The introduction of adrenocortical extract in 1930, improved life expectancy to between two and five years with further increases seen with the introduction of cortisone acetate from 1948. Most patients are now treated with synthetic hydrocortisone, and incremental advances have been made with optimisation of daily dosing and the introduction of multi-dose regimens. Today there remains a significant mortality gap between individuals with treated hypoadrenalism and the general population. It is unclear whether this gap is a result of glucocorticoid over-replacement, under-replacement or loss of the circadian and ultradian rhythm of cortisol secretion, with detrimental risk of excess glucocorticoid at later times in the day. The way forwards involves replacement of the diurnal cortisol rhythm with better glucocorticoid replacement regimens. The steroid profile produced by both prednisolone and dual-release hydrocortisone (Plenadren), provide a smoother glucocorticoid profile than standard oral multidose regimens of hydrocortisone and cortisone acetate. The individualisation of prednisolone doses and lower bioavailability of Plenadren offer reductions in total steroid exposure. Although there is emerging evidence of both treatments offering better cardiometabolic outcomes than standard glucocorticoid replacement regimens, there is a paucity of evidence involving very low dose prednisolone (2-4 mg daily) compared to the larger doses (~7.5 mg) historically used. Data from upcoming clinical studies on prednisolone will therefore be of key importance in informing future practice.
Sirazum Choudhury, Tricia Tan, Katharine Lazarus, and Karim Meeran
David J F Smith, Hemanth Prabhudev, Sirazum Choudhury, and Karim Meeran
Patients who need glucocorticoid replacement in both primary and secondary adrenal insufficiency (AI) have the choice of either once-daily prednisolone or thrice-daily hydrocortisone. A recent European study found no difference between prednisolone and hydrocortisone users in several markers including glucose, weight, body mass index, systolic and diastolic blood pressure and waist circumference, although an increase in cholesterol and low-density lipoprotein (LDL) was suggested in a subgroup of these patients. The aim of this study was to expand the evidence base for the use of these agents as replacement therapy.
Data from 82 patients on hydrocortisone and 64 patients on prednisolone for AI at Imperial College Healthcare NHS Trust were analysed.
There was no significant difference in total cholesterol, LDL levels or any other risk factors between hydrocortisone and prednisolone patients. Prednisolone was subjectively significantly more convenient than hydrocortisone (P = 0.048).
Prednisolone once daily is more convenient than hydrocortisone thrice daily, and there is no difference in the markers of cardiovascular risk measured. Because prednisolone mimics the circadian rhythm better than other glucocorticoids, it should be considered as an alternative to hydrocortisone for AI.