Congenital Adrenal Hyperplasia (CAH) & Related Conditions
Congenital Adrenal Hyperplasia (CAH):
- Most commonly caused by 21‑hydroxylase deficiency; elevated levels lead to an accumulation of 17‑hydroxysteroids and androgen excess. In females, this may cause virilization in early life.
Adrenal Overactivity:
- Conditions that stimulate the adrenal cortex (either due to stress or an ACTH‑producing tumor) can drive up these levels.
Autoimmune Processes:
- Early stages of autoimmune adrenal stimulation might show a transient increase before eventual exhaustion of steroidogenesis.
Adrenal Corticosteroid Production and Regulation
All these markers are part of the adrenal corticosteroid system, which is regulated by the hypothalamic–pituitary–adrenal (HPA) axis:
- 11‑Plasma Oxycorticosteroids: These reflect adrenal glucocorticoid production (such as cortisol and related steroids) measured in blood.
- 17‑Plasma Oxycorticosteroids: These indicate another set of adrenal steroids (often including precursors or androgens) in the blood.
- 17‑Urine Ketosteroids: These are urinary metabolites derived primarily from the 17‑hydroxylated adrenal steroids. They provide an integrated view of adrenal steroid production over time.
- Corticotropin (ACTH): This pituitary hormone stimulates the adrenal cortex to produce these corticosteroids.
In essence, ACTH drives the production of various adrenal hormones, which are then measured in blood (11‑ and 17‑oxy compounds) and metabolized to form ketosteroids excreted in urine. Together, these tests offer a comprehensive picture of adrenal function and HPA axis activity.
