An aspirin taken every morning didn't lower the blood pressure of prehypertensive people, but the evening regimen did, Dr. Ramon C. Hermida reported Wednesday at the American Society of Hypertension annual meeting, in New Orleans.

A previous study by Hermida, who is director of bioengineering and chronobiology at the University of Vigo, showed the same beneficial effect of bedtime aspirin for people with moderately high blood pressure. The new report is the first study to show the drug's benefit -- although only when taken at night -- with prehypertension, defined as blood pressure just below the 140/90 level. Prehypertension is a known warning sign of future risk of heart disease, stroke and other cardiovascular problems.

Why aspirin should do its good work for blood pressure at night but not in the daytime is not clear, Hermida said. Research indicates that it can slow the production of hormones and other substances in the body that cause clotting, many of which are produced while the body is at rest.

The three-month study included 244 adults diagnosed with prehypertension. A third of them were advised to follow general rules of hygiene and diet designed to reduce blood pressure, another third were told to take a 100-milligram aspirin tablet every night at bedtime, and the final third were told to take the same aspirin dose on awakening.

Researchers monitored blood pressure levels at 20-minute intervals from 7 a.m. to 11 p.m. and at 30-minute intervals at night before the trial began and three months later.

Systolic blood pressure (the higher number in the 140/90 reading) dropped 5.4 points and diastolic pressure by 3.4 points for those taking aspirin before bedtime. No drop in blood pressure was found in those taking morning aspirin or following the general guidelines.

"There is some evidence that taking a variety of medications, including those for hypertension, at night is associated with greater blood pressure reduction than taking them in the morning," said Dr. Suzanne Oparil, president of the American Society for Hypertension. "I don't think we know why."

It's possible that there might be better absorption of the medication by the gastrointestinal tract at night, said Oparil, who is a professor of medicine at the University of Alabama at Birmingham.

"It's all a little bit speculative about why, but I think the observation is solid," she said.

In a statement, Hermida said the new findings "show us that we cannot underestimate the impact of the body's circadian rhythms."

"The beneficial effects of time-dependent administration of aspirin have until now been largely unknown in people with prehypertension," he said. "Personalizing treatment according to one's own rhythms gives us a new option to optimize blood pressure control and reduce the risk of cardiovascular disease down the line."

More information

Aspirin in all its aspects is described by the U.S. National Library of Medicine.

WEDNESDAY, May 14 (HealthDay News) -- Italian researchers have some advice for those with high blood pressure: Breathe slowly. Turn on some quiet, rhythmic music. And watch your high blood pressure take a little tumble.

The researchers base their conclusions on a small new study. But they aren't suggesting anyone turn to breathing exercises and music instead of medicine.

Still, "easy and enjoyable daily music listening combined with slow abdominal breathing may help people naturally lower their blood pressure," said Dr. Pietro A. Modesti, a professor of internal medicine at the University of Florence.

In what's touted as the first study of its kind, Modesti and his colleagues recruited 48 patients to study the effect of listening to music on blood pressure. The patients, who ranged in age from 60 to 76, all suffered from mild high blood pressure and took medication for it.

Of the patients, 28 listened to 30 minutes of classical, Celtic or raga music a day while conducting slow, controlled deep-breathing exercises. (Raga, an ancient kind of music, was developed in India.)

All the music was slow and rhythmic.

Another 20 patients served as a control group and didn't undergo the music and breathing therapy.

On average, the blood pressure among those who listened to music dropped by 3 mmHG at one week and 4 mmHG at one month, compared to people in the control group.

Doctors consider healthy blood pressure to be below 140/90 mmHG. High blood pressure -- hypertension -- is thought to affect one in three adult Americans, although many don't realize they have it. The condition can lead to heart disease, kidney failure and stroke, among other problems.

The study authors also found that other non-drug "interventions" -- including restriction of salt intake, exercise and limits on alcohol consumption -- had about the same effect.

"Further studies are needed to confirm the effect in the long term," Modesti said.

Researchers have previously found that relaxation can relieve people's cardiovascular symptoms. But the researchers behind the new study discovered that relaxation significantly affected blood pressure only if it was combined with quiet music.

The findings were to be presented Wednesday at the American Society of Hypertension's annual meeting, in New Orleans.

Modesti said the key appears to be the slow breathing that the patients engaged in during the study.

The findings are useful, he added, because they can complement existing treatments. "The side effects and cost of antihypertensive drugs have led to a consensus about the need for effective non-pharmacological treatment alone or adjunctive to drug therapy," he said.

