Hyperparathyroidism and Vitamin D Deficiency Predispose to Bone Loss in Renal Transplant Recipients

Abstract

Background. Bone disease is common postrenal transplantation resulting in increased fracture rates and morbidity. The cause is multifactorial including hyperparathyroidism, corticosteroids, and possibly calcium and vitamin D deficiencies. The aim of this study was to identify modifiable factors contributing to bone disease in long-term renal transplant (RT) recipients. Methods. Ninety-seven RT recipients were prospectively recruited over a 6-month period from a single center. Bone-related parameters were collected including bone mineral density at lumbar spine and total hip sites, serum and urinary markers of bone-turnover and calcium metabolism, and intact parathyroid hormone levels. Results. The mean time posttransplant of RT recipients was 9.5 years and mean estimated glomerular filtration rate was 70.3 mL/min. Up to 50% of recipients had biochemical evidence of calcium and vitamin D deficiencies. In the multiple regression models, elevated intact parathyroid hormone levels and calcium deficiency, which are affected by estimated glomerular filtration rate and vitamin D levels, are significantly associated with reduction in bone mineral density measurements. Conclusions. Hyperparathyroidism and vitamin D deficiency are common and are likely to contribute to bone loss postrenal transplantation. Measures aim to correct these problems pre- and posttransplant may improve bone health in RT recipients.