Archive for August, 2008

FOR CORONARY ARTERY DISEASE PATIENTS, B VITAMINS MAY NOT REDUCE CARDIOVASCULAR EVENTS

Tuesday, August 19th, 2008

In a large clinical trial involving patients with coronary artery disease, use of B vitamins was not effective for preventing death or cardiovascular events, according to a study published in the August 20 issue of JAMA.”Observational studies have demonstrated that the concentration of total homocysteine in blood is associated with risk of coronary artery disease and stroke,” the authors provide as background information. Plasma total homocysteine levels can be lowered by oral administration of folic acid and vitamin B12. In this study, the authors’ objective was “to evaluate the effects of homocysteine-lowering treatment with folic acid plus vitamin B12 on mortality and cardiovascular events.”

Marta Ebbing, M.D. of Haukeland University Hospital, Bergen, Norway and colleagues, conducted a randomized controlled study with 3,096 patients in two Norwegian hospitals between 1999 – 2006. Patients were randomly assigned to one of four groups receiving a daily oral dose of one of the following treatments: folic acid, 0.8mg, plus vitamin B12 , 0.4mg, plus vitamin B6 , 40mg (n= 772); folic acid plus vitamin B12 (n = 772); vitamin B6 alone (n = 772); or placebo (n = 780). Patients were scheduled for follow-up visits with an interview, clinical examination, and blood sampling at one month, one year, and at a final study visit. The main outcome measure (primary end point) was a composite of all-cause death, nonfatal acute myocardial infarction (heart attack), acute hospitalization for unstable angina pectoris, and nonfatal thromboembolic stroke.

The study was stopped early because of concerns among the participants about preliminary results from another similar Norwegian study suggesting no benefits from the treatment and an increased risk of cancer from the B vitamins.

“Mean (average) plasma total homocysteine concentration was reduced by 30 percent after 1 year of treatment in the groups receiving folic acid and vitamin B12,” the authors report. “During a median (midpoint) 38 months of follow-up, the primary end point was experienced by a total of 422 participants (13.7 percent): 219 participants (14.2 percent) receiving folic acid/vitamin B12 vs. 203 (13.1 percent) not receiving such treatment and 200 participants (13.0 percent) receiving vitamin B6 vs. 222 (14.3 percent) not receiving vitamin B6.”

“We could not detect any preventive effect of intervention with folic acid plus vitamin B12 or with vitamin B6 on mortality or major cardiovascular events among patients with stable coronary artery disease undergoing intensive conventional treatment. We found a numerically lower incidence of stroke and higher incidence of cancer in the groups receiving folic acid, but these observations were not statistically significant,” the authors conclude. “Our findings do not support the use of B vitamins as secondary prevention in patients with coronary artery disease.”

AIR POLLUTION DAMAGES MORE THAN LUNGS: HEART AND BLOOD VESSELS SUFFER TOO

Thursday, August 14th, 2008

Beijing Olympics focuses attention on pollution-related health problems

As athletes from around the world compete in the Beijing Olympics, many are on alert for respiratory problems caused by air pollution. They should also be concerned about its toxic effects on the heart and cardiovascular system, mounting research shows.

According to an article published in the August 26, 2008, issue of the Journal of the American College of Cardiology (JACC), air pollution has both short- and long-term toxic effects that injure the heart and blood vessels, increase rates of hospitalization for cardiac illness, and can even cause death.

“We used to think air pollution was a problem that primarily affects the lungs. We now know it is also bad for the heart,” said Robert A. Kloner, M.D., Ph.D., director of research at the Heart Institute of the Good Samaritan Hospital, and a professor of medicine at the Keck School of Medicine, University of Southern California, both in Los Angeles.

When pollutants are inhaled, they trigger an increase in “reactive oxygen species”-superoxiding molecules that damage cells, cause inflammation in the lungs, and spark the cascade of harmful effects in the heart and cardiovascular system. Recent research suggests that ultrafine air pollutants, such as those coming from car exhaust, may pass into the blood stream and damage the heart and blood vessels directly. Hearts directly exposed to ultrafine air pollutants show an immediate decrease in both coronary blood flow and the heart’s pumping function, as well as a tendency to develop arrhythmias, according to studies conducted at the Heart Institute.

