Prevalence of osteoporosis, osteopenia, and vertebral fractures in long-term renal transplant recipients

Abstract

Background: Osteopenia and osteoporosis are frequent complications early after transplantation. Their long-term prevalences and associations with the risk of fractures are not well known. The objective of the present work was to determine the incidence of osteopenia and osteoporosis versus vertebral fractures in renal transplant recipients with stable graft function and with a follow-up of at least 10 years.

Patients and methods: Forty renal transplant recipients, 24 men and 16 women, were included in the study. The mean age was 41.8 years and the follow-up was 130 +/- 14 months. Initial immunosuppression consisted of cyclosporine with or without an antiproliferative agent. Measurements of bone mass density (BMD) were performed by dual-energy X-ray absorptiometry (DEXA). The assessment of vertebral fracture using conventional radiography was evaluated by semiquantitative criteria.

Results: Eleven patients (27.5%) displayed lumbar spine osteoporosis (T-score < -2.5); 21 (52.5%), osteopenia (T-score > -2.5 and < -1) and 8 (20.0%), normal BMD. However, BMD was better preserved at the femoral neck: 14 patients (35.0%) had normal BMD; 20 (50.0%) osteopenia, and 6 (15.0%), osteoporosis. When analyzed together, patients with osteoporosis or osteopenia showed worse graft function at 1 and 8 years compared with normal BMD patients (1.75 +/- 0.634 vs 1.32 +/- 0.33 mg/dL at 1 year; P < .014) and (1.7 +/- 0.4 vs 1.2 +/- 0.2 mg/dL at 5 years; P < .01) and a greater number were prescribed vitamin D (50% vs 23%). Mild vertebral fractures were observed in 60.0% patients with osteoporosis; 70% with osteopenia; and 43% with normal lumbar BMD. Peripheral fractures were more common in patients with osteoporosis (P = .053).

Conclusions: Osteoporosis and osteopenia are common among long-term renal transplant recipients are associated with poorer graft function. Lumbar spine BMD osteoporosis is associated with peripheral fractures. However, mild vertebral deformities are not associated with the presence of osteopenia or osteoporosis.