Relationship between blood pressure level and activity of renin-aldosterone axis in patients with essential hypertension—a retrospective study

Background A study indicates that elevated aldosterone levels increase the risk of hypertension by 16%. This retrospective cohort study examines the relationship between blood pressure and renin-aldosterone levels in patients with essential hypertension (EH), aiming to elucidate the clinical features and risk factors of inappropriate hyperaldosteronism in Chinese individuals with essential hypertension. Methods Clinical data of 309 EH patients were analyzed. The participants were divided into three groups with a high (H)/medium (M)/low (L) blood pressure level: Group H (BP≥160 / (or) 100 mmHg, n = 151), Group M (BP 140–160/90–100 mmHg, n = 101), Group L (BP < 140/90 mmHg, n = 57). Since the data were all non-normal distributions, they were represented by the median and extreme values, and the Wilcoxon rank sum test was used. Categorical data were analyzed using the χ 2 test. In the one-factor variance analysis, those with P < 0.05 were included in the multivariate analysis, and the multiple linear regression analysis method was used for the multivariate analysis. The study assessed the relationship between the plasma renin activity (PRA), plasma aldosterone concentration (PAC), and the aldosterone/renin activity ratio (ARR) in patients with EH and their blood pressure levels. Results Among the 309 EH patients, 65 cases (21.04%) had elevated aldosterone levels, and 94 cases (30.42%) had increased renin activity. The diastolic blood pressure of patients with elevated aldosterone levels was higher than that of patients with normal or decreased aldosterone levels (100 vs. 95, 87, p < 0.05), while there was no significant difference in systolic blood pressure between patients with elevated aldosterone levels and those with normal or decreased aldosterone levels (152 vs. 151.5, 142, p > 0.05). The proportion of patients with heightened aldosterone levels was greater in Group H compared to the others (23.8% vs. 20.8% and 14.0%, p < 0.05). Multiple linear stepwise regression indicated that higher aldosterone levels correlated with increased diastolic blood pressure. PAC increased by 3.66 ng/dL for every 10 mmHg of DBP. Conclusion The increase in aldosterone levels is relatively common among EH patients in China. The increase in aldosterone levels is correlated with the elevation of diastolic blood pressure. The elevated aldosterone levels are an independent risk factor for the increase in diastolic blood pressure in EH patients.