“There doesn’t have to be an environmental catastrophe for air pollution to cause injury,” said Boris Z. Simkhovich, M.D., Ph.D, a senior research associate at the Heart Institute of the Good Samaritan Hospital, and an assistant professor of research medicine at the Keck School of Medicine, University of Southern California. “We’re talking about very modest increases. Air pollution can be dangerous at levels that are within the accepted air quality standards.”

Studies in both humans and animals have shown that exposure to air pollution can affect heart rate, blood pressure, blood vessel function, blood clotting, and heart rate variability (a factor in developing heart rhythm disturbances), and speed the progression of atherosclerosis.

Researchers who study large populations of people over time have found that increased levels of air pollution are linked to emergency hospital admissions for heart attack, chest pain, and congestive heart failure and even to death from heart disease, arrhythmias, heart failure and cardiac arrest.

The elderly and patients who have already been diagnosed with heart disease or diabetes (which damages the blood vessels) are particularly vulnerable to the cardiovascular effects of air pollution.

“Patients with cardiovascular disease shouldn’t exercise outside on days with increased air pollution levels. On very polluted days, they should consider staying inside, and during the winter, they should limit exposure to fireplace smoke,” Dr. Kloner said. “Of course, the real solution is to reduce air pollution.”

Alfred Bove, M.D., Ph.D., agreed. “The review by Dr. Simkhovich and his fellow authors make it quite clear that air pollution is linked to cardiovascular disease,” said Dr. Bove, ACC’s president-elect and cardiology section chief at Temple University School of Medicine in Philadelphia. “They suggest that this is another compelling reason to campaign for improved air quality, while at the same time studying therapies to minimize the risk of exposures.”

Press release/ American College of Cardiology/ Aug. 13, 2008

EAT OILY FISH AT LEAST ONCE A WEEK TO PROTECT YOUR EYESIGHT IN OLD AGE

Friday, August 8th, 2008

Eating oily fish once a week may reduce age-related macular degeneration (AMD) which is the major cause of blindness and poor vision in adults in western countries and the third cause of global blindness, according to a study published today in the American Journal of Clinical Nutrition.

There are two types of AMD, wet and dry. Of the two, wet AMD is the main cause of vision loss. A team of researchers across seven European countries and co-ordinated by the London School of Hygiene & Tropical Medicine sought to investigate the association between fish intake and omega 3 fatty acids with wet AMD, comparing people with wet AMD with controls. Participants were interviewed about their dietary habits including how much fish they ate and what type. Information on the main omega 3 fatty acids (docosahexaenoicacid (DHA) and eicosapentaenoic acid (EPA) was obtained by linking dietary data with food composition tables.

The findings show that people who habitually consume oily fish at least once a week compared with less than once a week are 50% less likely to have wet AMD. There was no benefit from consumption of non oily white fish. There was a strong inverse association between levels of DHA and EPA and wet AMD. People in the top 25% of DHA and EPA levels (300 mg per day and above) were 70% less likely to have wet AMD.

Astrid Fletcher, Professor of Epidemiology at the London School of Hygiene & Tropical Medicine, who led the study, commented: “This is the first study in Europeans to show a beneficial association on wet AMD from the consumption of oily fish and is consistent with results from studies in the USA and Australia. Two 3oz servings a week of oily fish, such as salmon, tuna or mackerel, provides about 500 mg of DHA and EPA per day”.

The research team is not, however, recommending omega 3 supplements as the study did not investigate whether supplements would have the same benefit as dietary sources.

Press release lshtm.ac.uk/ Aug. 8, 2008

New Implant Device Remotely Monitors Heart Failure Patients

Thursday, August 7th, 2008

CHICAGO—Chest pain and shortness of breath are common symptoms that send tens of thousands of heart failure (HF) patients into U.S. hospitals each month. Cardiologists at the Bluhm Cardiovascular Institute of Northwestern Memorial Hospital may be able to curb such visits for some of their HF patients as they recently became Chicago’s first researchers using a new wireless pressure sensor technology that allows them to track the pulmonary artery pressure of the subjects while these subjects remain at home.

