Tuesday, March 23, 2010

10 Habits of Highly Effective Brains

by Alvaro Fernandez

First of all, please take the time to say Hello to the new neurons that are being generated in your brain every single day. This morning you’ll have some “baby neurons” that weren’t there last night, thanks to lifelong neurogenesis. Then, consider, how will you put them to good use and help them thrive over time? To guide you here, Dr. Deb summarized the gist of 10 Habits of Highly Effective Brains:

Use it or lose it.
Take care of your nutrition.
Exercise your brain and your body. They nourish each other.
Practice positive thoughts until they become your default mindset.
Thrive on learning and mental challenges.
Aim high and keep learning.
Explore and travel.
Don’t Outsource Your Brain. Make your own decisions.
Develop and maintain stimulating friendships.
Laugh often.
Your brain will surely appreciate.

Friday, March 19, 2010

Undercover Medic: When do you Admit You're a Doctor?

Sam Pannick, MB, Internal Medicine, 05:58PM Mar 8, 2010

I dread being asked for medical assistance.

It's not that I don't want to help. Really, I do. Let me just finish my snack.

Away from the hospital, requests for medical aid invariably come at the worst possible moment. In the cinema, for example, with your attention already divided between a tortuous Hollywood plot and the need to find the popcorn that's dropped inside your shirt.

Or in the theatre, trapped between frustratingly obese 'Sound of Music' fans, unable to make your way to the aisle - let alone get to the crisis developing in Row C.

The pitfalls are obvious. In these high-stakes situations, you don't just carry your own reputation. You represent doctors everywhere, the accumulated medicinal knowledge of thousands of years of civilization, fighting an age-old battle against disease. Even if you've just been woken up by a stewardess on a transatlantic flight, and you're not wearing any socks.

For some reason, the dignity of the medical profession tends to take a hit in these moments of crisis.

Closer to home, the burden of an unexpected enquiry can also take its toll.

When you're accosted by a neighbour at a dinner party, an informal request for a second opinion can prove a real conversational stumbling block. It's hard to convince your erstwhile drinking buddy that an impromptu diagnosis may not be accurate, especially if you've spent longer talking about sports cars and holidays than you have symptoms. And if the consultation is interrupted by requests to pass the ketchup, it's hard to take your role as trusted physician seriously.

So if you're never off-duty, are you allowed to have an off day? 'Good Samaritan' acts are largely protected by the courts, who recognise that they're performed in less-than-ideal circumstances. And the patients are universally grateful that the popcorn-covered delinquent who came to the rescue did actually have a medical degree.

Whatever the downside, being a doctor still carries enormous social perks. In a world full of "Workflow Priority Managers", "Information Tasking Consultants" and "Bankers", this job is recognisable, recognised and respected.

It just happens to be recognised and respected all the time. If it gets any worse, I might have to take my ID badge off when I leave the hospital. But then how would everyone know I was a doctor?

Healthcare Around the World

From American Academy of Emergency Medicine
Michael Ybarra, MD

AAEM and the Resident & Student Association continue to be involved in advocating for physicians' practice rights, emergency medicine's place in the "house of medicine," and national tort and reimbursement issues, as well as broader health care reform. As the national debate on the future of health care smolders on, here is a glimpse of health care around the world.

In the wake of World War II, The United Kingdom faced the challenge of rebuilding their country. It was in this tumultuous decade that Winston Churchill, a conservative icon, spoke to the Royal College of Physicians and Surgeons, stating:

"The discoveries of healing science must be in the inheritance of all... Our policy is to create a national health service in order to ensure that everybody in the country, irrespective of means, age, sex, or occupation, shall have equal opportunities to benefit from the best and most up-to-date medical and allied services available."[1]

The official bill authorizing the National Health Service (NHS) in England and Wales was signed in to law in 1946. It provides free point of care health services to all citizens of England and is paid for by tax dollars. The budget was roughly $200 billion in 2008-2009 and has seen an approximately 3% annual rise in costs since it's founding in the late 1940s.[2] For comparison, the 2007 budget of Medicare in the United States was over $400 billion and rises annually anywhere from 5-15%.[3] 60% of the NHS budget pays salaries for the staff, 20% for drugs and supplies and 20% for buildings and equipment.

The NHS is the world's largest provider of health care and is also the world's fourth largest employer. There is a small market for private health care, paid for out-of-pocket or by insurance policy. Life expectancy at birth in the United Kingdom is 79 years, higher than in the U.S. Though outcomes are generally exceptional, there is less access to some novel therapies, contributing to a lower survival rate for certain cancers.

China currently has a disorganized health system. In the late 1970s, the government privatized the health care system and took away a chunk of government subsidies. Now, the nearly 700 million rural Chinese citizens have little to no access to care, and most of the 1.3 billion citizens must pay for any care they receive almost entirely out of pocket. According to The Lancet, the average cost of hospitalization exceeds the average person's wage.[4] The Chinese have one of the world's highest personal savings rates, and many believe this is because individuals shoulder the majority of the cost of illness.[5]

The government has introduced a plan called Healthy China 2020, which ambitiously intends to create universal health care for 1.3 billion people over the next ten years. The plan provides some form of health insurance and drug coverage to all citizens. China has invested $120 billion on hospital infrastructure and set price controls on 300 of the most commonly used drugs.[6]

Health care in France, like in England, is provided to all citizens, financed through a national health insurance system, paid for by the government through tax revenue. France spends approximately 11% of their GDP on health care, which is the highest of any country in Europe but less than the 16% spent in the United States.[7]

Physicians are "self-employed" but receive reimbursement from a single-payer government insurance fund on a fee-for-service basis. The government sets the reimbursement schedule. Individuals have the option of purchasing private supplemental insurance. Many employers offer supplemental insurance as part of their benefits package. The government programs pay the vast majority of hospitals' (public institutions) and doctors' fees, and private insurance can be purchased to pay for drugs, prostheses, dental care and health care at private for-profit hospitals.

