Minireview: Primary Aldosteronism—Changing Concepts in Diagnosis and Treatment

Abstract

Primary aldosteronism affects 5-13% of patients with hypertension. Patients with hypertension and hypokalemia and most patients with treatment-resistant hypertension should undergo screening for primary aldosteronism with a plasma aldosterone concentration to plasma renin activity ratio. A high plasma aldosterone concentration to plasma renin activity ratio is a positive screening test result, a finding that warrants confirmatory testing. For those patients that want to pursue a surgical cure, the accurate distinction between the subtypes (unilateral vs. bilateral adrenal disease) of primary aldosteronism is a critical step. The subtype evaluation may require one or more tests, the first of which is imaging the adrenal glands with computed tomography, followed by selective use of adrenal venous sampling. Because of the deleterious cardiovascular effects of aldosterone, normalization of circulating aldosterone or aldosterone receptor blockade should be part of the management plan for all patients with primary aldosteronism. Unilateral laparoscopic adrenalectomy is an excellent treatment option for patients with unilateral aldosterone-producing adenoma. Bilateral idiopathic hyperaldosteronism should be treated medically. In addition, aldosterone-producing adenoma patients may be treated medically if the medical treatment includes mineralocorticoid receptor blockade.

Feline primary hyperaldosteronism: an emerging endocrine disease

“…In contrast to what is observed in humans, in which the primary bilateral idiopathic hyperaldosteronism (60-65% of cases), and aldosterone secretory adenoma (30-35% of cases) represent the majority of cases (YOUNG, 2003;YOUNG, 2007), in cats, hyperaldosteronism is mostly attributed to adenomas or adenocarcinomas of adrenal glands (DJAJADININGRAT-LAANEN et al, 2011). Of 25 cases in cats with histopathological confirmation described in the literature, 13 were related to carcinoma, seven to unilateral adenomas, two to bilateral adenomas and three to bilateral hyperplasia (DJAJADININGRAT-LAANEN et al, 2011).…”

“…Young (2003) reported adrenocortical cancer as part of a recognized syndrome in humans, known as multiple endocrine neoplasia (MEN), in which, in the presence of autosomal dominance, the patient develops tumors in endocrine organs, especially pancreas, thyroid, and pituitary. In another case reported the cat presented adrenal adenoma, insulinoma and parathyroid adenoma (REIMER et al, 2005).…”

Relationships of Plasma Renin Levels with Renal Function in Patients with Primary Aldosteronism

“…An elevated plasma aldosterone-to-plasma renin ratio is an indicator of autonomous aldosterone secretion and is widely used as a screening test for primary aldosteronism (2,4,5). Our results indicate that some patients with primary aldosteronism might differ in some respects from the majority of patients with this endocrine disorder, inasmuch as development of intrarenal vascular damage, occurring as a complication of severe hypertension, may lead to a reversal of renin suppression, a condition that may veil the typical hormonal characteristics of this clinical condition.…”

“…Such increased frequency, which may exceed 10% (1,2), may be the result of a more efficient identification of this endocrine disorder in which excess aldosterone secretion causes hypertension, hypokalemia, and suppression of renin secretion (3). High plasma or urinary aldosterone and low plasma renin concentrations are the typical hormonal findings that lead to a diagnosis of primary aldosteronism, and the aldosterone-to-renin ratio has come to widespread use as a screening diagnostic test (4,5).…”

Prevalence of Primary Aldosteronism among Unselected Hypertensive Patients: A Prospective Study Based on the Use of an Aldosterone/Renin Ratio above 25 as a Screening Test

“…An increased ratio is believed to identify individuals who have an increased ALD for the measured renin, with or without low renin. The ARR has been advocated as a convenient and effective method to screen for PA, with some limitations concerning a possible reduction of its accuracy by various antihypertensive drugs, posture changes, time of day, potassium levels and renal insufficiency (7)(8)(9). An elevated ARR is not diagnostic by itself and PA must be confirmed by other tests, such as a saline infusion test, fludrocortisone suppression test, captopril test and oral salt loading test, which are able to demonstrate an inappropriate autonomous ALD production (8,(10)(11)(12)(13)(14).…”