Age-Related Eye Disease on the Increase

(HealthDay News) -- Twice as many women as men in the United States are diagnosed with vision-threatening eye disease every year, but the numbers are increasing for both genders as the baby boomer generation enters its golden years, a newly updated report shows.

The study, from the Prevent Blindness America and the government-backed National Eye Institute, found that of more than 3.6 million Americans aged 40 and older who suffer from visual impairment, including blindness, 2.3 million are women. Potentially blinding diseases such as glaucoma, cataracts, macular degeneration and diabetic retinopathy strike women in some cases almost twice as much as men.

"Some may be under the impression that losing vision is just a simple part of the aging process, but these numbers include many women in their 40s," Daniel D. Garrett, senior vice president of Prevent Blindness America, said in a prepared statement. "It's never too early to start caring for our eyes, and we strongly encourage women to make eye health a priority for themselves and their families today."

The report shows age-related eye disease has risen for both sexes, but especially among women, who represent more than 1.3 million of the more than 2 million Americans aged 50 and older that have age-related macular degeneration.

And, approximately 6 million women and 3 million men have moderate to severe symptoms of dry eye syndrome, a condition caused when not enough natural tears are produced, according to the National Women's Health Resource Center. Postmenopausal and pregnant women are most at risk because of hormonal fluctuations, and without proper lubrication, their corneas can become damaged.

"Fortunately, there is a simple way for women to protect their vision: Get regular eye care," Garrett said.

More information
Prevent Blindness America has more about eye disease.

'Testosterone link' to depression

Older men with lower levels of the male sex hormone testosterone in their blood may be more prone to depression, a study suggests.
A study of about 4,000 men aged over 70 found those with lowest testosterone were three times more likely to be depressed than those with the most.

Researchers suspect the hormone may affect levels of key brain chemicals.

The study, by the University of Western Australia, features in Archives of General Psychiatry.

Research has found that women are more likely to be depressed than men until the age of 65, when the difference between the genders almost disappears.

Testosterone levels decline with age - but there is wide variation.

The Australian team studied 3,987 men over the age of 70. Each gave blood samples and took part in tests to determine whether they were depressed.

In total 203 of the participants were assessed as being depressed.

They had significantly lower levels of both total testosterone, and free testosterone, which is not bound to proteins.

The researchers then adjusted the data to take account of factors such as educational attainment and body fat levels.

They found those men whose level of free testosterone was in the bottom 20% were three times more likely to be depressed than those in the top 20%.

The researchers said further work was required to confirm their findings.

But their work raised the possibility that treatment to boost testosterone levels in older men may be an effective way to treat depression.

Raised death risk

A previous study of 800 men over the age of 50 found that those with low levels of testosterone had a 33% increased risk of death over an 18-year period than those with higher levels.

They appeared significantly more likely to have a cluster of risk factors associated with cardiovascular disease and diabetes.

This raises the possibility that men with low testosterone levels may be prone to depression because they are also more likely to be in poor physical health.

However, the Australian researchers concluded that this could not fully explain the link, and that some other factor must also be in play.

Testosterone replacement therapy has also been shown to help elderly men with mild Alzheimer's disease.

Research has suggested that levels of testosterone in men of all ages are falling.

Professor David Kendall, an expert in pharmacology at the University of Nottingham, said there was a wealth of evidence to show that testosterone levels were linked to mood.

For instance, farmers had long castrated their stock to pacify them.

Research on animals had also shown that removal of their gonads blocked the action of anti-depressants on key mood-controlling chemicals in the brain.

"It would be no surprise that low testosterone reduces mood," he said.

"Testosterone therapy offers a relatively simple intervention, potentially, for some groups of older depressives with hypogonadism (low production of sex hormones)."

Professor Stafford Lightman, a hormone expert at the University of Bristol, said testosterone potentially had many small effects which could raise the risk of depression. For instance, low levels had been linked to poor cognitive performance.

However, he warned that depression, particularly in elderly people, was often the result of many different, inter-relating factors, and warned against placing too much emphasis on one in isolation.

"My view is that low testosterone could be a contributory factor to depression, but probably not a very powerful one," he said.

http://news.bbc.co.uk/1/hi/health/7274481.stm

Most Older Americans Living Longer and Better

(HealthDay News) -- Older Americans are living longer than ever and enjoying better health and financial security, a new report finds.

Yet there continue to be lingering disparities between racial and ethnic groups.

In 2006, there were an estimated 37 million Americans 65 and older -- 2 percent of the population. By 2030, it's estimated at 71.5 million people will be 65 and older -- almost 20 percent of the population, according to the report, Older Americans 2008: Key Indicators of Well-Being.

