Stress prompts some to retain as much salt as eating fries
When stressed, about 30 percent of blacks hold onto too much sodium, the equivalent of eating a small order of fast food French fries or a small bag of potato chips, according to research being done by Dr. Gregory Harshfield, hypertension researcher at the Institute of Public and Preventive Health at Georgia Health Sciences University. Credit: Phil Jones, Georgia Health Sciences University Photographer
When stressed, about 30 percent of blacks hold onto too much sodium, the equivalent of eating a small order of fast food French fries or a small bag of potato chips, researchers say.
"This response pattern puts you under a greater blood pressure load over the course of the day and probably throughout the night as well, increasing your risk of cardiovascular disease," said Dr. Gregory Harshfield, hypertension researcher at the Institute of Public and Preventive Health at Georgia Health Sciences University.
In response to stress, they hold onto about 160 milligrams of salt, and the top number of their blood pressure – indicating the pressure inside blood vessels each time the heart beats - goes up about seven points more than normal and stays elevated about an hour longer, said Harshfield, who is presenting his findings Sept. 7 during the Behavioural Economics, Hypertension Session of the Psychogenic Cardiovascular Disease Conference in Prato, Italy.
Over the course of the day, this response adds a daily sodium load of about 500 milligrams on top of typically salt-heavy diets. The Institute of Medicine recommends a daily sodium intake of less than 2,300 milligrams – preferably under 1,500 milligrams – while average consumption is about 3,700.
"Everybody knows stress is bad for you and everybody has the perception that a high-salt diet is bad for you, and both are particularly bad for these individuals," said Harshfield who is trying to find an easy way to identify them. "Every time they are stressed, they hold onto as much salt as you get eating a small order of French fries and this can occur many times over the course of even a good day."
The worse news is this increased retention likely causes blood pressures to stay elevated even during sleep, which should be a recuperative time for the body, Harshfield said. Nighttime blood pressures often are considered the truest reading since they should not be impacted by stress.
In a handful of young blacks identified as sodium retainers through a complex research protocol, Harshfield has shown that the dangerous sodium load can be lifted with angiotensin receptor blockers, a common blood pressure treatment. Ironically these drugs are rarely used in blacks who tend not to have high levels of the powerful blood vessel constrictor angiotensin. However, Harshfield's group has evidence that sodium retainers would definitely benefit because they have a version of the angiotensin receptor gene that exacerbates problems with sodium handling. A truly low-salt diet likely would be beneficial as well.
Angiotensin increases blood pressure by directing the kidneys to hold onto more salt and by increasing levels of the hormone aldosterone, which also directs the kidneys to retain salt. The normal response to stress is to temporarily increase blood vessel constriction, which actually increases sodium excretion, Harshfield said.
His studies have long focused on the kidney and years ago found that about 30 percent of blacks and about 10 percent of whites tend to hold onto more sodium for longer periods in response to stress. Stress activates the sympathetic nervous system, which drives the – hopefully temporary – increase in blood pressure.
The latest findings come from a $10.6 million Program Project grant from the National Heart, Lung and Blood Institute focused on how the body regulates blood pressure in response to stress. Part of that grant includes a study in which half of 140 young adult sodium retainers take an angiotensin receptor blocker for about a week while the remainder take a placebo. Harshfield "un-blinded" a small number of study participants to collect data for a grant renewal proposal.
In the ongoing search for an easy way to identify sodium retainers, Evan Mulloy, a first-year student at the Medical College of Georgia, is working with Harshfield to collect urine samples from 7- to 21-year-old GHS Children's Medical Center patients being seen for hypertension. Using the doctor's visit as the stressor, they are looking at sodium levels in the urine before and after a visit. Harshfield also is working with MCG Molecular Geneticist Haidong Zhu to develop a genetic profile that could be used for screening.
One in three Americans is hypertensive, according to the NHLBI. The majority of sodium consumed is from processed and restaurant foods.