In general, taxes in France are higher than in the United States, but because of the complexity of both nations' tax codes, it is difficult to compare apples to apples. Individuals in France pay 5.25% of their income to the health care plan.[8] The government then plays a role in managing the health insurance funds themselves and negotiates drug costs and physicians' reimbursements.

The Japanese have one of the longest life expectancies in the world. They have a two-pronged approach to health insurance: employer-based health premiums and taxes. Profits at health insurance companies are banned. The program costs 8% of the GDP.[9]

The Japanese see their physician on average 14 times per year (four times more frequently than U.S. citizens). Patients have access to preventive services and low cost prescription drugs, all leading to a lower prevalence of chronic diseases than in the United States, contributing to their longer lifespan.

Despite the inexpensive, easy access system, the limitations on doctors' fees and a number of novel therapies may be unacceptable to many well-insured Americans. And, while the Japanese have a much lower incidence of heart disease, the chances of surviving a heart attack are about two times higher in the U.S.

There are as many approaches to providing and funding health care as there are countries and localities in the world. The challenges we face in the United States today are not as unique as we may think. No one country has the perfect system, but there is always something to be learned by looking at others' successes and shortcomings along with our own.


FDA Approves Combined Diabetes Management System

From Medscape Medical News > Alerts, Approvals and Safety Changes > FDA Approvals
Laurie Barclay, MD

March 18, 2010 — The US Food and Drug Administration (FDA) yesterday approved Medtronic's MiniMed Paradigm REAL-Time Revel System, a diabetes management system that combines an insulin pump with a glucose monitoring system. The system may represent the next step toward an artificial pancreas.

"The MiniMed Paradigm Revel System can help a patient feel more secure by giving early warning of one of their greatest concerns, hypoglycemia, while continuing to simplify the complexity of diabetes management with easy-to-use features," said Katie Szyman, president of the diabetes business and senior vice president at Medtronic, in a company news release.

The system includes "smart" insulin pump therapy and continuous glucose monitoring with predictive alerts that can give early warning of impending hypoglycemia or hyperglycemia. These alerts allow people with diabetes to intervene with appropriate action to prevent dangerous high or low glucose events.

In addition, the system includes online therapy management software that helps patients with diabetes and their healthcare providers evaluate and manage treatment and make needed adjustments based on easy-to-read reports, charts, and graphs.

Trend alerts detected by the system's glucose sensors can notify patients of rapid changes in glucose levels, which they need to confirm with a fingerstick glucose measurement and then take immediate corrective or preventative action, if needed.

Predictive and rate-of-change alerts, as well as other new features, help achieve optimal glucose target range by giving earlier warnings of potential glycemic excursions. These alerts can be tailored as appropriate for a specific patient's lifestyle; for example, by creating different settings for exercise or for management of nocturnal hypoglycemia. Compared with the standard low-glucose alert, the use of predictive alerts improved detection of hypoglycemic events by 36%, based on findings from a recent Medtronic study.

Similarly, insulin delivery can be customized to specific needs because of new features in the insulin pump. Children or other patients who are sensitive to insulin can now receive insulin in smaller increments (0.025 units per hour), and insulin-resistant patients with type 2 diabetes can more tightly control their glucose levels using the new 1:1 carbohydrate ratio. The system also allows for missed meal bolus reminders.

The Juvenile Diabetes Research Foundation International–funded studies and REAL Trend study, as well as other evidence, suggests that increased use of personal continuous glucose monitoring is associated with better average glucose control, as reflected in A1C, without increased hypoglycemic events. Nearly all US private and government insurance programs cover the costs of insulin pumps, and nearly 90% of type 1 diabetes patients with private insurance are covered for continuous glucose monitoring costs, provided they meet medical criteria. In the United States, personal continuous glucose monitoring is approved for use by people at least 7 years of age.

"Recent clinical evidence clearly supports that insulin pump therapy combined with continuous glucose monitoring improves patients' A1C while reducing the relative risk of severe hypoglycemia," said William Tamborlane, MD, professor of pediatrics and chief of pediatric endocrinology at Yale University School of Medicine in New Haven, Connecticut, in a company news release.

"Advances such as predictive alerts and smaller basal delivery rates can help physicians and patients customize therapy to meet individual needs. This ultimately simplifies some of the complexity of daily diabetes management," Dr. Tamborlane said.

The system is immediately available, Medtronic said.

Friday, March 12, 2010

Barbiturates Still Drugs of Choice in Geriatric Suicide

From Medscape Medical News
Pam Harrison

March 11, 2010 (Savannah, Georgia) — Barbiturates are still the drugs of first choice among adults 60 years and older who commit suicide by overdose, despite a significant decrease in their use since 1990.

In a study presented here at the American Association for Geriatric Psychiatry 2010 Annual Meeting, Robert C. Abrams, MD, Weill Cornell Medical College, New York City, found that 27.2% of adults 60 years and older living in New York City who overdosed fatally between 1990 and 2006 used barbiturates. Furthermore, 26% of adults 60 years and older died of antidepressant overdose.

In contrast, only 11.8% of New York adults between the ages of 18 and 59 years died by using barbiturates during the same study interval, whereas 42.8% of them used antidepressants.

Approximately 85% of both age groups died from overdose using psychotropics, analgesics, or ethanol during the 16 years surveyed. Barbiturate use decreased from approximately 30% in 1990 to 10% in 2006.

"The comparatively high rates of antidepressant overdose in young adults could reflect problems of delivery of antidepressants to depressed elders," Dr. Abrams told Medscape Psychiatry.
However, he added, "physicians should be aware of the persistent potential of barbiturates to be lethal agents among elderly patients."

Dr. Abrams noted that people who commit suicide by overdose often take more than 1 medication. However, if the medical authorities at the time thought that an antidepressant or a barbiturate had contributed to the death, the medication was counted; as a result, percentages of patients who used different medications to commit suicide were expected to exceed 100%.

Dr. Abrams also told Medscape Psychiatry that suicidal overdose using nonnarcotic analgesics, such as nonsteroidal anti-inflammatory drugs, is increasing among older adults as well.

"Most old people do not commit suicide by overdosing — falls from height and firearms still proportionally outweigh overdosing as the method of choice for suicide," said Dr. Abrams. "But," he added, "the barbiturates are highly lethal, and people may use them if they still have them in their medicine cabinets."

Ellen Whyte, MD, University of Pittsburgh Medical Center, Pennsylvania, told Medscape Psychiatry that the first message from this study is that there is a need for physicians to attend to the risks for suicide in late life, especially among older white men who are at high risk for suicide, though, typically, through more violent means, such as guns.

"This study points to the fact that older individuals still may kill themselves through overdose, and we have to be careful about the medications we prescribe and the quantities we prescribe them in when treating elderly patients."

American Association for Geriatric Psychiatry (AAGP) 2010 Annual Meeting: Abstract NR5. Presented March 6, 2010.


Higher Physical Activity Levels Strongly Linked to Lower Levels of Depression in Older Adults

From Medscape Medical News
Pam Harrison

March 11, 2010 (Savannah, Georgia) — Higher levels of physical activity objectively measured by an accelerometer are strongly associated with lower levels of depressive symptoms and a lower prevalence of depressive disorders, according to an analysis of the 2005 to 2006 National Health and Nutrition Examination cohort and presented here at the American Association for Geriatric Psychiatry 2010 Annual Meeting.

Chad Rethorst, PhD, University of Rochester Medical Center, New York, and colleagues found that moderate physical activity as measured by an accelerometer totaling only 12 minutes a day was still significantly associated with lower levels of depressive symptoms (P < .0001) and a lower prevalence of depressive disorders (P = .003). An accelerometer gives a reading of movement intensity.

There was also a trend toward lower levels of depressive symptoms and a lower prevalence of depressive disorders in those who met American College of Sports Medicine (ACSM) recommendations for activity levels. Somewhat paradoxically, there was no association between sedentary behaviors and depressive symptoms or disorders, possibly because the cohort was extremely sedentary overall.

"Participants were only wearing an accelerometer for 1 week, so you have an idea of how much they did during that 1 week, but you don’t know how representative that week is of what they are doing on a more regular basis," Dr. Rethorst told Medscape Psychiatry. "Still, what I found most interesting in this analysis is the relationship between physical activity and depression that we expected to find and which has been previously reported in older adults."

Exercise Good for Other Comorbidities

A total of 1103 adults (mean age, 67.6 years) were included in the analysis. Depressive symptoms were measured by the Patient Health Questionnaire 9 (PHQ-9) total score, and subjects were categorized into subjects with major or minor depression or nondepressed subjects based on their PHQ-9 responses.

Physical activity was quantified in 3 ways — mean counts per minute, amount of time spent in 3 levels of activity, and physical activity levels meeting ACSM recommendations.

Based on PHQ-9 scores, 92.6% of the cohort was categorized as nondepressed, 5.6% had minor depression, and 1.7% had major depression. Measured in minutes, participants also spent 276 minutes a day in sedentary behavior, 12 minutes a day in moderate physical activity, and 0.25 minute a day in vigorous physical activity.

Time spent in vigorous activity was not associated with depressive symptoms or disorders because the amount of time the cohort spent in vigorous physical activity was extremely limited, said Dr. Rethorst. The association between those who adhered to ACSM recommendations for physical activity was also nonsignificant, very likely because few individuals met these requirements.

"When you are looking at depression in older adults, you are usually dealing with a host of comorbid medical illnesses, and what’s good about exercise is that it has the potential to not only affect depressive symptoms, but it may influence some of the other medical comorbidities that often exist in depressed patients as well," Dr. Rethorst said.

Chicken or the Egg?

Ellen Whyte, MD, University of Pittsburgh Medical Center, Pennsylvania, agreed that the analysis showed that the more sedentary people tended to be more depressed. "However," she told Medscape Psychiatry, "it doesn’t answer the chicken or the egg question, which is, are people more sedentary because they are depressed or does a sedentary lifestyle contribute to the depression? It could probably go both ways, and it is probably more complex than just saying it’s one causing the other," she said.

On the other hand, there is a growing body of literature that indicates that exercise seems to have a therapeutic effect on older people with depression.

"This suggests that maybe those individuals who are exercising more vigorously are actually giving themselves a prophylactic antidepressant through their exercise. Although once again in this study, we cannot rule out the possibility that being sedentary was a symptom of depression," she added.

Dr. Rethorst and Dr. Whyte have disclosed no relevant financial relationships.

American Association for Geriatric Psychiatry (AAGP) 2010 Annual Meeting: Abstract EI 9. Presented March 7, 2010.

Thursday, March 11, 2010

New Nicotine Inhaler May Help Smokers Quit

From WebMD Health News
Daniel J. DeNoon

March 3, 2010 — A new type of smoke-free inhaler gives would-be quitters a vapor with nearly as much nicotine as a cigarette.

Nicotine replacement is one of the most effective tools for helping smokers quit, says Jed Rose, PhD, director of the Duke Center for Nicotine and Smoking Cessation Research.

"There is the patch, gum, lozenges, and the current inhaler. But none effectively satisfy a smoker's craving for the act of inhaling and feeling nicotine going into the lungs and giving that rapid boost of nicotine into the bloodstream in a user-friendly way," Rose tells WebMD.

The problem is that cigarettes are still the most efficient nicotine-delivery device ever created, says Scott McIntosh, PhD, associated director of the smoking research program at the University of Rochester, N.Y., who was not involved in the Rose project.

"It would be great to have a product that would deliver nicotine as well as a cigarette," McIntosh tells WebMD.

That's exactly what Rose's and colleagues -- including James E. Turner, co-inventor of the older Nicotrol/Nicorette inhaler -- set out to invent.

The device they came up with does not use fire or heat. Instead, as the smoker draws air through the cigarette-shaped device, a chemical called pyruvic acid is drawn into contact with nicotine, creating a cloud of nicotine pyruvate vapor.

As pyruvic acid is a naturally occurring chemical that's part of the metabolism of every cell in the body, Rose says it does not add toxicity to nicotine. In this regard, the device is very unlike a cigarette, which delivers tars and a number of other cancer-causing substances along with nicotine.

But would smokers use it? In the device's first test, Rose and colleagues tried it on nine healthy smokers who had refrained from smoking overnight.

Each smoker took 10 puffs on the new device, 10 puffs on a Nicotrol/Nicorette inhaler, and 10 puffs of room air. Before and after each set of 10 puffs, the researchers measured the amount of nicotine in the smokers' blood and determined their smoking withdrawal symptoms.

The Nicotrol/Nicorette inhaler did raise smokers' nicotine levels. But it does not deliver nicotine deep into the lungs. Consequently, smokers did not get as much nicotine from this FDA-approved device as they did from equal amounts of nicotine in the new inhaler.

Moreover, the smokers said that puffing on the new device was less harsh and irritating than puffing on the Nicotrol/Nicorette inhaler.

"We are trying to give smokers the whole package they really are addicted to by trying to recreate that in a way we hope is far less harmful," Rose says. "We think most problems in cigarettes -- carcinogens and so forth -- come from things in smoke other than nicotine. We avoid them by giving nicotine without all those problems."

Rose says that although the device would be used to help people quit smoking entirely, it might also help people who are not ready to quit -- such as people self-medicating with nicotine for depression or schizophrenia.

If more stringent tests of the device's safety go well, Rose says the device would be commercially available in three to five years. Duke University has filed patents on the product.

Quitting Smoking and Nicotine Replacement

Nicotine is not a benign drug. It's addictive, of course, but has a wide range of effects on the body. McIntosh says nicotine may itself be a carcinogen, and appears to promote the spread of existing tumors.

But McIntosh notes that smokers aren't just addicted to nicotine.
They're also addicted to the behaviors that go along with smoking.
By allowing people to get over these addictions before they tackle their nicotine addiction, McIntosh says nicotine replacement devices double smokers' odds of quitting for good.

Even so, nicotine replacement by itself isn't enough.

"One of the best ways to quit is to get four to six sessions of face-to-face counseling -- and telephone and web-based quit lines are almost as effective," McIntosh says.

Counselors in many states offer smokers several weeks worth of free nicotine patches; free nicotine replacement is also available via quit-smoking web sites. To find out about services available in the U.S., call the national smoking hot line: 1-800-QUIT-NOW.

"Smoking is more addictive than heroin or alcohol or cocaine," McIntosh says. "About 5% of people are able to quit on their own. But if people trying to quit check in with their doctors or counselors, the success rates are as high as 45%."

One hint McIntosh has for would-be quitters is how best to use nicotine replacement. The body gets over nicotine dependence rather quickly, but studies show that quitters have the most success when they stay on nicotine replacement for eight to 12 weeks.

"One big reason people relapse is they think they have it beaten at two weeks," McIntosh says.

Another hint is to use nicotine replacement devices properly. The point of nicotine replacement is to keep a constant level of nicotine in the body so that quitters can avoid the constant cycles of nicotine use and nicotine withdrawal that a smoker experiences throughout the day and night.

"If you only use nicotine when you are having withdrawal symptoms, you will stay addicted," McIntosh says. "So if a person were to use the patch, for example, they could then use this new Rose device or nicotine gum for symptom relief. There is some evidence this is better than using just a single nicotine-replacement medication."

Rose announced his study results in a presentation to the Society for Nicotine and Tobacco Research in Baltimore.

Purpose in Life May Reduce Alzheimer's Risk

From Medscape Medical News
Allison Gandey

March 3, 2010 — Elderly people with a strong sense of purpose in life are almost 2½ times less likely to develop Alzheimer's disease (AD), report researchers.

The new finding adds to emerging data suggesting that psychological and experiential factors are associated with cognitive impairment.

"Our results suggest that positive factors, such as having a sense of goal-directedness that guides behavior, may provide a buffer against negative health outcomes, particularly in old age," coauthor Lisa Barnes, PhD, from the Rush University Medical Center, Chicago, Illinois, told Medscape Psychiatry.

"These results are important because of the potential public health implications," she noted. "Purpose in life is something we can actually modify in old age by giving older adults specific strategies they can use to find meaning in activities, achieve purposes, and goals."

Investigators conducted a prospective, longitudinal, epidemiologic study of more than 900 community-dwelling, older people without dementia.

The group, led by Patricia Boyle, PhD, also at Rush University, evaluated purpose in life and a mean of 4 years of detailed annual follow-up clinical evaluations. Participants were from the Rush Memory and Aging Project.

Just more than 16% of the study population developed AD. In a proportional hazards model adjusted for age, sex, and education, investigators found that a greater purpose in life was associated with a substantially reduced risk for disease. The hazard ratio was 0.48, with a 95% confidence interval of 0.33 to 0.69 (P < .001).

In subsequent analyses, Dr. Boyle and her team examined the association of purpose in life with mild cognitive impairment, an early preclinical manifestation of AD.

They found that purpose in life also reduced the risk for incident cognitive impairment. The hazard ratio was 0.71, with a 95% confidence interval of 0.53 to 0.95 (P = .02).

"We cannot establish causality with certainty," Dr. Barnes said.
"However, we found that purpose in life was protective against Alzheimer's disease even after adjusting for important factors, such as depressive symptoms, neuroticism, social networks, and number of chronic medical conditions.
It also persisted in sensitivity analyses in which we sequentially excluded persons who developed Alzheimer's disease during each of the first 3 years of follow-up."

This, Dr. Barnes explains, was to address concerns that perhaps those in the cohort had undiagnosed or mild AD.

"Although our ability to infer causation may be limited, these kinds of additional controls strengthen our confidence in the findings," she noted.

Psychological Well-Being

Another recent study found that a sense of purpose in life was the most important factor in determining mental health outcomes after serious trauma (Am J Psychiatry. 2008;165:1566-1575).

"We found that the most important psychosocial factor associated with resilience or recovered status was a sense of higher purpose in life," Adriana Feder, MD, from the Mount Sinai School of Medicine, New York City, told Medscape Psychiatry when the study was first published online in November.
"We also found that mastery, or having a strong sense of control over one's life, was significantly associated with recovered status."

This new study is reportedly the first to evaluate purpose in life and the risk for AD, but the investigators have evaluated other health outcomes in this same cohort and observed a reduced risk for death.

"Purpose in life is an indicator of human thriving that has been hypothesized to be related to better psychological well-being," Dr. Barnes said.

This study was funded by the National Institute on Aging, the Illinois Department of Public Health, and the Robert C Borwell Endowment Fund. The researchers have disclosed no relevant financial relationships.

Arch Gen Psychiatry. 2010;67:304-310.

Friday, March 5, 2010

Vigorous Physical Activity Modestly More Protective Than Moderate Activity

From Heartwire
Michael O'Riordan

March 5, 2010 (San Francisco, California) — Vigorous physical activity is associated with a modestly lower risk of cardiovascular disease when compared with activities of moderate intensity, a new study shows
The researchers found that the total volume of activity may be associated with the greatest reduction in risk, however, and that increased physical activity, even vigorous activity, did not appear to have any detrimental effects.

"If two people are expending a thousand calories per week, does it matter if they do that by running or by walking?" said lead investigator Dr Andrea Chomistek (Harvard Medical School, Boston, MA) in explaining the rationale of the study to heartwire .
We found that there might be some benefit to doing it with vigorous activity such as running, but it doesn't appear to be a very strong benefit.
As long as you're burning a certain amount of calories per week, between 600 or 1000 calories per week, it's okay if you do that by walking. You don't necessarily have to go out and run a marathon."

Presenting the results of the study here this week at EPI|PNAM 2010, the Cardiovascular Disease Epidemiology and Prevention and Nutrition, Physical Activity, and Metabolism 2010 Conference, Chomistek said that approximately 2.5 hours per week of moderate to vigorous physical activity has been shown to lower the risk of cardiovascular disease, but the dose-response curve is not well defined.

There is limited evidence, for example, to support the beneficial effects of large amounts of vigorous activity, and some researchers have even observed cardiovascular injury, as evidenced by elevated troponin levels, among marathon runners and endurance athletes, she noted.

Health Professionals Follow-Up Study

In this analysis of 43 647 individuals participating in the Health Professionals Follow-Up Study, the researchers, with senior investigator Dr Eric Rimm (Harvard Medical School), wanted to determine whether vigorous activity, independent of the amount of time spent exercising, was associated with a lower risk of cardiovascular disease compared with moderate exercise, and if it was, whether more was better.

In the study, baseline physical activity levels were first collected in 1986 and assessed every two years thereafter until 2004. To control for the time spent exercising, researchers calculated the average intensity of weekly exercise, and this was based on the time spent exercising and the number of metabolic-equivalent-task (MET)-hours expended per week. The primary end point of the study, total cardiovascular disease, included fatal coronary heart disease, nonfatal MI, and fatal and nonfatal stroke.

Among individuals who exercised the same number of MET-hours per week, vigorous activity was associated with a trend toward lower risk of cardiovascular disease compared with individuals who performed moderate activity. For example, for those who expended six to 15 MET-hours per week, there was a modestly lower risk of cardiovascular disease among those who performed vigorous activity, such as bicycling or running, compared with those walked briskly or lifted weights.

The researchers point out that the total volume of physical activity at all intensity levels appeared to be associated with the largest reduction in risk, and that there doesn't appear to be any harm in the amount of exercise done weekly.

"There has been some concern among individuals, such as those who run triathlons and marathons, that doing long amounts of endurance activity could actually damage the heart," said Chomistek.
"We've seen elevations in troponin levels in these athletes, so we wanted to see whether there was a point at which maybe too much running isn't good. We found that wasn't really true. You can really do as much as you want. It's still effective."

The researchers did report that the lowest risk of cardiovascular disease was observed in men performing 6 to 7.9 hours of vigorous activity per week, and the risk of cardiovascular disease was slightly higher, but not statistically so, in those who performed more exercise.

Nadir of Cardiovascular Risk

Commenting on the results of the study for heartwire , Dr William Krauss (Duke University Medical Center, Durham, NC), who was not involved in the analysis, noted the Harvard Alumni Health Study, led by the late Dr Ralph Paffenbarger (Stanford University School of Medicine, CA), suggested there might be a nadir of cardiovascular risk among runners who ran 20 miles per week, but an increased risk among those who ran 50 to 60 miles per week. Krauss noted that this increased risk was not statistically significant, and other studies have not shown an inverse risk with more time spent exercising.

"This is still an open question," said Krauss. "Six hours of vigorous activity per week is lot. When you're starting to get to eight or 10 hours per week, that's training for marathons and other endurance events. I wouldn't suspect there would be an adverse cardiovascular effect, but more adverse noncardiac effects, such as injuries, that would lead to long-term inactivity. But this study is reassuring in that there is no adverse effect on the cardiovascular system."

Asked about the current guidelines, Chomistek told heartwire that the focus remains on getting individuals active.

"There are still so many people in the population who don't do anything," she said. "If we tell these patients that they have to go out and run a marathon, they're probably not going to do it. We can still have the guidelines for those people, but for people who are already active, we can tell them to keep increasing their activity, because you're going to get greater benefit.
So even if you're doing the two-and-a-half hours a week that you're supposed to do, there is still greater benefit if you do more than that."

Exercise Produces Hormone Changes That May Cut Breast Cancer Risk

From Reuters Health Information

NEW YORK (Reuters Health) Mar 04 - A year-long aerobic exercise program for sedentary postmenopausal women produced hormone changes that may reduce the risk of breast cancer, researchers say.

"Exercise is a healthy, noninvasive, inexpensive and achievable lifestyle factor that can be used to reduce cancer risk," lead author Dr. Christine M. Friedenreich from Alberta Health Services, Canada, told Reuters Health by email. "Unlike some other options, e.g., chemoprevention, there are no harmful side effects and the benefits are considerable for many other chronic diseases as well."