"This report comes at a critical time," Edward Sondik, director of the National Center for Health Statistics, said Thursday in a prepared statement. "As the baby boomers age and America's older population grows larger and more diverse, community leaders, policymakers and researchers have an even greater need for reliable data to understand where older Americans stand today and what they may face tomorrow."

The report examined five broad areas of well-being: economics, health status, health risks and behaviors and health care.

Even though life expectancy for Americans continues to increase for those 65 years of age, it is lower than in countries such as Canada, France Japan and Sweden. For example, Japanese women 65 years of age live 3.2 years longer than women in the United States. Among men, the difference is 1.2 years, according to the report.

In terms of overall health, key indicators such as smoking rates, flu and pneumonia vaccinations and screening for breast cancer have improved but have leveled off in recent years.

As for chronic conditions, women reported higher levels of arthritis compared with men. Men reported higher levels of heart disease and cancer. Among African-Americans, there were higher levels of high blood pressure and diabetes compared with whites. Hispanics reported higher levels of diabetes than did non-Hispanic whites.

The number of people 65 and older who are obese increased from 22 percent in 1988-1994 to 31 percent in 2000-2006. At the same time, there was no significant change in the number of older people who engaged in physical activity. In fact, most days Americans 65 and older reported spending half their time watching television. Those 75 and older, however, spent more time reading and relaxing and thinking, compared with people 55 to 64 years old.

In addition, as people aged, they spent less time visiting friends or attending social functions. Socializing declined from 13 percent of those 55 to 64 to 10 percent of those 75 and older. And, time spent devoted to sports, exercising, recreation and travel also declined with age, according to the report.

Older people's ability to obtain, process and understand health information or services -- called health literacy -- declined with age. Thirty-nine percent of people 75 and older had below basic health literacy, compared with 23 percent of people ages 65 to 74, and 13 percent of people 50 to 64.

Escalating health-care costs, particularly for prescription drugs, also affected older Americans: From 1992 to 2004, costs rose from $8,644 to $13,052. In 2004, prescription drugs made up 61 percent of out-of-pocket health costs for older Americans, the report found.

These costs are expected to be mitigated by the Medicare Part D prescription drug benefit. From 2006 to 2007, the number of people enrolled in the program increased from 18.2 million to 19.7 million, according to the report.

Despite these rising costs, many older Americans are more economically secure. From 1974 to 2006, the number of older Americans living below the poverty line decreased from 15 percent to 9 percent. In addition, the number of older Americans with higher incomes increased from 18 percent to 29 percent.

However, racial disparities existed, with net worth among whites 65 and older six times that of older African-Americans. And, more older Americans, particularly women, continued to work after 55.

The report was prepared by the Federal Interagency Forum on Aging-Related Statistics, which represents 15 agencies responsible for collecting data on aging. The last report was released in 2006.

One expert thinks that lack of physical activity and lack of social activity are the two biggest factors affecting the health of older Americans.

"It's kind of sad when you think about all the money and all the effort that has gone into physical activity awareness and that the actual amount has not increased over the last 10 years," said Colin Milner, chief executive officer of the International Council on Active Aging. "What that is saying is, we're doing something wrong."

Milner thinks new ways of getting people to be more active are needed. People don't realize that only a little physical activity can have a major impact on their health, he said.

"People see athletic activity, and they say: 'Forget it. I can't do that, I'm old,' " Milner said."We can save roughly $77 billion in health-care costs by increasing physical activity," he noted.

Milner said he's also concerned that older people spend too much time watching TV and becoming socially isolated.

"How long is it going to be before we engineer socialization out of our lifestyle," Milner said. "By 2020, depression will be the second-leading cause of premature death according to the World Health Organization. And now, you're taking socialization out of a lifestyle."

More information
To see the full report, visit the U.S. Federal Interagency Forum on Aging-Related Statistics.

Older Women Have Harder Time Preserving Muscle Than Men

(HealthDay News) -- Keeping in good shape is more difficult for older women than men because it's harder for women to replace muscle that's lost naturally as they age, say U.S. and British researchers.

The study of 29 healthy women and men, aged 65 to 80, found that women were less able to use protein to build muscle mass -- a key difference in the way women's and men's bodies react to food. This may be due to menopause-related hormone changes in women, said the researchers from the Washington University School of Medicine in St. Louis and The University of Nottingham. One possible culprit is estrogen, which is known to be needed to maintain bone mass.

The findings, published in the current issue of the Public Library of Science One, seem to fit with preliminary results showing that older women have less muscle-building response to weight training than older men. This difference is not apparent in younger women and men.

