Comparative assessment of ACTH and lipotropin plasma levels in the diagnosis and follow-up of patients with Cushing's syndrome: a study of 210 cases.

PURPOSE: A series of 210 patients with Cushing's syndrome was evaluated at a single center to assess the relative values of adrenocorticotropic hormone (ACTH) and lipotropin (LPH) plasma levels in the etiologic diagnosis of Cushing's syndrome and in the follow-up of treated Cushing's diseases. PATIENTS AND METHODS: These patients included 149 patients with Cushing's diseases, 20 with adrenal tumors, and 41 with ectopic ACTH/LPH syndromes. Hormone levels were measured before therapy and during the follow-up of treated Cushing's diseases.
RESULTS: ACTH and LPH plasma levels were moderately elevated in Cushing's diseases, low or undetectable in adrenal tumors, and highly elevated in ectopic ACTH/LPH syndromes, but the overlap between the three etiologic groups was less for LPH than for ACTH. LPH appeared to be as sensitive as ACTH in evaluating the outcome of trans-sphenoidal surgery and in detecting the occurrence of Nelson's syndrome after bilateral adrenalectomy.
CONCLUSION: Therefore, plasma LPH determinations provide a better index than ACTH measurements, probably for technical reasons as well as because of the greater stability of LPH in blood.