Monday, September 29, 2008

Is Comprehensive Screening Good Enough to Detect Sudden Cardiac Death?

Is comprehensive heart screening sufficient for young people who are engaging in aggressive exercises such as Marathon running, military training, etc? Should they also undergo additional testing with treadmill exercise and echocardiography (cardiac ultrasound)?

What is sudden cardiac death? As defined by American Heart Association, sudden cardiac death (SCD) or cardiac arrest is the sudden, abrupt loss of heart function in a person who may or may not have diagnosed heart disease. It just occurs immediately or shortly after the symptoms appear.

Every year, sudden cardiac death causes about 166,200 deaths among adults in the United States before reaching a hospital or emergency room.

For people below the age of 35, SCD has many causes. Not all of these causes are due to cardiac problems and only some of these can be detected by screening. Patients who die suddenly are commonly caused by cardiovascular disease, in particular, coronary heart disease (CAD), but it rarely happens to younger age group.

No doubt treadmill ECG stress testing can be used to detect CAD. Nevertheless, it does have its own limitations. For example, it has a false positive result of 10 to 20 percent. In other words, if CAD occurs in 1 per 1,000 people screened, out of 25,000 persons tested, 25 might have CAD. This means that 2,500 to 5,000 might have false positive stress results, and these people have to undergo further testing, such as nuclear imaging and coronary angiography, which may have other risks such as radiation exposure.

It is unjustified to place such a big percentage of people to these risks, as this would certainly outweigh the benefit of detecting a few with CAD. Obviously, stress testing should only be used for those at higher risk such as older men or those with significant risk factors for heart disease.

For youngsters, a more common cause of SCD is hypertrophic cardiomyopathy (HCM). It is an inherited condition with abnormal thickening of the heart muscle. People with HCM will show ECG abnormalities.

In fact, adding ECG to a history and physical examination in athletes, and referring only those with ECG abnormalities for more tests was proved to be an effective mean to minimize the risk of SCD due to HCM. Such approach has also been shown by studies in Italy and endorsed by the International Olympic Committee and European Society of Cardiology.

Meanwhile, prevention and control of risk factors like diabetes, high cholesterol, hypertension (high blood pressure), obesity, and smoking through healthy lifestyles should be encouraged to reduce SCD.

Friday, September 26, 2008

Heart Damage May Be Reduced By Folate!

When the blood flow is cut off, the damage to the heart muscle could be reduced with the help of high doses of folate, as suggested by an animal study carried out by researchers from Johns Hopkins Medical Institutions in Baltimore. The findings were published in the April 2008’s addition of “Circulation”.

What is folate? It is a water-soluble B vitamin obtainable from food. The synthetic form of folate that is found in supplements and added to fortified foods is known as folic acid. Folate helps produce and maintain new cells. It can be found in natural foods like leafy vegetables (such as spinach and turnip greens), fruits (for example, citrus fruits and juices), and dried beans and peas.

In the animal study, rats were treated with folate or placebo. After 1 week, their left coronary arteries were blocked for 30 minutes. As we know, blood normally carries oxygen to the heart muscle. Any sudden and severe blockage could just trigger a heart attack or an abnormal heart rhythm, which is considered as fatal conditions.

The researchers performed a 90-minute of reperfusion to some rates and do nothing to the others. Reperfusion is the restoration of the coronary blood flow to the heart muscle. Preserving or restoring heart function is a necessary procedure, but it can well cause a disturbance in the function of the cells in the heart muscle known as reperfusion injury.

Rats that were treated with folate had significantly less functional damage of the heart than those that were treated with placebo. When the researchers looked at reperfusion, smaller areas of dead heart muscle were found among rats pretreated with folate.

Further analysis also indicated that folate might have achieved these beneficial effects, in part, by maintaining levels of the high-energy phosphates ATP and ADP in the heart.

Despite of the positive findings, the researchers felt that it is still premature for people to start taking high doses of folate. However, if future studies on human beings can prove equally effective, then high-dose folate could be given to those people with high-risk factors (diabetes, heart disease, high blood pressure, high cholesterol, etc.) for preventing possible heart attack or to people who have suffered heart attack.

Wednesday, September 24, 2008

Can Aromatherapy Products Help Relieve Stress?

People spend a fortune on aromatherapy products marketed by health and beauty companies believing that this would help them relieve their stress and improve their health conditions. Stress is known to be a risk factor for heart disease, high blood pressure, cancer, and many other medical disorders.

