title: Blood pressure usually considered normal is associated with an elevated risk of cardiovascular disease.
abstract: OBJECTIVE
  Research on the risk of cardiovascular disease among individuals with prehypertension (blood pressure 120/80 to 139/89 mm Hg) is incomplete. Additional information among individuals with a high risk of cardiovascular disease complications may help to focus current and future efforts.
  
  
  METHODS
  We performed a prospective cohort analysis among 8960 middle-aged adults in the Atherosclerosis Risk in Communities (ARIC) study. The exposure variables were blood pressure levels: high normal blood pressure, systolic blood pressure 130-139 mm Hg or diastolic blood pressure 85-89 mm Hg; and normal blood pressure, systolic blood pressure 120-129 mm Hg or diastolic blood pressure 80-84 mm Hg. The outcome was incident cardiovascular disease defined as fatal/nonfatal coronary heart disease, cardiac procedure, silent myocardial infarction, or ischemic stroke. Subgroup analysis was performed among blacks, diabetics, individuals aged 55-64 years, individuals with renal insufficiency, and among individuals with varying levels of low-density lipoprotein (LDL) cholesterol and body mass index (BMI).
  
  
  RESULTS
  Compared with optimal blood pressure (systolic blood pressure <120 mm Hg and diastolic blood pressure <80 mm Hg), the relative risk (RR) of cardiovascular disease for high normal blood pressure was 2.33 (95% confidence interval [CI], 1.85-2.92), and RR for normal blood pressure was 1.81 (1.47-2.22); among blacks: RR for high normal blood pressure was 3.29 (95% CI, 1.68-6.45); among diabetics: RR for high normal blood pressure 4.10 (95% CI, 2.26-7.46); age 55-64 years: RR for high normal blood pressure 2.41 (95% CI, 1.75-3.30) among individuals with renal insufficiency: RR for high normal blood pressure was 1.90 (95% CI, 1.34-2.70); among individuals with BMI >30 kg/m2: RR for high normal blood pressure was 3.56 (95% CI, 1.99-6.35); and among individuals with LDL >160 mg/dL, RR for high normal blood pressure was 1.85 (95% CI, 1.26-2.72).
  
  
  CONCLUSIONS
  Individuals with prehypertensive levels of blood pressure have an increased risk of developing cardiovascular disease relative to those with optimal levels. The association is pronounced among blacks, among individuals with diabetes mellitus, and among those with high BMI.
authors.affiliation: UNC Kidney Center, School of Medicine, University of North Carolina at Chapel Hill, USA. sagar@med.unc.edu
authors.forename: Abhijit V
authors.initials: AV
authors.lastname: Kshirsagar
authors.forename: Myra
authors.initials: M
authors.lastname: Carpenter
authors.forename: Heejung
authors.initials: H
authors.lastname: Bang
authors.forename: Sharon B
authors.initials: SB
authors.lastname: Wyatt
authors.forename: Romulo E
authors.initials: RE
authors.lastname: Colindres
mesh_terms: D001794:Blood Pressure; D002318:Cardiovascular Diseases / Q000209:etiology / Q000503:physiopathology*; D015331:Cohort Studies; D003327:Coronary Disease / Q000209:etiology / Q000503:physiopathology; D048909:Diabetes Complications; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012016:Reference Values; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000503:physiopathology