“Some heart failure patients spend a lot of time in and out of the hospital due to chest pain and trouble breathing,” says John B. O’Connell, MD, co-director of the Bluhm Cardiovascular Institute, director of its Center for Heart Failure and professor of medicine at Northwestern University’s Feinberg School of Medicine. “At any time, such as when the subject is beginning to feel poorly, we immediately get readings of pulmonary pressure. We are hopeful we can avoid a hospitalization by adjusting the subject’s medication based on the pressure recording. As we evaluate the CardioMEMS Wireless Pressure Monitoring System, we see great potential to increase convenience to patients and hospital efficiency by cutting back on frequent trips to the emergency room.”

The implanted pressure sensor is about the size of a standard paperclip. It is implanted into the subject’s pulmonary artery through a catheter-based procedure from the groin region. The technology that allows for subjects to get readings remotely from home is a proprietary electronic monitoring system that works when they lie on a pillow containing an antenna that interacts with the implanted device to get readings on heart and lung pressures. Northwestern Memorial has implanted three subjects to date and seven more are planned as part of the CHAMPION (CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Patients) clinical study.

As O’Connell explains, when your heart doesn’t pump normally, adequate blood (oxygen and nutrients) may not reach your body tissues. When this occurs, the body believes that there is not enough fluid inside its vessels. The body’s hormone and nervous systems try to make up for this (or compensate) by holding on to sodium and water in the body, and by increasing heart rate—all of which are symptoms often seen in HF patients, but in many cases, can be managed with medication. The back pressure in the lungs due to the inability of the heart to pump the blood effectively can be measured and transmitted by this device.

With this system, pressure data is transmitted to a secure database that makes the data available to physicians from a proprietary Web site. Data can also be made available to physicians on a handheld device, like a BlackBerry for instance.

The device is for investigational use only.

News release- Bluhm Cardiovascular Institute/ Aug 6, 2008

SPICES MAY PROTECT AGAINST THE CONSEQUENCES OF HIGH BLOOD SUGAR

Wednesday, August 6th, 2008

Athens, Ga. – Herbs and spices are rich in antioxidants, and a new University of Georgia study suggests they are also potent inhibitors of tissue damage and inflammation caused by high levels of blood sugar.

Researchers, whose results appear in the current issue of the Journal of Medicinal Food, tested extracts from 24 common herbs and spices. In addition to finding high levels of antioxidant-rich compounds known as phenols, they revealed a direct correlation between phenol content and the ability of the extracts to block the formation of compounds that contribute to damage caused by diabetes and aging.

“Because herbs and spices have a very low calorie content and are relatively inexpensive, they’re a great way to get a lot of antioxidant and anti-inflammatory power into your diet,” said study co-author James Hargrove, associate professor of foods and nutrition in the UGA College of Family and Consumer Sciences.

Hargrove explained that when blood sugar levels are high, a process known as protein glycation occurs in which the sugar bonds with proteins to eventually form what are known as advanced glycation end products, also known as AGE compounds. The acronym is fitting because these compounds activate the immune system, resulting in the inflammation and tissue damage associated with aging and diabetes.

The researchers found a strong and direct correlation between the phenol content of common herbs and spices and their ability to inhibit the formation of AGE compounds. Spices such as cloves and cinnamon had phenol levels that were 30 percent and 18 percent of dry weight, respectively, while herbs such as oregano and sage were eight and six percent phenol by dry weight, respectively. For comparison, blueberries – which are widely touted for their antioxidant capabilities – contain roughly five percent phenol by dry weight.

Study co-author Diane Hartle, associate professor in the UGA College of Pharmacy, said various phenols are absorbed differently by the body and have different mechanisms of action, so it’s likely that a variety of spices will provide maximum benefit.

“If you set up a good herb and spice cabinet and season your food liberally, you could double or even triple the medicinal value of your meal without increasing the caloric content,” she said.