"Nobody has ever discovered any mechanistic differences between men and women in muscle loss before. This is a significant finding for the maintenance of better health in old age," and reducing demand on health-care systems, Michael Rennie, a professor of clinical physiology at the University of Nottingham, said in a prepared statement.

The findings of this new study show that it's important for older women to consume plenty of protein-rich foods such as eggs, fish, chicken and lean red meat and to do resistance training (lifting weights in a gym), the researchers said.

"Rather than eating more, older people should focus on eating a higher proportion of protein in their everyday diet. In conjunction with resistance exercise, this should help to reduce the loss of muscle mass over time. There is also a case for the beneficial hormonal effect of limited HRT (hormone replacement therapy), although this has to be balanced against the other risks associated with such treatment," Rennie said.

The researchers noted that maintaining muscle is essential in reducing the risk of falls, one of the major causes of premature death in older adults. After age 50, people lose up to 0.4 percent of muscle mass per year.

Women are at particular risk for muscle mass decline, because they tend to have less muscle and more fat than men in early and middle age, which means they're already closer to the "danger" threshold of becoming frail when they're in their 50s and 60s, the researchers said.

More information
The U.S. Centers for Disease Control and Prevention has more about healthy aging for older adults.

Study: Being fit can lower stroke risk

Being merely moderately fit — walking briskly half an hour a day — can lower the risk of having a stroke, according to a new study whose findings apply to women as well as men.

Much of the previous research on stroke and fitness has been on men and relied on participants to report their physical activity, said Steven Hooker, who heads the University of South Carolina's Prevention Research Center in Columbia and led the study. About a quarter of those in the new study were women, and everyone had a treadmill test to measure his or her fitness level.

"It seems that benefits we've been observing in men for many years ... are also observed in women," Hooker said.

He said even those who were moderately fit had a lower risk of stroke. Most people can reach that fitness range by walking briskly for 30 minutes a day, five times a week, said Hooker, who presented the findings Thursday at the International Stroke Conference in New Orleans.

Stroke is the nation's third-leading cause of death. It occurs when blood flow to the brain is stopped when a blood vessel is blocked by a clot or bursts. Hooker said physical activity can help prevent blood clots and the buildup of artery-clogging plaque.

For their research, Hooker and his colleagues used data from a study of more than 61,000 adults at the Cooper Aerobics Center in Dallas. After taking a treadmill test, the participants periodically answered health surveys. The latest research divided the group into four levels of fitness and looked at how many of them had strokes, following them an average of 18 years.

Overall, there were 692 strokes in men and 171 in women.

The study found that men in the most fit group had a 40 percent lower risk of stroke than the least fit men. The most fit women had a 43 percent reduction in their risk of stroke compared with women in the least fit group.

For moderate levels of fitness, the risk reduction ranged from 15 to 30 percent for men and 23 to 57 percent in women.

The lower risks held true even when taking into account other risk factors for stroke such as smoking, weight, high blood pressure, diabetes and family history.

Fitness is "a strong predictor of stroke risk all by itself," Hooker said.

The study's participants were mostly white, well-educated and middle-income or higher; other populations should be studied, he said. Fitness tests were only done when people entered the study so the researchers didn't know if their fitness level changed over time.

In its stroke prevention guidelines, the American Stroke Association recommends at least 30 minutes of physical activity of moderate intensity on most days of the week. The new study "is certainly consistent with all of the recommendations that we already have in place," said Dr. Larry Goldstein, a spokesman for the group and director of the Stroke Center at Duke University.

http://news.yahoo.com/s/ap/20080222/ap_on_he_me/fitness_stroke

Starved for Sleep? Watch Your Waistline

(HealthDay News) -- Could the key to weight loss for some people be as simple as getting some extra shuteye?

Possibly. New research suggests that people who don't get enough sleep tend to weigh more -- and that sleep can affect levels of the appetite-regulating hormones leptin and ghrelin.

"There is a dynamic balance between proper sleep and proper health. Sleep deprivation affects weight and a lot of other things. If you cheat sleep, there are a number of consequences, including affecting your hormones, appetite and mood," said Dr. Patrick Strollo, medical director of the University of Pittsburgh Medical Center's Sleep Medicine Center.

Two out of three Americans are overweight, and almost one in five are obese, according to the U.S. Centers for Disease Control and Prevention. And, while most people are aware of the relationship of diet and exercise to excess weight, few realize that the amount of sleep they get each night can also affect their weight.

Researchers at the Sleep Disorders Center at Sentara Norfolk General Hospital in Virginia conducted two studies, each included 1,000 men and women, and they found that those who reported sleeping less tended to weigh more.

