Manifest hostility may affect habituation of cardiovascular reactivity in blacks.

In a study of cardiovascular reactivity to dietary manipulation of sodium and calcium, we pretested 30 young black normotensive males who were equally divided by positive and negative parental histories of hypertension with a 12-item anger questionnaire we devised and the Cook-Medley Hostility, Manifest Hostility, Overcontrolled Hostility, and Inhibited Hostility scales of the Minnesota Multiphasic Personality Inventory. Contrary to expectations, we found no correlation of resting blood pressure or cardiovascular reactivity to repeated mental demands with the two measures of inhibited hostility. We did, however, find resistance to habituation of cardiovascular reactivity in subjects with high Manifest Hostility and positive family histories of essential hypertension. Our findings suggest that vulnerability to hypertension may be revealed by the perseveration of blood pressure reactivity to repeated mental challenge. We propose that the perseveration of blood pressure reactivity is a disinhibitory phenomenon caused by a difficulty in the management of multiple inhibitory demands that disrupts the natural course of habituation and could be an important etiologic factor in essential hypertension.