Primary prevention of gluccocorticoid-induced osteoporosis with intravenous pamidronate and calcium: A prospective controlled 1-year study comparing a single infusion, an infusion given once every 3 months, and calcium alone

The aim of this study was to compare the action of two regimens of intraven ous (iv) pamidronate in the primary prevention of glucocorticoid-induced os teoporosis (GC-OP). The primary purpose of the study was to determine wheth er any differences in bone mineral density (BMD) appeared after 1 year. A s econdary endpoint aimed at assessing the remodeling parameters in order to better understand the mechanisms of action of the various regimens. Thirty- two patients, who required first-time, long-term glucocorticoid therapy at a daily dose of at least 10 mg of prednisolone, were studied. Simultaneousl y with the initiation of their glucocorticoid treatment, patients also were randomly allocated to receive a single iv infusion of 90 mg of pamidronate at the start (group A); a first infusion of 90 mg of pamidronate followed, subsequently, by an iv infusion of 30 mg pamidronate every 3 months (group B); and a daily 800-mg elemental calcium supplement given as calcium carbo nate (group C), which also was taken by patients in groups A and B. Patient s were matched for starting glucocorticoid doses, sex, menopausal status, a nd hormonal replacement therapy. Lumbar spine and hip (total and subregions ) BMDs were measured at the outset and repeated at 6-month intervals by dua l-energy X-ray absorptiometry (DXA; Hologic QDR-2000). Bone turnover was as sessed by measurement of total and bone-specific serum alkaline phosphatase activity (B-ALP), serum osteocalcin (OC), and serum C-telopeptide cross-li nks of type I collagen (CTX). After 1 year, the mean BMD changes for groups A, B, and C were, respectively, 1.7, 2.3, and -4.6% at the lumbar spine; 1 .2, 1.2, and -3.1% at the femoral neck; 1.0, 2.6, and -2.2% for the total h ip region. No difference was observed between pamidronate regimens but a hi ghly significant difference was observed between both pamidronate regimens and the control group at the lumbar spine (p < 0.001), at the femoral neck (p < 0.01), and for the total hip (p < 0.05). A significant decrease of ser um C-telopeptide was observed, after 3 months, in groups A and B (p = 0.029 ), but a sustained decrease of bone resorption over time was observed only in group B. As far as BMD evolution over 1 year was concerned, iv pamidrona te, given either as a single infusion or once every 3 months, effectively a chieved primary prevention of GC-OP.