Hypertension common amongst young people

In the NIH-funded National Longitudinal Study of Adolescent Health (Add Health), the prevalence of hypertension in 24- to 32-year-olds was 19% in 2008, according to Quynh Nguyen, MSPH, a doctoral student at the University of North Carolina's Gillings School of Global Public Health in Chapel Hill, and colleagues.  That compares with a rate of 4% among young adults participating in the National Health and Nutrition Examination Survey (NHANES) for a similar time period, the researchers reported online in Epidemiology.

"We tend to think of young adults as rather healthy, but a prevalence of 19% with high blood pressure is alarming, especially since more than half did not know that they had high blood pressure," Harris said.  Although the issue warrants further study, she added, "we think that the prevalence probably lies somewhere in between these two estimates."

Add Health was started in 1994-1995 by enrolling more than 20,000 U.S. adolescents in middle school and high school. The students have been followed up periodically since then, most recently with Wave IV in 2008, when researchers began collecting in-home blood pressure measurements.  For comparison, the researchers used participants of similar age from NHANES 2007-2008. The cross-survey comparison included 14,252 Add Health participants and 733 NHANES participants.

Both the rate of blood pressure of 140/90 mm Hg or greater (19% versus 4%) and mean blood pressure (125/79 mm Hg versus 114/67 mm Hg) were higher in Add Health than in NHANES, which remained consistent in all sociodemographic subgroups.

Survey weights and propensity for differential selection into Add Health did not account for the different rates of hypertension observed in the two studies.

After adjustment for numerous participant characteristics, examination time, use of antihypertensives, and consumption of food, caffeine, and cigarettes before blood pressure measurement, there was still a significantly increased likelihood of hypertension in Add Health (OR 6.6, 95% CI 4.0 to 11.0).

The researchers then examined other potential methodologic concerns, including digit preference, validity, reliability, measurement context, and interview content.

"We looked at numerous possible explanations, and we're not able to explain the difference," Harris said. "We've ruled out any possible explanation that's due to the design of the study or the characteristics of the people in the study."  In their paper, the researchers called their results robust, but acknowledged that such a high rate of hypertension in young adults raises questions about biologic plausibility.

They added, however, that even higher rates of hypertension have been seen among Latin American and Caribbean men.  "Prior findings in the global context suggest that [the hypertension rates] are neither biologically implausible nor without epidemiologic precedent," they wrote.  There were some limitations of the study, including the fact that the validity of blood pressure measurements was not monitored on an ongoing basis, and that the sample size was not large enough to provide adequate power to look at subgroup differences in the reliability of blood pressure measurements.  In addition, the proportion of Add Health participants defined as having hypertension based on elevated blood pressure alone may have been affected by variation in blood pressure measurement.

Source: MedPage Today

High blood pressure: stand up coffee, alcohol and lack of exercise!

Evidence continues to build that lifestyle modifications help control blood pressure (BP) levels. Data evaluating the consumption of coffee and alcohol and the impact of low fitness levels will be presented at the American Society of Hypertension, Inc.'s 26th Annual Scientific Meeting and Exposition (ASH 2011) and will be featured in the May 22 ASH press briefing.

"It's critical that we fully understand how lifestyle factors impact the ability of patients and physicians to screen, diagnosis, and treat high blood pressure," explains ASH press briefing moderator Lawrence J. Appel, MD, MPH, Professor of Medicine, Epidemiology and International Health (Human Nutrition) Director, Welch Center for Prevention, Epidemiology, and Clinical Research Johns Hopkins Medical Institutions. "As we continue to develop our understanding of how diet and exercise choices impact hypertension, including the nuances among specific patient populations, we are gathering evidence to help us best counsel and advise our patients."

Studies highlighted in the press briefing include:

Coffee

Effect of Coffee on Blood Pressure and Cardiovascular Disease among Hypertensive Individuals:

Studies have shown that it is possible for caffeine to cause a short, but dramatic increase in your BP, even if you don't have high BP. A new meta-analysis shows that, among hypertensive individuals, caffeine intake of 1.5 - 2 cups produces an acute increase in BP, which lasts for at least three hours. However, present evidence does not support an association between longer-term coffee consumption and increased BP or increased risk of cardiovascular disease among patients with HBP.

In five trials, the administration of 200-300 mg caffeine (the content of 1.5-2 cups of filtered coffee) produced a mean increase of 8.2 mm Hg (95% confidence interval [IC] 6.2-10 mm Hg) in systolic BP and of 5.6 mm Hg (95% CI 4.2-6.9 mm Hg) in diastolic BP. The increase in BP was observed in the first hour after caffeine intake and lasted for at least three hours. In six trials on the longer-term effect (1 week) of coffee, there was no increase in BP when comparing caffeine versus placebo, coffee versus a caffeine-free diet, or coffee versus decaffeinated coffee.

