ArticlesPrevalence of primary hyperaldosteronism in resistant hypertension: a retrospective observational study
Introduction
In the decades after Jerome Conn's initial description of the condition,1 the prevalence of primary hyperaldosteronism—increased aldosterone secretion from the adrenal glands—has remained an unresolved issue.2, 3 Conn himself suggested that as many as 20% of people with hypertension could have this disorder; however, the ability to confirm this theory was hindered by the scarcity of widely available assays for renin and aldosterone determination.
For more than three decades primary hyperaldosteronism was thought to be a rare disease, diagnosed only in academic institutions by interested clinicians; studies of unreferred patients supported a prevalence of around 1%.4, 5, 6, 7 By contrast, several studies published since 1999 suggest that the prevalence of primary hyperaldosteronism is about 10% of the population of patients with hypertension.8, 9, 10, 11, 12, 13
The aldosterone to renin ratio (ARR) can be used as the screening test for primary hyperaldosteronism. However, its use is accompanied by a high percentage of false positive results, especially in patients taking β blockers, mainly due to methodological problems in accurate detection of low renin concentrations. Thus, a confirmatory salt suppression test is needed for an accurate diagnosis. From all available tests, the acute 4-h intravenous saline loading14 and the 4-day fludrocortisone administration15 seem to be the most reliable and offer accurate diagnosis of primary hyperaldosteronism.
Although there is still debate, most researchers agree that resistant hypertension is the condition with the highest probability of primary hyperaldosteronism detection.2, 3, 16, 17 The true prevalence of resistant hypertension is unknown. Although some studies estimated the prevalence as between 2·9% and 13%,18 other observational studies and outcome trials have suggested that up to 30% of patients with hypertension could be resistant to therapy.19
The aim of our study was to contribute the 20-year data of our clinic, reporting the prevalence of primary hyperaldosteronism in a large white population of patients with resistant hypertension.
Section snippets
Methods
We did a retrospective, observational study at the Hypertension Clinic of the Second Propedeutic Department of Internal Medicine, in Thessaloniki, Greece. The study was done in accordance with the principles of the Helsinki declaration and the procedures followed were in accordance with institutional guidelines. The study was approved by the Hospital Ethics Committee and all patients gave written informed consent.
The study included all consecutive patients with resistant hypertension that
Results
Over 20 years, 1616 patients with truly resistant hypertension were studied in our Department. The baseline characteristics of the patients are shown in table 1. Hypokalaemia was detected in 311 (20·5%) patients with resistant hypertension.
A positive test, defined as the combination of a high aldosterone to plasma renin activity ratio (more than 65·16) and serum aldosterone concentrations of more than 416 pmol/L was seen in 338 patients (20·9%)—ie, one in five patients with resistant
Discussion
Although the ARR was positive in about 20% of patients with resistant hypertension, after three confirmatory tests the diagnosis of primary hyperaldosteronism was confirmed only in about half, resulting in a prevalence of 11·3% of the total study population. Thus, only one in ten patients with resistant hypertension was finally diagnosed as having primary hyperaldosteronism. If we take into account that resistant hypertension is seen in 10–30% of people with hypertension19, 22 and primary
References (37)
- et al.
Potentially high prevalence of primary aldosteronism in a primary-care population
Lancet
(1999) - et al.
A prospective study of the prevalence of primary aldosteronism in 1,125 hypertensive patients
J Am Coll Cardiol
(2006) Is primary aldosteronism a benign disorder? Old evidence reconfirmed
Am J Hypertens
(2006)- et al.
Primary aldosteronism—careful investigation is essential and rewarding
Molecular Cellular Endocrinol
(2004) - et al.
Diagnosis of primary aldosteronism: from screening to subtype differentiation
Trends Endocrinol Metab
(2005) - et al.
Treatment of refractory hypertension
Lancet
(1982) - et al.
Screening for primary hyperaldosteronism without discontinuing hypertensive medications: plasma aldosterone-renin ratio
Am J Kidney Dis
(2001) - et al.
Increased arterial wall stiffness in primary aldosteronism in comparison with essential hypertension
Am J Hypertens
(2006) - et al.
Evidence for an increased rate of cardiovascular events in patients with primary aldosteronism
J Am Coll Cardiol
(2005) Presidential address. I. Painting background. II. Primary aldosteronism, a new clinical syndrome
J Lab Clin Med
(1955)
Is there an unrecognized epidemic of primary aldosteronism? (Con)
Hypertension
Is there an unrecognized epidemic of primary aldosteronism? (Pro)
Hypertension
Hypokalemia in the hypertensive patient: with observations on the incidence of primary aldosteronism
Ann Intern Med
Secondary hypertension in a blood pressure clinic
Arch Intern Med
Evaluation of the hypertensive patient with emphasis on detecting curable causes
Melbank Mem Fund Q
The incidence rate of phaeochromocytoma and Conn's syndrome in Denmark, 1977–1981
J Human Hypertens
Increased diagnosis of primary aldosteronism, including surgically correctable forms, in centers from five continents
J Clin Endocrinol Metab
Prevalence of primary hyperaldosteronism in moderate to severe hypertension in the Central Europe region
J Human Hypertens
Cited by (444)
Primary aldosteronism: It's time to become reacquainted with this familiar stranger
2024, Journal of the Formosan Medical AssociationDevelopment of a risk-prediction model for primary aldosteronism in veterans with hypertension
2024, Surgery (United States)MicroRNAs in aldosterone production and action
2024, Vitamins and HormonesApproaching Primary Aldosteronism as a Common Disease
2023, Endocrine PracticeUtility of Carbon Dioxide Venography and Intraprocedural CT for Adrenal Venous Sampling in Patients with an Allergy to Iodinated Contrast Media
2023, Journal of Vascular and Interventional Radiology