Wednesday, 30 September 2009

What sends blood pressure soaring? Salt, and more

Perhaps nothing in medicine more aptly depicts the paradoxical statement "doing better, feeling worse" than high blood pressure. Despite an extraordinarily easy way to detect it, strong evidence for how to prevent it and proven remedies to treat it, more Americans have undetected or poorly controlled hypertension than ever before.

The aging of the population is a reason but not the only one, said Dr. Aram V. Chobanian, a hypertension expert at Boston University Medical Center. He summarized the problem in an interview and in The New England Journal of Medicine in August: Americans are too sedentary and fat. They eat too much, especially salt, but too few potassium-rich fruits and vegetables. The makers of processed and fast foods created and persistently promote a craving for high-salt foods, even in school lunch programs. And Americans without health insurance often don't know that their blood pressure is too high because they wait for a calamity to strike before seeking medical care.

Solutions to the blood pressure problem require broad-scale approaches by the public, by government, by industry and by health care professionals. Several measures are similar to those that have been so effective in curbing cigarette smoking; others require better, affordable access to medical care for everyone at risk, including children and the unemployed. Still others need the cooperation of government, industry and the public to improve the American diet and enhance opportunities for health-promoting exercise.

No one claims that the solutions are cheap. But failure to fix this problem portends even greater costs down the line, because uncontrolled hypertension sets the stage for astronomically expensive heart and kidney disease and stroke -- diseases that will become only more common as the population ages.

Doing the numbers
Once, the prevailing medical opinion was that lowering an elevated blood pressure was hazardous because it would deprive a person's vital organs of an adequate blood supply. But a few pioneering medical researchers thought otherwise and eventually showed that lowering high blood pressure could prevent heart attacks, heart failure, strokes and kidney disease -- and save lives.

Even then, it was long thought that the only important indicator was diastolic pressure -- the bottom number, representing the pressure in arteries between heartbeats. Further studies showed that the larger top number, systolic pressure, representing arterial pressure when the heart beats, was also medically important.

And as the various studies reached fruition, it became apparent that the long-accepted numbers for desirable blood pressure were too high to protect long-term health. Now the upper limit of normal blood pressure is listed as 120 over 80; anyone with a pressure of 140 over 90 or higher is considered hypertensive. Those with pressures in between are considered pre-hypertensive and should take steps to bring blood pressure down or, at least, prevent it from rising more. The change mirrors what happened with serum cholesterol, for which "normal" was once listed as 240 milligrams per deciliter of blood and is now less than 200 to prevent heart disease caused by clogged arteries.

It was also long thought that blood pressure naturally rises with age. Indeed, the Framingham Heart Study showed that when 65-year-old people whose blood pressure was below 140 over 90 were followed for 20 years, about 90 percent of them became hypertensive because their arteries narrowed and stiffened with age, causing blood to push harder against artery walls. But in many societies where obesity is rare, activity levels are high and salt intake is low, blood pressure remains low throughout life. This is the best clue we have for the lifestyle changes needed to prevent illness and premature death caused by hypertension.

Dr. Claude Lenfant, who served as director of the National Heart, Lung and Blood Institute, is 81 and has a blood pressure of 115 over 60, a level rarely found among older Americans not taking medication for hypertension. His secret: a normal body weight, 4 or more miles of walking daily and no salt used to prepare his meals, most of which are made from scratch at home.
In an interview, Lenfant, who now lives in Vancouver, Wash., said the problem of hypertension was rising all around the world and added that by 2020 the number of people with uncontrolled hypertension was projected to rise 65 percent. One reason is that doctors today are more likely to diagnose the problem, so it is reported more often in population surveys.
"But I'm much more concerned about the fact that so much high blood pressure is not controlled," he said, and called "therapeutic inertia" an important reason.

It is not enough for doctors to write a prescription and tell patients to return for a checkup in six months, he said. Rather, a working partnership between health care professionals and patients is needed to encourage people to monitor their pressure, adopt protective habits and continue to take medication that effectively lowers pressure.

