Blood Pressure Control--Racial and Psychosocial Influences
To examine racial and psychosocial influences on blood pressure control.
|Study Start Date:||September 1983|
|Estimated Study Completion Date:||July 2002|
Environmental and psychosocial factors relating to hypertension and cardiovascular disease are incompletely understood, particularly for women and African Americans. Recent research has suggested that job strain is more strongly linked to elevated work blood pressure 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 blood pressure in women and African American men, but not Caucasian men.
The grant has been ongoing since September 1983. The original study had as its purpose to ascertain similarities and differences in the etiology of hypertension for Blacks and whites and to identify those biobehavioral factors contributing to the excess risk for hypertension among Blacks. Myocardial, blood pressure, and renal responses (sodium and potassium handling) to laboratory and naturalistic stressors were evaluated in young adult normotensive or marginally hypertensive Black and white men. Behavioral stressors included competitive, reaction time tasks (active coping) as well as more passive coping conditions. Data were collected on family history of hypertension, family social class background, Type A behavior, propensity for anger and hostility, and coping style. The role of the sympathetic nervous system in mediating these effects was assessed by the use of beta-adrenergic antagonists.
When the grant was renewed in 1991, the goal of the research was to evaluate the interactive effects of environmental stressors and sodium chloride (NACl) and potassium (K) intake as they related to hypertension development in a biracial population.
There were two studies in the current grant. Study 1 reexamined hypothesized relationships of high effort coping and job strain to elevated ambulatory blood pressure (BP) at work and at home in a sample of 288 Black and white men and women stratified by job status. Also, assessments were made of the relationships of these traits to increased epinephrine and norepinephrine responses, other measures of sympathetic activation, adverse lipid profiles, and cardiac and vascular structural changes. Job strain and high effort coping were also 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) was also examined.
Study 2 built on prior research on gender differences in total peripheral resistance during stressors which enhance alpha-adrenergic activity, and on a recent observation that among young adults, slow sodium excretion during stress is seen in five times as many men as women. It also built on recent work suggesting that estrogen may attenuate total peripheral resistance responses to stress by reducing vasoconstrictive effects of alpha-adrenergic activity. The study was designed to examine cardiovascular, lipid, epinephrine, norepinephrine, and sodium excretion responses to stressors in 120 subjects maintained for a week on a controlled high salt diet. Thirty subjects were 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 included 15 Black and 15 white subjects, and each subject was tested twice, once after receiving placebo and once after receiving either an alpha- or a beta-receptor antagonist.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00005685
|Investigator:||Kathleen Light||University of North Carolina|