If you’ve been looking for excuses to skip exercise, a predisposition to atrial fibrillation shouldn’t be one of them.

For years, the prevailing wisdom has been that exercise – at least vigorous endurance training – increases a person’s risk of atrial fibrillation, an irregular heart beat linked to the formation of blood clots that can potentially cause a stroke.

By extension, many people feared the same might be true even for leisurely physical activity.

But new research has determined that being inactive may be just as bad. Scientists recently found that light to moderate exercise appears to actually prevent this health condition from occurring in older adults.

In fact, after following more than 5,400 people for 12 years, they concluded that 26 percent of atrial fibrillation cases were the result of a lack of moderate exercise.

It’s still not recommended that out-of-shape seniors at above-average risk of atrial fibrillation go out and compete in the Ironman triathlon. But going for leisurely strolls or engaging in appropriate exercise is not a bad idea – if you have your doctor’s blessing.

In the study noted above, seniors – the very people at the greatest risk for atrial fibrillation – who engaged in moderate exercise had a 28 percent reduction in their risk of developing the condition compared with older adults who did not exercise at all. On the other hand, those who exercised too vigorously fared just as poorly as those who were averse to exercising. The seniors who walked 60 or more blocks per week had the best results.

In one sense, the findings weren’t entirely surprising. Two years ago, the American Heart Association and the American College of Cardiology noted that obesity is “an important risk factor” for the development of atrial fibrillation, and wrote that previous research raised “the intriguing possibility that weight reduction may decrease the risk” of developing this condition.

Indeed, the researchers behind the new study found that those who exercised modestly had lower body mass indexes than those who did not. Guess what? They also had lower blood pressure, a lower heart rate and better lipid levels—in addition to the lower risk of atrial fibrillation. Not a bad return on your investment in a little exercise. While your risk of atrial fibrillation has a genetic component, it is helpful to remember that by getting yourself moving, your choices can affect that risk as well.

There’s been much ado lately about bisphenol-A, a chemical used in the packaging of some foods and drinks – and found in the bodies of 93 percent of Americans.

While some scientists insist it is impossible to say that BPA is safe, others say there isn’t enough evidence yet to conclude that it’s unsafe.

Among the research studies raising eyebrows – and concerns that consumers may be better off avoiding the substance: a large study published in September, the first to link BPA to heart disease and type 2 diabetes in humans.

Researchers found that the 25 percent of the adult population with the highest BPA levels were more than twice as likely to have heart disease or diabetes as the 25 percent with the lowest BPA levels. High BPA levels were also linked to liver enzyme abnormalities.

“Our study has revealed, for the first time, an association between raised BPA loads and two common diseases in adults,” said David Melzer, one of the study’s authors, in a written statement. “At the moment we can’t be absolutely sure that BPA is the direct cause of the extra cases of heart disease and diabetes: if it is, some cases of these serious conditions could be prevented by reducing BPA exposure.”

Stanford researcher Dr. David Feldman and his colleagues were the first to recognize that BPA had potential health effects. In the early 1990s, they stumbled across the discovery while studying receptors for steroid hormones in yeast. They noticed that a molecule was leaching out of the polycarbonate plastic containers being used in their experiment. They quickly recognized that the substance was BPA, which is ubiquitous in plastic containers like baby bottles and in the lining of metal cans. Their findings, they said, “raise concerns” about humans’ possible exposure to BPA through the food supply, since the substance is so widely used in food packaging.

Although many scientists will tell you the verdict is still out on BPA – more research is needed to fully understand the chemical and how it affects the human body – Feldman believes it is wise to limit your exposure to it in the interim.

“Well, I feel there’s enough evidence to support a ‘better safe than sorry’ approach, particularly for fetuses, infants and children,” he said in an interview with a Stanford science writer.

So how do you go about limiting your exposure to BPA? Follow these simple suggestions:

• Never microwave food in plastic containers. Nuke your meals in glass dishes instead.
• Reduce your use of canned foods and drinks.
• Whenever possible, use glass, porcelain or stainless steel containers, especially for hot foods or drinks.
• Buy BPA-free baby bottles.
• Read the packaging. Many polycarbonate plastic containers that contain BPA have a #7on the bottom of them.

Soon, doctors will be able to learn about genetic testing – and get professional credits for their efforts.

In a major advancement for the burgeoning genetic testing industry, the American College of Preventive Medicine has announced it is creating a medical education program on the use of genomic tools in medicine.

Called “Genetic Risk, Screening and Intervention,” the course is aimed at improving physicians’ understanding of the use of genetic testing in disease prevention. Available in early 2009, the class will discuss the genetic risk factors for disease, as well as the current evidence about the ability of genetic tests to assess risk.

