High Prevalence Of Primary Aldosteronism Research Articles

Primary aldosteronism and hypertensive disease.

Recent studies in hypertensive populations that have used the serum aldosterone (SA) to plasma renin activity (PRA) ratio as a screening test have demonstrated a high prevalence of primary aldosteronism (PA). This frequency is higher than that previously described when hypokalemia was used as a screening tool. However, other factors, such as the characteristics of hypertensive disease, could also influence the prevalence of PA. We studied 609 essential hypertensive patients, classified according to the Joint National Committee VI (JNC VI), in 3 different stages depending on the severity of their hypertensive disease. We measured SA and PRA and calculated the SA-PRA ratio for all patients. An SA-PRA ratio >25 was detected in 63 of 609 patients, and the fludrocortisone test confirmed the PA diagnoses in 37 of 609 (6.1%) cases. PA prevalence according to hypertension stage was as follows: stage 1, 6 of 301 cases (1.99%); stage 2, 15 of 187 cases (8.02%); and stage 3, 16 of 121 cases (13.2%). PA patients were slightly younger than the other hypertensive patients (48.4+/-10.5 vs 53.6+/-10.2 years; P<0.05). Serum potassium levels were normal in 36 of 37 PA patients; only 1 patient had minor hypokalemia. Computed tomography scans showed bilateral adrenal enlargement in 7 and an adrenal nodule in 2 cases. In summary, we found a high frequency of PA in essential hypertensives classified in stages 2 and 3 according to the JNC VI. The low frequency of computed tomography scan abnormalities and hypokalemia suggests that the diagnosis for most PA patients corresponds to attenuated forms of the disease.

High prevalence of primary aldosteronism using postcaptopril plasma aldosterone to renin ratio as a screening test among Italian hypertensives

The prevalence of primary aldosteronism (PA) was assessed in a specialized hypertension center. Baseline and postcaptopril (50 mg orally) aldosterone to plasma renin activity ratio (A/R) as a screening tool were preliminarily tested in a sample including 22 patients with histories of PA and 53 patients with low-renin essential hypertension (EH). Sensitivity and specificity of A/R ≥35 were 95.4% and 28.3% at baseline, compared with 100% and 67.9% after captopril. Using postcaptopril A/R ≥35 and confirmation by acute saline loading, a PA prevalence of 6.3% was found among 1046 consecutive hypertensive patients with normal renal function. Of those 66 PA patients, 16 (24.2%) had a unilateral adenoma, whereas 50 (75.8%) had idiopathic hyperaldosteronism. At presentation, 45.4% of the PA and 16.3% of EH patients were treated with two or more antihypertensive drugs (χ 2 = 33.117, P < .0001). However, among untreated patients ( n = 553), the prevalence of mild-to-moderate hypertension (ie, <180/110 mm Hg) was not different between patients with PA and those with EH (70.6% v 76.7%, χ 2 = 0.086, P = .770). Serum potassium ≥3.6 mEq/L was found in 60.6% of PA patients. In conclusion, we observed the following: 1) postcaptopril compared with baseline A/R is a better screening tool for PA; 2) PA is relatively frequent among hypertensive individuals; 3) PA is not necessarily associated with severe hypertension; and 4) hypokalemia is an insensitive screening criterion for PA.

High prevalence of primary aldosteronism among black and white subjects with resistant hypertension

High prevalence of primary aldosteronism among black and white subjects with resistant hypertension

High prevalence of primary aldosteronism in the Tayside hypertension clinic population.

Primary aldosteronism (PA) was thought to be rare but recent evidence from Australia suggests that it may be more common. As this has important implications in terms of hypertension management, we undertook to screen for this treatable condition in our hypertension clinic. We obtained blood samples in sequential patients referred for assessment in our hypertension clinic in Tayside for plasma renin activity (PRA) and aldosterone. The aldosterone to PRA ratio (ARR) was used as an initial screening test to identify potential patients with PA. Those patients with an elevated ratio (> or =750) were admitted for the salt loading and fludrocortisone suppression test. These patients also underwent adrenal CT scanning, and in selected patients, adrenal scintigraphy. Between May 1995 and January 1997 (21 months), we screened a total of 495 patients. ARR was available in 465 (93.9%) patients. Out of that number, 77 (16. 6%) had an elevated ratio of > or =750, five of whom had an adrenal adenoma (one had previous adrenalectomy). Forty-five of these patients were admitted for the salt loading and fludrocortisone suppression test with 41 positive test results suggesting PA. One patient with a negative salt loading test result however had an adenoma proven on histology. A total of 43 cases of PA were identified, giving a minimum prevalence of 9.2% (43/465). Potentially the prevalence may be up to 15% assuming that the ARR has a sensitivity of 93% (42/45) in predicting PA. In conclusion, about one in 10 patients attending a hypertension clinic may have PA. This suggests that the prevalence of PA in Tayside is as high as that in the Australian hypertensive population, and this is likely to be true elsewhere, with obvious important implications for hypertension management.

Potentially high prevalence of primary aldosteronism in a general practice population in Tayside, Scotland.

Potentially high prevalence of primary aldosteronism in a general practice population in Tayside, Scotland.

Potentially high prevalence of primary aldosteronism in a primary-care population

Primary aldosteronism as a cause of secondary hypertension is suggested to have a prevalence of 15%. 1 Gordon RD Stowasser M Tunny TJ Klemm SA Rutherford JC High incidence of primary aldosteronism in 199 patients referred with hypertension. Clin Exp Pharmacol Physiol. 1994; 21: 315-318 Crossref PubMed Scopus (440) Google Scholar , 2 Anis Anwar Y White WB Mansoor GA Tendler BE Hyperaldosteronism is a common cause of secondary hypertension missed by primary care physicians and associated with normokalaemia. Am J Hypertens. 1998; 11: 199A Crossref Google Scholar , 3 Lim PO Brennan G Shiels P et al. Unexpectedly high prevalence of primary aldosteronism in a hypertensive population in Dundee. British Endocrine Society, Edinburgh1998 Google Scholar These studies have, however, been done in specialist or regional hypertension units that see more patients with resistant hypertension than in primary-care centres. Our centre reported that 16·6% (77 of 495) of patients referred to our hypertension clinic between May, 1995, and January, 1997, had raised ambulant ratio of aldosterone (pmol/L) to renin (ng mL−1 hr−1) of 750 or more. 3 Lim PO Brennan G Shiels P et al. Unexpectedly high prevalence of primary aldosteronism in a hypertensive population in Dundee. British Endocrine Society, Edinburgh1998 Google Scholar Salt loading and fludrocortisone suppression tests confirmed primary aldosteronism in 40 (93%) of 43 patients who were investigated further. A raised aldosterone/renin ratio was, therefore, predictive of primary aldosteronism. We investigated whether the high prevalence of primary aldosteronism was also true in primary-care populations. We screened hypertensive patients in one primary-care population. We obtained approval for the study of the Tayside committee on research medical ethics.