Of course, it could be that being overweight might make it harder to get a restful night sleep.

"People who are overweight may have less restful sleep due to heartburn, snoring or more serious sleep disorders like sleep apnea or night eating syndrome," said Dr. Michelle May, author of "Am I Hungry? What To Do When Diets Don't Work."

But, she said, "It works both ways," and that a lack of sleep can affect your weight. Sleep deprivation affects your body chemistry, appetite and the choices that you make throughout the day, May said.

Another recent study included 12 healthy men in their 20s. Each of the men slept only four hours for two nights. The study found that levels of leptin, a hormone that tells the brain it's time to stop eating because the stomach is full, decreased by 18 percent during the two-day study period. Levels of another hormone, ghrelin, which turns the hunger mechanism on, increased by 28 percent.

On average, the men reported that their hunger pangs increased by 24 percent.

"Hormones change with sleep loss and deprivation," said Strollo. "Sleep deprivation can affect appetite and also the type of food that one desires. When you're sleep-deprived, you generally don't crave carrot sticks."

May agreed, adding, "When you're tired, you're less resilient to stress and other common emotional triggers for eating. When you eat to help you cope with emotions, you're more likely to choose comfort foods like chocolate, ice cream or chips. And, since eating only helps temporarily, you may find yourself reaching for food again and again to try to make yourself feel better.

"Getting enough sleep is the best way to prevent sleep deprivation from contributing to weight gain," May advised. "When you aren't able to get your Zzzs, pay more attention to how much you eat and how you handle fatigue and stress. A short walk will be a better energy boost than a trip to the candy machine."

Strollo said that while most people need between seven and eight hours of sleep a night, there are some people who need as many as 10 and others who may do well on just five hours.

The best way to figure out how much sleep you need, he said, is to take a long vacation and after a couple of days of catching up on your sleep debt, see how many hours of sleep you need to wake without an alarm clock. Since many Americans don't take long vacations, if you feel that you're not fully functional all day, or that you're doing things to stay awake, like a double-espresso shot, you're probably not getting enough sleep, he said.

May added that it's important to remember that "healthy eating, physical activity and sleep are not luxuries, they are necessities."

More information

To learn more about the connection between sleep and your weight, visit the National Sleep Foundation.

Prostate cancer screening 'hope'

UK researchers have discovered seven new genes associated with prostate cancer, which could be used to identify high-risk men more accurately.

Some of the genes could also lead to new treatments, the study in Nature Genetics suggests.
A trial is starting later this year to screen for the risk genes in men with a family history of the cancer.

The genes, found through analysis of 10,000 individuals, are present in over half of all prostate cancer cases.

Prostate cancer is the most common cancer in men in the UK.

There is currently no routine screening programme in the UK, although men with a family history of the disease can have a prostate specific antigen (PSA) blood test to detect signs of the disease.

But this is notoriously inaccurate and although 10-15% of men will have high enough PSA levels to warrant carrying out a prostate biopsy, only 2-3% will require any treatment.

Genome-wide scan
More than half a million single letter variations in the DNA code were analysed in men in the UK and Australia.

Researchers said the seven genes they found had not previously been linked to prostate cancer.
One of them, MSMB, can be measured in the blood and may be particularly helpful in screening for or monitor progression of the disease.

Another, LMTK2, is a potential target for new treatments, the researchers said.

Within three to four years, it should be possible to offer "genetic profiling" to men to assess their risk of developing the condition, the researchers believe.

It will enable doctors to more accurately decide which men need more regular monitoring or a biopsy.

Dr Ros Eeles, who led the study at the Institute of Cancer Research said: "From a public health point of view, this could be very helpful because it will allow us to target scarce resources to where they are really needed.

She said genetic profiling would definitely happen but researchers were not in a position to offer the test just yet.

"We're doing the trial because we need to see who would come forward for the test, who would benefit, what kind of results do they get on their biopsies and what kind of cancer develops."
Professor Doug Easton, genetic epidemiology expert at the University of Cambridge, who analysed the data said the results would "greatly improve" the understanding of how prostate cancer develops.

He added that most people would have at least one of the genes but it was the combination of a few that would increase a person's risk above the population average.

Targets

Nick James, professor of clinical oncology at the University of Birmingham and consultant in clinical oncology at the Queen Elizabeth Hospital, said it had proved much more difficult to find genes in prostate cancer compared with some other cancers.

He said: "This work provides two useful avenues."
"One is that finding faulty genes gives researchers a chance to look at their products that may be good targets for new treatments.

