Objective: To observe the impact of systolic blood pressure (SBP) on visit-to-visit blood pressure variability (BPV) in middle-aged and elderly people.
Methods: Visit-to-visit BPV was determined in 5440 workers in the Kailuan study cohort from 2006 to 2007. The subjects were ≥ 40 years-old and had no history of stroke, transient ischemic attack or myocardial infarction. Participants were divided into five groups according to different levels of SBP. Linear regression was used to analyze the related factors which might affect BPV.
Results: Mean systolic BPV of all subjects was 10.35 mm Hg [coefficient of variation (CV 7.96%)]. The mean systolic BPV of males was 10.54 mm Hg (CV 7.90%) while the mean SBPV of females was 10.06 mm Hg (CV 7.90%). The BPV of males was significant higher than that of females (P < 0.001). CV of SBP was similar between males and females. Furthermore, higher SBP was associated with higher BPV. There were significant differences in BPV between different groups with different levels of SBP (P < 0.001). Linear regression analysis demonstrated that SBP, age, gender, high-sensitivity C-reactive protein (hsCRP) were affecting factors of BPV. Twenty mm Hg SBP increase was linked with 2.02 mm Hg BPV increase and 0.388%CV increase. Age increase of 1 year was associated with 0.044 mm Hg BPV increase and 0.029% CV increase.
Conclusion: SBP, age, gender and hsCRP are important factors affecting BPV in middle-aged and elderly people. Higher SBP is closely related to greater BPV in this cohort.