Navigation Links
Understanding hypertension in African Americans proves elusive
Date:8/15/2007

Exercise cannot reduce a sodium-retaining hormone in African Americans known to potentially cause hypertension, found Michael D. Brown, Ph.D., the senior author of a study in the September issue of Experimental Physiology. Brown is an associate professor of kinesiology at Temple Universitys College of Health Professions.

The hormone, aldosterone, influences the kidneys regulation of blood pressure, but too much of it can contribute to the development of hypertension because it causes the kidney to retain salt. Aldosterone, released by the adrenal glands on top of the kidneys, plays a role in the complex system used by the body to regulate blood pressure.

Although the results are discouraging for African Americans and hypertension, itll point us in other directions that may have more potential and could be the key to reducing hypertension, said Brown, who has a background in exercise physiology.

Many African Americans develop the salt-sensitive form of hypertension. Approximately 40 percent of African Americans have hypertension the highest rate of any racial or ethnic group in the United States but there is little data about what makes them more susceptible to this condition, Brown said.

This study is based on the premise that the prevalence of blood pressure sensitivity to salt is extremely high is African Americans. Alterations in aldosterone regulation may play a role because aldosterone causes the kidney to retain salt. Brown said he wanted to find out if exercise could lower the levels.

In the study, he found that the level of aldosterone was related to how the two racial groups distributed body fat. Caucasians generally stored fat in the abdomen area, whereas African Americans had fat distributed throughout the body in a layer under the skin. The six-month study involving 35 Caucasians and African Americans with hypertension found that aerobic exercise training program reduced aldosterone levels in Caucasians by 32 percent, but levels for African Americans were reduced by only 8 percent. Total body fat was reduced only in Caucasians, which might be a clue to the drop in aldosterone.

The kidneys help to regulate blood pressure by changing the levels of salt and water in our body. Sometimes the kidneys reset at a higher blood pressure level if it has retained too much salt, Brown said.

While the study showed exercise did not lower aldosterone in African Americans, exercise still has many other benefits for this population, Brown said.

Exercise has the capacity to affect so many things. Its a way for the body to correct itself, he added.

Brown will continue his research in this area with a $3.5 million National Institutes of Health grant awarded earlier this year. In September, Brown will recruit African Americans with hypertension for a study on how exercise can improve the blood vessel condition. The study will also take an in-depth look at how genes can contribute to hypertension.

Solving the cause of hypertension is similar to solving a big puzzle. Each piece of the puzzle represents a contributing factor to hypertension. Each of these pieces, or possible causes of hypertension, needs to be studied in a systematic way, Brown said.


'/>"/>
Contact: Anna Nguyen
anna.nguyen@temple.edu
215-707-1731
Temple University
Source:Eurekalert

Related biology news :

1. UCSB scientists probe sea floor venting to gain understanding of early life on Earth
2. Zebrafish may hold key to understanding human nerve cell development
3. Novel ultrafast laser detection of cancer cells also may improve understanding of stem cells
4. Researchers make gains in understanding antibiotic resistance
5. Brain-mapping technique aids understanding of sleep, wakefulness
6. New understanding of DNA repair may pave way to cancer treatments
7. NYU and MSKCC research provides model for understanding chemically induced cancer initiation
8. The circadian clock: Understanding natures timepiece
9. Virologists make major step towards understanding the process of HIV infection
10. Breakthrough System for Understanding Ocean Plant Life Announced
11. Understanding how bacteria communicate may help scientists prevent disease
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:8/23/2017)... -- The general public,s help is being enlisted in what,s thought to be ... on the human body –and are believed to affect health.  ... The Microbiome Immunity Project is the largest study ... gut. The project's goal is to help advance scientific knowledge of the ... ...
(Date:7/20/2017)... 20, 2017 Delta (NYSE: DAL ) customers now ... aircraft at Reagan Washington National Airport (DCA). ... Delta launches biometrics to board aircraft at ... Delta,s biometric boarding pass experience ... is now integrated into the boarding process to allow eligible Delta SkyMiles ...
(Date:6/23/2017)... and ITHACA, N.Y. , June 23, ... University, a leader in dairy research, today announced a ... to help reduce the chances that the global milk ... of this dairy project, Cornell University has become the ... the Food Supply Chain, a food safety initiative that ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... Irvine, ca (PRWEB) , ... October 12, 2017 ... ... for the Surgical Wound Market with the addition of its newest module, US ... the $1.2B market for thrombin hemostats, absorbable hemostats, fibrin sealants, synthetic sealants and ...
(Date:10/11/2017)... ... ... eye wash is a basic first aid supply for any work environment, but most personal ... rinse first if a dangerous substance enters both eyes? It’s one less decision, and likely ... dual eye piece. , “Whether its dirt and debris, or an acid or alkali, getting ...
(Date:10/11/2017)... ... October 11, 2017 , ... Disappearing forests and increased emissions are ... 5.5 million people each year. Especially those living in larger cities are affected by ... in one of the most pollution-affected countries globally - decided to take action. , ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... FirstHand program has won a US2020 STEM Mentoring Award. Representatives of the FirstHand ... Excellence in Volunteer Experience from US2020. , US2020’s mission is to change the ...
Breaking Biology Technology: