Treating people with prehypertensive blood pressure readings with antihypertensive medications reduces the risk of stroke, but comes at the cost of more side effects, a meta-analysis showed.

In a pooled analysis of 16 trials, antihypertensive therapy lowered the risk of incident stroke by a relative 22% versus placebo in patients with a baseline blood pressure of 120 to 139/80 to 89 mm Hg (RR 0.78, 95% CI 0.71 to 0.86), according to Ilke Sipahi, MD, of University Hospitals Case Medical Center in Cleveland, and colleagues.

But, although reporting was not consistent between trials, active treatment was also associated with possible harm, indicated by higher rates of hyperkalemia, renal failure, hypotension, and peripheral edema, the researchers reported online in Stroke: Journal of the American Heart Association.

Guidelines do not currently recommend using drugs to lower blood pressure in patients with prehypertension, which can occur in up to 40% of individuals depending on the age, sex, and ethnicity of the population, Sipahi and colleagues wrote.  They said that any decision to use antihypertensives in these patients would have to include consideration of the costs of the initial treatment and of dealing with the potential side effects.

"Thus, although the risk reduction in incident strokes in patients with prehypertensive blood pressure levels is well elucidated in our meta-analysis, the clinical implications are uncertain," they concluded.  Although lowering blood pressure with medications has been shown to reduce rates of cardiovascular events, including stroke, in patients with hypertension, the effects of treatment are less clear in patients with prehypertension because of the lack of randomized trials.

To explore the issue, Sipahi and colleagues gathered data from 16 randomized, placebo-controlled trials that evaluated antihypertensive treatment for other conditions and included patients with prehypertensive blood pressure values at baseline. The studies included a total of 70,664 patients.  Half of the trials included angiotensin converting enzyme (ACE) inhibitors, four included angiotensin receptor blockers (ARBs), two included calcium channel blockers, one included both a calcium channel blocker and ACE inhibitor arm, and one studied an ACE inhibitor and/or a calcium channel blocker.

Active treatment reduced blood pressure in all of the trials. The average readings at the end of the trials were 130.5/76.5 mm Hg with antihypertensive treatment and 134.2/78.4 mm Hg with placebo.  There was a lower rate of incident stroke with antihypertensive therapy in all but two of the trials, and in the pooled analysis. An analysis restricted to the five trials in which participants had an average baseline blood pressure less than 130/85 mm Hg yielded a similar result.  The findings were largely consistent across drug classes, although the risk reduction did not reach statistical significance for ARBs.

In terms of absolute risk, 2.01% of patients in the treatment arm had a stroke during follow-up, compared with 2.61% of those in the placebo arm.  Meta-regression analysis did not show that risk reduction was related to the magnitude of average blood pressure reduction.  The researchers calculated that the number needed to treat was 169 (with an average treatment duration of 4.3 years), adding, however, that the figure is likely to vary widely depending on the patient population studied.  To put that number into context, they noted that the number needed to treat to prevent one stroke was 642 with statins for primary prevention.

Two other outcomes -- MI and cardiovascular death -- were not significantly reduced with antihypertensive treatment, although the risk ratios leaned toward a benefit.  "However, these trends were likely driven by the ACE-inhibitor trials in patients with established atherosclerotic disease or very high cardiovascular risk (i.e., HOPE and EUROPA trials)," the authors wrote. "Exclusion of the above trials caused the trend toward risk reduction to disappear."

The analysis was limited, the authors wrote, by the lack of access to patient-level data, the inclusion of some patients who had a diagnosis of hypertension but who had been treated to prehypertensive levels at baseline, and the uncertainty about the type and severity of strokes that were prevented through treatment.

Source: Todd Neale, Senior Staff Writer, MedPage Today 9/12/2011

Up to a third of patients home monitor - do you?

