Background: Studies of prehypertension and mortality are controversial after adjusting for other cardiovascular risk factors. This meta-analysis sought to evaluate the association of prehypertension with all-cause and cardiovascular disease (CVD) mortality.
Methods: The PubMed, EMBASE, Cochrane Library databases, and conference proceedings were searched for studies with data on prehypertension and mortality. The relative risks (RRs) of all-cause, CVD, coronary heart disease (CHD), and stroke mortality were calculated and presented with 95% CIs. Subgroup analyses were conducted according to blood pressure, age, gender, ethnicity, follow-up duration, participant number, and study characteristics.
Results: Data from 1,129,098 participants were derived from 20 prospective cohort studies. Prehypertension significantly increased the risk of CVD, CHD, and stroke mortality (RR 1.28, 95% CI 1.16-1.40; RR 1.12, 95% CI 1.02-1.23; and RR 1.41, 95% CI 1.28-1.56, respectively), but did not increase the risk of all-cause mortality after multivariate adjustment (RR 1.03, 95% CI 0.97-1.10). The difference between CHD mortality and stroke mortality was significant (P < .001). Subgroup analyses showed that CVD mortality was significantly increased in high-range prehypertension (RR 1.28, 95% CI 1.16-1.41) but not in low-range prehypertension (RR 1.08, 95% CI 0.98-1.18).
Conclusion: Prehypertension is associated with CVD mortality, especially with stroke mortality, but not with all-cause mortality. The risk for CVD mortality is largely driven by high-range prehypertension.