[Aldosterone-to-renin ratio threshold for screening primary aldosteronism in Chinese hypertensive patients].
OBJECTIVE
In recent years, the assessment of the plasma aldosterone-to-renin ratio (ARR) has become a most effectively and commonly used method for screening primary aldosteronism from hypertensive patients. It is known that there is a large variance in ARR value between races and ARR is affected by many factors, such as drugs, posture and serum potassium etc. The objective of this study is to establish the threshold of ARR for screening primary aldosteronism in Chinese hypertensive patients.


METHODS
A total of 110 hypertensive patients were recruited and divided into essential hypertension group (n=65) and adenoma/hyperplasia group (n=45) according to the adrenal contrast CT scan. Antihypertensive drugs which can affect ARR such as beta-blockers, dihydropyridine calcium channel blockers (CCBs), ACE inhibitors (ACEIs), angiotensin II receptor blockers (ARBs) and clonidine, were withdrawn for at least 2 weeks. Washout period for diuretics including spironolactone were 4 weeks. Non-dihydropyridine calcium channel blockers (slow released verapamil) and/or alpha-blocker (terazosin) are allowed for controlling blood pressure when needed. If the serum potassium value<3.6 mmol/L, an oral potassium supplement was prescribed. After keeping upright position for 2 hours, blood samples were drawn for PRA and PAC measurement between 9:00AM-10:00AM.


RESULTS
ARR was 100.00+/-48.65 (14.19-285.16) pg/ml vs ngxml-1xh-1 in patients with essential hypertension and 699.33+/-213.33 (185.8-2150) pg/ml vs ngxml-1xh-1 in patients with adenoma/hyperplasia. ARR value was greater than 240 in 42 out of 45 patients (93.3%) with adenoma/hyperplasia and was less than 240 in 59 out of 65 (90.7%) patients with essential hypertension. We used ARR 240 as the cut-off threshold for screening primary aldosteronism in another 178 hypertensive patients and ARR was greater than 240 in all 15 patients with confirmed primary aldosteronism.


CONCLUSIONS
It is suitable to use upright ARR 240 as a cut-off threshold for screening primary aldosteronism in Chinese hypertensive patients.
Chen
Shao-xing
SX
Department of Hypertension, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200025, China.
Du
Yue-ling
YL
Zhang
Jin
J
Gong
Yan-chun
YC
Hu
Ya-rong
YR
Chu
Shao-li
SL
He
Qing-bo
QB
Song
Yan-yan
YY
Zhu
Ding-liang
DL
D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000097:blood*; D002681:China / Q000453:epidemiology; D019963:Clinical Chemistry Tests / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000175:diagnosis* / Q000453:epidemiology; D006973:Hypertension / Q000150:complications* / Q000453:epidemiology; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012016:Reference Values; D012083:Renin / Q000097:blood*; D012084:Renin-Angiotensin System
D000450:Aldosterone; D012083:Renin; D011188:Potassium