Dr. George Bakris, director of the hypertensive disorders unit at the University of Chicago, noted that the study only looked at people with mild high blood pressure.

In those patients, he said, it's important to note that "this does not prevent hypertension, but helps to alleviate it."

More information

Learn more about high blood pressure from the American Heart Association.

The findings may explain why air pollution can trigger a range of cardiovascular events such as heart attack, heart failure and stroke, the researchers said.

Particulate matter (PM) is a component of air pollution emitted from vehicles, power plants, and factories. It's believe that PM is the 13th leading cause of death worldwide, but the link between PM and death hasn't been well understood.

"Not everyone is equally at risk to the effects of poor air quality," researcher Robert Brook, an assistant professor of medicine, division of cardiovascular medicine, University of Michigan, said in a prepared statement.

"Yet, as traffic worsens and millions of vulnerable people are exposed to PM, it is incumbent upon us to understand how and why people are affected so that we can take steps to limit our personal exposure -- and consider making broader changes to the public agenda to control air pollution," Brook said.

In the study, researchers looked at adults living in Toronto and Ann Arbor, Mich.

In Toronto, 30 adults, aged 18 to 50, were exposed for two hours to concentrated ambient PM (CAPS alone), CAPS and ozone, ozone alone, or filtered air. Exposure to air pollution that contains PM (CAP or CAP and ozone) resulted in an average diastolic blood pressure increase of 3.6 mm/Hg. Blood vessel function was impaired 24 hours after (but not immediately after) all exposures to all exposures containing PM, but not ozone alone.

In Ann Arbor, 50 adults were pre-treated with either the antioxidant vitamin C -- which blocks the vasoconstrictor hormone endothelin (bosentan) -- or placebo. Diastolic blood pressure increased between 2.5 and 4.0 mm/Hg during all exposures. However, blood pressure function was not impaired at any time after all exposures, and blood pressure returned to normal within 10 minutes after exposure.

The fact that vitamin C didn't block the blood pressure response suggests that it's likely caused by a sudden increase in sympathetic nervous system activity.

The findings confirm that PM, not ozone, is responsible for the rapid increase in diastolic blood pressure and that this occurs only during actual inhalation of PM. The research also confirms that PM impairs blood vessel function one day after exposure. However, this blood vessel function response occurred only in Toronto, which suggests that the composition of PM or its source may play a role in determining that kind of response, the researchers said.

The study was expected to be presented Wednesday at the American Society of Hypertension annual meeting, in New Orleans.

"These findings are a springboard for further study that will specifically determine how the sympathetic nervous system responds and to what types of particles in air pollution," Brook said. "But this glimpse helps us determine the triggers behind a range of CV events -- some deadly. Learning how this dangerous cascade starts can help the medical and public health community make advances toward limiting their impact in the future."

More information

The American Academy of Family Physicians has more about air pollution and health.

Men who drink more than 21 units of alcohol per week and women who drink more than 14 units of alcohol a week put themselves at serious risk for hypertensive heart disease, heart failure and stroke, the researchers found.

"These shocking findings illustrate the extreme risks that heavy drinkers are exposing themselves to -- some of which are particularly pronounced in women," lead investigator Dr. Azra Mahmud, a cardiovascular lecturer and hypertension specialist at the Trinity Centre for Health Science, St. James Hospital, Dublin, Ireland, said in a prepared statement.

"We want to make sure people aren't getting mixed messages about alcohol. The potentially fatal effects of heavy drinking may more than counteract the well-documented benefits of sensible alcohol intake," Mahmud said.

The study included 100 women and 100 men (mean age 46, all healthy) who were divided into three groups: non-drinkers, moderate drinkers (males, less than 21 units of alcohol per week; females, less than 14 units per week) and heavy drinkers (males, more than 21 units per week; females, more than 14 units per week).

The participants underwent a number of tests including ultrasound of heart to assess arterial stiffness and pulse wave velocity to measure aortic blood pressures and wave reflections in the aorta.

The results showed that heavy drinking is associated with arterial stiffening and impaired left ventricular (LV) relaxation in males, and LV structural changes, including LV enlargement (hypertrophy), in females. Of special note, women who were heavy drinkers had an enlarged heart even without high blood pressure or stiff arteries.

