Endocrine Abstracts

Introduction: In adrenal insufficiency (AI), hydrocortisone in divided doses is recommended as first-line replacement therapy, with once-daily prednisolone (3–5 mg) as an alternative. Hydrocortisone’s short half-life may affect adherence, whereas once daily prednisolone may better mimic the physiological diurnal cortisol rhythm.

Aim: To compare the effects of standard-dose hydrocortisone and low-dose prednisolone on cardiometabolic markers and wellbeing

Methods: This ongoing, prospective, open-label, multicentre crossover study includes adults with AI stable on glucocorticoid therapy for ≥4 months. Participants attended two visits: visit 1 before switching from hydrocortisone to prednisolone or vice versa and visit 2 after ≥4 months of switching.

Results: A total of 291 participants were enrolled nationally (mean age 57 years, 61% female, 73% with secondary AI); 205 completed the study, including 189 who switched from hydrocortisone to prednisolone (median dose was 4 mg [IQR 3–4 mg]). After ≥4 months on prednisolone, mean body weight decreased from 87.1 ± 20.6 to 85.3 ± 20.7 kg (P < 0.001), and systolic blood pressure fell from 135.6 ± 19.6 to 129.2 ± 18.3 mmHg (P = 0.016), with no change in diastolic blood pressure. Mean HbA1c improved from 42.0 ± 9.7 to 40.4 ± 8.3 mmol/mol (P = 0.009). Modified SF-36 scores improved in General Health (+4.2 ± 23.5, P = 0.0478), Energy (+7.6 ± 27.4, P = 0.0024), and Well-being domains (+4.3 ± 21.9, P = 0.031), with no change in nausea (+2.2 ± 17.4, P = 0.154). In those who switched to hydrocortisone (n = 16), mean body weight increased from 77.5 ± 21.2 to 79.8 ± 20.8 kg (P < 0.001), with no change in blood pressure or HbA1c.

Conclusion: In this real-world study, once-daily low-dose prednisolone improved cardiometabolic markers and wellbeing compared with hydrocortisone, supporting its use in favour of hydrocortisone for patients with AI.