In a randomized trial reported online February 16th in the Journal of Oncology, Dr. Friedenreich and her colleagues examined the effect of an aerobic exercise intervention on circulating estradiol, estrone, sex hormone-binding globulin, androstenedione, and testosterone levels in 320 women, ages 50 to 74.

The exercise program involved at least 45 minutes of aerobic exercise 5 days a week. In the control group, women merely maintained their usual level of activity.

Women in the intervention group exercised for a mean of 3.6 sessions per week for an average of 178.4 minutes/week. At 12 months, the exercisers had significant reductions in estradiol and free estradiol compared to controls, and significant increases in sex hormone-binding globulin.

There were no significant differences between the groups in estrone, androstenedione, and testosterone levels at 12 months.

"This study is quite exciting since it is the first one ever published that has found a statistically significant effect of exercise on estrogen levels, hence, we now have evidence that exercise may influence breast cancer risk through estrogens, which was previously only hypothesized to be one of the pathways," Dr. Friedenreich said.

She and her colleagues are now examining what level of exercise is required to influence these biologic mechanisms, so that more precise exercise guidelines can be developed for breast cancer prevention.

J Clin Oncol 2010.

Thursday, March 4, 2010

Altitude and the Heart: Is Going High Safe for Your Cardiac Patient?

From American Heart Journal
John P. Higgins, MD, MPhil; Troy Tuttle, MS; Johanna A. Higgins, MD
Posted: 02/22/2010; American Heart Journal © 2010

Our aging population combined with the ease of travel and the interest in high altitude recreation pursuits exposes more patients to the acute physiologic effects of high altitude and lower oxygen availability.
Acute exposure high altitude is associated with significant alterations to the cardiovascular system. These may be important in patients with underlying cardiovascular disease who are not able to compensate to such physiologic changes. Exacerbating factors pertinent to patients with cardiovascular disease include acute hypoxia, increased myocardial work, increased epinephrine release, and increased pulmonary artery pressures.
This review summarizes the physiology and clinical evidence regarding acute altitude exposure on the cardiopulmonary system with practical recommendations to address the question: "Is it safe for me to ski in the Rockies or climb Mt. Kilimanjaro?"

More than 100 million people travel to high altitudes annually, which place some at risk for complications involving the acute effects of hypobaric hypoxia.[1] High altitude trekking and recreational activities provide a unique physiologic challenge to the cardiopulmonary system.[2,3] Often, people are acutely exposed to high altitude for 4 to 6 hours for specific recreational activities, and thus, there is limited time for physiologic adaptations to occur.[4] Environmental changes when moving from sea level to altitude include reductions in atmospheric pressure, oxygen pressure, humidity, and temperature.[5] The exact altitude at which physiologic changes affect health and cardiopulmonary performance is not constant, but significant changes typically begin at > 2,500 m (8,200 ft).[6] At this moderate altitude, the partial pressure of oxygen in the arterial blood is about 60 mm Hg, compared with 98 mm Hg at sea level.[7] The degree to which changes occur depend on the change in elevation, degree of hypoxia, rate of ascent, level of acclimatization, exercise intensity, genetics, and age.[5,8,9] For the purpose of this review, low altitude is considered to range from sea-level to 1,500 m (4,950 ft), moderate altitude from 1,500-2,500 m (4,950-8,250 ft), and high altitude > 2500 m (8,250 ft).

On the basis of this review, we advocate the following recommendations for unacclimatized patients who are considering ascent to high altitude and/or exercise at elevation. To review, low: sea-level to 1,500 m (4,950 ft), moderate: 1,500-2,500 m (4,950-8,250 ft), high altitude: > 2,500 m (8,250 ft).

Recommendations for every patient:

At moderate or high altitude, limit activity to a lower maximal level than at sea level. Based on the available literature, limitation of exercise workload or exercise time to about 80% to 90% of what one can do at sea level.
Raise your sleeping altitude gradually by < 305 m (1,000 ft) per day each night > 3,050 m (10,000 ft), especially if a prolonged trek is planned "the sleeping rule."[27]
A moderate degree of physical conditioning is encouraged at sea level before exercise at altitude.[62]
Alcohol consumption should be minimized and proper hydration should be maintained to keep blood viscosity and volume within normal parameters.
If unsure of a patient's cardiac status, in any male or female > 40 years, consider performing an exercise treadmill stress test for the evaluation of heart disease before planned activity at high altitude.[40]
In addition to the above, recommendations specific for cardiac patients:

Patients with unstable angina, uncontrolled ventricular or supraventricular arrhythmias, uncompensated heart failure, myocardial infarction in prior 2 weeks, or revascularization or major thoracic surgery in prior 3 weeks should not exercise above low altitude.[62]
Patients with severe heart failure, severe angina, or severe valvular disease should not ascend to high altitude.[27]
Patients who have had coronary events within last 14 days should avoid traveling to altitude until a maximal stress test (treadmill, echocardiographic, or nuclear) rules out significant ischemia; for patients who have undergone revascularization in the mean time, a submaximal or pharmacologic stress test should be considered.[63]
Elderly people and/or those with significant structural but stable heart disease should limit their activity the first few days at moderate or high altitude.[34,38]
Patients with significant cardiovascular disease that is borderline compensated at sea level should limit their ascent to low or moderate altitude.[39]
Patients with CAD, arrhythmia, or congestive heart failure should be advised that they may become symptomatic at lower exercise workloads at altitude than at sea level.[35,36]
Individual activity limits should be based on peak heart rate or rate pressure product rather than workload because ischemia may occur at a lower workload at altitude.[6]
Patients with prior HAPE and known intracardiac shunts will likely experience an increase in right heart and pulmonary artery pressures, which may result in worsening of their condition, and therefore should be advised to avoid travel to high altitude.[56]
Patients with a history of HAPE or ascending rapidly to high altitude should be aware of the signs and symptoms of HAPE, with plans for immediate descent to lower altitude and oxygen administration as the first priority; also, prophylactic use of and emergency medical treatment consisting of calcium antagonists and phosphodiesterase inhibitors should be considered.[10]
Patients with pacemakers can be safely exposed to high altitudes with no impact on ventricular stimulation thresholds;[64] effects of altitude on implantable cardioverter-defibrillators are unknown at this time.

