The relation between blood pressure level and reactivity to mental arithmetic and isometric exercise was investigated in 169 men and 120 women (average age, 32.3 years) from the village of Tecumseh, Mich. In the entire population, the correlation between baseline blood pressure and blood pressure response to both stressors was not significant. Blood pressure reactivity to both stressors was not increased in participants with borderline hypertension (one clinic reading of more than 140 mm Hg systolic and/or 90 mm Hg diastolic). When subjects were classified according to blood pressure response (below and above the 80th percentile), the hyperreactors to mental and physical stress had normal baseline blood pressure values. The hyperreactors also had clinic-to-home blood pressure differences similar to those of the rest of the population. Participants who had borderline hypertension at age 32 years had significantly elevated blood pressures at ages 5, 8, 12, 21, and 22 years. Those who were hyperreactors at age 32 years had normal blood pressures as children and young adults. Results of the present study lend no support to an association between higher blood pressures and blood pressure hyperreactivity. Study participants in Tecumseh will be recalled for future examinations. The independence of blood pressure levels from blood pressure reactivity offers a unique opportunity to prospectively evaluate their separate effects on cardiovascular morbidity.
During a survey of young subjects not receiving treatment for hypertension in Tecumseh, Michigan, clinic and self-monitored blood pressures taken at home (14 readings in 7 days) were obtained in 737 subjects (387 men, 350 women, average age 31.5 years). Hypertension in the clinic was diagnosed if the clinic blood pressure exceeded 140 mm Hg systolic or 90 mm Hg diastolic. In the absence of firm criteria for what constitutes hypertension at home, subjects whose average home blood pressure was in the upper decile of the whole population were considered to have hypertension at home. By these criteria, 7.1% of the whole population had "white coat" hypertension (i.e., high clinic but not elevated home readings). The prevalence of "sustained" hypertension (i.e., high readings in the clinic and at home) was 5.1%. Subjects with white coat and sustained borderline hypertension in Tecumseh were very similar. Both groups showed, at previous examinations (at ages 5, 8, 21, and 23 years), significantly higher blood pressure readings than the normotensive subjects. As young adults (average age 33.3 years), the parents of both hypertensive groups had significantly higher blood pressure readings than the parents of normotensive subjects. Both hypertensive groups had faster heart rates, higher systemic vascular resistance, and higher minimal forearm vascular resistance. Both hypertensive groups were more overweight, had higher plasma triglycerides, insulin, and insulin/glucose ratios than normotensive subjects. The white coat hypertensive group also had lower values of high density lipoprotein than the normotensive group. White coat hypertension is a frequent condition.(ABSTRACT TRUNCATED AT 250 WORDS)