South Wales Pituitary Pathway

b. Plasma cortisol. Loss of the diumal rhythm in cortisol secretion is one of the characteristics of Cushing's. syndrome. However, because of the variability in the plasma cortisol levels, measurement of AM and. PM cortisol levels is not a very reliable test for screening patients with Cushing's syndrome. c. 24 hour urine free-cortisol ................
................