A Retrospective Study on Weaning Glucocorticoids and Recovery of the Hypothalamic-Pituitary-Adrenal Axis

Context Glucocorticoids suppress the hypothalamic-pituitary-adrenal (HPA) axis, resulting in tertiary adrenal insufficiency (AI). When weaning patients off glucocorticoids there is no consensus on whether to maintain patients on prednisolone or convert to hydrocortisone.Objective To investigate HPA axis recovery in patients on long-term prednisolone and assess outcome after hydrocortisone conversion.Methods This was a retrospective cohort study at an outpatient endocrine steroid clinic. Patients were on long-term prednisolone and referred for HPA axis testing between 2015 and 2022. The main outcomes measured were (1) HPA axis recovery rate in patients on prednisolone demonstrated by a normal adrenocorticotrophic hormone (ACTH) stimulation test (AST) and (2) HPA axis recovery rate subanalysis of dose-matched patients with confirmed tertiary AI on prednisolone or hydrocortisone were measured.Results In total, 206 patients on prednisolone were tested for tertiary AI. Of these, 176 remained on prednisolone while 30 were converted to hydrocortisone. The overall HPA axis recovery rate for patients on prednisolone after interval testing was 137/206 (66.5%). The HPA axis recovery rate in dose-matched prednisolone and hydrocortisone conversion groups was 7/10 (70%) and 2/13 (15%) (P = .008), respectively. There was no difference in mean (SD) age (67.1 [12.2] vs 63.4 [11.1] years; P = .464) and baseline cortisol (5.3 [4.2] vs 4.6 [3.1] mu g/dL; P = .648) and median [interquartile, IQR] glucocorticoid duration (1213 [1114] vs 2316 [4808] days; P = .693) and baseline ACTH (20.5 [29.0] vs 16.3 [14.8] ng/L; P = .905) between dose-matched prednisolone and hydrocortisone groups. Follow-up duration in the prednisolone group was significantly lower (median [IQR] 348 [975] vs 667 [884] days; P = .012).Conclusion Patients with glucocorticoid-induced AI maintained on once-daily prednisolone can recover HPA axis function when weaning. There is no apparent advantage to recover HPA axis function in converting to multiple-dosing hydrocortisone.