"Secondly, this discovery may mean that we can target screening for prostate cancer - a process that has been very controversial due to over diagnosis of clinically insignificant cancer - to groups of men that we know to have higher risk of developing the disease." The research was funded by Cancer Research UK.
http://news.bbc.co.uk/1/hi/health/7234922.stm

Facelifts 'fuel cosmetic op rise'

A record number of women having facelifts fuelled a 12% rise in cosmetic operations in Britain last year, figures show.

A total of 32,453 surgical procedures were carried out, compared with 28,921 in 2006, the British Association of Aesthetic Plastic Surgeons said.

Some 91% of patients were women, but "tummy tucks" and breast reductions on men also increased to record levels.

Association members reported a 37% rise in face or necklifts on women to 4,238.
The annual audit covers only members of the association, so the true number of procedures is likely to be higher.

The most popular operation for women remained breast enlargement surgery, with 6,847 cases.
This was followed by eyelid surgery (5,148 - up 13%), face or neck lifts, liposuction (3,990 - up 15%), and breast reduction (3,178).

The association says it is the rise of non-surgical versions, involving fillers and Botox, that is responsible for the increase in facelifts.

Rajiv Grover, the association's secretary, said: "Ten years ago there may not have been much choice between a face cream and a facelift, but more recently non-surgical procedures have introduced a large number of patients to gradual facial rejuvenation."

Liposuction
The most popular operation among men was rhinoplasty, or nose job, with more than 700 men taking this option, a rise of more than a third.

Liposuction was the next most popular, with 582 procedures (up 18%), then eyelid surgery, ear correction and neck or facelifts (230 - up 21%).

There were 224 breast reductions on men, up 27% on the 177 in 2006, and 10 times the 22 operations carried out in 2002.

The biggest rise was in "tummy tucks" as 98 men underwent the procedure, up from 61 in 2006 - a rise of 61%.

Douglas McGeorge, the association's president, said that the continuing rise in operations reflected a "continued acceptance" of cosmetic surgery.

"Wide media coverage has helped to educate the public about the latest advances and choices available, but it is crucial that people do their research carefully when choosing a provider."

Which? concerns

An investigation by the consumer group Which? recently found cases in which would-be patients felt pressurised into going ahead with cosmetic procedures such as "non-surgical" facelifts, often after misleading marketing.

Campaigner Jenny Driscoll said: "Our investigations have revealed a relaxed attitude to non-surgical treatments such as Botox and it is worrying to find that it is being prescribed by doctors without them having seen or even spoken to the patient.

"The Health and Social Care Bill is currently going through Parliament and Which? will be calling for the government to make sure that regulation of this industry is more robust."

http://news.bbc.co.uk/2/hi/health/7223176.stm

Study: Being fit can lower stroke risk

Being merely moderately fit — walking briskly half an hour a day — can lower the risk of having a stroke, according to a new study whose findings apply to women as well as men.

Much of the previous research on stroke and fitness has been on men and relied on participants to report their physical activity, said Steven Hooker, who heads the University of South Carolina's Prevention Research Center in Columbia and led the study.

About a quarter of those in the new study were women, and everyone had a treadmill test to measure his or her fitness level."It seems that benefits we've been observing in men for many years ... are also observed in women," Hooker said.

He said even those who were moderately fit had a lower risk of stroke. Most people can reach that fitness range by walking briskly for 30 minutes a day, five times a week, said Hooker, who presented the findings Thursday at the International Stroke Conference in New Orleans.

Stroke is the nation's third-leading cause of death. It occurs when blood flow to the brain is stopped when a blood vessel is blocked by a clot or bursts. Hooker said physical activity can help prevent blood clots and the buildup of artery-clogging plaque.

For their research, Hooker and his colleagues used data from a study of more than 61,000 adults at the Cooper Aerobics Center in Dallas. After taking a treadmill test, the participants periodically answered health surveys.

The latest research divided the group into four levels of fitness and looked at how many of them had strokes, following them an average of 18 years.Overall, there were 692 strokes in men and 171 in women.The study found that men in the most fit group had a 40 percent lower risk of stroke than the least fit men.

The most fit women had a 43 percent reduction in their risk of stroke compared with women in the least fit group.For moderate levels of fitness, the risk reduction ranged from 15 to 30 percent for men and 23 to 57 percent in women.

The lower risks held true even when taking into account other risk factors for stroke such as smoking, weight, high blood pressure, diabetes and family history.Fitness is "a strong predictor of stroke risk all by itself," Hooker said.

The study's participants were mostly white, well-educated and middle-income or higher; other populations should be studied, he said. Fitness tests were only done when people entered the study so the researchers didn't know if their fitness level changed over time.

