Therapy With Intravenous Methylprednisolone Pulses Is Associated With Loss of Bone Microarchitecture in Trabecular Bone Score -Assessment Among Patients With Moderate-to-Severe Graves' Orbitopathy: A Pilot Study

Abstract

Background: Therapy with intravenous glucocorticoids (GCs) is associated with various side effects, however, the impact on bone remains elusive. Trabecular bone score (TBS) is a diagnostic tool providing information on bone microarchitecture based on images obtained from dual-energy X-ray absorptiometry. We investigated the influence of the intravenous methylprednisolone (IVMP) pulse administration on TBS in patients with moderate-to-severe Graves' orbitopathy (GO).

Methods: Fifteen patients with GO were treated with 12 IVMP pulses (6x0.5g, 6x0.25 g on a weekly schedule). They received supplementation with 2000 IU of vitamin D and 1.0 g of calcium throughout the study period. TBS was assessed at baseline and after last IVMP pulse. To determine the difference between values at baseline and after treatment the least significant change (LSC) methodology was used. We compared pre- and posttreatment mean TBS values.

Results: We found a significant decrease of TBS in 5 out of 15 (33%) patients. Mean TBS value decreased becoming 2.4% lower than at baseline (p<0.05).

Conclusions: IVMP pulse therapy exerts negative effect on bone microarchitecture in TBS assessment. The analysis of the clinical risk factors for osteoporosis and the evaluation of bone mineral density and TBS should be considered before initiating IVMP therapy.

Keywords: EUGOGO; graves’ ophthalmopathy; graves’ orbitopathy; methylprednisolone; trabecular bone score.

Figure 1

Percentage of TBS and BMD changes according to the LSC criteria in 15 patients after IVMP therapy. TBS trabecular bone score BMD bone mineral density LSC least significant change IVMP intravenous methylprednisolone. Bullets and squares represent individual percentage of BMD and TBS changes (black squares represent a decrease in TBS or BMD – equal to or exceeding LSC calculated to be 4.6% change for TBS, 5.4% change for femoral neck and 3% change for lumbar spine; black bullets represent an increase in BMD equal to or exceeding LSC; white bullets represent no change in TBS or BMD). BMD, bone mineral density; IVMP, intravenous methylprednisolone therapy; LSC, least significant change; TBS, trabecular bone score.

Figure 2

Mean bone mineral density and trabecular bone score values before (white) and after (gray) intravenous methylprednisolone (IVMP) therapy. Values shown above are Δ, calculated as 100 x (after IVMP value – before IVMP value)/before IVMP value. Data are expressed as mean ± SD. *p<0.05 vs. baseline. BMD, bone mineral density; TBS, trabecular bone score; IVMP, intravenous methylprednisolone therapy; SD, standard deviation.