"The excessive consumption of alcohol causes significant arterial and ventricular stiffening and an enlarged heart; factors associated with poor cardiovascular outcomes in hypertensive populations," Mahmud said. "Trends in heavy drinking continue to rise, and it is high time to recognize the potential of an alcohol-induced epidemic of cardiovascular disease. Binge and heavy drinkers must consider their behavior and control their intake before it's too late."

The study was expected to be presented Wednesday at the American Society of Hypertension annual meeting, in New Orleans.

Cardiovascular disease (CVD) is the leading cause of death worldwide. About 17.5 million people die from CVD each year, and that toll could increase to almost 20 million by 2015.

More information

The U.S. National Heart, Lung, and Blood Institute has more about heart and vascular diseases.

TUESDAY, May 13 (HealthDay News) -- Patients who received the blood pressure-lowering drugs known as beta blockers after having non-cardiac surgery were at higher risk of dying or having a stroke, a new Canadian study found.

However, the patients receiving the medications were less likely to have a heart attack, according to the report in the May 13 online issue of The Lancet.

"For a decade now there are guidelines saying you should give beta blockers to people having non-cardiac surgery," said lead researcher Dr. P.J. Devereaux, an assistant professor in the Department of Clinical Epidemiology and Biostatistics at McMaster University in Hamilton, Ontario.

The reason for giving beta blockers is that surgery increases the heart's need for oxygen and beta blockers help reduce blood pressure and heart rate, reducing strain on the heart, Devereaux explained.

Around the world, an estimated 100 million people have major non-cardiac surgery each year, so the finding could have serious consequences for many patients, Devereaux noted.

"In the last decade, even if only 10 percent of patients undergoing non-cardiac surgery were given beta blockers, that means 100 million people were given beta blockers, and that means 800,000 people died unnecessarily and a lot of people suffered a major stroke because they were given a beta blocker," Devereaux said.

In the study, 8,351 patients at 190 hospitals across 23 countries who were at risk for atherosclerotic disease [hardening of the arteries] and undergoing non-cardiac surgery were randomly selected to receive a beta blocker or a placebo. The beta blocker was given two to four hours before surgery, and continued for 30 days after the procedure.

The researchers found that patients receiving beta blockers were 16 percent less likely to have died from heart disease, compared with those receiving a placebo. In addition, those taking a beta blocker were 27 percent less likely to have a heart attack than patients receiving a placebo.

But, more people taking a beta blocker died than those taking a placebo. In fact, patients taking a beta blocker had a 33 percent increased risk of dying compared with patients taking a placebo.

Also, there were more strokes among people taking a beta blocker than among patients receiving a placebo. Those receiving the beta blocker had double the risk of suffering a stroke compared with patients receiving a placebo, the researchers reported.

The most likely explanation for the increase in deaths and stroke among those taking beta blockers was that these patients could go into shock if their blood pressure were too low, a not uncommon complication of surgery, Devereaux said. "If they were on the beta blockers they were in big trouble, and [it] increased their likelihood of dying or suffering a stroke," he said.

Devereaux doesn't think reducing the risk of heart attack is worth increasing the risk of stroke or death. "I don't think most patients would be willing to accept the excess death and excess stroke for preventing a heart attack," he said.

Using a beta blocker to prevent heart attacks in these patients is not the right strategy, Devereaux said. "If we are causing so much harm to prevent heart attacks, we need to find another solution which will prevent these events, but not have the same risk."

One expert thinks that the doses of beta blockers given in the trial were too high.

"The increase in hypotension [low blood pressure] and resulting strokes and cardiovascular deaths may be a result of this overly aggressive dosing rather than perioperative beta blocker therapy in general," said Dr. Gregg C. Fonarow, a professor of cardiology at the University of California, Los Angeles.

"While further studies of other beta blockers and dosing regimens for perioperative use are still needed, the rapid up-titration to high dose of a beta blocker regimen employed in this study should be avoided," Fonarow said.

Another expert thinks that if beta blockers are given cautiously, the dangers found in the study can be greatly reduced.

"We don't want people to misinterpret this study," said Dr. Lee A. Fleisher, chair of the Department of Anesthesiology and Critical Care at the University of Pennsylvania School of Medicine, and author of an accompanying editorial in the journal. "The study did not say anybody who is on beta blockers should stop them."

Fleisher agrees that starting beta blockers the morning of surgery with high doses is not a good way to go. "That type of protocol is not good," he said.

More information

For more on beta blockers, visit the American Academy of Family Physicians.