Effect of single dose intravenous zoledronic acid on bone mineral density in post-menopausal osteoporosis of Bangladeshi women

The osteoporosis is a major health threat that affects every third post-menopausal women. Postmenopausal osteoporosis is complicated with vertebral, femoral or radius fracture. This prospective study on post-menopausal osteoporosis was carried out in the Pain Centre, Department of Anaesthesia, Analgesia and Intensive Care Medicine of BSMMU, Dhaka during the period of January 2008 to January 2010. The post-menopausal women with back pain were screened by spinal radiographs and dual-energy X-ray absorptiometry (DXA) of lumbar spine to determine the bone mineral density (BMD). The woman after menopause with a BMD T-score of -2.5 or less with or without evidence of vertebral fracture is considered as post-menopausal osteoporosis. A total of 55 post-menopausal osteoporotic patients were assigned to receive a single dose of IV infusion of zoledronic acid (5 mg) along with dietary calcium and vitamin-D. The spinal radiographs and dual-energy X-ray absorptiometry (DXA) were repeated in all the 55 patients at 12 months following zoledronic acid infusion. The mean BMD of lumbar spine increased significantly from pre-infusion value of 0.75695 g/cm2 to post-infusion of 0.80216 g/cm2. The T-score also increased from pre infusion value of -3.567 +/- 0.77 to -3.158 +/- 0.08 in 12 months following the infusion (P < 0.01). The increase is 5.026% higher than pre infusion values. The spinal radiographs taken before infusion of zoledronic acid, showed 14 fractures. There was no new fracture in any case during the 12 months study period. So, it can be concluded that once yearly IV infusion of zoledronic acid is associated with a significant increase in BMD and decrease in the risk of vertebral fracture.