LOSS OF REGIONAL BONE-MINERAL DENSITY IN THE 1ST 12 MONTHS FOLLOWING RENAL-TRANSPLANTATION

A high incidence of osteopenia is likely in renal transplant recipient s in whom pre-existing uraemic osteodystrophy, persisting hyperparathy roidism and glucocorticoids constitute a formidable array of risk fact ors. The correction of some biochemical and hormonal abnormalities, an increase in body weight and an increase in physical activity followin g transplantation could favour improvements in skeletal integrity. Usi ng dual energy X-ray absorptiometry (DEXA), we studied prospectively t he regional bone mineral density (BMD) of 34 consecutive cadaveric ren al allograft recipients who were already established on dialysis. BMD of these patients was measured at the time of transplantation and was repeated at 3, 6 and 12 months following the transplantation. Immunosu ppression was achieved using triple therapy: azathioprine, cyclosporin -A and prednisolone. At baseline, total BMD and BMD at the lumbar spin e and femoral neck did not differ from age- and sex-matched controls. Females experienced marked and progressive bone loss at the lumbar spi ne, with less marked changes at the femoral neck. Males, in contrast, experienced substantial reduction of BMD at the femoral neck at 6 mont hs and a recovery at 12 months without significant change at the lumba r spine. Whole body bone mineral content fell transiently in males, wi th partial recovery by 6 months. No significant correlation was found with the cumulative doses of either corticosteroids or cyclosporin-A, the duration of hospitalisation, the function of the transplant, patie nt age or menopausal status. In females the loss of BMD at the lumbar spine at 6 months was closely associated with a high parathyroid hormo ne level (PTH) at transplantation, and in males, the loss of BMD at th e femoral neck was associated with a low PTH level at transplantation. We conclude that rapid falls in BMD appear to be inherent to the proc ess of renal transplantation and that strategies to prevent this loss should be evaluated.