Serum cortisol

✔ 8 A.M. cortisol & 24-hour urine free cortisol (Cortisol urine test)

Serum cortisol measurements are primarily used to diagnose states of cortisol excess (hypercortisolism) or deficiency (hypocortisolism).

Remission from Cushing disease (CD) after pituitary neuroendocrine tumor resection may be predicted by a postoperative reduction in serum cortisol level.

Liu et al. retrospectively enrolled 92 consecutive patients with a confirmed diagnosis of Cushing's disease. Voxel-based analysis was performed to investigate the association between cerebral 18F positron emission tomography uptake and serum cortisol level. Relatively impaired metabolism of specific brain regions correlated with serum cortisol level was found. Specifically, notable correlations were found in the hippocampus, amygdala, and cerebellum, regions considered to be involved in the regulation and central action of glucocorticoids. Moreover, some hormone-associated regions were found in the frontal lobe cortex and occipital cortex, possibly mediating the cognitive decline seen in Cushing's disease. The findings link patterns of perturbed brain metabolism relates to individual hormone level, thus presenting a substrate for cognitive disturbances seen in Cushing's disease patients, as well as in other conditions with abnormal cortisol levels ¹⁾.