Many studies have indicated that aldosterone-renin ratio (ARR) is closely related to the development of hypertension and the occurrence of cardiovascular events. The purpose of this study is to assess correlations between ARR and nighttime blood pressure, as well as the correlations between ARR and target organ damage in essential hypertension.Design and method:
237 patients with essential hypertension were investigated. They were classified into three groups according to tertiles of ARR: group 1: ARR<58, n = 79; group 2: 58 ≤ ARR < 126, n = 79; group 3: ARR ≥ 126, n = 79. Blood and urine samples were collected for the measurement of fasting blood-glucose (FBG), hemoglobin A1c (HbA1c), cystatinC (CysC), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterin (LDL-C), high density lipoprotein cholesterin (HDL-C), potassium ion, sodium ion, brain natriuretic peptide (BNP), hypersensitive C-reactive protein (hsCRP), resting and standing aldosterone (ALD) and angiotensin I (AngI), urinary albumin to creatinine ratio (UACR). All the patients underwent ambulatory blood pressure monitoring, echocardiography and arterial wave detection, and their blood pressure, left ventricular mass index (LVMI), brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI) were recorded.Results:
HsCRP, ABI, BNP, LVMI, nighttime systolic pressure and diastolic pressure (nSBP and nDBP) were significantly higher in the group with higher ARR (P < 0.01, P < 0.05, P < 0.01, P = 0.01, P < 0.01, P < 0.05), and nocturnal blood pressure decline was significantly reduced in the group with higher ARR (P < 0.01). Bivariate correlation analysis indicated that ABI, BNP, LVMI, nSBP were positively correlated with ARR (P < 0.05, P < 0.01, P < 0.01, P < 0.01; r = 0.161, r = 0.270, r = 0.190, r = 0.225); nSBP and nDBP decline were negatively correlated with ARR (P < 0.01; r = −0.360, r = −0.285), and multivariate logistic regression analysis found that ARR was an independent risk factor of nSBP and nDBP decline in essential hypertension.Conclusions:
1. In essential hypertension, those with higher ARR had higher nSBP and nDBP, and characterized by loss of circadian rhythms. 2. ARR was an independent risk factor of nSBP and nDBP decline in essential hypertension. 3. The elevation of ARR was correlated with target organ damage in essential hypertension.