Controlling High Blood Pressure
Posted by on May 1, 2014 - 9:51am

May Is National High Blood Pressure Education Month, and nearly one in three adults in the United States has high blood pressure, also called hypertension. High blood pressure is dangerous because it increases the risk of stroke, heart attack, heart failure, kidney failure, death.

High blood pressure is called the "silent killer" because it has no symptoms until it causes major damage. A number of FDA-approved drugs, along with lifestyle changes, can help treat this condition.
Read the Consumer Update to get tips for controlling blood pressure and to learn more about approved medications.

Hypertension during Pregnancy May Mean Hot Flashes later
Posted by on December 30, 2013 - 1:11am

New research shows that women with high blood pressure during pregnancy may be at higher risk of having troublesome menopausal symptoms in the future. A research study from the Netherlands examined the relationship between hypertensive diseases and hot flashes and night sweats.

Investigators looked at 853 women who regularly visited a cardiology clinic. Among these women, 274 had a history of high blood pressure during their pregnancy, such as preeclampsia. Participants were classified as having hypertension (high blood pressure) if her systolic blood pressure was 140 mmHg or higher, if her diastolic was 90 mmHg or higher, or if she took antihypertensive medication.

The study revealed that women with a history of hypertensive pregnancy disease were more likely to have vasomotor symptoms of hot flashes and night sweats during menopause. Hot flashes and night sweats are considered vasomotor because of sudden opening and closing of blood vessels near the skin. 82% women with history of hypertension during pregnancy had hot flashes and night sweats, compared to 75% women without. Moreover, women with hypertension during pregnancy reported experiencing hot flashes and night sweats for a longer time period.

Researchers concluded that the findings were modest but more research needs to be done to establish a definite association. One must also consider that every woman experiences menopause differently; you  might have symptoms that are barely noticeable, while your friends could experience almost all of them. To learn more about the different types of symptoms during menopause, visit the Women's Health Research Institute's menopause website here.

 

 

 

Your genes at work
Posted by on October 2, 2011 - 1:16pm

In one of the largest genomic studies ever, an international research consortium identified 29 genetic variations that influence blood pressure. More than half of these variants were previously unknown. The findings provide insights into the biology of blood pressure and may lead to new therapeutic strategies.

High blood pressure, or hypertension, affects over 1 billion people worldwide. It can damage the body in many ways over time, leading to heart disease, stroke, kidney failure and other health problems.

More than 230 researchers across 6 continents scanned the genomes of over 200,000 European people to identify genetic variants that influence systolic and diastolic blood pressure. They followed up by analyzing the genomes of 70,000 people of East Indian, South Asian and African ancestry. The study was funded by the National Institutes of Health. The results appeared in the September 11, 2011, issue of Nature.

The researchers discovered 16 previously unknown variations. Six were found in genes already suspected of regulating blood pressure. The remaining 10 were found in unexpected locations and provide new clues into how blood pressure is controlled. Individually, the genetic variations increased the risk of hypertension by only a tiny amount. However, for people with multiple variants, the effects were significant.

The researchers developed a blood pressure genetic risk score based on the 29 variants they found. Among people with the top 10% of genetic risk score, 29% had hypertension, compared with 16% of those in the lowest risk group. Higher genetic risk scores were associated with increased blood pressure across ethnic groups. The risk score was also a good indicator of hypertension complications, such as increased thickness of the heart chambers, heart failure, stroke and coronary artery disease.

“This is one of the most important studies of the genetics of high blood pressure to date and a significant step toward finding better therapies for it,” says NHLBI Acting Director Dr. Susan B. Shurin.

A related study by the research group, the International Consortium of Blood Pressure Genome-Wide Association Studies, appeared on the same day in Nature Genetics. This other genome-wide association study identified 4 new genetic regions associated with pulse pressure and 2 linked to mean arterial pressure. The influence of these variants on systolic and diastolic blood pressure turned out to be more complex than expected.

Taken together, these findings suggest new genetic pathways underlying blood pressure regulation. They will also likely open new doors to research into treating high blood pressure.

RELATED LINKS:

What is High Blood Pressure?:
http://www.nhlbi.nih.gov/health/health-topics/topics/hbp/

The Pill, HRT and Pregnancy may Increase Risk for High Blood Pressure
Posted by on March 31, 2011 - 3:32pm

Women who tend to have high blood pressure (HBP) should be particularly vigilant if they are on oral contraceptives, are pregnant, or on hormone replacement therapy.

