Programs and Disease Treatment
Hypertension (high blood pressure) affects millions of Americans. Hypertension is a serious problem because it increases the risk of heart attack, stroke, kidney disease, and death. There are two main forms:
Primary hypertension, also known as essential hypertension, accounts for the vast majority of cases of hypertension. It is associated with genetic factors. Hypertension can worsen in patients who are obese, do not exercise, and in those who consume too much salt, alcohol or caffeine. Hypertension is more common in the elderly.
Secondary hypertension is caused by a specific abnormality in the organs or systems in the body. Many types of secondary hypertension have specific treatments to improve or potentially cure the hypertension.
Endocrine hypertension is a type of secondary hypertension associated with endocrine hormone imbalance. Most types of endocrine hypertension involve the pituitary or adrenal gland. Excess hormone production due to either pituitary or adrenal dysfunction leads to an elevated blood pressure. Patients who develop hypertension before the age of 30 who have a strong family history of hypertension, adrenal tumors, or develop a low potassium level (hypokalemia) should be screened for endocrine hypertension. Patients who have poor blood pressure control despite taking three or more blood pressure medications are defined as having resistant hypertension and should also be screened.
Endocrine Hypertension DisordersEndocrine hypertension includes the following disorders.
Primary aldosteronismThe most common form of endocrine hypertension. It has been estimated to affect 5 percent to 10 percent of all patients with hypertension and is often underdiagnosed. Excessive aldosterone production by the adrenal glands leads to fluid retention, loss of potassium and hypertension. Eventually, hyperaldosteronism may cause enlargement of the heart (left ventricular hypertrophy). The two most common forms of primary aldosteronism are Conn’s syndrome whereby a single adrenal tumor produces excessive aldosterone versus bilateral adrenal hyperplasia, in which both adrenal glands are enlarged and cause hyperaldosteronism. Blood tests, including an aldosterone, plasma renin activity (PRA) and electrolytes should be ordered first. Further urine or blood testing should be done to confirm the diagnosis. A CT scan of the adrenal glands is then completed. In some cases, adrenal vein sampling may be necessary to help differentiate the cause of the primary aldosteronism. Conn’s syndrome can potentially be cured by surgical removal of the affected adrenal tumor. Bilateral adrenal hyperplasia is best treated with medications such as spironolactone or eplerenone.
Cushing’s syndromeA hormonal disorder of excess cortisol production by the adrenal glands. ACTH is the hormone signal from the pituitary gland that stimulates cortisol production by the adrenal glands. Excess cortisol levels lead to Cushing’s syndrome. This can be due to direct adrenal involvement (adrenal Cushing’s) which is independent of ACTH secretion (i.e., ACTH-independent). ACTH-dependent Cushing’s disease is either due to a pituitary tumor (common) or to ectopic ACTH syndrome (uncommon). ACTH-dependent Cushing’s syndrome accounts for about 80 percent of all cases of Cushing’s. People with Cushing’s syndrome often have other endocrine-related disorders including diabetes, obesity, hypertension, kidney stones and osteoporosis. Many patients also suffer from depression. Testing for Cushing’s syndrome includes blood, urine and salivary testing. An MRI of the pituitary or a CT scan of the adrenal glands will then be done. If the patient has ACTH-dependent Cushing’s syndrome, inferior petrosal sinus sampling (IPSS) is often needed to differentiate the pituitary from the ectopic form. Cushing’s syndrome can often be quite challenging to diagnose. Cushing’s syndrome is potentially cured by surgery but can also be treated with certain types of medications. Even after surgical cure, the disease can recur, so careful follow-up of all patients is needed.
PheochromocytomaA syndrome caused by tumors of the adrenal glands. This syndrome is rare but should always be excluded in patients who have adrenal tumors. These tumors produce excessive amounts of adrenaline, noradrenaline or other catecholamines. While symptoms often include sweating, palpitations and headache, patients can also have many other symptoms. Patients with a pheochromocytoma have episodic or sustained hypertension. Some patients present with markedly elevated blood pressure readings known as hypertensive crisis, which is a medical emergency. About 10 percent of these tumors are located outside the adrenal glands (extra-adrenal) in various locations in the body. Extra-adrenal pheochromocytomas are also known as paragangliomas. About 10 percent of the tumors are malignant. Another 10 percent of pheochromocytomas are part of multiple endocrine neoplasia syndromes (MEN syndrome I or II) which are genetic conditions that run in families. MEN syndromes can involve other endocrine organs such as the parathyroid glands, the pituitary, thyroid as well as other organs such as the kidney, pancreas or stomach.
AcromegalyA tumor of the pituitary gland that leads to excess growth hormone (GH) and IGF-1 levels. Symptoms include joint and muscle problems, headache and vision problems. Patients tend to have very large hands, feet and tongue, and a prominent jaw. They can develop hypertension and diabetes as well.
Severe untreated hyperthyroidism or hypothyroidismThese disorders, if severe enough, can be associated with elevated blood pressure. Treatment of the thyroid disorder usually lowers the blood pressure to normal.
Other types of endocrine hypertension:
- Primary adrenal hyperplasia — a subtype of primary aldosteronism. Surgery may cure this disorder.
- Glucocorticoid remediable aldosteronism (GRA) — a rare form of primary aldosteronism caused by a genetic mutation; it occurs in many family members.
- Familial hyperaldosteronism — rare form of primary aldosteronism in which about half of each generation develops hyperaldosteronism.
- Pseudohypoaldosteronism type 2 (Gordon’s syndrome) — patients develop hypertension and have high potassium levels (hyperkalemia).
- Liddle’s syndrome — another rare genetic form of hypertension in which patients have very low levels of aldosterone (pseudoaldosteronism)
- Apparent mineralocorticoid excess (AME) — another rare genetic form of hypertension.
- Licorice ingestion — pseudoaldosteronism due to ingestion of certain types of licorice (usually black licorice). This leads to high blood pressure and low potassium levels.
Other syndromes of low potassium (hypokalemia) without associated hypertension:
- Bartter’s syndrome — detected in infancy or childhood with symptoms of severe hypokalemia and other birth defects.
- Gitelman’s syndrome — a milder form of hypokalemia that occurs in young adults. Patients usually have low magnesium levels as well. These patients do not have hypertension.
Last Review Date: August 31, 2009