"These results have clinical implications for the control of hypertensive patients. Because caffeine intake acutely increases blood pressure, hypertensive patients with uncontrolled blood pressure should avoid consuming large doses of caffeine. Also, the consumption of caffeine in the hours before measuring blood pressure may elevate the reading and give the erroneous impression that blood pressure is poorly controlled," explains lead study author, Esther Lopez-Garcia, PhD, Department of Preventive Medicine and Public Health, Autonoma University of Madrid, Spain. "Finally, in well-controlled hypertensive patients, there is no evidence to justify avoidance of habitual caffeine consumption and healthcare providers should emphasize other lifestyle modifications, such as maintaining weight control, increasing physical activity, and stopping smoking."

Alcohol

Alcohol Consumption and the Risk of Hypertension: A Systematic Review and Meta-Analysis. The Risk for Hypertension Increases Linearly with Alcohol Consumption in Men

Drinking too much alcohol can raise BP to unhealthy levels, especially among men. The meta-analysis evaluated a total of 16 prospective studies, which included 158,142 men and 314,258 women. Among men, a linear dose-response relationship between alcohol intake and risk of development of hypertension was noted. As compared to non-drinkers, men consuming < 10g/day of alcohol had a relative risk (RR) of 1.006, those consuming 10-20 g/day had a RR of 1.091, and those consuming > 30g/day had a RR of 1.416. Among women, the meta-analysis indicated protective effects at < 10g/day (RR -0.867) and 10-20g/day (RR - 0.904) of alcohol consumption, while the risk increased in women consuming > 30g/day (RR - 1.188). The risk of hypertension significantly increases with consumption of more than 30g/day in men in women alike.

"For patients, especially men, it's very important to ask about alcohol consumption and to recommend moderation when trying to maintain blood pressure control," explains Agarwal, MD, MPH, Department of Medicine, St. Luke's-Roosevelt Hospital, Columbia University College of Physicians and Surgeons.

Not enough exercise

Excessive Blood Pressure Elevation during Exercise Correlates with Low Fitness among Normotensive Firefighters. Lower Fitness is Associated with a Higher Risk of an Exaggerated Blood Pressure Response

Surprisingly, the leading cause of on- duty death among US firefighters (40% of cases) is coronary heart disease (CHD), rather than burns or smoke inhalation. The strain of suppressing a fire is associated with a markedly increased risk of cardiovascular mortality as compared to non-emergency duties and firefighters with low cardiorespiratory fitness are at increased risk for cardiovascular death. A study examined the prevalence of peak exercise hypertension among firefighters who do not have hypertension to see whether it correlates with low cardiorespiratory fitness.

The study evaluated 691 firefighters without hypertension and found that 14% (93) had an exaggerated BP response to exercise and 31.1% of the "exaggerated BP" firefighters were in a low fitness group, compared to 18% in the normal responders (p=0.016). Only 13.5% of "exaggerated BP" group had high fitness (third quartile) compared to 30.6% in the normal responders (p=0.0024). Thus, lower fitness is associated with a higher risk of an exaggerated BP response.

"Firefighters present a unique opportunity to evaluate the role of fitness and its association with high blood pressure at peak exercise ," explains lead study author, Adi Leiba, MD, MHA, Fellow, Nephrology and Hypertension, Sheba Medical Center, Israel Clinical Instructor, Mount Auburn Hospital, Harvard Medical School, Boston, MA. "This data is important because it provides further evidence that improved fitness helps control blood pressure spikes, including those spikes during exercise and stress."

Source:American Society of Hypertension (ASH)

Passive smoking may raise blood pressure in boys.

Passive smoking can raise blood pressure levels in boys, scientists have found. This will put them at higher risk in later life of hypertension – which is itself associated with a greater chance of developing heart and kidney disease.  In her study, Jill Baumgartner of the University of Minnesota's Institute on the Environment looked at more than 6,400 children aged eight to 17 who had been exposed to secondhand tobacco smoke. She found an average rise of 1.6 mmHg – or a 1% increase on average healthy levels – in the systolic blood pressure of boys who had been exposed to secondhand smoke compared to boys who had not.

"For that individual child, it won't have a huge impact," said Mike Knapton, associate medical director at the British Heart Foundation. "But, if you've got two million kids with a 1% increase, you start to see changes in the prevalence of respiratory disease, heart disease and cancer."  Baumgartner, who presented her work on Sunday at the annual meeting of the Paediatric Academic Societies in Denver, Colorado, said more than a third of children in the US and globally were exposed to secondhand smoke levels similar to those associated with adverse cardiovascular effects in her study.

Previous research has linked secondhand smoke and increased blood pressure in adults, but the effect had not been measured in children.  Systolic pressure is the maximum during a heartbeat and measures the surge of blood when the heart contracts. A healthy level in adults is about 120mmHg but the level changes for children as they grow older. Knapton said a one-month-old child's average systolic blood pressure was 60mmHg, rising to 115mmHg at 15.

