Comparison of alendronate vs alendronate plus mechanical loading as prophylaxis for osteoporosis in lung transplant recipients: a pilot study

Background: Osteoporosis is known to complicate outcomes after lung transplantation (Tx). Methods: To determine the efficacy of bisphosphonate therapy combined with the osteogenic stimulus of mechanical loading, 30 lung transplant recipients (LTRs) were randomly assigned either to alendronate (10 mg/day; n = 10), alendronate (10 mg/day) + resistance exercise (n = 10) or to a control group (n = 10). Alendronate was initiated at 7 days after Tx. Bone mineral density (BMD) of the lumbar spine was measured by dual-energy X-ray absorptiometry before and 2 and 8 months after Tx. Resistance training was initiated at 2 months after Tx and consisted of lumbar extension exercise performed I day/week for 6 months. Results: Lumbar BMD decreased significantly to below pre-transplant baseline at 2 months after Tx in controls (- 12.5 +/- 2.1%), but not in the alendronate (1.5 +/- 1.2%) or alendronate + training (1.5 +/- 0.9%) groups. At 8 months after Tx, lumbar BMD in controls was 14.1 +/- 3.9% below baseline (p 0.05), but was 1.4 +/- 1.1% above baseline in alendronate recipients (P 0.05). The alendronate + training group showed a significantly increased lumbar BMD with values 10.8 +/- 2.3% greater than before Tx. Conclusions: These results suggest that resistance exercise plus alendronate is more effective than alendronate alone in restoring BMD. Anti-osteoporosis therapy in LTRs should include both an anti-resorptive agent and an osteogenic stimulus, such as mechanical loading.