Women on oral contraceptives (OC) experience small but detectable increase in both systolic and diastolic blood pressure, usually in the normal range.  If it runs higher than normal make sure you talk to your doctor about it.   Women taking OCs who are 35 years and older and who smoke cigarettes are at even greater risk for heart disease and stroke and are encouraged to quit smoking.   If they are unable to quit smoking, they should talk to their doctor about using other forms of contraception.

Most studies show that blood pressure does not increase significantly with hormone replacement therapy in most women with and without high blood pressure.   However, a few women may experience a rise in blood pressure attributable to estrogen therapy.   It is recommended that women on HRT have their blood pressure monitored more often.

Many woman with HBP can have healthy babies but HBP during pregnancy can be dangerous for both mother and fetus.  Women with pre-existing, or chronic, high blood pressure are more likely to have certain complications during pregnancy than those with normal blood pressure.   Some women who have normal blood pressure before pregnancy may develop high blood pressure during pregnancy, called gestational hypertension.   The effects of high blood pressure range from mild to severe.   High PB can harm the mother's kidneys and other organs, and it can cause low birth weight and early delivery.  In the most serious cases, the mother develops pre-eclampsia or "toxemia of pregnancy" which can be life threatening.  More guidance for handling HPB during pregnancy can be found HERE.

Below is a chart for average normal blood pressure ranges.   However, age can effect the range, with slightly higher normal ranges as one ages.

Systolic pressure (mm Hg) Diastolic pressure (mm Hg) Pressure Range
130 85 High Normal Blood  Pressure
120 80 Normal Blood Pressure
110 75 Low Normal Blood  Pressure

Source:   National Heart, Lung and Blood Institute

Sex Hormones Influence Heart Function
Posted by on October 29, 2010 - 1:05pm

In the largest human study to date on the topic, researchers have uncovered evidence of the possible influence of human sex hormones on the structure and function of the right ventricle (RV) of the heart.

The researchers found that in women receiving hormone therapy, higher estrogen levels were associated with higher RV ejection fraction (ejection refers to the amount of blood pumped out during a contraction; fraction refers to the residue left in the ventricle after the contraction)  with each heart beat and lower RV end-systolic volume — both measures of the RV’s blood-pumping efficiency — but not in women who were not on hormone therapy, nor in men. Conversely, higher testosterone levels were associated with greater RV mass and larger volumes in men, but not in women, and DHEA, an androgen which improves survival in animal models of pulmonary hypertension, was associated with greater RV mass and volumes in women, similar to the findings with testosterone in men.

“This study highlights how little is known about the effects of sex hormones on RV function. It is critical from both research and clinical standpoints to begin to answer these questions,” said Steven Kawut, M.D., M.S.,  director of the Pulmonary Vascular Disease Program at the University of Pennsylvania School of Medicine in Philadelphia.

The study was published online ahead of the print edition of the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

Study participants were part of The MESA-Right Ventricle Study (or MESA-RV), an extension of the Multi-Ethnic Study of Atherosclerosis (MESA), a large, NHLBI-supported cohort focused on finding early signs of heart, lung and blood diseases before symptoms appear. Using blood samples and magnetic resonance imaging (MRI) of the heart, researchers measured sex hormones and RV structure and function in 1957 men and 1738 post-menopausal women. Because the MESA population is ethnically mixed and covers a broad age range of apparently healthy people, the results may be widely applicable to the general U.S. population.

“One of the most interesting things about this research is that we are focusing on individuals without clinical cardiovascular disease so that we may learn about determinants of RV morphology before there is frank RV dysfunction, which is an end-stage complication of many heart and lung diseases,” said Dr. Kawut. “When we study people who already have RV failure from long-standing conditions, the horse has already left the barn. We are trying to assess markers that could one day help us identify and intervene in individuals at risk for RV dysfunction before they get really sick.”

Because the RV plays a critical role in supplying blood to the lungs and the rest of the body, RV function is closely tied to clinical outcomes in many diseases where both the heart and lungs are involved, such as pulmonary hypertension, COPD and congestive heart failure. However, the RV is more difficult to study and image than the left ventricle and comparatively little is known about its structure and function and how to treat or prevent right heart failure.