However, a recent study by a group of researchers at Ohio State University might just make them disappointed. The researchers reported in April 2008 in the Journal “Psychoneuroendocrinology” that these expensive scented oils may help people’s mood but would not do much on their health. Just like many home remedies, there is no hard evidence to support that these so-called ‘good smell’ would be good for the body.

Knowing that the placebo effect could have a very strong impact on one’s health, the researchers hope to test the claimed stress-relieving and healing properties of 2 of the most popular aromatherapy scents, lavender and lemon, in a measurable way.

In the study, 56 healthy male and female volunteers underwent a series of tests over 3 half-day sessions. Each of them was tested in advance to make sure that each had a normal sense of smell.

To test the impact of the smells, the nostrils of the participants were taped with cotton balls laced with essential oils and distilled water.

To see if the smells could help manage pain responses, the subjects’ feet were dunked in ice-cold water.

To see if it would improve healing, a standard test was performed in such a way that tape was applied and removed repeatedly on the same spot of skin.

To test the impact on the mood, the subjects were asked to complete 3 standard psychological tests during each session.

To test the impact on stress levels, the subjects’ period blood tests were taken and their blood pressure and heart rates monitored.

The series of experiments conducted on lemon or lavender oils did not show any positive health effect on the immune system or on the body’s ability to mitigate pain or stress. Nevertheless, the lemon oil did show a clear mood enhancement

The researchers claimed that the current study is probably the most comprehensive study ever done in the area, but they admitted that they still failed to discover any quantitative results on whether these oils provide any physiological effect for people in general.

The human body is infinitely complex. Therefore, if one uses these oils and feels better, there is no way for scientists to prove that it does not improve that individual’s health.

In conclusion, good smells may make people feel better but one should not rely on them to change the physiology.

Monday, September 22, 2008

What Is the Link Between Sleep Duration and Stroke?

I used to hear from friends or relatives that one should sleep at least 8 hours per night to stay healthy. Is this a justified statement? Does it mean that we should sleep as long as we can?

In reality, “the more is better” may not be true, at least not for the sleep duration.

A report published in July 2008 in the medical journal “Stroke” indicated that middle-aged women who slept 9 hours or more per night would have their risk of stroke increased by 70 percent. This is the finding obtained by United States researchers from the University of North Carolina in Chapel Hill.

Although a number of studies have established a link between sleep duration and mortality, there is still a lack of evidence to associate sleep patterns and cardiovascular disease.

Of the 93,175 women of age between 50 and 79, who were enrolled in the Women’s Health Initiative Study, 8.3 per cent normally slept no more than 5 hours per night, while 4.6 percent slept at least 9 hours per night.

At the end of the study (span over a period of average of 7.5 years), it was found that 1,166 women got ischemic stroke. This is the most common type of stroke, which occurs when blood vessels in the brain block. When this happens, oxygen will be prevented from reaching the brain and will thus cause the brain's tissue to die.

When comparing with women sleeping 7 hours, those slept 6 hours or less, 8 hours, or 9 hours or more increased the risk of stroke by 14 percent, 24 percent, and 70 percent, respectively.

For women who slept 6 hours or less and had cardiovascular disease at the beginning of the study, their chance of getting stroke was increased by 22 percent. Furthermore, women who slept longer hours during the night were not associated with frequent snore or sleepiness. Therefore, sleep during, either shorter or longer than the norm (7 hours), could be independent risk factors for stroke.

Women sleeping long hours during the night is not so common than those who slept less than 6 hours, therefore, the overall health impact of a short sleep is probably greater than long sleep.

However, the researchers caution that their data do not imply that women of long sleep duration would cut their risk of stroke if they reduce their sleep duration. Further studies are still required to help understand the possible mechanisms behind the associations found in this study.

Sunday, September 21, 2008

Will Weight Loss Drugs Benefit Obese Patients?

While some doctors do agree upon the difficulty to help overweight or obese patients lose weight successfully by taking weight loss drugs alone, others would think that the few kilos loss would make a significant difference for patients suffering from heart disease or diabetes problems. Nevertheless, those people who take the drugs for cosmetic reasons may not see much benefit.

A study carried out by researchers from the University of Alberta in Canada revealed that patients on weight loss drugs might lose little more than their money, and yet face many unpleasant side effects. The report, which was published in the “British Medical Journal” on November 16, 2007, indicated that close to 20,000 patients, weighing an average of 100 kilos lost less than 5 kilos because of these weight loss drugs. These patients had been on one of 3 weight loss drugs, Xenical, Reductil and Accomplia for one to 4 years.

