Navigation Links
Understanding hypertension in African Americans proves elusive

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
Temple University

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:
(Date:11/20/2015)... 20, 2015 NXTD ) ("NXT-ID" ... the growing mobile commerce market and creator of the ... , was recently interviewed on The RedChip Money ... this weekend on Bloomberg Europe , Bloomberg Asia, ... --> NXTD ) ("NXT-ID" or the "Company"), a ...
(Date:11/19/2015)... Nov. 19, 2015  Based on its in-depth analysis ... recognizes BIO-key with the 2015 Global Frost & Sullivan ... & Sullivan presents this award to the company that ... the needs of the market it serves. The award ... and expands on customer base demands, the overall impact ...
(Date:11/19/2015)... 2015  Although some 350 companies are actively involved ... few companies, according to Kalorama Information. These include Roche Diagnostics, ... market share of the 6.1 billion-dollar molecular testing market, ... for Molecular Diagnostic s .    ... controlled by one company and only a handful of ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... LOS ANGELES and HOLLISTON, Mass. ... Regenerative Technology, Inc. (Nasdaq: HART ), a biotechnology ... announced that CEO Jim McGorry will present ... Tuesday, December 1, 2015 at 2:30 p.m. PT. The ... (link below) for 30 days. Management will also be ...
(Date:11/25/2015)... DIEGO , Nov. 25, 2015 Orexigen® ... management will participate in a fireside chat discussion at ... New York . The discussion is scheduled ... .  A replay will be ... Media Contact:McDavid Stilwell  , Julie NormartVP, Corporate Communications ...
(Date:11/24/2015)... ... November 24, 2015 , ... The United States Golf Association (USGA) today announced ... Section Award. Presented annually since 1961, the USGA Green Section Award recognizes an individual’s ... , Clarke, of Iselin, N.J., is an extension specialist of turfgrass pathology ...
(Date:11/24/2015)... ... November 24, 2015 , ... Copper is an ... is bound to proteins, copper is also toxic to cells. With a $1.3 ... Institute (WPI) will conduct a systematic study of copper in the bacteria Pseudomonas ...
Breaking Biology Technology: