The Endocrine Society has issued a scientific statement on screening for endocrine causes of hypertension. It reviews the different forms of endocrine hypertension with a focus on prevalence, clinical presentation, and guidance on when to perform case-detection testing, and currently available case detection tests. Among the topics covered and recommendations:
- Pheochromocytomas are rare and should not be screened for unless there are symptoms. The classic triad of symptoms includes pounding headache, profuse sweating, and palpitations occurring in spells that last from several minutes to 1 hour.
- Primary aldosteronism (PA) is a disorder that clinicians should consider in most patients with hypertension, and should consider PA screening in patients with hypertension.
- Nonaldosterone-mediated mineralocorticoid excess causes such as congenital adrenal hyperplasia can be considered in the right settings, particularly children with high blood pressure.
- Renovascular hypertension can cause secondary aldosteronism.
- Other causes include Cushing’s syndrome, hyperthyroidism and hypothyroidism, hyperkalemia with hyperparathyroidism, acromegaly, and obstructive sleep apnea.
Young Jr. WF, Calhoun DA, Lenders JWM, Stowasser M, Textor SC. Screening for endocrine hypertension: An Endocrine Society scientific statement. Endocr Rev. 2017;38(2):103-122. doi:10.1210/er.2017-00054.
Of the endocrine causes of hypertension, primary hyperaldosteronism (PA) is by far the most common, with a prevalence of occurrence in 5-10% of hypertensive patients. Classically thought to present with hypokalemia, only about a quarter of patients with PA actually have hypokalemia. It is important to make a specific diagnosis, as treatment with aldosterone antagonists, most often spironolactone, provides excellent control of BP. When that alone is not sufficient, surgery of identified adrenal adenomas is sometimes indicated. The recommended screening test is the aldosterone/renin ratio (ARR) because ARR is elevated before either aldosterone is elevated or hypokalemia develops. Diuretics, dihydropyridine calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors, or angiotensin receptor antagonists can cause false-negative ARR. Beta-adrenergic blockers, alpha-methyldopa, clonidine, and NSAIDs can suppress renin levels and produce false-positive ARRs. For these reasons, diuretics should be held for 4 weeks prior to checking ARR, and other medications that might interfere should be held for 2 weeks, if possible. Renovascular hypertension and intrinsic renal disease are also common secondary causes. Intrinsic renal disease is screened for using a urinalysis. Renal artery duplex ultrasound measurements are the test of choice for renovascular stenosis and have a sensitivity >85% and specificity of 92% for atherosclerotic disease with more than 60% lumen occlusion. In the right circumstances, it is important to think of secondary causes of hypertension and then perform an appropriate evaluation. —Neil Skolnik, MD