Provided by Georgia Health Sciences University
- Urine protein may be present before hypertension diagnosis in at-risk adolescents Feb 27, 2008 | not rated yet | 0
- Blood pressure response to daily stress provides clues for better hypertension treatment Aug 14, 2008 | not rated yet | 0
- Risk factors for hypertension start young Dec 22, 2006 | not rated yet | 0
- Too much salt may damage blood vessels, lead to high blood pressure Jun 18, 2012 | not rated yet | 0
- System that regulates blood pressure is amiss in some healthy, young blacks May 08, 2009 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
question on coriolis effect with drag force
3 hours ago I really need help with this question. A small floating object initially moves with velocity v on the surface of a liquid at latitude λ. The...
Question of reflection and transmission of TEM wave in normal incidenc
9 hours ago Suppose TEM wave in +z normal to a boundary on xy plane at z=0. We know *E* & *H* are tangential to the boundary. Let ##\vec E_i=\hat x E##, be the...
the rudyak-krasnolutski effective potencial
10 hours ago Hi ... anyone now how to calculate or the formula of the rudyak-krasnolutski EFFECTIVE potencial ? the effective potencial includes the angular...
Normal force for a lever model
11 hours ago My model is a lever on a table top. One arm is horizontal on the table, while the other arm is raised at an angle alpha. I'm assuming the weight of...
gravity is std. therefore can we rate a 'mass at height' by watts?
16 hours ago For example.... wind turbines are primarily listed by their wattage (1.5MW etc.) Presumably their output is varied according to rotational speed, so...
Calculating on-axis elements of a solenoid
May 22, 2013 I wanted to mention that this solenoid has many winds over many layers. The thickness of the windings is 2.4 inches coming off of the engineering...
- More from Physics Forums - Classical Physics
More news stories
(HealthDay)—In patients who have previously been considered difficult to image, dual-source cardiac (DSC) computed tomography (CT) can identify clinically significant coronary artery disease, according ...
Cardiology 7 hours ago | not rated yet | 0
UCLA researchers examining outcomes for advanced heart-failure patients over the past two decades have found that, coinciding with the increased availability and use of new therapies, overall mortality has decreased and sudden ...
Cardiology 10 hours ago | not rated yet | 0
22 May 2013, Paris, France: The Lotus Valve, a second-generation transcatheter aortic valve implantation (TAVI) device, was successfully implanted in all of the first 60 patients in results from REPRISE II reported at EuroPCR ...
Cardiology 14 hours ago | not rated yet | 0
Costs to treat stroke are projected to more than double and the number of people having strokes may increase 20 percent by 2030, according to the American Heart Association/American Stroke Association.
Cardiology May 22, 2013 | not rated yet | 0
Blood thinners are the preferred treatment option to prevent heart attacks, blood clots and stroke, but they are not without risk, and not just because of their side effects. These high-risk drugs, known as anticoagulants, ...
Cardiology May 22, 2013 | not rated yet | 0
(Medical Xpress)—Regulating the distribution of power in neurons is done by a system that makes the national electric grid look simple by comparison. Each neuron has several thousand mitochondria confined ...
8 hours ago | 4.8 / 5 (5) | 0 |
A brief visual task can predict IQ, according to a new study. This surprisingly simple exercise measures the brain's unconscious ability to filter out visual movement. The study shows that individuals whose ...
13 hours ago | 4.4 / 5 (9) | 0 |
Teams of highly respected Alzheimer's researchers failed to replicate what appeared to be breakthrough results for the treatment of this brain disease when they were published last year in the journal Science.
11 hours ago | 5 / 5 (1) | 2 |
High blood glucose is associated with poor outcomes in hospitalized patients, and use of intensive insulin therapy (IIT) to control hyperglycemia is a common practice in hospitals. But the recent evidence does not show a ...
1 hour ago | not rated yet | 0
Scientists at the National Institutes of Health report they have discovered in mouse studies that a small molecule released in the spinal cord triggers a process that is later experienced in the brain as ...
11 hours ago | 5 / 5 (2) | 0 |
Little is known about why asthma develops, how it constricts the airway or why response to treatments varies between patients. Now, a team of researchers at Weill Cornell Medical College, Columbia University Medical Center ...
12 hours ago | not rated yet | 0 |