Call for Increased Awareness, Identification of Prediabetes

From Heartwire
Lisa Nainggolan

March 4, 2010 (Atlanta, Georgia) — Less than 10% of adults in the US with prediabetes are aware that they are at high risk of developing diabetes, according to the first nationally representative survey of adults there [1]. Dr Linda S Geiss (Centers for Disease Control and Prevention, Atlanta, GA) and colleagues report their findings online March 2, 2010 in the American Journal of Preventive Medicine.

"We know from clinical trials that people at high risk of diabetes--blood sugar levels higher than normal but not high enough to be diabetic--can reduce their risk of diabetes through lifestyle modifications that include dietary changes, increased physical activity, and weight loss,"
"The first step in getting people to do something and getting lifestyle-modification programs into place is being able to efficiently identify people at risk and increase awareness of that risk."

Geiss and her colleagues found that almost 30% of the 1402 adults they surveyed from the 2005–2006 National Health and Nutrition Examination Survey had prediabetes, but only 7.3% were aware of it--that is, had been told they were "borderline" diabetic; had impaired glucose tolerance; had blood sugar higher than normal but not high enough to be called diabetes; or had a prediabetes condition.

Physician Advice to Change Behaviors Is Key

Although most people surveyed had actually seen a physician in the past year, only a third of the adults with prediabetes had received advice from healthcare professionals about improving behaviors.

But physician advice is key, says Geiss, because the proportion of people who actually tried to change their behavior was higher if they had been advised to do so by a healthcare professional.

Around 75% of people advised by a doctor to adopt healthier lifestyles had tried to do so, compared with around 50% of those surveyed overall, she noted. She cautions, however, that the data are self-reported, so this is a limitation of the study.

In multivariate analysis, in addition to healthcare provider advice, female gender and being overweight or obese were positively associated with all three risk-reduction behaviors: losing/controlling weight; reducing fat or calories in the diet; and increasing physical activity or exercise.

Reasons for physicians not providing advice could not be determined in this study, Geiss and colleagues note, but prior research suggests a number of reasons likely play a role. These include: lack of time and reimbursement for preventive services; poor physician training or insufficient knowledge of obesity management and nutrition; lack of understanding about successful strategies to help patients or of community resources; and the perceived futility of patients' efforts to make changes.

"One of the big issues is that physicians may not have adequate resources in the community to refer these folks to, because this is not a medical problem, it's a community-based problem," Geiss explains.

"In the US, we are trying to institute lifestyle-modification programs for people at risk. Diabetes has been really increasing over the past 20 years, and in order to reduce the incidence of disease we are going to have to get these people efficiently identified and into prevention programs," she concluded.


Monday, March 1, 2010

Childhood Obesity and Glucose Intolerance Linked With Premature Death

From Heartwire CME

News Author: Michael O'Riordan
CME Author: Désirée Lie, MD, MSEd

February 19, 2010 — Obesity, glucose intolerance, and hypertension in childhood are strongly linked with premature death from endogenous causes in young adulthood and middle age, according to the results of a new epidemiological study in a cohort of American Indian children [1].
Elevated cholesterol levels, on the other hand, were not associated with early mortality, although investigators caution against concluding that hypercholesterolemia in childhood is not harmful.

"The linking factor here is almost certainly the obesity," lead investigator Dr Paul Franks (Umeå University Hospital, Sweden) told heartwire . "When we adjusted the risk associated with glucose levels and blood pressure for obesity, the effect of those risk factors substantially diminished. We also know the causal mechanisms with blood pressure, glucose, and obesity suggest that obesity is probably the primary metabolic derangement that causes hyperglycemia and high blood pressure, and not the other way around."

The results of the study are published in the February 11, 2010 issue of the New England Journal of Medicine.

BMI Associated With Increased Risk of Premature Death From Endogenous Causes

Speaking with heartwire , Franks noted that his group previously published studies examining the association between glucose levels during pregnancy and the risk of obesity and diabetes in the offspring, as well as studies linking clinical risk factors in children with diabetes in adulthood. The purpose of this study was to study the effect of childhood risk factors for cardiovascular disease on adult mortality.

In a cohort of 4857 American Indian children aged five to 19 years without diabetes, body-mass index (BMI), glucose tolerance, blood pressure, and cholesterol levels were assessed to determine the extent to which they predicted premature death. The analyses included data from the date of the baseline examination until the person's death, their 55th birthday, or the end of 2003.

During a median follow-up of 24 years, there were 166 deaths, 3.4% of the cohort, from endogenous causes. Of these deaths, 59 were attributed to alcoholic liver disease, 22 to cardiovascular disease, 21 to infections, 12 to cancer, 10 to diabetes or diabetic nephropathy, nine to alcoholic poisoning or drug overdose, and 33 to other causes.

BMI was associated with a significantly increased risk of premature death from endogenous causes, with those in the highest quartile having a mortality rate 230% greater than those in the lowest BMI quartile.
The two-hour plasma glucose level assessed during an oral glucose-tolerance test was not associated with premature death, but children with elevated blood glucose, those in the highest quartile, had a 73% greater risk of premature death than those in the lowest quartile.

Incidence-Rate Ratios for Premature Death (Quartile 4 vs Quartile 1) Variable Premature death from endogenous causes, incidence-rate ratio (95% CI)
BMI 2.30 (1.46–3.62)
2-h glucose 1.73 (1.09–2.74)
Total cholesterol 1.28 (0.81–2.02)
Systolic blood pressure 1.34 (0.83–2.15)
Diastolic blood pressure1 1.40 (0.89–2.19)

In models looking only at children with impaired glucose tolerance, there was no significant association with premature death.

