Age at transplant--one of the factors affecting bone mineral density in kidney recipients--a single-center retrospective study.

BACKGROUND

Osteoporosis/osteopenia after kidney transplantation is multifactorial, and the mechanism responsible for this condition is unclear. A cumulative steroid dose and female gender are two likely major risk factors for osteoporosis/osteopenia after transplantation, but there is no consensus as to which risk factors are most strongly associated with reduced bone mineral density (BMD).

METHODS

We assessed 84 kidney recipients who had received transplants at least 5 months prior to enrollment in the study. BMD at the lumbar spine, hip, and femoral neck was evaluated by dual-energy X-ray absorptiometry. We used the average BMD (BMDa), defined as the average of the sum of the lumbar spine, hip, and femoral neck mineral density values, as representative of body BMD.

RESULTS

This retrospective study revealed inverse correlations between the BMDa and creatinine level and age at transplant as well as a positive correlation with male gender. Osteoporosis occurred in transplantations where the duration since transplantation was longer.

CONCLUSION

This retrospective study demonstrated that a decrease in BMD, reflecting a bone condition tending toward osteoporosis/osteopenia, is inversely correlated with male gender, creatinine level, and age at transplant in kidney recipients. Nonetheless, the time since transplant is higher in the osteoporosis group than in the osteopenia group.