Corey E. Ventetuolo, M.D., lead author of the study from  Columbia University College of Physicians and Surgeons, reported,  “Our results have generated some interesting questions about RV response to the hormonal milieu. For example, the finding that higher levels of testosterone (and DHEA) were associated with greater RV mass would first appear to have adverse clinical consequences, since increasing cardiac mass is traditionally thought to be maladaptive. However, another study from MESA-RV has shown that higher levels of physical activity are also linked to greater RV mass, which would suggest an adaptive effect. So, whether the increased RV mass seen with higher hormone levels is helpful or harmful is not yet clear. The sex-specific nature of the associations we found was unexpected and reflect the complexity of the actions of sex hormones.”

Sex hormone levels could help explain a key paradox in pulmonary arterial hypertension (PAH), where the RV response is an important determinant of survival.  While women are far more likely to develop PAH, they also have better RV function and may have a better survival than men. “It is possible that hormone balance could predispose them to developing PAH, but confer a protective benefit in terms of RV adaptation,” explained Dr. Kawut.

The ultimate goal would be strategies to treat or prevent RV failure in those at high risk.

Source:   American Thoracic Society

Hypertension in Women
Posted by on August 13, 2010 - 9:49am

Postmenopausal women have an increased risk of hypertension (high blood pressure), and among older adults, more women than men have hypertension.   As with many other health issues, hypertension research has been conducted predominately in males, and little is known about how women's bodies manage blood flow.   Research conducted by Heidi A. Kluess at the University of Arkansas is focusing on a  better understanding of hypertension in women by using a new technique to examine the release of a neurotransmitter in small blood vessels.

Kluess, an exercise scientist, believes the answer seems to be in the "synapse".  The synapse is the space between the nerve and the vascular smooth muscle, the place where the nerve and blood vessel interact.   A neurotransmitter crosses the "synapse" to activate a receptor, which then causes the artery to constrict.   "There's been a little evidence to say that some of the neurotransmitter breakdown is different in women.   It suggests that when we've been looking at receptors on the smooth muscle, we may have been missing a big part of the story, particularly in women," Kluess said.

The team measured the neurotransmitter adenosine triphosphate (ATP) coming from the small blood vessels (arterioles).  ATP plays a key role in controlling blood flow and blood pressure by causing the diameter of blood vessels to change.   Thus, the constriction of veins associated with hypertension could be related to relatively high levels of ATP in arterioles. So this raises the questions:   Where is the ATP coming from, what tissues are releasing it and how does this change with aging?

To study this,the researchers had to overcome the difficulty of working with very small blood vessels that produced minute amounts of ATP.   A biosensor that was only previously used in brain researcher was utilized that uses a set of enzymes to indirectly measure ATP as it is released.

The research findings suggest that ATP from small arterioles can be measured and that the arteriole wall plays an important role in release and management of ATP. The researchers found that ATP is released mostly from the sympathetic nerves in the arteriole wall and that only a small part comes from the smooth muscle. Considerable research suggests that having a lot of ATP floating around in the blood vessels is not a good thing. The upside of this finding is that the nerve releases ATP in response to nerve signals. However, the mechanisms involved in the release of ATP by smooth muscles are less well understood, Kluess explained, and may result in chronically high ATP release.

The researchers found that the ATP overflow varied considerably with age. Because ATP is associated with vascular growth, it is important during early development when blood vessels are growing, but levels generally decline when people reach their twenties. Elevated levels can be a bad sign during aging when the body is no longer growing and may be a predictor of vascular changes that can be detected years before hypertension is a problem.

Some previous research had suggested that the endothelium – the outer layer of the smooth muscle – produced ATP. However, Kluess’ research showed that the endothelial tissue did not produce ATP. Rather, it decreased levels of ATP and potentially plays a positive role in controlling ATP levels.

“That’s an interesting finding because we know that as people age or develop disease that their endothelium doesn’t work as well,” Kluess said. “That may be a way that ATP increases during aging because the endothelium doesn’t function as well and so can’t buffer ATP quite as well.”

More research is needed to investigate the factors that control ATP overflow and metabolism to reveal the mechanisms associated with age-related change. “We are very much at the beginning of this story,” Kluess said.

Source:   University of Arkansas

Kluess HA, Stone AJ, Evanson KW. ATP overflow in skeletal muscle 1A arterioles. J Physiol.