Effect of alendronate on bone metabolic indices and bone mineral density in patients treated with high-dose glucocorticoid: a prospective study

This prospective study, in the very early phase after initiation of glucocorticoid (GC) treatment, showed that alendronate was effective in suppressing accelerated bone resorption and subsequent decrease in bone mineral density (BMD) at the lumbar spine of patients with high-dose GC treatment. How bisphosphonates affect bone metabolism and BMD of patients with high-dose GC in the early phase, especially within 1 month is unclear. We examined the prospective effects of daily 5 mg alendronate on bone metabolism and BMD in 20 patients with high-dose GC (at least 40 mg prednisolone/day) and compared them to 34 high-dose GC-treated patients without alendronate. Serum levels of calcium decreased at day 28 in the alendronate group. Urinary calcium excretion significantly increased after day 7 in both groups. The increase in serum parathyroid hormone (PTH) level at day 7 in the control group was not observed in the alendronate group, but PTH levels increased at day 28 and month 3 in the alendronate group. As for the bone turnover markers, the serum osteocalcin level decreased in both alendronate and control groups, but serum bone-type alkaline phosphatase levels did not show significant changes. Although the urinary type I collagen cross-linked N-telopeptide (NTX) level showed significant increases on days 7 and 28 in the control group; such early increases in urinary NTX were not observed in the alendronate group. Thereafter, the urinary NTX levels fell slowly in the alendronate group significantly. BMD at the lumbar spine significantly decreased from month 1 in the control group, whereas in the alendronate group, BMD at the lumbar spine maintained almost the same level at all time points observed. Alendronate was effective in suppressing bone resorption and subsequent BMD decrease at the lumbar spine in patients with high-dose GC treatment.