The overall goal of this study is to obtain a more complete understanding of the role that physiologic changes induced by stress play in the development of ethnic differences in essential hypertension. The physiologic response to stress is a dynamic process. It includes the response to the stressor per se AND the physiologic response, which bring the body into homeostasis. The vast majority of research has focused on the physiologic response during stress while homeostatic changes following stress have largely been ignored. There is very little information about group differences. The general hypothesis of this proposal is as follows: African-Americans compared to Caucasians show slower natriuresis during and following the stress coupled with greater vasoconstriction. This will result in an extended period of elevated blood pressure following stress, exposing these individuals to an increased BP load, which leads to the premature development of end organ changes. Therefore, the aims of this study are: 1) contrast hemodynamic regulation in African-American and Caucasian subjects before, during, and two hours following a 60 minute stress period; 2) contrast hormonal regulation in African-American and Caucasian subjects during the procedure; 3) contrast levels of Na+ handling between African-American and Caucasian subjects during the procedure; 4) determine the relationship between measures of target organ change and BP changes during the recovery period. The proposed study will add considerably to the minimal knowledge of the factors underlying, and significance of, an impaired homeostatic process by a) for the first time identifying hormonal mechanism associated with the response; and b) for the first time determining the clinical significance of the response by relating it to target organ changes.
| Su, Shaoyong; Zhu, Haidong; Xu, Xiaojing et al. (2014) DNA methylation of the LY86 gene is associated with obesity, insulin resistance, and inflammation. Twin Res Hum Genet 17:183-91 |
| Murro, Diana G; Beavers, Melinda; Harshfield, Gregory A et al. (2013) Aldosterone contributes to elevated left ventricular mass in black boys. Pediatr Nephrol 28:655-60 |
| Kapuku, G K; Davis, H C; Shah, N et al. (2008) Gender differences in diastolic function among youth. Pediatr Cardiol 29:102-7 |
| Hanevold, Coral D; Pollock, Jennifer S; Harshfield, Gregory A (2008) Racial differences in microalbumin excretion in healthy adolescents. Hypertension 51:334-8 |
| Harshfield, Gregory A; Hanevold, Coral; Kapuku, Gaston K et al. (2007) The association of race and sex to the pressure natriuresis response to stress. Ethn Dis 17:498-502 |
| Savoca, Margaret R; Evans, Conner D; Wilson, Martha E et al. (2004) The association of caffeinated beverages with blood pressure in adolescents. Arch Pediatr Adolesc Med 158:473-7 |
| Wilson, Martha E; Harshfield, Gregory A; Ortiz, Luis et al. (2004) Relationship of body composition to stress-induced pressure natriuresis in youth. Am J Hypertens 17:1023-8 |
| Harshfield, Gregory A; Wilson, Martha E; McLeod, Kathryn et al. (2003) Adiposity is related to gender differences in impaired stress-induced pressure natriuresis. Hypertension 42:1082-6 |
| Harshfield, Gregory A; Wilson, Martha E; Hanevold, Coral et al. (2002) Impaired stress-induced pressure natriuresis increases cardiovascularload in African American youths. Am J Hypertens 15:903-6 |