In its stroke prevention guidelines, the American Stroke Association recommends at least 30 minutes of physical activity of moderate intensity on most days of the week.

The new study "is certainly consistent with all of the recommendations that we already have in place," said Dr. Larry Goldstein, a spokesman for the group and director of the Stroke Center at Duke University.

http://news.yahoo.com/s/ap/20080222/ap_on_he_me/fitness_stroke

Strokes among middle-aged women triple

Strokes have tripled in recent years among middle-aged women in the U.S., an alarming trend doctors blame on the obesity epidemic. Nearly 2 percent of women ages 35 to 54 reported suffering a stroke in the most recent federal health survey, from 1999 to 2004. Only about half a percent did in the previous survey, from 1988 to 1994.

The percentage is small because most strokes occur in older people. But the sudden spike in middle age and the reasons behind it are ominous, doctors said in research presented Wednesday at a medical conference.

It happened even though more women in the recent survey were on medicines to control their cholesterol and blood pressure — steps that lower the risk of stroke.Women's waistlines are nearly two inches bigger than they were a decade earlier, and that bulge corresponds with the increase in strokes, researchers said.

In addition, women's average body mass index, a commonly used measure of obesity, rose from 27 in the earlier survey to 29. They also had higher blood sugar levels.No other traditional risk factors like smoking, heart disease or diabetes changed enough between the two surveys to account for the increase in strokes.

In a "pre-stroke population" of middle-age women, a tripling of cases is "an alarming increase," said Dr. Ralph Sacco, neurology chief at the University of Miami Miller School of Medicine.The study was led by Dr. Amytis Towfighi, a neurology specialist at the University of Southern California in Los Angeles, and presented at the International Stroke Conference in New Orleans.

She used the National Health and Nutrition Surveys, a federally funded project that gives periodic health checkups and questionnaires to a wide sample of Americans. Participants are routinely asked whether a doctor had ever told them they had had a stroke, and about 5,000 middle-aged people answered that question in each survey.

Researchers saw that the stroke rate had spiked in middle-aged women but stayed about the same — around 1 percent — in middle-aged men. So they looked deeper at the responses to see if they could learn why.Belly fat stood out, Towfighi said. The portion of women with abdominal obesity rose from 47 percent in the earlier survey to 59 percent in the recent one.

The change in men was smaller, and previous studies have shown that "abdominal obesity is a stronger risk factor for women than men," she said.Men traditionally have had a greater risk of stroke than women, and "women start catching up to men five or 10 years after menopause," said Dr. Philip Gorelick, neurology chief at the University of Illinois in Chicago and chairman of the stroke conference.

The new research means "we need to redefine our textbooks about stroke in women," because they may now be more at risk in middle age than men.Obesity "sets the stage for all the other risk factors to come in" like diabetes and heart disease, Gorelick added.In other news at the conference, two studies found that stroke patients were more likely to die if they went to hospitals on nights or weekends, echoing other recent studies that found similar risks for heart attack and surgery patients.

Michigan State University doctors analyzed 222,500 stroke cases at more than 850 hospitals participating in an American Heart Association quality improvement program from 2003 to 2007.In-hospital deaths were about 6 percent for those who arrived during normal business hours and had strokes caused by a clot, compared with 5 percent of those who entered the hospital after-hours. Deaths were 27 percent for off-hour strokes caused by bleeding in the brain versus 24 percent during normal hours.

A second study of 2.4 million stroke patients in California found death rates of 10 percent on weekends and nights versus 8 percent during weekdays.Despite the poorer outcomes, doctors said no one should ever delay getting help, since any delay raises the risk of death. The best treatments can only be given in the first few hours after symptoms appear.

http://news.yahoo.com/s/ap/20080221/ap_on_he_me/obesity_strokes

Weighty Evidence

Living large can mean dying large, as familiar reminders about obesity's link to cardiovascular disease and diabetes repeatedly emphasize. But those warnings often overshadow another threat from obesity: cancer. Excess weight accounts for 14 percent of cancer deaths in men, and 20 percent in women, researchers estimate. Among all preventable cancer risk factors, only smoking claims more lives.

Obesity's link to cancer should come as no surprise. Signs of that relationship began to emerge 2 decades ago. In the late 1980s, laboratory researchers found connections between cancer and insulin—one of the major hormones that responds to obesity.

While the findings got little attention then, today at least a half-dozen companies are developing cancer drugs that interfere with the hormone's cousin—insulinlike growth factor 1 (IGF-1).
"We've been working on this for 20 years," says Derek LeRoith of the Mount Sinai School of Medicine in New York City. Yet until recently, "nobody ever bought into it." After all, even if a tumor does need insulin, the rest of the body does too. The early research was seen as hardly relevant for disease treatment.

