Intake of exogenous steroid causes –
**Core Concept**
Exogenous steroid intake leads to suppression of the hypothalamic-pituitary-adrenal (HPA) axis, resulting in decreased production of endogenous cortisol. This phenomenon is known as adrenal insufficiency or secondary adrenal insufficiency.
**Why the Correct Answer is Right**
When exogenous steroids are administered, they occupy the glucocorticoid receptors in the hypothalamus and pituitary gland, leading to a decrease in the production of corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH). Consequently, the adrenal glands receive less stimulation to produce cortisol, resulting in decreased endogenous cortisol production. This is a classic example of negative feedback inhibition, where the introduction of an exogenous substance (steroid) suppresses the production of its endogenous counterpart (cortisol).
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the intake of exogenous steroid does not cause an increase in endogenous cortisol production. In fact, it has the opposite effect.
**Option B:** This option is incorrect because adrenal insufficiency is a condition characterized by decreased production of endogenous cortisol, not increased production.
**Option C:** This option is incorrect because the intake of exogenous steroid does not cause an increase in ACTH production. In fact, it leads to a decrease in ACTH production.
**Clinical Pearl / High-Yield Fact**
It is essential to note that the suppression of the HPA axis by exogenous steroids can last for several months after discontinuation of the steroid. Therefore, patients who have been on long-term steroid therapy should be tapered off the medication gradually to avoid adrenal crisis.
**Correct Answer: D. Adrenal insufficiency.**