She added that controlling blood sugar and the formation of AGE compounds can also decrease the risk of cardiovascular damage associated with diabetes and aging. She explained that high blood sugar accelerates heart disease partly because AGE compounds form in the blood and in the walls of blood vessels. The AGE compounds aggravate atherosclerosis, which produces cholesterol plaques.

The UGA researchers tested for the ability to block AGE compounds in a test tube, but animal studies conducted on the health benefits of spices lend support to their argument. Cinnamon and cinnamon extracts, for example, have been shown to lower blood sugar in mice. Interestingly, cinnamon lowers blood sugar by acting on several different levels, Hargrove said. It slows the emptying of the stomach to reduce sharp rises in blood sugar following meals and improves the effectiveness, or sensitivity, of insulin. It also enhances antioxidant defenses.

Hargrove said their findings suggest it’s likely that the herbs and spices they studied will provide similar benefits in animal tests. He points out that because humans have been consuming herbs and spices for thousands of years, they come without the risk of possible side effects that accompany medications.

“Culinary herbs and spices are all generally recognized as safe and have been time-tested in the diet,” he said. “Indeed, some of spices and herbals are now sold as food supplements because of their recognized health benefits.”

Study co-author Phillip Greenspan, associate professor in the College of Pharmacy, noted that most people don’t get their recommended five to nine servings of fruits and vegetables a day. Rather than seasoning their food with salt – which provides no beneficial phenols and has been linked to high blood pressure – he recommends that people use a variety of herbs and spices to help boost the nutritional quality of their meals.

“When you add herbs and spices to food, you definitely provide yourself with additional benefits besides taste,” Greenspan said.

News release U. of Georgia/ Aug 6. 2008.

THE BENEFITS OF GREEN TEA IN REDUCING AN IMPORTANT RISK FACTOR FOR HEART DISEASE

Saturday, August 2nd, 2008

More evidence for the beneficial effect of green tea on risk factors for heart disease has emerged in a new study reported in the latest issue of European Journal of Cardiovascular Prevention and Rehabilitation.

1. The study found that the consumption of green tea rapidly improves the function of (endothelial) cells lining the circulatory system; endothelial dysfunction is a key event in the progression of atherosclerosis. The study, performed by Dr Nikolaos Alexopoulos and colleagues at the 1st Cardiology Department, Athens Medical School in Greece, was a randomised trial involving the diameter measurement (dilatation) of the brachial artery of healthy volunteers on three separate occasions - after taking green tea, caffeine, and hot water (for a placebo effect). The measurements were taken at 30, 90 and 120 minutes after consumption. Dilatation of the brachial artery as a result of increased blood flow (following a brief period of ischaemia of the upper limb) is related to endothelial function and is known to be an independent predictor of cardiovascular risk.

2.Results showed that endothelium-dependent brachial artery dilatation increased significantly after drinking green tea, with a peak increase of 3.9 per cent 30 minutes after consumption. The effect of caffeine consumption (or hot water) was not significant.

While black tea has been associated with improved short and long-term endothelial performance, this is the first time that green tea has been shown to have a short-term beneficial effect on the large arteries. Another study has already shown that green tea reverses endothelial dysfunction in smokers.

Green tea, which originates in China but is now consumed throughout the world, is made with pure leaves, and has undergone little oxidisation during processing. The cardiovascular benefits of all teas - as well as dark chocolate and red wine - are attributed to the flavonoids they contain and their antioxidant activity.3 However, says investigator Dr Charalambos Vlachopoulos, flavonoids in green tea are probably more potent antioxidants than in black tea because there has been no oxidisation.

“These findings have important clinical implications,” says Dr Vlachopoulos. “Tea consumption has been associated with reduced cardiovascular morbidity and mortality in several studies. Green tea is consumed less in the Western world than black tea, but it could be more beneficial because of the way it seems to improve endothelial function. In this same context, recent studies have also shown potent anticarcinogenic effects of green tea, attributed to its antioxidant properties.”

Press release escardio.org July 2, 2008