Dehydroepiandrosterone sulfate in the assessment of the hypothalamic-pituitary-adrenal axis.
BACKGROUND
The role of dehydroepiandrosterone-sulfate (DHEA-S) in assessing the integrity of the hypothalamic-pituitary-adrenal (HPA) axis in patients with suspected insufficiency is uncertain.


OBJECTIVE
The objective of the study was to prospectively evaluate the diagnostic value of DHEA-S on HPA function in consecutive patients with suspected HPA insufficiency with and without pituitary lesions at a tertiary referral center.


METHODS
In 70 consecutive patients, insulin tolerance test was accompanied by measurement of basal DHEA-S. Assessment of HPA axis was based on peak cortisol response in insulin tolerance test (normal > or = 550 nmol/liter). To account for the age and gender dependency of DHEA-S, a z-score was calculated using age- and gender-specific reference values of the assay.


RESULTS
Individuals with HPA insufficiency had significantly lower z-scores than those with normal HPA function (-1.66 vs. -0.62, P < 0.0001). In individuals up to 30 yr of age, a z-score of -2.0 had 100% sensitivity and specificity regarding HPA function [area under receiver operating characteristics (ROC) curve 1.00], whereas z-scores proved less useful in older individuals. In individuals with pituitary macroadenoma, a z-score below -2.0 had 100% specificity to predict HPA insufficiency (area under ROC curve 0.82). In the absence of a pituitary adenoma, the diagnostic value of the z-score was reduced (area under ROC curve 0.71).


CONCLUSIONS
Individuals with HPA insufficiency have lower z-scores for DHEA-S than those with normal HPA function. There is evidence that a z-score could be of diagnostic value in assessing HPA integrity, especially in younger patients and patients with pituitary macroadenoma, but further studies are needed to consolidate these findings.
Fischli
Stefan
S
Division of Endocrinology, Diabetes, and Clinical Nutrition, Division of Clinical Epidemiology and Biostatistics, Inselspital, University of Bern, CH-3010 Bern, Switzerland.
Jenni
Stefan
S
Allemann
Sabin
S
Zwahlen
Marcel
M
Diem
Peter
P
Christ
Emanuel R
ER
Stettler
Christoph
C
D000309:Adrenal Insufficiency / Q000097:blood* / Q000503:physiopathology; D000328:Adult; D000367:Age Factors; D001786:Blood Glucose / Q000378:metabolism; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007018:Hypopituitarism / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D007027:Hypothalamic Diseases / Q000097:blood* / Q000503:physiopathology; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology*; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D010913:Pituitary-Adrenal System / Q000503:physiopathology*; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity
D001786:Blood Glucose; D007328:Insulin; D019314:Dehydroepiandrosterone Sulfate; D006854:Hydrocortisone