234; p=0.034) and use of tacrolimus (35% x 72%; p=0.025). Univariate analysis revealed that age (OR: 1.13; p=0.004), KT time (OR: 1.01; p=0.01) and use of tacrolimus (OR: 0.21; p=0.025) were associated with osteoporosis. In the multivariate analysis, only age (OR: 1.12; p=0.025) was an independent risk for osteoporosis. We observed a positive correlation between iPTH and the T-score, in the lumbar spine (R 0.25; p=0.028) and in the femoral neck (R 0.35; p=0.003).

Conclusion

In long-term kidney transplant recipients, we observed a high prevalence of osteoporosis and confirmed that the loss of bone mass is determined by aging. In the late phase of KT, lower iPTH levels seem to be more associated with loss of bone mass.