Bone turnover markers, BMD and TBS after short-term, high-dose glucocorticoid therapy in patients with Graves' orbitopathy: a small prospective pilot study.

Chronic GC administration has numerous side effects, but little is known about the side effects of their short-term use (< 3 months)-particularly, when high doses are involved, as in the treatment of Graves' orbitopathy (GO). We investigated the effects of short-term, high-dose GC on bone turnover markers, bone mineral density (BMD), and trabecular bone scores (TBS). Eleven patients (10 females and 1 male; median age 56 years) with active GO who were candidates for treatment with intravenous (iv) methylprednisone were consecutively enrolled. All patients were pretreated with a loading dose of 300,000 units of cholecalciferol, then given a median cumulative dose of 4.5 g (range 1.5-5.25 g) iv methylprednisone. Biochemical parameters of bone metabolism (25OHD3, PTH, P1NP, CTX and bALP) were measured at the baseline, and then 1 week and 1, 3, 6 and 12 months. BMD and TBS were obtained by X-ray absorptiometry (DXA) at the baseline and at 6 and 12 months. On DXA image, morphometric vertebral fracture assessment (VFA) was done. There were no significant changes in PTH, bALP or P1NP. A significant drop in CTX was seen at 1 month (down Δ49.31% from the baseline, p = 0.02), with a return to the baseline at the 3-month measurement. There was a moderate (not significant), but persistent reduction in P1NP. No changes in BMD or TBS came to light. No vertebral fractures were documented. Short-term, high-dose GC treatment caused a rapid, transient suppression of bone resorption, with no effects on BMD or bone micro-architecture (TBS).