Up to a third of patients in primary care with hypertension are self-monitoring their blood pressure, suggesting home readings could be incorporated more closely into clinical practice, a new study concludes. Self-monitoring of blood pressure was particularly common among patients with diabetes who were monitoring their blood glucose, and even among patients who were not self-monitoring, the majority said they would consider doing so. Researchers sent questionnaires to 1,815 patients who had hypertension, across four GP practices in the West Midlands, between November 2008 and April 2009. Among the 53% who responded, 31% reported they currently self-monitored blood pressure, with two-thirds monitoring at least once a month. Of participants who did not self-monitor, 58% reported they would consider doing so. Patients who had diabetes and monitored their blood glucose were five times more likely to monitor their blood pressure that those with diabetes who did not monitor blood glucose. Study leader Professor Richard McManus, professor of primary care research at the University of Oxford and a GP in Birmingham, conceded the survey could have been affected by response bias. But Professor McManus, a member of the NICE guideline development group that recommended ambulatory blood pressure monitoring, said: ‘GPs should be aware around a third of their patients with hypertension could be monitoring their own blood pressure and of the opportunities this could bring to daily management.' Co-author Sabrina Grant, research associate at the University of Birmingham, said the results ‘indicate home blood pressure monitoring is more popular than we might think'. Dr Chris Arden, a cardiology GPSI in Southampton, said self-monitoring could play an important role, particularly in diagnosis: ‘I've been encouraging patients to purchase their own monitors – and we've got monitors we loan out.' He said it was an effective use of resources, moving responsibility back to patients and easing pressures on practice time.  Dr Terry McCormack, council member of the Primary Care Cardiovascular Society and a GP in Whitby, Yorkshire, said: ‘What is interesting is the high uptake amongst diabetic patients who already appreciate the advantages of self-monitoring. We do want more people to self monitor but we are not there yet.' Dr Kathryn Griffith, a cardiology GPSI in York, said: ‘I would agree that 30-50% of my patients have monitors. My concern is that they may have had them for a long time and that they may not be calibrated.' New NICE hypertension guidance recommends using clinic measurements to monitor response to anti-hypertensive drugs or lifestyle modifications, but suggests using ambulatory blood pressure monitoring or home blood pressure monitoring – in addition to clinic readings - in patients who have a white-coat effect. Source: Pulse

Hypertension risk greatly increased for children in top 15% of BMI

Children in the 85th percentile for body mass index (BMI) are at greatly elevated risk for high blood pressure and require regular monitoring as well as possible interventions, according to a study from the American Heart Association.

The study of 1,111 healthy Indiana school children—42% black, equally divided by sex (mean enrollment age, 10.2 years)—found that the adiposity effect on blood pressure was minimal until patients reached the overweight category, when it increased 4-fold. Researchers observed a similar effect on children younger than 10 years, those aged 11 to 14 years, and those older than 15 years. The group underwent 9,102 semiannual blood pressure and height/weight assessments during that time period (mean follow-up, 4.5 years).

“Higher blood pressure in childhood sets the stage for high blood pressure in adulthood,” said Wanzhu Tu, PhD, lead researcher and professor of biostatistics at Indiana University School of Medicine in Indianapolis. “Targeted interventions are needed for these children. Even small decreases in BMI could yield major health benefits.”

Researchers emphasized the importance of viewing overweight and obese children differently from their normal-weight cohort, even if they seem healthy. “The adiposity effects on blood pressure in children are not as simple as we thought,” Tu said.

He especially cautioned parents and pediatricians to monitor weight gain in already heavy children.

“If they see a dramatic weight gain in a child who already is overweight, they need to intervene with behavioral measures, such as dietary changes and increased physical activity, to improve overall health and minimize cardiovascular risk,” Tu said.

Researchers noted that leptin, the adipose tissue-derived hormone, together with heart rate, showed an almost identically patterned relationship to blood pressure as did BMI, suggesting a role of the hormone in the elevated blood pressure.

Obese girls at greater risk of high blood pressure

Although obesity does not help teens of either gender, the impact on girls is vastly greater than those of boys, according to a study.  The results from researchers at the University of California Merced were released on Friday and were presented during the American Physiological Society Conference.  The study may apply to the approximately 17 percent of U.S. children and adolescents between the ages of 2 and 19, a total of 12.5 million people. About 3 percent of children have high blood pressure, according to a 2007 study by the CDC.  Approximately 17 percent or 12.5 million children and adolescents age 2-19 are obese.  An estimated 3 percent of kids have high blood pressure according to a study in 2007 by the CDC.

In the study Dr. Rudy M. Ortiz, PhD, Associate Professor at School of Natural Sciences at UC Merced and his team, measured the systolic blood pressure and calculated the body mass index of 1,700 teenagers ages 13 through 17 during the school district health survey and physicals.

The researchers found that boys are 3.5 times more likely to develop elevated systolic blood pressure than non-obese boys.

Meanwhile, obese girls were 9 times more likely to develop elevated systolic blood pressure than non-obese girls.  Systolic blood pressure is the pressure in blood vessels when the heart beats; Body mass index helps calculate human body fat based on an individual’s height and weight.

"We were able to categorize the students in different ways, first based on BMI within each of the three blood pressure categories. Then we flipped that around and looked at each category of blood pressure for different weight categories said Dr. Ortiz."

Researchers found a connection between body mass index and systolic blood pressure. The effect of body mass index on systolic blood pressure is much greater when assessed by blood pressure.  "In each case, we are looking at SBP as the dependent variable, said Dr. Ortiz."

"The results do not bode well for obese teens later in life, especially for the girls,” said Dr. Ortiz.  "We know, for example, that obese adolescent females participate in 50 to 60 percent less physical activity than boys in the population surveyed."

Source: Medical Daily

Overweight children at risk of high blood pressure

Children who are overweight compared to their peers are nearly three times more likely to have high blood pressure, a new study shows.  The study, published in the journal Hypertension, followed 1,111 school-aged children in Indiana for an average of four years.  Twice each year, researchers visited schools to take blood pressure measurements and record the kids’ heights and weights.

About 40% of the children in the study were above the 85th percentile on growth charts for their height and weight. When children are above the 85th percentile, doctors consider them to be overweight.  Among the overweight kids, 14% had blood pressure that was higher than normal, while only 5% of normal-weight kids had elevated blood pressure.

The study also found that extra pounds are especially dangerous for kids who are already big.

"For an overweight and obese child, if you increase your BMI percentile a little bit, that would increase your blood pressure strongly,"says researcher Wanzhu Tu, PhD. Tu is a research scientist at Regenstrief Institute and professor of biostatistics at Indiana University School of Medicine, both in Indianapolis.  "In the same way," Tu says, for just a little bit of weight loss "you could benefit greatly in terms of blood pressure."

The risks of overweight were the same, regardless of the child’s sex or race. About 42% of the kids in the study were black.

Pediatricians say the study is wake-up call.  "We’ve tended to look at the overweight category as a lower-risk category," says Stephen R. Daniels, MD, PhD, chairman of the department of pediatrics at the University of Colorado School of Medicine in Denver. He was not involved in the research.  "This suggests to me that we really need to worry about kids who are in that overweight category," says Daniels, who is also pediatrician-in-chief at Colorado Children’s Hospital.

Other experts say the findings are concerning because having high blood pressure has been shown to set kids up for health complications.  Not only are children with high blood pressure much more likely to turn into adults who have high blood pressure, but newer studies have shown that kids can get the same kinds of organ damage -- to the heart, blood vessels, and kidneys -- that doctors once thought was only a problem for adults with the condition.

One study even found that kids with high blood pressure have subtle changes in the brain area that controls attention, problem solving, and working memory.  "For physicians, we have to take much more seriously this concept of the childhood origins of adult diseases and look beyond the weight and beyond the blood pressure level because we’re finding more evidence, subtle evidence, of injury," says Bonita Falkner, MD, professor of medicine and pediatrics at Thomas Jefferson University in Philadelphia.

"So it’s not going to be a risk that’s going to be in the future. It’s a risk that’s now," says Falkner, who wrote an editorial on the study, but was not involved in the research.

"It jacks up the concern about preventing childhood obesity and also not waiting until they are obese.  Even overweight can be problematic for children."

Source: WebMD/Hypertension

Hypertension increases cancer risk

A large study has found that hypertension is associated with an increased risk for cancer death, and that hypertension increases the risk of developing cancer — although the latter effect reached statistical significant only in men, not women.