Not so today. If clinical trials find that dampening IGF-1 shrinks tumors in cancer patients, scientists will have not only a new kind of cancer drug but also a new source of insight into the interplay between body weight, metabolism, and cancer. In 2003, a study in the New England Journal of Medicine estimated that if the U.S. population were of a healthier weight, "90,000 deaths due to cancer could be prevented each year." That number may not fall for generations, as obesity rates among even the youngest Americans continue to soar.

Heavy hormones
Lower weight and more physical activity can affect the production of insulin, the hormone that allows the body to soak up fuel. After a meal, food is broken down into glucose, which is the body's main source of energy. Insulin triggers cells to take up and use glucose. As a person gains excess weight, the cells can become resistant to insulin's actions. To compensate, the pancreas begins to produce more insulin, but it can't stay in overdrive indefinitely. Eventually, insulin production will fall and blood glucose levels rise in some people.

The potent hormone IGF-1 and the related IGF-2 are very similar to insulin, helping support rapidly dividing cells, especially during childhood and adolescence. IGF-1 is a powerful driver of cell growth and body size: A toy poodle is a standard poodle with a faulty IGF-1 system.

The link between these insulinlike hormones and obesity is less clear than the connection between insulin and obesity. Although insulin and IGF-1 have individual parking places, or receptors, on a cell, some experiments suggest that at high enough levels, insulin starts to trespass on the IGF-1 receptor, LeRoith says.

In the late 1980s, laboratory researchers demonstrated that IGF-1 might have a role in cancer. Tumor cells were found to contain the IGF-1 receptor. In 1989, experiments with mice showed that blocking the receptor with an antibody could stop tumor growth. Researchers also found that mice bred to lack IGF-1 receptors in all their tissues were born tiny, thereby establishing the hormone's significance in growth. More important for cancer research, cells taken from the miniature mice lacking IGF-1 receptors could not be transformed into tumor cells.

"A cancer cell has to have the IGF-1 receptor," says Renato Baserga of the Kimmel Cancer Center at Thomas Jefferson University in Philadelphia, one of the field's pioneers. "If not, it cannot grow."

At first, results like these were puzzling. Unlike cancer genes that encode other proteins and start down the path to cancer after mutating, the IGF-1 receptor gene wasn't altered in tumors. Also, IGF-1 receptors show up in normal tissues throughout the body. The hormone itself is such a basic substance for animal life that even flies produce it. It was hard to imagine that a normal receptor found in normal cells could have anything to do with cancer.

Then scientists had an idea. Malignant cells may be overly dependent on IGF-1 receptors, on a scale far surpassing the dependence of normal cells. A tumor is like a car—a gas-guzzling Hummer—with a stuck accelerator and no brakes. Even if IGF-1 doesn't spark the ignition, the hormone keeps the gas tank full. Block IGF-1, according to this line of thinking, and the tumor suddenly finds itself running on empty.

Fueling cancer
Still, this notion might have stalled without two other developments. First, epidemiological studies began to find links between cancer and the insulin-IGF axis in people. Then, the entire field of cancer treatment underwent a transformation.

"What got people's attention was the epidemiologic data," says Doug Yee of the University of Minnesota Cancer Center in Minneapolis. In 1998, researchers reported in the journal Science that the risk of prostate cancer among men with the highest circulating levels of IGF-1 was four times as great as the risk among men with the lowest IGF-1 levels. Similar findings quickly followed in breast, colon, and other cancers.

So far, colon cancer has the most consistent association with insulin and IGF-1 levels, says Edward Giovannucci of the Harvard School of Public Health, a coauthor of the 1998 Science study. In 1999, he and his colleagues reported that colon cancer rates were more than twice as high among men who had the highest levels of IGF-1 as they were among men with the lowest IGF-1 levels.

Such findings fit with global patterns of the disease. "If you look at the rates of colon cancer across the world, populations where you expect people to have low insulin invariably have low rates of colon cancer," Giovannucci says. Physical activity and reduced calorie intake can lower insulin levels; populations with more sedentary jobs and calorie-dense diets have higher rates of obesity and higher insulin levels.

"Once you become economically developed, colon cancer rates go up," Giovannucci says. Also, the risks for colon cancer read largely like a list of red flags for type 2 diabetes. Diabetes itself is a risk factor for colon cancer.

Scientists are quick to point out that a higher insulin level isn't the only chemical change that can occur with obesity. Levels of hormones that cause inflammation also rise, as do sex hormones, which can be produced in fat tissue. These and other changes in the body could themselves drive cancer. Or all these fluctuations could work in concert to feed malignancies.