This is an exciting time for the field of medicine.

“We are beginning to see healthcare’s evolvement from a discipline focused primarily on treating existing diseases and conditions to one that gives equal credence to preventing those diseases in the first place,” said Michael Barry, executive director of the American College of Preventive Medicine.

“We are excited to be helping physicians on the frontline of care become more familiar with multiple risk assessment strategies and the evidence behind new technologies—including genomic applications—that can help patients better understand their risk for disease and take appropriate actions to mitigate that risk,” he said.

To that end, national experts in genomics, prevention and epidemiology are designing the course to explore many issues related to genetic testing and disease prevention, including:

• The evidence for genetic screening and risk factors to epidemiological approaches typically used to identify disease risk
• The potential benefits and harms derived from different types of genetic tests
• The current evidence around genomic association studies and how a physician can evaluate their quality

As we’ve been saying, through genetic testing, patients can learn whether they are at increased risk of developing some health conditions that may be prevented with lifestyle changes, such as increased exercise and modified diets. The tests may also help physicians detect health conditions such as celiac disease much earlier in patients, and early treatment could improve patient outcomes.

The ACPM has a long history of helping physicians incorporate preventive medicine into their practices.

Navigenics is very pleased to provide support to the college, enabling it to educate physicians about the current scientific and clinical frameworks underlying preventive genomic medicine.

In just a few months, the continuing medical education (CME) course will be available on the college’s website as well as on DVD-ROM. It meets the standards of the Accreditation Council for Continuing Medical Education.

Hot flashes, a common and annoying rite of passage for many women entering menopause, may truly be something to sweat over.

Long seen as a nuisance, an unavoidable quality-of-life issue, hot flashes have been linked to insomnia, irritability and depressed mood, not to mention soaking bedsheets. But now there’s increasing evidence that hot flashes may have medical implications as well.

The habitual flushing and perspiration many women have come to dread may actually be a harbinger – a warning – of heart disease.

A series of studies has helped put some – but not all – of the pieces together on this puzzling physiological phenomenon.

• “A growing body of research has suggested that women who have severe hot flashes may also be experiencing underlying blood vessel changes.
• Estrogen withdrawal, which plays a role in the physiology of hot flashes, can harm blood vessels.
• Obesity and smoking, which may cause hot flashes in some women, are also associated with heart problems.
• Hot flashes appear to go hand-in-hand with high blood pressure, a major risk factor for heart disease.

Scientists say that more research is needed to complete the picture. But what they know so far is certainly interesting.

“Our advice to older women who have persisting hot flashes and night sweats is that they try to get off of hormone therapy, and have themselves checked and treated for cardiovascular risk factors,” said Dr. Jacques Rossouw, chief of the Women’s Health Initiative at the National Institutes of Health, in a Newsweek article.

In their groundbreaking study on hormone replacement therapy and menopause, Rossouw and his team of researchers noticed that women with moderate or severe hot flashes had more risk factors for coronary heart disease, signaling the need for more aggressive heart disease screening in that subset of women.

In September, a separate study found that women with hot flashes were much more likely to have both coronary artery calcification and aortic calcification – buildups of calcium deposits in the heart. These can be early signs that heart disease is present, even if there have been no other symptoms.

Taken along with the Rossouw team’s research, “these findings suggest potential adverse vascular changes among women with hot flashes,” the scientists concluded.

Having severe hot flashes is not a cause for panic, nor are hot flashes always a bad thing. One new study, in fact, found that in women with breast cancer taking tamoxifen or anastrozole, hot flashes seem to have a protective effect. Women who had hot flashes and night sweats after they started one of the medications were less likely to have their breast cancer return than women who did not experience the symptoms.

But it may be prudent to discuss your hot flashes with your physician, along with any other cardiac risk factors you have so that appropriate evaluation and screening can be done. The Navigenics genetic risk assessment panel adds an additional dimension to classical cardiac risk assessment as well as to the evaluation of numerous other actionable conditions.

“Luckily, most risk factors are treatable, and presumably, you can lower your risk of heart disease by taking action,” Rossouw told Newsweek. “If you look at it that way, these symptoms could be seen as a useful clue.” Knowledge of increased risk is the first step to lowering that risk.

Sitting in my mailbox last week was a sign of the times.

No, it wasn’t a political brochure or a notice about homes for sale in my neighborhood. It was a scientific journal, tightly wrapped in plastic, attesting to the evolving importance of genetics in the delivery of medical care.

“Circulation: Cardiovascular Genetics,” a journal of the American Heart Association, was launched this month to much fanfare, and has started arriving in the offices of physicians and the labs of researchers.

