Predictor of Steroid Replacement Duration after Removal of Cortisol-producing Adenoma

Objective Cortisol-producing adenoma (CPA) is a major subtype of functional adrenal tumors. CPAs are generally treated with adrenalectomy; however, it is difficult to predict the ideal duration of glucocorticoid replacement after resection. This study explored pre-operative factors predictive of glucocorticoid replacement therapy duration after CPA resection. Mehtods This multicenter retrospective observational study was conducted as part of the Advancing Care and Pathogenesis of Intractable Adrenal Diseases in Japan (ACPA-J) from January 2006 to December 2015. Patients This study was conducted at 10 referral centers and included 124 patients who received hydrocortisone replacement therapy after adrenalectomy for CPA. Results The median duration of replacement therapy was 12 (interquartile range, 5-24) months. In the single regression analysis, the sex (p=0.04), morning adrenocorticotropic hormone (ACTH) level (p=0.02), morning serum cortisol level (p=0.003), midnight serum cortisol level (p<0.001), serum cortisol level after a 1-mg dexamethasone suppression test (p<0.001), presence of lumbar compression fracture (p=0.015), and Cushingoid appearance (p<0.001) were all significantly associated with the replacement therapy duration. In multiple regression analyses, the midnight serum cortisol level and presence of lumbar compression fracture were significantly correlated with the replacement therapy duration after adjusting for other parameters. Conclusion Our results suggest that high midnight serum cortisol levels, which cause persistent suppression of the hypothalamic-pituitary-adrenal axis (HPA axis), contribute to a delay in HPA axis recovery. Lumbar compression fracture is an important symptom that reflects the severity and persistence of cortisol secretion.