Background: Osteoporosis and vertebral fractures are a consequence of glucocorticoid immunosuppression therapy in lung transplant recipients (LTR). The purpose of this study was to determine the therapeutic efficacy of a 6-month program of specific resistance exercise designed to reverse glucocorticoid-induced vertebral osteoporosis.
Methods: Sixteen lung transplant candidates were randomly and prospectively assigned to a group (n=8) that performed 6 months of exercise on a lumbar extensor machine or to a control group (n=8). Resistance exercise was initiated at 2 months after transplantation. Bone mineral density (BMD) of the lumbar vertebra (L2-3) was assessed using a dual-energy X-ray absorptiometer (DXA). DXA scans were performed before and 2 months after transplantation and after 6 months of lumbar extensor training or control period.
Results: Lumbar BMD did not differ (P>0.05) between the two groups at study entry. Both the trained (0.63 to 0.54 g/cm2 of hydroxyapatite) and control groups (0.62 to 0.53 g/cm2 of hydroxyapatite) lost significant and comparable amounts (-14.5%) of BMD between study entry and 2 months posttransplantation. The control group lost further (P<or=0.05) lumbar BMD between 2 and 8 months posttransplantation (0.53 to 0.50 g/cm2 of hydroxyapatite), decreasing to values that were 19.5% less than pretransplantation baseline. Lumbar BMD in the trained group increased significantly (+9.2%) after 6 months (0.54 to 0.60 g/cm2 of hydroxyapatite) and returned to values that were within 5% of pretransplantation baseline.
Conclusion: Mechanical loading associated with progressive resistance exercise, using a specific exercise that isolated the lumbar spine, was efficacious in preventing steroid-induced osteoporosis in LTR.