BACKGROUND 　Prehypertension is considered a precursor of stage 1 hypertension and a predictor of excessive cardiovascular risk. We investigated whether pharmacologic treatment of prehypertension prevents or postpones stage 1 hypertension.

METHODS 　Participants with repeated measurements of systolic pressure of 130 to 139 mm Hg or lower and diastolic pressure of 85 to 89 mm Hg ,were randomly assigned to receive two years of candesartan (Atacant ,As traZeneca )or placebo, followed by two years of placebo for all.When a participant reached the study end point of stage 1 hypertension, treatment with antihypertensive agents was initiated. Both the candsartan group and the placebo group were instructed to make changes in lifestyle to reduce blood pressure throughout the trial.

RESULTS　 A total of 409 participants were randomly assigned to candesartan, and 400 to placebo.Data on 772 participants (391 in the candesartan group ;mean age 48.5 years ;59.6 percent men) were available for analysis. During the first two yeaars ,hypertension developed in 154 participants in the placebo group and 53 of those in the candesartan group (relative risk reduction, 66.3 percent; P<0.001). After four years ,hypertension had developed in 240 participants in the placebo group and 208 of those in the candesartan group (relative risk reduction,15.6 percent; P<0.007). Serious adverse events occurred in 3.5 percent of the participants assigned to candesartan and participants assigned to candesartan and 5.9 percent of those receiving placebo.

CONCLUSIONS　 Over a period of four years stage 1 hypertension develooped in nearly two thirds of patients eith untreated prehypertension (the placebo group). Treatment of prehypertension with candesartan appeared to be well tolerated and reduced the risk of incident hypertension during the study period .Thus ,treatment of prehypertension appears to be feasible.

(N Engl J Med 2006;354: 1685-97. April 20,2006