Fight-or-Flight Response ‘Silent’ Signs of Hypertension Found in Young, Healthy Black Women
'Exercise by AfricanAmerican women at a young age could prevent, or at least delay, the start of hypertension.' Peter Latchman, assistant professor of exercise science In a Southern neurophysiology lab, Peter Latchman measures the pulse wave velocity of graduate assistant, Whitley Roper, while graduate assistant, Pam Winkler, watches the results on a computer screen.
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HIGHER PREVALENCE OF HYPERTENSION among African-American women compared with white women is well documented — with diet and quality of health care often identified as likely culprits. While these factors almost certainly contribute to that health disparity, a new Southern study shows evidence of a deeper, physiological factor that appears to be at least partially responsible for the difference. The study, led by Peter Latchman, assistant professor of exercise science, looks at a number of factors, including the baroreflex, which is responsible for the body’s ability to stabilize blood pressure when elevated. Among young, sedentary women with normal blood pressure readings, the baroreflex appears to be generally less sensitive in black women than in their white peers. Conversely, sympathetic sensitivity — commonly known as the “fight-or-flight” response (which raises blood pressure) — is greater among the black women. The study shows that their scores are almost twice as high as white women on this aspect of the testing. “What we found is that the body’s ability to regulate a stable blood pressure was not as strong in young AfricanAmerican women as it was in young white women,” Latchman says. “In effect, these young black women were already showing very early signs of prehypertension that were not yet measurable with the standard sphygmomanometer [blood pressure machine].” The research compares a group of nearly two dozen healthy white women of college age with an almost identical number of healthy black women of the same age. The women are also comparably healthy and have a similar body mass index. While the participants do not have hypertension based on traditional measuring devices, all are living a generally sedentary lifestyle in terms of exercise. The study was published in the August 2013 edition of the journal, “Clinical Autonomic Research.” Latchman was joined in the research by Robert Axtell, graduate coordinator of the SCSU Exercise Science Department; Jason Pereira, who was then an SCSU graduate fellow; Gregory Gates of Albert Einstein College of Medicine at Yeshiva University in the Bronx; Matthew Bartels of the Department of Rehabilitation Medicine of Columbia University; and Ronald Edmond De Meersman of the College of Medicine at Alfaisal University in Riyadh, Saudi Arabia. Latchman hopes the research will enable scientists and
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the medical community to conduct related studies and help develop earlier methods of controlling blood pressure in African-American women — before a diagnosis of hypertension or prehypertension. “The mechanisms explaining these differences remain elusive, but future studies examining baroreflex under stressful conditions may provide additional insight into these different responses,” he says. In fact, Latchman already has begun exploring the role of exercise in preventing these very early signs of prehypertension in young black women. That research, while still underway, shows that young black women who engage in regular physical activity do not exhibit these same signs, which can set the stage for prehypertension or hypertension.
In effect, their results are the same as white women who also are regularly physically active. “That would seem to indicate that exercise by AfricanAmerican women at a young age could prevent, or at least delay, the start of hypertension,” he says. “While this is also true among young white women, it is even more crucial among young black women because of a predisposition toward high blood pressure.” Latchman adds that this test helps to shed new light on the onset of hypertension, especially among AfricanAmerican women. He said he is unaware of any other research comparing the baroreflex and sympathetic sensitivity of young black and white women who have normal blood pressure readings.
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