title: Prehypertension and the risk of stroke: a meta-analysis.
abstract: OBJECTIVE
  In this meta-analysis, we sought to evaluate the association between prehypertension and the risk of stroke.
  
  
  METHODS
  We searched PubMed and EMBASE databases for studies with data on prehypertension and stroke. Two independent reviewers assessed the reports and extracted data. Prospective studies were included if they reported multivariate-adjusted relative risks (RRs) with 95% confidence intervals (CIs) for the associations between stroke and prehypertension or its 2 subranges (low-range prehypertension: 120-129/80-84 mm Hg; high-range prehypertension: 130-139/85-89 mm Hg). We conducted subgroup analyses according to blood pressure ranges, stroke type, endpoint, age, sex, ethnicity, and study characteristics.
  
  
  RESULTS
  Pooled data included the results of 762,393 participants from 19 prospective cohort studies. Prehypertension increased the risk of stroke (RR 1.66; 95% CI 1.51-1.81) compared with optimal blood pressure (<120/80 mm Hg). In the secondary outcome analyses, even low-range prehypertension increased the risk of stroke (RR 1.44; 95% CI 1.27-1.63), and the risk was greater for high-range prehypertension (RR 1.95; 95% CI 1.73-2.21). The RR was higher with high-range than with low-range prehypertension (p < 0.001). There were no significant differences in any of the subgroup analyses (all p > 0.05).
  
  
  CONCLUSIONS
  After adjusting for multiple cardiovascular risk factors, prehypertension is associated with stroke morbidity. Although the increased risk is largely driven by high-range prehypertension, the risk is also increased in people with low-range prehypertension.
authors.affiliation: From the Department of Cardiology (Y.H., Y.L., L.S., S.W., D.X.), Nanfang Hospital, Southern Medical University, Guangzhou; Clinical Medicine Research Institute (X.C., Y.H., Y.W.), The First People's Hospital of Shunde, Foshan; and Department of Cardiology (W.M.), The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Yuli
authors.initials: Y
authors.lastname: Huang
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Cai
authors.forename: Yingying
authors.initials: Y
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: Su
authors.forename: Weiyi
authors.initials: W
authors.lastname: Mai
authors.forename: Sheng
authors.initials: S
authors.lastname: Wang
authors.forename: Yunzhao
authors.initials: Y
authors.lastname: Hu
authors.forename: Yanxian
authors.initials: Y
authors.lastname: Wu
authors.forename: Dingli
authors.initials: D
authors.lastname: Xu
mesh_terms: D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination / Q000379:methods; D006801:Humans; D058246:Prehypertension / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*