The meta-analysis using data from 30 clinical trials found that up to 30 percent of the patients on Xenical had unpleasant digestive and intestinal side effects, such as incontinence. On average, they lost 3 kilos.

Patients who took Reductil lost 4 kilos and had improved cholesterol levels, but up to 20 percent of the patients suffered from high blood pressure, raised pulse rates, insomnia and nausea.

Accomplia was most effective as patients taking this drug lost the most weight, 5 kilos on average along with improved blood pressure and cholesterol levels. Nevertheless, the 6 percent of the patients had an increased risk of mood disorders.

In fact, another study reported also on November 16, 2007 in medical journal “The Lancet that patients who were prescribed Accomplia were very likely to suffer from depression, anxiety and even suicidal tendencies.

The worldwide annual sales of these 3 medicines is closed to US$1.2 billion. These drugs are meant for severely obese people, and many of them suffer from or are at higher risk of heart disease and diabetes.

Despite the side effects, which were explicitly listed by the drug manufacturers, many doctors do prescribed them to selected patients. According to their argument, fat people who lose 4 kilos could cut their risk of getting diabetes by 30 to 40 percent, and for those already suffer from diabetes, 4 kilos loss in weight would cut their blood sugar level and their risk of getting heart disease.

Thursday, September 18, 2008

Would Fruit Juice Benefit Women with Type-2 Diabetes?

Eat more vegetables and fruits to stay healthy! You would probably hear this very common statement frequently. How about fruit juice, is it good for health?

A recent study published in July 2008 by Tulane University School of Public Health and Tropical Medicine, New Orleans indicated that “women with Type-2 diabetes” should stay away from fruit juice. They should eat green leafy vegetables and whole fruits, instead, if they wish to ward off Type-2 diabetes.

The researchers found that with an additional 3 servings of whole fruit daily, or one more serving of spinach, kale or similar leafy green vegetable, the risk of developing diabetes over an 18-year-period was reduced among the 71,346 women enrolled in the Nurses’ Health Study.

The decrease was only modest, so if one with many other risk factors, for example, unhealthy diet, smoking, emotional stress, overweight, etc., then this may not be able to prevent one from diabetes, the researchers added.

Diabetes is a very common disease that affects some 150 million people worldwide. A person with diabetes will have high levels of sugar in their blood. This will lead to heart disease, heart attack, stroke, blindness, kidney failure, etc. if it is not managed appropriately.

In the study, 4,529 women, who developed Type-2 diabetes, were being followed and their data on the diets were analyzed. These women were divided into 5 groups based on fruit and vegetable intake, and on fruit juice consumption.

It was found that an additional of 3 servings a day of whole fruit would reduce the risk of Type-2 diabetes by 18 percent, while a single additional serving of leafy green vegetables only cut the risk by 9 percent. When an additional daily serving of fruit juice was introduced, the likelihood of developing diabetes was increased by 18 percent. A possible reason for such an increase in risk could be the big sugar load coming in liquid form that is absorbed rapidly.

The new findings seem to be contradicting with the current national dietary guidelines in United States, which recommend using 100 percent fruit juice to replace a serving of fruit. While the findings must be replicated, the researchers still warn people who wish to replace some beverages with fruit juices as healthier options to implement with caution.

Monday, September 15, 2008

Are There Gender Differences In Metabolizing Fructose?

Fructose is a simple sugar commonly used for sweetening drinks and foods. Short-term high fructose intake among young people is rather common. However, it appears that men and women have their own way of metabolizing high levels of fructose.

For men, such pattern of consumption will cause their blood triglycerides (fats) to increase and insulin resistance to decrease. This will also raise their risk for cardiovascular disease and Type-2 diabetes. On the other hand, women seem to get rid of the excess sugar load in a less harmful way.

In a study to evaluate the relationship between nutrition and metabolic disorders, researchers from Lausanne University School of Biology and Medicine in Switzerland enlisted 8 each of healthy, non-smoking men and women of normal weight and about 23 years of age to participate in 2 different 6-day diets separated by a 4-week wash-out period. The findings of the study were published in “Diabetes Care”

Not participated in sports or exercise, these men and women followed either the 'control' diet or the diet that included a lemon-flavored drink containing 3.5 grams of fructose.

The fructose load used for the study corresponded to several liters of sodas per day, which was considered quite large. 12 fasting metabolic parameters of the participants were tested the day after they completed each diet.

