Cardiovascular Reactivity in the Laboratory and the Role of Behavioral Factors in Hypertension: A Critical Review

This article reviews the concept that an increased blood pressure reactivity to noxious stimuli may play a causal role in the development of sustained hypertension (the “reactivity hypothesis”). We examine five aspects of this hypothesis. First, increased reactivity should be a characteristic of individual subjects that is stable both over time and across different tasks. Second, subjects with a family history of hypertension or who have borderline hypertension should show increased reactivity. Third, the physiological mechanisms underlying individual differences are discussed. A role for behavioral factors in the development of hypertension would receive the strongest support if such differences were mediated primarily in the central nervous system; the available evidence suggests that peripheral factors (e.g. structural changes in the arteries) are just as important. Fourth, increased reactivity in the laboratory should be demonstrable during the stresses of daily life. Fifth, increased reactivity should be demonstrable as an independent risk factor for the development of hypertension in prospective studies. We conclude that there is little support for the reactivity hypothesis at the present time, and that reactivity studies have played a limited role in providing evidence for the importance of behavioral factors in the development of hypertension.