CARDIOVASCULAR JOURNAL OF AFRICA • Volume 34, No 4, September/October 2023 AFRICA 229 compared the biochemical test results and ambulatory blood pressure monitoring parameters through univariate, multivariate and correlation analyses, with cervical–femoral pulse conduction velocity as the assessment index for vascular injury. They found that there was a positive correlation between 24-hour systolic standard deviation and cervical–femoral pulse conduction velocity. In a prospective study on 120 dialysis patients, Wang et al.26 explored the relationship between blood pressure variability and cardiovascular diseases, and confirmed that high 24-hour systolic blood pressure coefficient of variation was an independent influencing factor for cardiovascular death in dialysis patients. In our study, the clinical data were collected and related indices were detected among 730 patients with essential hypertension, followed by salt-sensitivity risk stratification based on 24-hour heart rate. Then the basic data, laboratory indices, ambulatory blood pressure-monitoring parameters and blood pressure variability were compared among groups with different grades of salt-sensitivity risk. The results showed that age, family history of cardiovascular diseases, low-density lipoprotein cholesterol, standard deviation of sequential five-minute normal-to-normal interval, 24-hour heart rate, daytime systolic and diastolic blood pressure, night-time systolic and diastolic blood pressure, 24-hour mean systolic and diastolic blood pressure, daytime systolic and diastolic pressure standard deviation, night-time systolic standard deviation, 24-hour systolic standard deviation, and daytime systolic and diatolic blood pressure coefficient of variation had significant differences among the groups with different grades of salt-sensitivity risk. According to correlation analysis, salt sensitivity was positively correlated with night-time systolic standard deviation, 24-hour systolic standard deviation and 24-hour systolic blood pressure coefficient of variation in patients with essential hypertension. It has been reported27 that patients with salt-sensitive essential hypertension have a higher risk of cardiovascular diseases and death. In the present study, age, family history of cardiovascular diseases, salt-sensitivity risk stratification, low-density lipoprotein cholesterol, standard deviation of sequential fiveminute normal-to-normal interval, 24-hour heart rate, nighttime systolic standard deviation, 24-hour systolic standard deviation and 24-hour systolic blood pressure coefficient of variation were incorporated into the Cox multivariate regression analysis model, so as to analyse the risk of cardiovascular events in patients with essential hypertension. The results manifested that age ≥ 55 years, family history of cardiovascular diseases, a high risk of salt sensitivity, night-time systolic standard deviation ≥ 14 mmHg, 24-hour systolic standard deviation ≥ 20 mmHg and 24-hour systolic blood pressure coefficient of variation ≥ 13.5% were risk factors for cardiovascular events. According to the ROC curve analysis of the above factors in predicting the risk of cardiovascular events in patients with essential hypertension, the area under the curve was 0.837, suggesting a good predictive effect. However, this study has limitations. The correlation between salt sensitivity and blood pressure variability in essential hypertension patients and its predictive value for hypertension complicated with cardiovascular events were only preliminarily analysed. Besides, the effects of dietary habits, body weight or metabolism of the included patients were not considered. Hence, the results may be biased. 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