Fructose supplementation caused the men a significant increase in 11 of the 12 factors, including a 5 percent increase in fasting glucose and 71 percent increase in triglyceride levels. However, women had a significant increase in only 4 out of the 12 factors tested, and showed a 4 percent increase in fasting glucose and 16 percent increase in triglyceride levels.

As the current study only involved a very small number of participants, the researchers felt that further studies should be carried out to include a larger population so that gender differences in metabolic pathways could be accurately be identified and confirmed.

Meanwhile, the researchers also wonder if fructose may have effects that are more deleterious in individuals who are at high risk of metabolic disorders.

Wednesday, September 10, 2008

Young Adults, Do Not Ignore High Blood Pressure!

Hypertension (high blood pressure) is a disease that is not limited to only aging population. Evidence does show that there is significant number of young adults develop hypertension before the age of 35. In addition, one should not ignore the fact that a hypertensive (a person who has hypertension) is subject to a higher risk of getting heart disease, stroke, kidney failure, etc.

A recent study suggested that young adults with high blood pressure have raised their risk of developing plaque on the lining of their blood vessels, even if the blood pressure is closed to normal. The building of plaque is known as Atherosclerosis.

Accumulation of fat, cholesterol, calcium, and other substances found in the blood can lead to formation of plaque. Over time, plaque may cause the arteries to become harder and narrower. This may reduce the flow of oxygen-rich blood to various organs and other parts of the body. Once this happens, serious problems, including heart attack, stroke, or even death may be resulted.

In order to investigate the long-term effect of slightly high blood pressure, researchers from the University of California, San Francisco measured the blood pressure in 3,560 young adults who were followed from 1985 to 2005. At the end of the period, the presence of atherosclerosis in coronary arteries was determined by CT scan.

It was found that nearly 20 percent of the participants developed slightly increased blood pressure or 'pre-hypertension' before the age of 35. Pre-hypertension has something to do with atherosclerosis: the longer pre-hypertension was present, the greater was the risk and severity of atherosclerosis in middle age.

Before further data are obtained, the research team does not recommend the use of blood pressure drugs to treat pre-hypertension in young adulthood. Instead, they suggest lifestyle changes.

They also admit that optimizing blood pressure in young adults is a major challenge. However, they believe that efforts to do so is worthwhile, as this would yield substantial health benefits for individual in such way that population rates of heart disease and stroke could be reduced during middle age and beyond.

Monday, September 08, 2008

What Causes Young Females Put On Weight?

When we talk about weight gain, we usually relate it to health issues because overweight can lead to a number of medical complications like heart disease, diabetes, high blood pressure, and even cancer. Besides health issues, weight gain is certainly not proud of among young females.

Nevertheless, there are young girls or women find themselves gain in weight although they do not over-eat. Why is this so?

Perhaps the findings of a study published in July 2008 in “The Journal of Pediatrics” may explain. Researchers from Brigham & Women's Hospital and Harvard Medical School in Boston found that girls and young women, who devote much time to Internet, get insufficient sleep, or drink alcohol regularly, are more likely to gain excess weight comparing to their peers.

A total of 5,036 girls and young women between 14 and 21 years old participated in this study, and they were followed for 1 year. They were asked questions like number of recreational hours per week they spent on the Internet (ranging from 1 to 5 hours to 16-plus hours), how long they typically slept each night (anywhere from 5 hours or less, to 9 hours or more), how much alcohol they usually took (ranging from none to 2 or more drinks per week).

The researchers found that if the girls spent more time on the Internet, were lack of sleep and had regular alcohol consumption, their body mass index (BMI) increased. BMI is a measure of weight in relation to height and is commonly used as a gauge for weight gain.

Findings of the study showed that in general, the BMI would rise as Internet use climbed, particularly among young girls age below 18 years old. Those who slept 5 hours or less tended to gain more weight than those who had a standard 8 hours sleep. Moreover, girls and women who had 2 or more alcoholic drinks per week would put on weight than those who drank the least.

The effects over 1 year were modest, for example, a 19-year-old of average weight and height would gain only 4 pounds if she were in the high-risk groups for Internet use, sleep and alcohol consumption. However, the researchers feel that this could eventually translate into significant weight change over time.

Spending hours on the Internet would likely take time away from physical activity thus increasing the weight. Lack of sleep may well cause tiredness to people who may become less active during the day. Sleep deprivation could also affect hormones and metabolism in a way that might help weight gain. Alcohol contains a significant amount of calories. If people, who usually, do not make adjustment for liquid calories by eating or drinking less throughout the rest of the day, their weight would be naturally increased.