"The relative and absolute risk estimates were rather modest," said lead researcher Mieke Van Hemelrijck, PhD, from the cancer epidemiology group at King's College London, United Kingdom.

"This is important from a public health perspective, since a large proportion of the population in many western countries suffers from hypertension," she told delegates at a presidential session here at the 2011 European Multidisciplinary Cancer Congress. The paper was chosen as one of the best abstracts from the meeting.

One of the implications of this finding is the opportunity it offers for intervention, said Per Hall, MD, PhD, medical oncologist and professor of epidemiology at the Karolinksa Institute in Stockholm, Sweden, who acted as discussant for the paper.

"Primary prevention strategies developed by cardiologists have the potential to lower the risk of cancer," Dr. Hall explained.

For oncologists, this highlights the need for a more holistic approach, he continued. Oncologists must learn to think beyond cancer therapy and consider treatment of the whole person, including conditions such as hypertension and cardiovascular disease, he said. "If we look for other things also, it would definitely improve overall survival," he added.

Link With Hypertension

Previous studies exploring the link between hypertension and cancer have yielded mixed results, with some showing and some not showing an association, Dr. Van Hemelrijck told Medscape Medical News.

However, many earlier studies used just 1 measurement of blood pressure (BP), which can cause random error, she noted. To control for this, Dr. Van Hemelrijck and colleagues used data from a subgroup of individuals in their study (133,829 of the 577,799 participants) who had undergone several measurements of BP, and used these findings to correct for random error in the whole sample.

The researchers also controlled for smoking and obesity, which again was not controlled in some of the previous studies, and for age and sex. However, the study did not have any information on antihypertensive treatment; there were no records on whether and which drugs were being used to control BP, Dr. Van Hemelrijck noted.

Largest Study So Far

The study is the largest of its kind, analyzing data on 289,454 men and 288,345 women. The data come from Metabolic Syndrome and Cancer (Me-Can) project, which includes people from Norway, Sweden, and Austria who had undergone regular health examinations from 1972 to 2005.

After a median follow-up of 12 years, excluding the first year, cancer had been diagnosed in 22,184 men and 14,744 women, and 8724 men and 4525 women had died from cancer.

BP measurement was reported as mid-BP, which is the sum of systolic and diastolic pressure divided by 2. The average mid-BP in the study was 107 mm Hg for men and 102 mm Hg for women. The results for BP were divided into 5 groups, with individuals in the first quintile having the lowest BP and those in the fifth quintile having the highest BP.

Cox proportional hazard regression analysis showed that the risk of developing and of dying from cancer was linearly proportional to the increase in BP.

The increase in the incidence of cancer with increasing BP was statistically significant for men — specifically, the risk increased for oral, colorectal, lung, bladder, and kidney cancers, and for melanoma and nonmelanoma skin cancer. The overall risk of developing any cancer was increased by 29% between men in the lowest quintile and those in the highest quintile.

An increase was also seen in women, but did not reach statistical significance. An increase in incidence risk was seen for liver, pancreas, cervix, and endometrial cancers, and for melanoma.

Increasing BP also increased the risk of dying from cancer; this effect was statistically significant in both sexes. Men in the fifth quintile of mid-BP had a 49% increased risk for cancer death, compared with those in the lowest quintile; for women, this risk increased by 29%.

In terms of absolute risk, the increase from raised BP was rather modest, Dr. Van Hemelrijck noted. "Men with mid-blood pressure in the highest [quintile] had an absolute risk of developing cancer of 16%, compared with an absolute risk of 13% for those with mid-blood pressure in the lowest [quintile]," she said.

For cancer death, the absolute risk was 8% for men in the highest quintile, compared with 5% for men in the lowest quintile; for women, the risk was 5% in the highest quintile and 4% in the lowest quintile, she reported.

We cannot claim that there is a causal link between high blood pressure and cancer risk.

This study is observational, so "we cannot claim that there is a causal link between high blood pressure and cancer risk, nor can we say that the cause of cancer is a factor related to high blood pressure," Dr. Van Hemelrijck explained.

