Pituitary function tests: comparison of ACTH and 11-deoxy-cortisol responses in the metyrapone test and with the insulin hypoglycemia test.
OBJECTIVE
To compare the sensitivity of ACTH and 11-deoxy-cortisol (comp. S) responses in the short metyrapone test and the latter with the insulin hypoglycemia test.


METHODS
Retrospective evaluation of 115 short metyrapone tests and comparison of 18 pairs of metyrapone and insulin tests. 20 healthy controls and 95 patients with confirmed pituitary disease were studied. All hormones were measured by sensitive radioimmunoassays.


RESULTS
In patients with pituitary disease not requiring hydrocortisone substitution (n = 70), the ACTH response in the metyrapone test was subnormal in 47 cases (< 33 pmol/L), the comp. S response (< 200 nmol/L) in 21 cases only. Comparison of the relationship between ACTH and comp. S with an ACTH-cortisol dose-response curve obtained in normal subjects shows that subnormal ACTH responses after metyrapone in the range between 13 and 33 pmol/L still generate normal comp. S responses. The results of the metyrapone test correlated significantly with those of the insulin test.


CONCLUSIONS
Measuring plasma ACTH in the scope of the metyrapone test makes the test more sensitive to detect secondary adrenal insufficiency than with steroid measurements alone. Results of the metyrapone test correlate significantly with the cortisol response to insulin hypoglycemia.
Steiner
H
H
Department of Internal Medicine, Klinikum Steglitz, Freie Universität Berlin, Germany.
Bähr
V
V
Exner
P
P
Oelkers
P W
PW
D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism*; D003350:Cortodoxone / Q000097:blood*; D005260:Female; D006801:Humans; D007328:Insulin; D008297:Male; D008797:Metyrapone; D008875:Middle Aged; D010900:Pituitary Diseases / Q000175:diagnosis*; D012189:Retrospective Studies
D001786:Blood Glucose; D007328:Insulin; D000324:Adrenocorticotropic Hormone; D003350:Cortodoxone; D008797:Metyrapone