Endocrine Abstracts

Corticosteroid therapy is associated with potentially serious side effects, but there is no information available regarding glucocorticoid requirements in adult hypopituitary patients with partial adreno-corticotrophin hormone (ACTH) deficiency.

10 male adult hypopituitary patients with partial ACTH deficiency, baseline plasma cortisol > 200 nanomole/ litre but a peak stimulated cortisol < 550 nanomole/ litre, were randomised to a cross-over protocol of treatment with full dose hydrocortisone (10 mg twice daily), half-dose hydrocortisone (5 mg twice daily), or no treatment, for one week. Following each treatment, patients underwent an 11 hour cortisol day curve (CDC), and the results compared with those from 10 matched male control volunteers on no glucocorticoid treatment.

The integrated CDC values were significantly higher in patients taking full dose of hydrocortisone compared to controls (p<0.001). There was no significant difference in the integrated CDC between patients on half-dose (p = 0.37) or no hydrocortisone treatment (p = 0.13), compared to control subjects. Peak post-absorption cortisol values were higher with full-dose hydrocortisone treatment compared to no treatment (p < 0.001), and to controls (p<0.001). There was no significant difference in plasma sodium concentration, blood pressure or corticosteroid-binding globulin between patients on any treatment schedule, and controls.

Adult patients with pituitary disease and partial ACTH deficiency have a cortisol secretory pattern comparable to that of healthy controls. Standard dose replacement hydrocortisone produces hypercortisolaemia, whereas half the conventional treatment dose and no glucocorticoid treatment produce a cortisol day curve which is not statistically different from that of healthy controls. The results suggest that conventional glucocorticoid replacement may overtreat patients with partial ACTH deficiency under normal unstressed physiological conditions.