Glucocorticoid-induced adrenal insufficiency after therapy with intravenous methylprednisolone in patients with moderate-to-severe and active Graves’ orbitopathy: assessment with a low-dose corticotropin test

We aimed to assess adrenal function following treatment of moderate-to-severe and active Graves’ orbitopathy (GO) with intravenous methylprednisolone (IVMP) in weekly pulses in a cumulative dose of 4.5 or 7.5 g. We evaluated the impact of IVMP pulses on adrenal reserve using a low-dose (1 μg) ACTH stimulation test (LDT) for the first time.

In this prospective study we evaluated adrenal function in 21 patients with moderate-to-severe and active GO treated with 12 weekly IVMP pulses according to the European Group on Graves’ Orbitopathy (EUGOGO) recommendations. We assessed serum cortisol, plasma adrenocorticotropic hormone (ACTH), and dehydroepiandrosterone sulfate (DHEA-S) levels before the 1st and 12th IVMP pulse. We performed dynamic testing using LDT before the 12th IVMP pulse in all patients. In those who failed LDT, adrenal function was reassessed with LDT and the overnight metyrapone test after 4–7 weeks.

Two patients failed to achieve serum cortisol levels ≥ 18.1 μg/dL at 30 and 60 min in LDT and were diagnosed with glucocorticoid-induced adrenal insufficiency (GC-induced AI). They were recommended to take hydrocortisone in situations of acute stress. Both patients were reassessed within 4–7 weeks after treatment cessation and showed an adequate response in LDT and overnight metyrapone test. We observed a statistically significant decrease in DHEA-S levels (p = 0.004) before the 12th IVMP pulse compared to baseline in all patients.

For the first time, our research shows that administering IVMP in 12 weekly pulses can result in GC-induced AI. We suggest that patients should undergo careful evaluation for GC-induced AI, including LDT, after therapy with IVMP according to EUGOGO guidelines. Screening for altered adrenal reserve could prevent life-threatening complications, particularly during acute stress situations.