It is well known that blood pressure (BP) in the prehypertensive range, defined by the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) as a systolic BP (SBP) of 120–139mm Hg and/or a diastolic BP (DBP) of 80–89mm Hg, is associated with the future development of frank hypertension (HTN).1–5 But what is less well understood are the cardiovascular risks conferred by prehypertension, before frank HTN is manifest. It remains controversial whether prehypertension alone or higher BP within the prehypertensive range is independently associated with coronary heart disease (CHD) risk or whether any observed increased risk is the result of associated risk factors. In 1 report, 64% of prehypertensive subjects had >1 cardiovascular disease (CVD) risk factor.6 Several studies have reported on the CHD risk of prehypertension. Manious et al. analyzed participants in the first National Health and Nutrition Examination Survey (1971–1975) and ascertained major CVD events over the next 18 years.7 They divided prehypertension into categories, “low prehypertension” (120–129/80–84mm Hg) and “high prehypertension” (130–139/80–89mm Hg), and found that unadjusted analysis demonstrated risk for both groups but adjustment attenuated the statistical significance of the risk in the low prehypertension (unadjusted hazard ratio (HR) = 1.56, 95% confidence interval (CI) = 1.23–1.98; adjusted HR = 1.24, 95% CI = 0.96–1.59) but not in the high prehypertension group (unadjusted HR = 2.12, 95% CI = 1.64–2.76; adjusted HR = 1.42, 95% CI = 1.09–1.84).7 In the Framingham Heart Study, BP levels of 130–139/85–89mm Hg were associated with twice the risk of CVD compared with BP levels
