Bone turnover decreases and bone structure improves during treatment with weekly high-dose methylprednisolone for 12 weeks in Graves' orbitopathy.

PURPOSE

Weekly treatment with the intravenous glucocorticoid methylprednisolone for 12 weeks is mainstay in the treatment of Graves' orbitopathy but may decrease bone mass and impair bone structure. We therefore investigated bone turnover, -mass and -structure during the treatment cause in these patients.

METHODS

We included 32 patients with Graves' orbitopathy scheduled for treatment with methylprednisolone. Bone turnover and thyroid function was measured at baseline and after 3, 9, 12, and 24 weeks, bone mineral density (BMD) was measured using dual x-ray absorptiometry at baseline and after 12 and 24 weeks, and bone structure was measured using high-resolution peripheral quantitative computed tomography at baseline and after 12 weeks.

RESULTS

Bone turnover and tri-iodothyronine decreased throughout the study. Cortical volumetric BMD at both the radius and tibia increased significantly by 0.98 ± 0.38% (p = 0.01) and 1.35 ± 0.50% (p = 0.01), respectively and cortical porosity at both the radius and tibia decreased significantly by -7.67 ± 3.13% (p = 0.04) and -3.30 ± 2.17% (p = 0.04), respectively. Bone mineral density was stable during the first 12 weeks but increased significantly by 2.26 ± 3.61% at the femoral neck (p < 0.01) and by 2.24 ± 4.24% at the total hip towards week 24 (p = 0.02). Stratified analyses suggested that remission of hyperthyroidism was the most important determinant of changes in bone turnover, bone mass and structure.

CONCLUSION

During a 12-week course of high-dose intravenous methylprednisolone bone turnover and cortical porosity decreased and during 24 weeks follow up bone mineral density increased. In terms of bone, methylprednisolone therefore is a safe treatment for Graves' orbitopathy.