Environmental and psychosocial factors relating to hypertension and cardiovascular disease are incompletely understood, particularly for women and African Americans. Recent research in our laboratory has suggested that job strain is more strongly linked to elevated work blood pressure (BP) in men than women. In contrast, the combination of having a high status job plus the trait of high effort coping style (John Henryism) was related to higher work BP in women and African American men, but not Caucasian men. Study 1 of this proposal will reexamine hypothesized relationships of high effort coping and job strain to elevated ambulatory BP at work and at home in a larger sample of 288 black and white men and women stratified by job status. Also, relationships of these traits to increased epinephrine (EPI) and norepinephrine (NOREPI) responses, other measures of sympathetic activation, adverse lipid profiles, and cardiac and vascular structural changes will be assessed. Job strain and high effort coping will also be related to hypertension prevalence in 576 black and white men and women stratified by job status. The influence of additional psychosocial variables (social support, hostility, anger-in, depressed mood, anxiety) will also be examined. Study 2 of the proposal builds on our prior research on gender differences in total peripheral resistance (TPR) during stressors which enhance alpha-adrenergic activity, and on our recent observation that among young adults, slow sodium excretion during stress (which is prevented by combined alpha and beta blockade and may involve increased renal arteriolar resistance) is seen in 5 times as many men as women. It also builds on recent work suggesting that estrogen may attenuate TPR responses to stress by reducing vasoconstrictive effects of alpha-adrenergic activity. This study is designed to examine cardiovascular, lipid, EPI, NOREPI, and sodium excretion responses to stressors in 120 subjects who have maintained for a week on a controlled high salt diet. Thirty subjects will be tested in each of these groups: 1) premenopausal women, 2) postmenopausal women not using hormone replacement therapy, 3) postmenopausal women using hormone replacement, 4) men. Each group will include 15 black and 15 white subjects, and each subject will be tested twice, once after receiving placebo and once after receiving either an alpha- or a beta-receptor antagonist. Together, these studies employ a focused, mechanistic approach, which is expected to provide important information on the biological and behavioral factors which contribute to the etiology of hypertension and cardiovascular disease in a broad spectrum of ethnic, gender and socioeconomic groups.
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