Background: Steroid hormone replacement and recovery of adrenal function after unilateral adrenalectomy were studied in 12 patients with Cushing's syndrome due to adenocortical adenoma.
Patients and method: The patients were 3 males and 9 females aged 19 to 61 years old (mean 34.3 years old). Recovery of adrenal function was judged by plasma cortisol level and rapid ACTH test peridocally.
Results: Plasma cortisol level was 13.7 to 20.8 micrograms/dl without diurnal rythme before adrenalectomy. Average replacement period with low dose hydrocortisone was 15 +/- 9.2 months after adrenalectomy. Plasma ACTH and cortisol concentration was recovered to normal range after 3.4 +/- 2.9 months and 12.2 +/- 8.2 after adrenalectomy, respectively. Plasma ACTH concentration was recovered to normal range earlier than plasma cortisol level in all patients. Sufficient response of plasma cortisol concentration in rapid ACTH test was seen a little later than recovery of plasma cortisol level.
Conclusion: Present data suggest that it is insufficient to judge recovery of adrenal function only by the rise of plasma ACTH and/or cortisol concentrations. Therefore rapid ACTH test is useful to judge sufficient recovery of adrenal function during and after steroid hormone replacement.