States of excess mineralocorticoids

Question 1

Definition

Answer 1

Excess production of mineralocorticoids (such as aldosterone) independent of the renin-angiotensin system. This will lead to decreased renin secretion

Question 2

Characteristics of patients with excess mineralocorticoids

Answer 2

Usually they appear normal, asymptomatic. They may however present with hypertension, hypokalemia, weakness, cramps and paresthesia (which is the sensation of tingling, pricking or numbness in a persons skin). Sodium tends to be normal or mildly raised. Can also present with alkalosis. Polyuria, polydipsia.

Question 3

When to check for aldosterone excess

Answer 3

If the patient presents with hypokalemia, acute hypertension, or adrenal incidentaloma

Question 4

Characteristics of primary mineralocorticoid excess

Answer 4

Conn’s syndrome (aldosterone producing adenoma: aldosteronoma).
Aldosterone producing adenomas (secrete one type of steroids) or carcinoma (secrete more than one type of steroids)
Hyperplasia of zona glomerulosa
Deoxycorticosterone excess: such as in the case of 17-alpha hydroxylase or 11-alpha hydroxylase deficiency.

Question 5

Characteristics of secondary mineralocorticoid excess

Answer 5

With hypertension: renovascular disease: atherosclerosis, renal infarction. Renin secreting tumor. Accelerated hypertension. Estrogen therapy.

Without hypertension: edematous states (cirrhosis, nephritic disease, congestive heart failure). Barter’s syndrome: A salt wasting syndrome which means loss of sodium and chloride in the loop of Henle due to a defect channel (hypokalemia, hyperreninemia, hyperaldosteronism)

Question 6

Laboratry values

Answer 6

Aldosterone is above 15 ng/dl.
Aldosterone/renin ratio can elucidate 3 different origins:
- If there is increased renin, increased aldosterone (ratio less than 10) it is secondary
- If there is decreased renin, increased aldosterone (ratio more than 20) it is primary
- If there is decreased renin, decreased aldosterone -there is mineralocorticoid excess, but not aldosterone

Question 7

Tests which can be done

Answer 7

Renal vein sampling with CT
Salt loading: Na intake - normal aldosterone, increasing renin
Fludrocortisone suppression test: the hormone levels decrease
Captopril (ACE-inhibitor) test: Hormone levels decrease

Question 8

Treatment

Answer 8

Surgery

For hyperplasia: spironolactone