The performance of serum cortisol, plasma corticotropin and serum dehydroepiandrosterone sulfate levels in the diagnosis of hypothalamic pituitary adrenal dysfunction

Background:There is no single test can identify hypothalamic-pituitary-adrenal dysfunction (HPAD) perfectly. The study aimed to assess the performance of measuring serum cortisol, serum dehydroepiandrosterone sulfate (DHEA-S) and plasma corticotropin (ACTH) in comparison with standard-dose short cosyntropin (250 µg) testing for the diagnosis of HPAD.Methods:This is a cross-sectional study from Al-Faiha Specialized Diabetes, Endocrine, and Metabolism Center (FDEMC) in Basrah. For all patients with suspected HAD; baseline serum cortisol, serum dehydroepiandrosterone sulfate (DHEA-S) and plasma corticotropin (ACTH) and were measured, followed by a formal short cosyntropin test as the gold standard test.Results:The total number of the study participant was 169 patients. Of them, 134 (79.3%) were women. Their age ranges from 5-80 years. The cutoff serum cortisol that predicts abnormal short cosyntropin test was less than 5.31µg/dl with maximal sensitivity and specificity of 90.4 % and 92.3% respectively. The cutoff serum DHEA-S that predict abnormal short cosyntropin test was less than 31.11 µg/dl with a sensitivity of 89.2%and specificity of 62.7%.The least reliable parameter to predict the abnormal short cosyntropin was the plasma ACTH  level with a cutoff of less than 5.30 pg/ml and lowest sensitivity of 89.2% and specificity of 62.7%.Conclusion:To exclude HPAD, serum cortisol at 9-11 am having the highest predictive value, DHEA-S has the midway function and plasma ACTH is the least reliable for that.  Combination of serum cortisol and serum DHEA-S yield the best performance for combinations of test. Keywords: Hypothalamic pituitaryadrenal dysfunction, short  cosyntropin test, dehydroepiandrosterone sulfate, corticotropin,cortisol.