Rapid Diagnosis of Primary Aldosteronism: Oxymoron or One Small Step?

First, a seat; then, an upgrade

The Sir Stanley Peart Essay Competition is an annual event run by the British and Irish Hypertension Society to encourage Early Career Researchers to continue the ethos of Sir Stanley Peart. Sir Stanley Peart was a clinician and clinical researcher who made a major contribution to our understanding of blood pressure regulation. He was the first to demonstrate the release of noradrenaline in response to sympathetic nerve stimulation. He was also the first to purify, and determine the structure of, angiotensin and he later isolated the enzyme, renin, and carried out many important investigations of the factors controlling its release in the body. This year, the essay topic was "Do we need new classes of antihypertensive drugs?". In his prize-winning essay, "First, a seat; then, an upgrade", Dr Sathyanarayanan argues that we do not need new classes of antihypertensive drugs, instead we should focus our attention on addressing the factors that lead to high blood pressure in the first place and use our existing drug classes more effectively.

Recent Development toward the Next Clinical Practice of Primary Aldosteronism: A Literature Review

For the last seven decades, primary aldosteronism (PA) has been gradually recognized as a leading cause of secondary hypertension harboring increased risks of cardiovascular incidents compared to essential hypertension. Clinically, PA consists of two major subtypes, surgically curable and uncurable phenotypes, determined as unilateral or bilateral PA by adrenal venous sampling. In order to further optimize the treatment, surgery or medications, diagnostic procedures from screening to subtype differentiation is indispensable, while in the general clinical practice, the work-up rate is extremely low even in the patients with refractory hypertension because of the time-consuming and labor-intensive nature of the procedures. Therefore, a novel tool to simplify the diagnostic flow has been recently in enormous demand. In this review, we focus on recent progress in the following clinically important topics of PA: prevalence of PA and its subtypes, newly revealed histopathological classification of aldosterone-producing lesions, novel diagnostic biomarkers and prediction scores. More effective strategy to diagnose PA based on better understanding of its epidemiology and pathology should lead to early detection of PA and could decrease the cardiovascular and renal complications of the patients.

18-Oxocortisol Synthesis in Aldosterone-Producing Adrenocortical Adenoma and Significance of KCNJ5 Mutation Status

Peripheral 18-oxocortisol (18oxoF) level could contribute to the detection of aldosterone-producing adenoma (APA) in patients with primary aldosteronism. However, peripheral 18oxoF varies among such patients, which is a big drawback concerning its clinical application. We studied 48 cases of APA, 35 harboring KCNJ5 mutation, to clarify the significance of clinical and pathological parameters about peripheral 18oxoF. Peripheral 18oxoF concentration ranged widely from 0.50 to 183.13 ng/dL and correlated positively with intratumoral areas stained positively for steroidogenic enzymes ( P<0.0001). The peripheral 18oxoF level also correlated significantly with that of circulating aldosterone ( P<0.0001) but not with that of cortisol, a precursor of 18oxoF. However, a significant correlation was detected between peripheral 18oxoF and intratumoral glucocorticoids ( P<0.05). In addition, peripheral 18oxoF correlated positively with the number of hybrid cells double positive for 11β-hydroxylase and aldosterone synthase ( P<0.0001). Comparing between the cases with and those without KCNJ5 mutation, the KCNJ5-mutated group demonstrated a significantly higher concentration of peripheral 18oxoF (28.4±5.6 versus 3.0±0.9 ng/dL, P<0.0001) and a larger intratumoral environment including the hybrid cells ( P<0.001), possibly representing a deviation from normal aldosterone biosynthesis. After multivariate analysis, KCNJ5 mutation status turned out to be the most associated factor involved in 18oxoF synthesis in APA ( P<0.0001). Results of our present study first revealed that enhanced 18oxoF synthesis in APA could come from a functional deviation of aldosterone biosynthesis from the normal zona glomerulosa and the utility of peripheral 18oxoF measurement could be influenced by the prevalence of KCNJ5 mutation in an APA.

[Two case reports on resistant hypertension]

Primary aldosteronism (PA) is a frequent cause of resistant hypertension. The clinical presentation is heterogeneous, but a suppressed or low normal renin (especially with ACE inhibitors or sartans) should raise suspicion for primary aldosteronism, even when aldosterone levels are in the normal range. Diagnosis of unilateral hormone production from an adrenal adenoma (Conn syndrome), which is curable by surgery, requires adrenal vein sampling, which should be performed in experienced centers.