Treatment and prevention
Diuretics are a first-line and inexpensive remedy, but many patients with hypertension also need other drugs to lower pressures to a desirable level. Chobanian, whose New England Journal report was titled "The Hypertension Paradox: More Uncontrolled Disease Despite Improved Therapy," noted that "in the majority of patients, two or more antihypertensive drugs are required to achieve target blood-pressure levels." In the interview, he emphasized the detrimental role played by diets high in salt and calories and low in protective fruits and vegetables -- a result of portions that are too large and of too many fast and processed foods that rely on salt to enhance flavor.

"Generally, the average person in our society consumes more than 10 grams of salt a day," Chobanian said, "but the Institute of Medicine recommends a third of this amount as optimal."
A new RAND Corp. study finds that a one-third reduction in salt consumption could save $18 billion a year in direct medical costs. Chobanian called for better food labeling, changes in foods served in cafeterias, restaurants and schools and less advertising on children's television of unhealthy foods high in fat, salt and sugar. Also needed are better opportunities for all people to get regular exercise.

"We have to focus more on children," he said. "They're the ones who will be getting cardiovascular diseases in the future."

Jane Brody writes about health for The New York Times.

Source: HeraldTribune.com

Tuesday, 29 September 2009

Smokers less likely to receive hypertension advice

Despite being at greater risk for health problems, smokers are less likely than non-smokers to receive advice on controlling their hypertension, according to study findings presented Friday at the American Heart Association's 63rd High Blood Pressure Research Conference in Chicago.

"We found that healthcare providers were significantly less likely to tell their hypertensive patients who smoke to reduce their salt intake, exercise, and take their high blood pressure medication as compared to hypertensive patients who do not smoke," lead author Alberto Caban-Martinez, from the University of Miami Miller School of Medicine, told Reuters Health.

"Previous studies have examined the association between lifestyle modification advice and high blood pressure control in the general population. However, few have examined if smokers with hypertension receive the same advice on lifestyle modification," he noted.

The findings stem from an analysis of data from the 2007 Florida Behavioral Risk Factor Surveillance System (BRFSS) and the Florida Tobacco Callback Survey. The survey featured questions on hypertension control and smoking status, among others.

Among subjects with hypertension, smokers were 11%, 21%, and 26% less likely than non-smokers to receive advice on salt reduction, exercise, and medication usage, respectively. Smoking status, by contrast, did not influence receipt of dietary advice and was directly linked to receipt of advice for alcohol use (OR = 1.44).

Among smokers told to quit smoking, hypertension was predictive of not receiving advice on reducing salt intake (0.60), engaging in exercise (0.61), and changing dietary patterns (OR = 0.61).

"Smoking is a modifiable risk factor for cardiovascular disease, particularly high blood pressure. Practicing physicians should remain vigilant and sensitive in providing the same hypertension control advice but with greater intensity to their hypertensive smoker patients as they would for their patient populations who do not smoke," Caban-Martinez emphasized.

Source: Reuters Health

Vitamin D deficiency linked to high blood pressure

Pre-menopausal women who have a vitamin D deficiency are significantly more likely to develop high blood pressure in mid-life, latest study results suggest.

Between 1992 and 2007, US researchers took annual blood pressure measurements from 559 women aged 24 to 44. Vitamin D levels were measured once in 1993 and then compared with systolic blood pressure measurements taken in 2007.

The researchers found that women who had a vitamin D deficiency in 1993 had three times the risk of developing systolic hypertension 15 years later compared to women who had normal levels of vitamin D.

The number of women diagnosed with or being treated for hypertension, or who had undiagnosed systolic hypertension, rose from six per cent at the start of the study to 25 per cent at the end, they said.

“This study differs from others because we are looking over the course of 15 years, a longer follow-up than many studies. Our results indicate that early vitamin D deficiency may increase the long term risk of high blood pressure in women at mid-life,” the researchers said last week at the American Heart Association’s annual high blood pressure research conference in Chicago, Illinois.

