Background: Epidemiological studies reported an inconsistent association between stage 1 hypertension (SBP 130-139 mmHg or DBP 80-89 mmHg) defined by the 2017 American College of Cardiology/American Heart Association hypertension guidelines and cardiovascular disease (CVD) events. In addition, the proportion of CVD events that could be prevented with effective control of stage 1 hypertension is unknown.
Objectives: To assess the association between stage 1 hypertension and CVD events and estimate the population etiologic fraction.
Methods: PubMed, Embase, and Web of Science databases were searched from 1 January 2017 to 22 September 2019. Normal BP was considered SBP less than 120 mmHg and DBP less than 80 mmHg. Hazard ratios and 95% confidence intervals (95% CIs) were pooled by using a random-effects model.
Results: We included 11 articles (16 studies including 3 212 447 participants and 65 945 events) in the analysis. Risk of CVD events was increased with stage 1 hypertension versus normal BP (hazard ratio 1.38, 95% CI 1.28-1.49). On subgroup analyses, stage 1 hypertension was associated with coronary heart disease (CHD) (hazard ratio 1.30, 95% CI 1.20-1.41), stroke (1.39, 1.27-1.52), CVD morbidity (1.42, 1.32-1.53), and CVD mortality (1.34, 1.05-1.71). The population etiologic fraction for the association of CVD events, CHD, stroke, CVD morbidity, and CVD mortality with stage 1 hypertension was 12.90, 10.48, 12.71, 14.03, and 11.69%, respectively.
Conclusion: Stage 1 hypertension is associated with CVD events, CVD morbidity, CVD mortality, CHD, and stroke. Effective control of stage 1 hypertension could prevent more than 10% of CVD events.