Clinical assessment of the hypothalamic–pituitary–adrenal axis relies on measuring total serum cortisol levels. However, most circulating cortisol is bound to carrier proteins and only free cortisol is biologically available. This Review examines factors that regulate peripheral and tissue glucocorticoid bioavailability and highlights specific clinical indications for the measurement of bioavailable glucocorticoids.
- Ilias Perogamvros
- David W. Ray
- Peter J. Trainer