And it might be not only the IGF-1 of middle age that matters, but also the IGF-1 production that orchestrates development early in life. Studies have suggested that babies born at the highest birth weights—and children experiencing early growth spurts—have a greater risk of cancer as adults.

While epidemiologists gathered evidence for a relationship between insulin and cancer, a second, unrelated advance gave the insulin-cancer connection new life: treatment success using antibodies that can attach to precise targets. Antibody-based drugs are large molecules that take the parking space so its rightful owner can't use it. Herceptin, an antibody-based breast cancer treatment, came on the market in 1998, followed by others. Targeted antibodies were suddenly more than theory.

"I think once people got more comfortable making these drugs, the floodgates opened," says Yee. And when pharmaceutical companies started casting for other promising targets for antibody development, the IGF-1 receptor suddenly looked attractive.

"They turned around and said, 'You know, there's this IGF receptor,'" says LeRoith of Mount Sinai. Drug development didn't happen, and perhaps couldn't have, until epidemiology and the technology caught up with the laboratory evidence.

Broad target
Nonetheless, an antibody that interferes with IGF-1 in people raises concerns. Although the full role of IGF-1 in adult tissues is still being worked out, rapidly growing tissues such as those in bone marrow and the intestine might become innocent by-standers of chemotherapy.
"You're going to hit a receptor that's present on every cell in the body, except the liver," LeRoith says.

Also, in a case of molecular friendly fire, the drug might hit unintended targets. Because the insulin receptor and the IGF-1 receptor are cousins—they are actually more than 70 percent alike—some drugmakers worry about the possibility of accidentally interfering with the insulin receptor and making a cancer patient diabetic.

As an endocrinologist, LeRoith isn't as disturbed by these scenarios as some of his colleagues may be. He believes chemotherapy-induced diabetes would be only temporary, and treatable. In the larger picture, it would not be as grave a threat as the cancer itself. Also, he says, chemotherapies already on the market cripple rapidly growing cells in the intestine, bone, and elsewhere. While these drugs do cause notorious side effects, the complications are generally accepted as the price of disease treatment.

So far, though, the experimental drugs haven't caused major problems in early tests. Results of the first human-safety studies are starting to appear, most just in the past few months. The results are encouraging enough that companies are easing into larger studies.

"This was a target that was on everybody's radar screen, but nobody jumped so strongly at it," says Kapil Dhingra of Roche Pharmaceuticals in Nutley, N.J.

They have now. In October, at the International Conference on Molecular Targets and Cancer Therapeutics, researchers from Roche described a study of 34 patients with advanced tumors who received infusions of an experimental drug designed to target the action of IGF-1. Disease in nine patients stabilized. The most common side effects were fatigue, weight loss, and anorexia—complaints that are also often found in patients with advanced cancer. Subjects' blood sugar levels appeared to remain stable.

The trial was designed to test the safety, and not the effectiveness, of the drug. But the researchers noted that it seemed to have a remarkable result in one of the study participants with Ewing's sarcoma, a cancer of children and young adults that Yee in Minnesota had long ago identified as feeding heavily off IGF-1.

"We have a patient, a young woman in her 20s, who really has had honestly one of the best responses I've seen in 20 years," says Razelle Kurzrock of the University of Texas M.D. Anderson Cancer Center in Houston. "When you see something like that in cancer, you've usually hit the molecular target."

Within 6 weeks, the woman's tumor melted away. The results were promising enough that Roche plans to test more patients.

The antibody-based drug that appears to be the farthest along in testing comes from Pfizer Inc., which has moved beyond safety studies into tests that gauge its effectiveness on cancer. Last summer, during a meeting of the American Society of Clinical Oncology, company researchers described results of a trial involving 70 patients with advanced lung cancer. About 46 percent of patients who received the drug in combination with standard chemotherapy improved, compared with 32 percent of those who did not get the anti-IGF-1 drug. Twenty percent of the patients getting the treatment experienced a jump in blood-glucose levels, implying some interaction with insulin. Later this year, the company hopes to report the effects of treatment on patient survival.

Other companies are also working on antitumor antibodies or on smaller molecules that will block the IGF-1 receptor. In the end, researchers say, the drugs may have a role in combination with standard treatments, and trials will probably also find that some tumors are more dependent than others on IGF-1.

"It's not realistic to think that any one target is going to hit all of them," says Kurzrock. Still, she says, "I would say this is going to be a good molecule." If so, a line of research almost lost to the past could one day benefit cancer patients of the future.

http://www.sciencenews.org/articles/20080216/bob9.asp