Question

Which hormone is increased during Cushing's syndrome?

• A. Progesterone
• B. Aldosterone
• C. Testosterone
• D. Cortisol

Hint:

Remember the classic endocrine disorders associated with the adrenal gland:
- Cushing's syndrome = Hyperactivity of the adrenal cortex \(\rightarrow\) High Cortisol.
- Addison's disease = Hypoactivity of the adrenal cortex \(\rightarrow\) Low Cortisol and Aldosterone.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Cushing's syndrome, also known as hypercortisolism, is an endocrine disorder characterized by prolonged exposure to inappropriately high levels of glucocorticoids.
It can occur naturally (endogenous) due to pituitary or adrenal tumors, or iatrogenically (exogenous) through the long-term administration of synthetic corticosteroid drugs.

Step 2: Detailed Explanation:
The primary hormone involved in Cushing's syndrome is Cortisol, which is synthesized and secreted by the zona fasciculata of the adrenal cortex.
Cortisol is a vital glucocorticoid hormone that regulates metabolism, immune function, stress response, and blood pressure.
In patients with Cushing's syndrome, autonomous or over-stimulated production of cortisol leads to systemic clinical manifestations.
In dogs, which are frequently affected in veterinary medicine, these signs include polyuria, polydipsia, polyphagia, bilateral symmetrical alopecia, muscle wasting, and a characteristic pot-bellied appearance.
Let us review the other hormones:
- Progesterone (A) is a progestogen involved in pregnancy maintenance and the luteal phase of the estrous cycle.
- Aldosterone (B) is a mineralocorticoid regulating sodium and potassium balance, and its excess causes Conn's syndrome.
- Testosterone (C) is an androgen responsible for male sexual characteristics.
Therefore, only cortisol is elevated in Cushing's syndrome.

Step 3: Final Answer:
The hormone that is increased during Cushing's syndrome is Cortisol.