Osteoporosis and lung transplantation: a prospective study.

STUDY OBJECTIVE

Osteoporosis is a well-recognized complication of lung transplantation that may significantly impair the quality of life of transplant recipients. We performed a prospective study of bone mineral density (BMD) before and after transplantation to determine the degree of bone mass loss associated with lung transplantation Patients and design: We conducted a prospective study of BMD in 28 patients with various end-stage respiratory diseases pretransplantation and 6 to 12 months posttransplantation. The BMD of the lumbar spine (LS) and femoral neck (FN) were measured. All 28 patients were treated only with vitamin D and calcium supplementation posttransplant. The primary endpoint was the percentage change in BMD. The secondary endpoint was the incidence of fractures posttransplant. A univariate analysis was conducted to determine the various risk factors associated with bone mass loss pretransplant and posttransplant.

RESULTS

Prior to transplantation, moderate to severe bone disease was evident. The mean (+/- SD) pretransplant T score (the number of SDs from the peak bone mass) and Z score (the number of SDs from the age-matched mean) for the LS were -1.72 +/- 1.37 and -1.44 +/- 1.31, respectively. The mean pretransplant T score and Z score for the FN were -2.65 +/- 1.01 and -1.5 +/- 1.43, respectively. Within 6 to 12 months posttransplant, the mean BMD for the LS decreased by 4.76% (p < 0.001), while the mean BMD for the FN decreased by 5.3% (p < 0.001). Five of the 28 patients (18%) suffered osteoporotic fractures posttransplant, while no fractures were documented pretransplant. The cumulative steroid dose posttransplant was associated with a drop in BMD for the LS and FN (r = 0.39, p = 0.039 and r = 0.63, p < 0.001, respectively), while a negative association was found between cumulative steroid use pretransplant and baseline LS and FN T scores (r = -0.4, p = 0. 02 and r = -0.43, p = 0.023, respectively).

CONCLUSION

Within 6 to 12 months after lung transplantation, there is a significant decrease in BMD at both the LS and FN levels (approximately 5%) despite vitamin D and calcium supplementation. This drop in BMD is associated with a relatively high incidence of osteoporotic fractures posttransplant.