Hypertension might be a proxy for an unhealthy lifestyle, she speculated in comments made to Medscape Medical News. It is already established that cancer and diabetes are risk factors for cancer; hypertension might be part of the whole metabolic syndrome, which increases the risk, rather than just a factor on it's own, she said.

She did note that a meta-analysis reported some years ago (Am J Med. 2002;112:479-486) specifically linked hypertension to an increase in the risk for kidney cancer. In that case, a causality is perhaps more understandable because high BP increases the stress on the kidney.

The meta-analysis analyzed data from 10 studies (47,119 patients), and found that hypertension was associated with a 23% increase in the risk of dying from cancer. Those researchers found an association between hypertension and an increased risk of developing renal cancer, but not with cancer at any other site. The adjusted odds ratio for renal cell cancer among hypertensive patients, relative to their normotensive counterparts, was 1.75.

One of the coauthors on that meta-analysis, Franz H. Messerli, MD, FACC, FACP, professor of clinical medicine at the Columbia University College of Physicians and Surgeons and division of cardiology at St. Luke's-Roosevelt Hospital in New York City, was asked to comment on the study by Dr. Van Hemelrijck's team. "Since this is the largest study so far linking hypertension to cancer, it has be looked at thoroughly. However, in my opinion, the issue remains a can of worms," he told Medscape Medical News.

"We should remember that hypertension may not only be a proxy for an unhealthy lifestyle, as the authors state, but also a proxy for more frequent visits to physicians. The more often patients are seen by physicians, the greater the odds of malignancies being diagnosed," Dr. Messerli explained.

In addition, he pointed out that "patients with hypertension are commonly on antihypertensive therapy for years and decades. The long-term safety of antihypertensive drugs has not been well documented, since most safety studies only last 3 to 5 years. The present study did not provide any information on antihypertensive treatment. Thus, we don't know whether the link between hypertension and cancer was due to the blood pressure elevation per se, its treatment with various drugs, the "unhealthy lifestyle," or even to the more frequent physician visits."

"Clearly, studies like this one,...however thorough and well done, may create more heat than light and are prone to confuse patients and physicians alike," Dr. Messerli opined.

Modest Effect

Jan Willem Coebergh, MD, PhD, professor of cancer surveillance at the Eindhoven Cancer Registry in the Netherlands, and spokesperson for the European CanCer Organisation, said in a statement that "this extensive population-based study on the role of concomitant hypertension shows that it has a modest effect on the risk of certain cancers, especially the kidney and colorectum, but it is probably a smaller effect than that caused by diabetes and various vascular conditions."

Franco Berrino, MD, from the Instituto Nazionale Tumori in Milan, Italy, and spokesperson for the European Society of Medical Oncology, said that "there is increasing evidence that metabolic syndrome is associated with a higher risk of developing cancer, as well as other chronic diseases. As an unhealthy lifestyle is a major determinant of hypertension, these results from the highly productive Me-Can project add to the evidence that lifestyles affect both the risk and prognosis of cancer."

2011 European Multidisciplinary Cancer Congress (EMCC): Abstract 4LBA. Presented September 27, 2011.

Source: Medscape

Red wine may not lower blood pressure say researchers

Red wine may not lower blood pressure say researchers

We have been told a lot that a moderate intake of red wine is good for your heart health.  Some studies have suggested a glass a day lowered your heart disease risk.  The health benefits are said to come from antioxidants called polyphenols.  However, now Dutch researchers have found that the polyphenols don't seem to promote heart health by reducing blood pressure. "Our findings do not support [the idea] that potential cardiovascular benefits of red wine consumption result from blood pressure lowering by polyphenols," said researcher Ilse Botden, from Erasmus Medical Center in Rotterdam, Netherlands. The findings don't suggest red wine isn't still heart-healthy - just that it doesn't seem to work by lowering blood pressure.  The benefit of red wine and heart health, she says, ''apparently occurs in a blood pressure-independent manner." Botden presented her findings to the  American Heart Association's High Blood Pressure Research 2011 Scientific Sessions in Orlando.