Quick Reference Guide Endocrine Hypertension 2 2016 Version
Quick Reference Guide Endocrine Hypertension 2 2016 Version
Quick Reference Guide Endocrine Hypertension 2 2016 Version
Endocrine Hypertension
Version: SN/2-10-2016
Endocrine Hypertension accounts for about 3% of the secondary forms of hypertension and is a term
assigned to states in which hormonal derangements result in clinically significant hypertension. The most
common causes of endocrine hypertension are
1. primary hyperaldosteronism,
2. pheochromocytoma, and
3. Cushing’s syndrome.
Hypertension in young patients and refractory hypertension should alert the physician to screen for
secondary causes. The first step when evaluating a patient with suspected endocrine-related hypertension
is to exclude other causes of secondary hypertension.
• The screening test of choice is “plasma aldosterone to renin ratio or PAC/PRA ratio”.
• Protocol: (please refer to “up-to-date” under the session of "Approach to the patient with hypertension and hypokalemia" for detail)
Spironolactone and eplerenone should not be initiated until the evaluation is completed
since these can cause an elevation in PRA. The patients already receiving spironolactone,
therapy should be discontinued for at least six weeks. Other potassium-sparing diuretics,
such as amiloride and triamterene, usually do not interfere with testing unless the patient is
on high doses.
Pheochromocytoma is estimated to occur in 2–8 of 1 million persons per year, and ∼0.1% of
hypertensive patients harbor a pheochromocytoma. The mean age at diagnosis is ∼40 years, although
the tumors can occur from early childhood until late in life. The classic “rule of tens” for
pheochromocytomas states that ∼10% are bilateral, 10% are extra-adrenal, and 10% are malignant.
Its clinical presentation is so variable that pheochromocytoma has been termed “the great
masquerader”.
The screening test of choice is “24-hour urine fractionated catecholamines and metanephrines
and/or plasma fractionated metanephrines”.
Table: Biochemical and Imaging Methods Used for Diagnosis of Pheochromocytoma and Paraganglioma
Abbreviations:
MIBG, metaiodobenzylguanidine; PET/CT, positron emission tomography plus CT. For the biochemical tests, the
ratings correspond globally to sensitivity and specificity rates as follows: ++, <85%; +++, 85–
95%; and ++++, >95%.
Von Hippel–Lindau disease. A. Retinal angioma. All subsequent panels show findings on MRI: B–
D. Hemangioblastomas of the cerebellum (B) in brainstem (C) and spinal cord (D). E. Bilateral
pheochromocytomas and bilateral renal clear cell carcinomas F. Multiple pancreatic cysts.
Cushing’s syndrome reflects a constellation of clinical features that result from chronic exposure to
excess glucocorticoids of any etiology. The disorder can be ACTH-dependent (e.g., pituitary
corticotrope adenoma) or ACTH-independent (e.g., adrenocortical adenoma), as well as iatrogenic
(e.g., administration of exogenous glucocorticoids). The term Cushing’s disease refers specifically
to Cushing’s syndrome caused by a pituitary corticotrope adenoma.
Cushing’s syndrome is generally considered a rare disease. It occurs with an incidence of 1–2 per
100,000 population per year. In the overwhelming majority of patients, Cushing’s syndrome is
caused by an ACTH-producing corticotrope adenoma of the pituitary.
Clinical features of Cushing’s syndrome. (From Harrison's Principles of Internal Medicine, 19e)
A. Note central obesity and broad, purple stretch marks (B. close-up). C. Note thin and brittle skin in an elderly patient with
Cushing’s syndrome. D. Hyperpigmentation of the knuckles in a patient with ectopic adrenocorticotropic hormone (ACTH) excess.
>1.8 mcg/dL