Source: NursingTimes.net

Your sweet tooth could be boosting your blood pressure

From soft drinks to cereal, Americans eat four times more sugar than we did a century ago. A new study, co-authored by a Colorado doctor, shows all that fructose could be making your heart sick. Fructose is found in table sugar and high-fructose corn syrup.

Dr. Richard Johnson, with the University of Colorado Denver’s School of Medicine, gave high doses of fructose to a group of men over a two-week period.

In that short time, the men experienced significant average blood pressure increases and increases in metabolic syndrome, a group of risk factors for heart disease and diabetes. "The good news is after the study we put everyone on a low-fructose diet and were able to bring everyone back to baseline," said Johnson.

He said most Americans need to cut their sugar intake by as much as one-third, to about 35 grams a day. The study also found a drug used to treat gout, allopurinol, helped lower the elevated blood pressure, but that use is still in the experimental phase.

Source: www.thedenverchannel.com

Friday, 18 September 2009

Smoking and high blood pressure take years off of your life

Middle-aged male smokers with high blood pressure and raised cholesterol levels face dying about 10 years before healthier counterparts, a study warns. The UK study looked at more than 19,000 civil servants aged 40-69 and traced what happened to them 38 years later.
It concluded that men with these three risk factors could expect a 10-year shorter life from 50 years of age. The British Heart Foundation said it was an important reminder for everyone over 40 to have a heart health check.

The study, published in the British Medical Journal, was set up in 1967-70 at the peak of the vascular disease epidemic in the UK. Participants had their height, weight, blood pressure, lung function, cholesterol and blood glucose levels measured and completed a questionnaire about their previous medical history, smoking habits, employment grade and marital status.
Current smokers made up 42% of the men, 39% had high blood pressure and 51% had high cholesterol.

They were followed up nearly 40 years later in 2005 by which time 13,501 had died.
  • RISK FACTORS FACTS
    26% men & 25% women in England aged 35-49 smoke
    23% men & 22% women in England aged 50-59 smoke
    34% men & 26% women in England aged 45-54 have high blood pressure
    74% men & 78% women in England aged 45-54 have high cholesterol
    Source: BHF


The researchers from the University of Oxford focused on smoking, high blood pressure and cholesterol because they are the main cardiovascular risk factors. But when they broadened it out to look at all risk factors including obesity, diabetes and employment grade, they found a 15-year life expectancy difference between the 5% with the highest number of risk factors and the 5% who had the lowest number of risk factors. The proportion of deaths attributed to vascular disease in old age has declined from about 60% in 1950 to less than 40% in 2005 for both men and women.

Dr Robert Clarke, of the Clinical Trial Service Unit at the University, led the study. He said: "We've shown that men at age 50 who smoke, have high blood pressure and high cholesterol levels can expect to survive to 74 years of age, while those who have none of these risk factors can expect to live until 83. It is precisely this kind of very prolonged follow-up study that is necessary to get these results - that modest differences in heart risk factors can accurately predict significant differences in life expectancy."

"The results give people another way of looking at heart disease risk factors that can be understood more readily. If you stop smoking or take measures to deal with high blood pressure or body weight, it will translate into increased life expectancy. "

Professor Peter Weissberg, medical director at the BHF, said: "This important study puts a figure on the life-limiting effects of smoking, high blood pressure and high cholesterol.
"It provides a stark illustration of how these risk factors in middle-age can reduce life expectancy. The good news is that all of us can make changes to help us live a healthy life for longer, even after 50. We know that stopping smoking and reducing blood pressure and cholesterol, by lifestyle changes and/or tablets, can prevent the onset of heart disease - and these findings suggest it could make a decade of difference to our lives. Although the study only involved men, there is no reason why the same should not apply to women."

"So, I urge all men and women over 40 to have a health check - that all GPs can provide - which will include finding out their blood pressure and cholesterol levels, and starting to address any areas of concern."

Jane Landon, deputy chief executive of the National Heart Forum, said: "Public health strategies to discourage smoking and promote healthy eating and active lifestyles from childhood are vital to prevent the accumulation in middle age of these avoidable risk factors."

