Cortisol Response to Low Dose Cosyntropin Stimulation Test in the Late Afternoon

Each subject recruited in the study will undergo low dose cosyntropin stimulation test via intravenous short 2.5 cm plastic tube. 1 μg/ml ACTH aliquot stock solution will be pushed through, followed by 5 ml physiologic saline (0.9%). For each subject, serum and salivary cortisol will be measured just before cosyntropin administration and 30 minutes later.