Assessment of Risk Factors for Bone Disease in Renal Transplant Recipients

Background Renal allograft recipients are at increased risk of osteoporosis and fractures because of their multiple risk factors for reduced bone mineral density (BMD). Objective To retrospectively assess the risk factors that may predispose renal transplant recipients to reduced BMD. Methods Thirty-one consecutive renal allograft recipients who had their hip and spine BMD measured by dual energy X-ray absorptiometry were evaluated. Individual patient medical records were reviewed for risk factors including demographics, laboratory parameters, glucocorticoid use, medical history, physical activity, and gonadal status. Fisher's exact test and Kruskal-Wallis chi-square approximations were used to compare BMD groups (p < 0.05). Analysis of variance with a Bonferroni adjustment was used to compare differences between BMD groups (p = 0.01) Linear regression analysis was used to correlate BMD with clinical parameters. Results A trend for younger patients (mean 43 y) to have osteoporosis and older patients (mean 54 y) to be osteopenic (p = 0.056) was seen. Higher body weight (p = 0.003) and higher creatinine clearance (p = 0.008) were associated with normal BMD results. Linear regression analysis showed a strong correlation between hip and spine BMD and creatinine clearance. Our data failed to show a statistical relationship between cumulative glucocorticoid dose or daily doses of greater than 7.5 mg and lower BMD. Neither male gender nor premenopausal status seemed to provide protection from reduced BMD. Conclusions These results suggest that all renal allograft recipients, regardless of age, gender, or hormonal status, may be at risk for the development of osteoporosis.