Professor Alan Maryon-Davis, president of the UK Faculty of Public Health, said: "These findings also help to explain why people who are less well off are more likely to die younger.
"Poorer people tend to smoke more, eat less healthy diets and suffer more psychosocial stress - all adding to their risk of heart disease. These are the people who need help most."

Story from BBC NEWS:http://news.bbc.co.uk/go/pr/fr/-/1/hi/health/8260561.stmPublished: 2009/09/17 23:00:32 GMT

Wednesday, 16 September 2009

Researchers seek clues to high blood pressure's origins, impacts

How high blood pressure develops and the effects it has on the body are the focus of a two-part study under way at Penn State and Johns Hopkins University that will look at hypertension in the human body and in the laboratory.

"One quarter of the population in the United States has undiagnosed or is being treated for essential hypertension," said Lacy Holowatz, assistant professor of kinesiology, who is the principal investigator on the project. "Not only is it pervasive, but it takes an emotional, physical and financial toll on the people it affects. The results from our studies should provide new and important information on the how hypertension impacts the body's cardiovascular system."

The National Heart, Lung and Blood Institute of the National Institutes of Health will fund this five-year study for $1.7 million. The NIH's American Recovery and Reinvestment Act funding will supply $750,000 of the grant.

Essential hypertension, also known as primary hypertension, is high blood pressure with no identifiable cause. Secondary hypertension, in contrast, is high blood pressure that results from another condition or disease.

The research team will use a dual-examination approach analyzing hypertension and blood flow in the body and, in a more controlled situation, outside the body. The human studies will take place on Penn State's University Park campus and will use microdialysis, a method where researchers insert a microfiber into a portion of skin about the size of a quarter and infuse certain drugs or solutions to only that area. For the external examination, Holowatz will work with researchers from the Johns Hopkins University who will analyze skin biopsy samples.

Holowatz will heat and cool the skin to examine blood vessel function. She will see how this differs in someone with hypertension compared with someone with normal blood pressure. Holowatz's aim is to shed light on potential therapeutic strategies for people with hypertension. The work is an extension of previous work by Holowatz and her colleagues that provided a better understanding of how hypertension affects the body's vascular system.

Other key individuals working on the project include Larry Kenney, professor of physiology and kinesiology; Mosuk Chow, associate professor of statistics, and Jane Pierzga, research assistant, all at Penn State, and Daniel Berkowitz, associate professor of anesthesia and critical care medicine at Johns Hopkins University.

Thursday, 10 September 2009

Road noise link to blood pressure

People living near noisy roads are at greater risk of developing high blood pressure, a Swedish study suggests. A Lund University team found risk rose above an average daily exposure of 60 decibels, which accounts for about one in four people in western Europe.

They said it was likely noise caused stress - and maybe sleep disruption - leading to blood pressure problems. But UK experts questioned the findings, saying other factors such as diet and smoking were more important. Researchers analysed questionnaires completed by nearly 28,000 people as well as analysing neighbourhood traffic noise. They found that at above 60 decibels the risk of high blood pressure rose by more than 25%.

Above 64 decibels the risk rose by more than 90% although the team cautioned that the low numbers in this group could have skewed the findings. The report, published in the Environmental Health journal, said the findings were worrying as high blood pressure increased the chances of heart disease and stroke.

However, the link was not apparent for people above 60 years old. The researchers said this was either because they had become desensitised to the noise or already had high blood pressure.

Report author Theo Bodin said: "Road traffic noise is the most important source of community noise so we felt it was important to look at this. "I think what we have found is probably linked to the noise triggering stress. Previous research has found this, although we need to look at this issue further before we make firm conclusions."

But Professor Alan Maryon-Davis, president of the UK's Faculty of Public Health, said: "It seems to me that they have found an association rather than a cause. Other factors, such as smoking, diet and deprivation, are likely to be playing more of a role.

"However, it is an area of research which merits further work."

Source: BBC