Within-Visit Blood Pressure Variability in an Unselected Adult Population

Abstract

Abstract Background To investigate blood pressure variability among 3 successive blood pressure measurements in an unselected nationwide population in China. Methods A total of 77,549 participants were included from measurements in May 2017 in China. Blood pressure was measured 3 times consecutively with a half minute interval. Blood pressure variability was estimated with the standard deviation and coefficient of variation of the systolic and diastolic blood pressure. Results Not all participants showed a decreasing trend with increasing number of measurements. In fact, 14% of the participants showed at least 5 mm Hg increase in systolic blood pressure. The coefficient of variation of systolic and diastolic blood pressure in women was higher than in men [(4.2 ± 3.3)% vs. (4.1 ± 3.3)%, (4.7 ± 4.0)% vs. (4.6 ± 4.1)%; P < 0.05]. The differences were significant (P < 0.01) among different groups of age and blood pressure levels. Multiple linear regression analysis showed that the systolic blood pressure variability indexes were inversely associated with age but positively associated with the level of the first systolic blood pressure reading (P < 0.01). The systolic blood pressure standard deviation and coefficient of variation in females were higher than in males (P < 0.01). Conclusions Not all subjects demonstrate a decreasing trend with increasing number of blood pressure measurements. Within-visit blood pressure variability varies with age, gender, and blood pressure.