ObjectiveThe aim of this study was to examine whether blood pressure reactions to mental stress predicted future blood pressure and hypertension.MethodsBlood pressure was recorded at an initial medical screening examination after which blood pressure reactions to a mental stress task were determined. A follow-up screening assessment of blood pressure and antihypertensive medication status was undertaken 10 years later. Data were available for 796 male public servants, between 35 and 55 years of age upon entry to the study.ResultsSystolic blood pressure reactions to mental stress were positively correlated with follow-up screening systolic blood pressure and to a lesser extent, follow-up diastolic pressure. In multivariate tests, by far the strongest predictors of follow-up blood pressures were initial screening blood pressures. In the case of follow-up systolic blood pressure, systolic reactions to stress emerged as an additional predictor of follow-up systolic blood pressure. With regard to follow-up diastolic blood pressure, reactivity did not enter the analogous equations. The same outcomes emerged when the analyses were adjusted for medication status. When hypertension at 10-year follow-up was the focus, both systolic and diastolic reactions to stress were predictive. However, with correction for age and initial screening blood pressure, these associations were no longer statistically significant.ConclusionsThe results of this study provide modest support for the hypothesis that heightened blood pressure reactions to mental stress contribute to the development of high blood pressure. At the same time, they question the clinical utility of stress testing as a prognostic device.