Clinical investigation of a unique type of hypothalamic adrenal insufficiency

Hypothalamic adrenal insufficiency (AI) is a rare but distinct type of AI. The leading cause of hypothalamic AI is a secondary side-effect of exogenous steroid intake, particularly in large amounts and/or long-term periods. The next cause would be the effect of the tumor in the hypothalamic lesions. We show here 9 cases of hypothalamic AI without any disorder on imagings and a history of steroid administration. All patients had general fatigue; 7 patients (77.8%) had a history of hypoglycemia; 5 patients (55.6%) had a history of hypotension. None of the patients had hyponatremia, hyperkalemia, or eosinophilia. Their morning plasma adrenocorticotropic hormone (ACTH) value was low at 8.5 +/- 4.2 pg/mL, and serum cortisol value was low at 4.5 +/- 1.3 mu g/dL. All patients demonstrated normal responses during the corticotropin-releasing hormone loading (CRH) test but inadequate responses during the insulin tolerance test (ITT). After hydrocortisone replacement therapy, their morning plasma ACTH and serum cortisol values were significantly recovered (P < .05). Moreover, more than half of the patients were fine after discontinuing hydrocortisone replacement therapy. These results indicate that this unique type of hypothalamic AI has a curable clinical course making hydrocortisone replacement therapy a novel therapeutic option.

Automated summary

Hypothalamic adrenal insufficiency (AI) is a rare type of AI caused by the side-effects of exogenous steroid intake or the effect of a tumor in the hypothalamus. This study presents 9 cases of hypothalamic AI without any imaging abnormalities or history of steroid administration. Patients commonly experience symptoms such as general fatigue, hypoglycemia, and hypotension. Hydrocortisone replacement therapy significantly improves the morning plasma ACTH and serum cortisol levels.