"We know blood pressure tends to track upwards as you get older – my blood pressure will be greater now than as a child," he said. "The higher you start, the higher it gets to when you're an adult and we know that, in adults, high blood pressure is a risk factor for heart disease.

"The assumption might be that, if you're pushing your children's blood pressure up in childhood, that will put them at greater risk of blood pressure as an adult, which will put them at higher risk of heart disease and stroke."  Baumgartner's work showed that, unlike boys, girls exposed to secondhand smoke had lower systolic blood pressures than girls who were not – by 1.8 mmHg on average.

"These findings support several previous studies suggesting that something about female gender may provide protection from harmful vascular changes due to secondhand smoke exposure," she said. "An important next step is to understand why."

The researchers collected information on passive smoking from questionnaires conducted by the US Centres for Disease Control and Prevention between 1996 and 2006. The surveys collected information on which children lived with smokers and also on the levels of cotinine in a child's blood, which is a byproduct of the metabolism of nicotine by the body and seen as a reliable marker for exposure to tobacco smoke.
Baumgartner said the relationship between secondhand smoke exposure and blood pressure observed in her study provided "further incentive for governments to support smoking bans and other legislation that protects children from secondhand smoke".

Knapton said passive smoking was only part of the story. "There has been an association between cot death and smoking in the home – 86% of cot deaths occur in families where the mother smokes," he said.
"We know that children from families that smoke are more likely to smoke themselves. Children who live with two adult smokers are four times more likely to be smokers themselves than children who live with non-smokers."

Source: The Guardian

Faith probably doesn't lower your blood pressure

Although faith in a higher power may bring you great comfort, leading a religious life won't help reduce high blood pressure, a small study suggests.  In fact, the study found that people who tried to incorporate religion into all aspects of their lives were the most likely to have high blood pressure, also known as hypertension.

But, that doesn't mean that church attendance or a deep faith can cause high blood pressure.

"I don't think the take-home message from this study is that church is causing hypertension," said one of the study's authors, Amy Luke, an associate professor in the department of preventive medicine and epidemiology at Loyola University Chicago Stritch School of Medicine.  "It may be that the people who attend church the most have a stronger social network, which may make them more aware of their health and more likely to have their blood pressure checked," Luke theorized. She added that more research needs to be done to better understand why being more religious was related to a greater incidence of high blood pressure in this study.

Results of the study, which was mainly conducted by medical students led by student Laura Heinrich, were scheduled to be presented Saturday at the Society of Teachers of Family Medicine meeting in New Orleans.
Previous research has suggested a link between religious activity and lower blood pressure levels. In addition, religious activity can likely reduce stress, hostility, depression, hopelessness and loneliness, which have been linked to raised blood pressure levels. Having a strong social network, as you might find in a community church, has also been linked to better health, according to the study's authors.

The new study was a subset of a larger study designed to assess how the economic downturn has affected people's health. It was conducted in an area of Chicago that's relatively low income, according to Luke.
Two hundred people participated in the study. All were black and 52 percent were male. The average age was 42 years old, and nearly 29 percent were taking medication to treat high blood pressure.

Fifty-eight percent said they attended church at least a few times a month, and 35 percent of those people attended at least once a week. Forty-five percent of the study volunteers said they spent private time on religious activities, such as prayer, meditation or Bible study, the investigators found.

All of the study volunteers completed a 65-point interview and religiosity was measured using the Duke University Religion Index, which asks participants to respond "true," "tends to be true," "unsure" or "not true" to statements such as "In my life, I experience the presence of the Divine" or "My religious beliefs are what really lie behind my whole approach to life."

Thirty-five percent of those who said religion carried over to all parts of their lives had high blood pressure compared to 19.6 percent of those who said that religion didn't carry over, according to the report.
Luke said that Heinrich and the other medical students were quite surprised by their findings. They had expected to see an association between religion and lower blood pressure.
"I think the whole issue of religion and health is really complex," said Luke.

Dr. Jonathan Whiteson is director of the Cardiac and Pulmonary Wellness and Rehabilitation Program at NYU Langone Medical Center in New York City. He said: "I didn't think this study was so surprising. There's been a lot of conflicting data on religion and blood pressure and cardiac disease as well. It's a confusing area, and depending on how the studies are conducted, you may see different results.
"Generally, it seems that religion should have positive health benefits. People who aren't socially isolated tend to take better care of themselves," he added.  "But, there's been research on both sides -- positive and negative," said Whiteson, adding that it's definitely an area that needs further research.

Because this study was presented at a medical meeting, the findings should be viewed as preliminary until they are published in a peer-reviewed journal.

Source: Healthday News