"That might sound slightly counterintuitive, that these children with impaired glucose tolerance, those at the top end, are not the ones really driving mortality," explained Franks. "My feeling is that this is a population with a well-known risk for diabetes, so children diagnosed with the highest glucose levels, even though they are not diabetic, might have been picked up by the medical services early on and treated, which would make them less prone to the consequences of hyperglycemia. The children just below that level, they still have high glucose, they're the ones really driving the mortality rate in this study. The take-home message from this is that having a threshold for high glucose and saying that we're only going to intervene when it is above that threshold might not be good enough."

There was no significant association observed between systolic and diastolic blood pressure and premature death, but when investigators used a childhood definition of hypertension, one that takes three measurements and is standardized for height, there was a 57% increase in the risk of premature death among hypertensive children.

Regarding the absence of an association between childhood hypercholesterolemia and premature mortality, Franks told heartwire that only total-cholesterol levels were measured and that they did not have access to a full lipid profile. Moreover, a limited number of cardiovascular events might have influenced this finding, and as a result clinicians should err on the side of caution about concluding that there is no risk associated with elevated cholesterol levels.

"I would say that the absence of a statistically significant effect does not mean that high cholesterol levels in childhood are not harmful," he said. "It could mean that we did not observe enough events related to cardiovascular death to produce a statistically significant association between cholesterol in childhood and early death. Possibly, if this cohort is followed until later in life and more cardiovascular deaths occur, it's possible that one would observe an association between childhood cholesterol and mortality rates."

How Should the Findings Be Put Into Practice?

In an editorial accompanying the study [2], Dr Edward Gregg (Centers for Disease Control, Atlanta, GA) notes that the causes of obesity and diabetes appear to be rooted in culture--inactivity and large portion sizes of calorie-dense fast food--and that fighting these diseases with "clinical and adult-based approaches" is akin to "pasting a small bandage on a gaping wound."

While future approaches might target young people as a means of preventing these metabolic disorders, it should not be assumed that targeting youths will be effective for reducing their prevalence. "Bridging the wide gap between risk factors in youth and the prevention of illness in adults needs not only evidence that risk factors track strongly from childhood to adulthood but also efficient interventions with sustainable effects across different life stages," he writes.

Franks agrees.

"What we don't know is, if we intervene in these children, would we decrease the mortality rates; and we don't yet know the best way to intervene," he told heartwire . "Weight loss is not normally considered an appropriate strategy in children; instead, we try to get them to migrate toward a healthy growth trajectory. The message for frontline therapists is healthy diet and physically active lifestyles."

In highlighting one of the limitations of the study, Gregg points out that many deaths occurred before individuals were 45 years of age and were influenced by a large number of deaths from liver disease, something that warrants further study. He said the clinicians should not assume that follow-up into later life, when people die of typical causes, would yield similar associations with impaired glucose, obesity, and death. Like Gregg, Franks noted the cohort is unique, but that trends with respect to obesity and diabetes have mirrored trends in the US population in the past few decades.

No conflicts of interest reported.

Clinical Context

Although early diabetes and cardiovascular risk factors are known to raise mortality rates, it is uncertain whether cardiovascular risk factors in childhood influence subsequent mortality.

This is a longitudinal cohort study of American Indians from Arizona to examine the association between cardiovascular risk factors in childhood and risk for premature death.

Study Highlights

The study population consisted of a well-defined area in Arizona and included Pima and Tohono O'odham Indians born between 1945 and 2003.
Included were 4857 children who were of at least four-eighths American Indian heritage who were aged 5 to 20 years at the time of recruitment between 1966 and 2003.
BMI, 2-hour glucose after a 75-g glucose load, and blood pressure and total cholesterol were measured.
Children were followed up to age 55 years, death, or the end of 2003, whichever came first.
The outcome of interest was death, which was defined as endogenous or external.
Death was ascertained by death records, and copies of death certificates were obtained, as was the International Statistical Classification of Diseases and Related Health Problems, 9th Edition, code used for cause of death.
Premature death was defined as death before age 55 years.
Endogenous causes included disease or self-inflicted injury.
External causes were defined as those resulting from accidents or homicide.
The World Health Organization criteria were used to define diabetes based on the glucose tolerance test.
No measures of puberty were available.
Alcohol dependence in adulthood was ascertained using the CAGE questionnaire.
Cox proportional hazards models were used to test for associations between baseline childhood risk factors and risk for premature death.
During the follow-up period, 11.3% of the participants died before they reached 55 years of age.
166 deaths were from endogenous causes: 59 resulting from liver disease, 22 from cardiovascular disease, 21 from infection, 12 from cancer, 10 from diabetes or diabetic nephropathy, 9 from alcoholic poisoning or drug overdose, and 33 from other causes.
BMI was positively associated with risk for premature death from endogenous causes (incident rate ratio, 1.40 per 1 unit of BMI).
BMI was positively associated with death from external causes, but this was not significant.
The risk in the highest quartile of BMI was 2.30 times that of those in the lowest quartile.
28.7% of children were obese as defined by the 95th percentile of BMI.
In obese children, the incident rate ratio for all deaths was 1.31, and for endogenous death it was 1.90.
Children in the highest quartile of glucose intolerance had a 73% higher risk for premature death (incident rate ratio, 1.73).
Adjustment for childhood BMI reduced the incident rate ratio to 1.24.
When hypertension was defined by the criteria of the National High Blood Pressure Education Program, there was no significant increase in risk for premature death from all causes or from external causes.
However, childhood hypertension was significantly associated with risk for premature death from endogenous causes (incident rate ratio, 1.57).
There were no associations between childhood hypercholesterolemia and systolic and diastolic blood pressure and premature death from endogenous causes.
Most deaths occurred in those not known to have diabetes.
There were no associations between childhood obesity and alcohol dependence in adulthood.
The authors concluded that high BMI, glucose intolerance, and childhood hypertension were associated with premature death from endogenous causes.
They suggested that obesity may mediate the metabolic derangement that results in glucose intolerance, leading to increased risk for premature death.

Clinical Implications

High BMI, glucose intolerance, and childhood hypertension were associated with premature death from endogenous causes in American Indians.
Hypercholesterolemia is not associated with premature death in American Indians.