As the title suggests, the new publication will focus on the genetics of the cardiovascular system, exploring population genetics and biomarkers, pharmacogenetics, molecular genetics, genomics, proteomics, metabolomics and systems biology, among other pertinent topics.

In short, it delves into what those of us already firmly entrenched in the genetic testing industry have long known is the future of healthcare:  genomics and personalized medicine.

The launch represents “a small but important step” toward “practicing personalized preventive cardiovascular medicine,” said Dr. Ramachandran S. Vasan, the journal’s editor, in a press release. “We are beginning to understand how genetic factors interact with environmental influences over an entire lifetime to pattern and remodel function at the molecular, cellular, tissue and organ levels that ultimately manifest as subclinical or clinical cardiovascular disease.”

Only recently has medicine truly been moving away from its hallmark one-size-fits-all approach. The fact that an entire medical journal is now dedicated to cardiovascular genetics is pretty impressive, and speaks volumes about how seriously the medical community is taking this emerging field. This vote of confidence in personalized medicine only serves to legitimize the field even more.

“This new journal will serve as a venue for publishing highly relevant studies in the rapidly expanding fields of cardiovascular genetics, genomics, proteomics, and metabolomics,” said Dr. Joseph Loscalzo, editor-in-chief of Circulation, in a written statement. The journal “will emphasize the growing importance of these new scientific disciplines in defining cardiovascular risk, prognosis and therapeutic response and in laying the groundwork for the evolution of the field of personalized cardiovascular medicine.”

Among other things, the inaugural issue looks at the gene expression patterns in people with blocked coronary arteries, as well as the role of genes in the development of abdominal aneurysms.

The stakes are high. Heart disease is the most common cause of death in the United States, and about 900,000 Americans suffer a heart attack each year. Nearly 14,000 Americans die of a ruptured abdominal aneurysm each year.

The good news, however, is that there are steps patients and physicians can take to help prevent these and many other health conditions. The Navigenics genetic testing service currently helps members determine whether they have a genetic predisposition for either of these disorders, as well as for more than 20 other medical conditions.

I couldn’t agree more with Dr. Vasan, who states that “The field of cardiovascular genetics is exploding, with exponential increases in scientific investigations and manuscripts. These rapid advances,” he says, “bring with them the urgent need for continuous education of cardiologists, scientists and practitioners.”

And this is why Navigenics is committed to providing educational materials not only to members but also to physicians so that they can provide personalized care for their patients.

Crohn’s disease isn’t something that usually comes up in cocktail party conversations.  It isn’t featured prominently in television shows or radio spots. Ask your average person what Crohn’s is, and they likely will be hard-pressed to give you the right answer.

But this chronic inflammatory bowel disease is featured on the Web site of the New York Times, putting a face – or faces, in this case – to this rarely discussed disorder. In this interactive feature, seven people ranging in age from 19 to 61 share their experiences with the condition that has been diagnosed in more than 300,000 Americans.

“It takes forever to get diagnosed with Crohn’s,” recounts Ryan Walsh Horowitz, 19, of Brooklyn. “They thought I was anemic. They thought I had leukemia – and a bunch of other things.”

That is not surprising, nor an isolated problem.

Crohn’s has long been overlooked or misdiagnosed in the general public. The most common symptoms are, well, common: diarrhea, constipation, gas, abdominal pain, bloating and loss of weight. So it’s easy to see why many other health conditions are often suspected first.

It is quite sobering to read in the Times’ “Voices of Crohn’s Disease” vignettes that many of the people profiled said they experienced symptoms of the disease for years before getting an accurate diagnosis.

That is why it’s especially important to be aware of the symptoms – and whether you have a genetic predisposition for the disease. Although there is no simple diagnostic test for Crohn’s, the Navigenics genetic test can help you determine whether you have an above-average genetic risk.

Unlike some of the health conditions in the Navigenics genetic test, genes play a disproportionate role in the development of Crohn’s disease. Research indicates that 80 percent of a person’s risk is due to genetics.

Currently, there is no cure for Crohn’s, but treatment can help keep the symptoms under control, enabling people with the disease to lead a more normal life. But you can’t be treated effectively unless you’ve gotten a correct diagnosis.

Underscoring the importance of early detection, a study released earlier this month suggests that a vitamin D deficiency can make the disease even worse, resulting in what researchers said was greater disease activity.

The study’s lead researcher, Dr. Alex Ulitsky, said that all Crohn’s disease patients should have their vitamin D levels checked regularly and “corrected aggressively” when an insufficiency is found. That’s yet another reason for an early and accurate diagnosis.

With Crohn’s disease now beginning to appear in the news, my hope is that the public will have a greater awareness of this health condition. And with the availability of genetic risk assessment, the probability of early diagnosis and treatment should hopefully increase.