Within-patient reproducibility of the aldosterone: renin ratio in primary aldosteronism.
The plasma aldosterone concentration:renin ratio (ARR) is widely used for the screening of primary aldosteronism, but its reproducibility is unknown. We, therefore, investigated the within-patient reproducibility of the ARR in a prospective multicenter study of consecutive hypertensive patients referred to specialized centers for hypertension in Italy. After the patients were carefully prepared from the pharmacological standpoint, the ARR was determined at baseline in 1136 patients and repeated after, on average, 4 weeks in the patients who had initially an ARR > or =40 and in 1 of every 4 of those with an ARR <40. The reproducibility of the ARR was assessed with Passing and Bablok and Deming regression, coefficient of reproducibility, and Bland-Altman and Mountain plots. Within-patient ARR comparison was available in 268 patients, of whom 49 had an aldosterone-producing adenoma, on the basis of the "4-corner criteria." The ARR showed a highly significant within-patient correlation (r=0.69; P<0.0001) and reproducibility. Bland-Altman plot showed no proportional, magnitude-related, or absolute systematic error between the ARR; moreover, only 7% of the values, for example, slightly more than what could be expected by chance, fell out of the 95% CI for the between-test difference. The accuracy of each ARR for pinpointing aldosterone-producing adenoma patients was approximately 80%. Thus, although it was performed under different conditions in a multicenter study, the ARR showed a good within-patient reproducibility. Hence, contrary to previously claimed poor reproducibility of the ARR, these data support its use for the screening of primary aldosteronism.
Rossi
Gian Paolo
GP
DMCS-Internal Medicine 4, University Hospital, Via Giustiniani 2, 35126 Padova, Italy. gianpaolo.rossi@unipd.it
Seccia
Teresa Maria
TM
Palumbo
Gaetana
G
Belfiore
Anna
A
Bernini
Giampaolo
G
Caridi
Graziella
G
Desideri
Giovambattista
G
Fabris
Bruno
B
Ferri
Claudio
C
Giacchetti
Gilberta
G
Letizia
Claudio
C
Maccario
Mauro
M
Mallamaci
Francesca
F
Mannelli
Massimo
M
Patalano
Anna
A
Rizzoni
Damiano
D
Rossi
Ermanno
E
Pessina
Achille Cesare
AC
Mantero
Franco
F
D000236:Adenoma / Q000097:blood / Q000175:diagnosis; D000310:Adrenal Gland Neoplasms / Q000097:blood / Q000175:diagnosis; D000450:Aldosterone / Q000097:blood*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000097:blood* / Q000150:complications / Q000175:diagnosis*; D006973:Hypertension / Q000150:complications; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012083:Renin / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000450:Aldosterone; D012083:Renin; D011188:Potassium