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Changes in blood pressure and cardiovascular disease in middle-aged to older Chinese: the Guangzhou Biobank Cohort Study

Background: Most studies on the associations of blood pressure (BP) with cardiovascular disease (CVD) risk were based on single or average BP levels. Knowledge on the association between BP trajectories and CVD in middle-aged individuals who are not on antihypertensive medication may inform the care of individuals in this group whose BPs are not controlled. Methods: Eight thousand nine hundred and sixty-nine participants aged 50–70 years, without CVD at baseline and not taking antihypertensive medication throughout the study, were included. Four time-points data from the Guangzhou Biobank Cohort Study were used to identify BP trajectories using latent class mixed model. Cox regression was used to investigate the association of BP trajectories with fatal and nonfatal CVD till April 2021. Results: Three SBP trajectories were identified: ‘low-slow-increase’ characterized by SBP from 110 to 125 mmHg (86.5%); ‘low-increase’ from 110 to 150 mmHg (8.1%) and ‘moderate-increase’ from 125 to 155 mmHg (5.4%). Compared with the low-slow-increase group, the moderate-increase had the highest risk of CVD (hazard ratio = 1.76, 95% confidence interval = 1.34–2.29), ischemic heart disease (1.77, 1.01–3.09), myocardial infarction (3.52, 1.58–7.85), all strokes (1.88, 1.37–2.60), ischemic stroke (1.65, 1.10–2.49), haemorrhagic stroke (3.98, 1.30–12.12) and CVD mortality (2.41, 1.55–3.76). Higher risks of CVD (1.27, 1.01–1.61) and ischemic stroke (1.49, 1.07–2.09) in the low-increase group were also found. Conclusion: Most people between 50 and 70 years of age and not taking antihypertensive medication maintained a slow increase SBP trajectory over a follow-up period of approximately 7 years. However, those whose SBPs increased from low and moderate levels were associated with higher CVD risks.