Bone Loss In Renal Transplant Recipients Research Articles

Plasma n-3 Polyunsaturated Fatty Acids and Bone Mineral Density in Renal Transplant Recipients

Renal transplant recipients (RTR) suffer high rates of bone loss and increased risk of fracture. Marine n-3 polyunsaturated fatty acids (n-3 PUFA), found mainly in fish and seafood, may have beneficial effects on bone and are positively associated with bone mineral density (BMD) in healthy elderly. The aim of this study was to investigate if this association prevails despite the more complex causes of bone loss in RTR. A total of 701 RTR were included in a cross-sectional analysis. BMD of lumbar spine, proximal femur, and distal forearm were measured by dual energy x-ray absorptiometry scan, and blood samples were drawn in the fasting state for measurement of plasma fatty acid composition 10weeks posttransplant. Multiple linear regression analysis was used to assess the association between plasma marine n-3 PUFA levels and BMD. Mean age was 52.2years, and two-thirds were men. Based on femoral neck T-scores, 26% of patients were osteoporotic and 52% osteopenic. Z-scores increased significantly across quartiles of marine n-3 PUFA levels, and marine n-3 PUFA was a positive predictor of BMD at total hip and lumbar spine after multivariate adjustment. No association was found between n-6 PUFA content and BMD. Plasma marine n-3 PUFA levels were positively associated with BMD at the hip and lumbar spine 10weeks posttransplant.

Bisphosphonates for prevention of osteopenia in kidney-transplant recipients: a systematic review of randomized controlled trials.

We conducted a systematic review of randomized controlled trials (RCTs) of bisphosphonates for the prevention of osteopenia in kidney-transplant recipients. Bisphosphonates improved bone mineral density at the lumbar spine and femoral neck after 12months. However, additional well-designed RCTs are required to determine the optimal treatment strategy. Osteopenic-osteoporotic syndrome is a bone complication of renal transplantation. Bisphosphonates, calcitonin, and vitamin D analogs may be used to prevent or treat osteoporosis or bone loss after renal transplantation. However, there is currently no widely recognized strategy for the prevention of corticosteroid-induced osteoporosis. This study aims to assess the available evidence to guide the targeted use of bisphosphonates for reducing osteoporosis and bone loss in renal-transplant recipients. We searched the Cochrane Central Register of Controlled Trials, PubMed, and EMBASE for randomized controlled trials of bisphosphonates for osteoporosis or bone loss after renal transplantation. A total of 352 abstracts were identified, of which 55 were considered for evaluation and 9 were included in the final analysis. The primary outcome measure was change in the bone mineral density (BMD) of the lumbar spine and femoral neck after 12months. Data extraction was performed independently by two investigators. BMD at the lumbar spine was improved after treatment with bisphosphonates [9 trials; 418 patients; weighted mean difference (WMD), 0.61; 95% confidence interval (CI), 0.16-1.06]. Eight trials (406 patients) that reported changes in BMD at the femoral neck also showed improved outcomes after treatment with bisphosphonates (WMD, 0.06; 95% CI, 0.03-0.09). Bisphosphonates improve BMD at the lumbar spine and femoral neck after 12months in renal-transplant recipients.

Calcium supplements lower bone resorption after renal transplant

Bone loss in renal transplant (RT) patients is a problem that begins during end-stage kidney disease and persists after transplantation. Suppression of parathyroid hormone (PTH) may decrease bone loss and improve fracture rate. A single-group prospective intervention study involving 30 patients was performed at a large RT unit. Investigations included dual-emission X-ray absorptiometry scan, vertebral X-ray, calcium absorption test, 24-h urinary calcium and serum measurements of total and ionized calcium, PTH, C-telopeptide cross-links (CTX), osteocalcin, alkaline phosphatase, 25 hydroxyvitamin D (25[OH]D), and 1,25-dihydroxyvitamin D3. Patients were given 500 mg elemental calcium daily for seven d, and serum measurements were repeated. Two-tailed Wilcoxon rank-sum test showed significant decreases in PTH (p<0.01) and CTX (p<0.01) after calcium load. Dietary calcium, mean calcium absorption, and urinary calcium excretion were below desirable levels. Mean 25 hydroxyvitamin D (25(OH)D) was low, but levels of 1,25-dihydroxyvitamin D3 were normal. Calcium absorption significantly correlated with change in PTH (p<0.001), baseline 25(OH)D (p<0.001), and mycophenolate dose (p=0.024). Calcium malabsorption is prevalent in RT recipients, contributing to bone destruction and compounded by poor dietary intake and low 25(OH)D. Calcium supplementation appears to help overcome this deficiency and acutely suppress PTH. Calcium may be an effective and inexpensive therapy for bone loss in RT recipients.