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 > or =35 were 95.4% and 28.3% at baseline, compared with 100% and 67.9% after captopril. Using postcaptopril A/R > or =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 (chi(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%, chi(2) = 0.086, P =.770). Serum potassium > or =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.
Rossi
Ermanno
E
Second Unit of Internal Medicine, Department of Medicine, Santa Maria Nuova Hospital, Reggio Emilia, Italy. rossi.ermanno@asmn.re.it
Regolisti
Giuseppe
G
Negro
Aurelio
A
Sani
Carlo
C
Davoli
Simona
S
Perazzoli
Franco
F
D000328:Adult; D000450:Aldosterone / Q000097:blood*; D000806:Angiotensin-Converting Enzyme Inhibitors; D002216:Captopril; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D006973:Hypertension / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D007558:Italy; D007668:Kidney / Q000502:physiology; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D015995:Prevalence; D012017:Referral and Consultation; D012083:Renin / Q000097:blood*; D012680:Sensitivity and Specificity
D000806:Angiotensin-Converting Enzyme Inhibitors; D000450:Aldosterone; D002216:Captopril; D012083:Renin