Friday, September 05, 2008

What Is The Risk Factor For Sudden Death in Patients With Myotonic Dystrophy?

When we talk about muscular dystrophy (MD), we refer it to a group of more than 30 genetic diseases characterized by progressive weakness and degeneration of the skeletal muscles that control movement.

Myotonic muscular dystrophy or in short myotonic dystrophy, being the most common form of MD, will cause a person prolonged muscle spasms, cataracts, cardiac abnormalities, and endocrine disturbances. Patients with myotonic dystrophy have long, thin faces, drooping eyelids, and a swan-like neck.

Statistics showed that approximately 1 of every 8,000 people in the United States was affected by myotonic dystrophy. The heart muscle of the people with such disease is adversely affected.

Over the period of 10 years, neurologists and cardiologists at 23 clinics studied 406 adults with myotonic dystrophy. During that period, 20 percent of the patients enrolled in the study died, one-third of them in sudden death were likely due to cardiac arrhythmia.

Cardiac arrhythmia (also known as dysrhythmia) is a condition in which abnormal electrical activity occurred in the heart. The heartbeat, either regular or irregular, may become too fast or too slow. Some arrhythmias are life threatening, which can cause cardiac arrest and sudden death. Sudden death means death occurs in a stable patient within 1 hour of the onset of symptoms.

The study carried out by the Indiana University School of Medicine found that adults having myotonic dystrophy and abnormal electrocardiograms are more than 3 times more likely to die suddenly than patients who have normal ECG, while those with atrial (upper) chamber arrthymias had a 5 times higher risk.

The researchers had identified the risk factors that predict a high risk of sudden death in people with myotonic dystrophy and their findings were published in the June 19, 2008 edition of the New England Journal of Medicine.

The report also revealed that pacemakers, commonly used to treat some forms of arrhythmia, did not help these patients prevent sudden death. However, using electrophysiological studies or by surgically implanting a cardioverter-defibrillator, doctors can guard against sudden death in patients showing this risk factor.

Wednesday, September 03, 2008

Is Rapid Heartbeat Just a Benign Side Effect In Athletes?

There has been news that elite athletes who were seemed healthy died during or after their games. As suggested by health experts, the athletes might have hidden heart disease and their death could be caused by the rapid heartbeat developed during the game.

Researchers from the Italian Olympic Committee in Rome found more evidence that the rapid heartbeat seen in many hard-training athletes is typically a benign side effect of physical conditioning. Their findings were published in July 2008 in the “American Journal of Cardiology”.

It is known that the heart rate for elite athletes is usually lower than the normal when they are at rest. However, when they are active, rapid heart rhythms known as ventricular tachyarrhythmia might be developed. In fact, up to 30 percent of those high-level athletes have irregular ventricular rhythms, as shown from previous studies.

People with ventricular tachycardia may have symptoms such as palpitations, shortness of breath, or lightheadedness, depending on the rate of the arrhythmia, its duration, and the underlying heart disease. Faster heart rates may cause athletes who already have underlying heart disease loss of consciousness (syncope) or even sudden death.

If the athletes have no underlying heart abnormality, the irregular rhythm is just the effects of training and is considered as a part of a benign condition known as ‘athlete’s heart’. Furthermore, there might be enlargement in the heart’s main pumping chamber of the athletes known as left ventricular hypertrophy (LVH).

Another feature of athlete's heart is an enlargement of the heart's main pumping chamber, known as left ventricular hypertrophy, or LVH. In non-athletes, pathological LVH usually increases the risk of ventricular tachyarrhythmia as it worsens. Therefore, in the current study, Italian researchers looked at whether there is a similar relationship in elite athletes.

The researchers studied 175 Olympic and world-class athletes using portable monitors to record their heart's electrical activity over 24 hours. They also had them undergo ultrasound scans to detect LVH. It was found that 14 percent of these athletes were found to have evidence of LVH, though there was no indication that LVH raised the risk of ventricular tachyarrhythmia.

From the findings, the researchers suggested that, in contrast to pathological cases, the ventricular arrhythmias found in elite athletes, are not caused by LVH-induced changes in the heart's electrical activity. In fact, it is the alterations in nervous system activity, brought on by high-level athletic training, should be responsible. Previous research had indeed shown that ventricular tachyarrhythmia does decline after athletes stop training and playing at a competitive level.

The findings do offer a measure of clinical reassurance about the benign nature of ventricular tachyarrhythmia in elite athletes and the expression of so-called athlete's heart.