Stress and diastolic dysfunction contribute to increased cardiovascular (CV) morbidity and mortality in hypertension. However, the relationship between these two mechanisms of CV disease is not well understood. We will employ an alternative theoretical model to the reactivity hypothesis which we refer to as the """"""""pressure natriuresis"""""""" hypothesis. The focus of this model is on longer-term blood pressure (BP) control systems that maintain an increased pressure load within the heart for an extended period of time, increasing the likelihood of developing diastolic dysfunction.
The specific aims of the proposed study are to test the following primary (1,2) and secondary hypotheses (3, 4, 5 and 6): (1) Stress will be associated with changes in the separate components (isovolumetric relaxation, early and late filling phases) of diastolic function (DFx). (2) The effect of stress on the components of DFx will differ by race and/or gender. (3) Stress- induced sodium excretion will correlate with concomitant stress-induced changes in DFx. (4) Stress-induced sodium excretion will correlate with concomitant stress-induced changes in natriuretic peptides (ANP, BMP). (5) Changes in BP during recovery (20-40 minutes post stress) will correlate with stress-induced changes in DFx. (6) Stress induced changes in catecholamines will be associated with changes in the components of DFx. The subjects population will consist of a bi-racial sample of 160 adults (African American, European American) aged 30-50 years. They will be placed on a controlled diet of sodium: 4,000+/-200 mg/day prior to testing. The experimental design is a two treatment, crossover design in which each subject receives both the experimental (mental stress task) and the control (watching a movie) treatments. The overall goal is to examine the role of psychological stress in the development of diastolic dysfunction. This will be the first comprehensive study to identify the role of natriuretic peptides in the stress-induced pressure natriuresis phenomenon and the link between pressure natriuresis and cardiac function in normotensive adults. Relevance to public health: The study will provide more efficacious early markers of cardiac malfunction before the development of overt signs of congestive heart failure. In so doing, it will contribute to development of population oriented prevention interventions that may help curb the epidemic spread of heart failure.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL076696-04
Application #
7629683
Study Section
Biobehavioral Mechanisms of Emotion, Stress and Health Study Section (MESH)
Program Officer
Stoney, Catherine
Project Start
2006-09-01
Project End
2012-05-31
Budget Start
2009-06-01
Budget End
2012-05-31
Support Year
4
Fiscal Year
2009
Total Cost
$356,843
Indirect Cost
Name
Georgia Regents University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
966668691
City
Augusta
State
GA
Country
United States
Zip Code
30912
Kapuku, G; Treiber, F; Raouane, F et al. (2017) Race/ethnicity determines the relationships between oxidative stress markers and blood pressure in individuals with high cardiovascular disease risk. J Hum Hypertens 31:70-75
Choksy, Pratik; Davis, Harry C; Januzzi, James et al. (2014) Brain natriuretic hormone predicts stress-induced alterations in diastolic function. Am J Med Sci 348:366-70
Kapuku, Gaston K; Davis, Harry; Murdison, Kenneth et al. (2012) Stress reduces diastolic function in youth. Psychosom Med 74:588-95
Kapuku, Gaston K; Davis, Harry C; Thomas, Patrick et al. (2012) Does the relationship between natriuretic hormones and diastolic function differ by race? Am J Med Sci 344:96-9
Kapuku, G K; Davis, H C; Shah, N et al. (2008) Gender differences in diastolic function among youth. Pediatr Cardiol 29:102-7