Health and Fitness Blog

TUESDAY, June 30 (HealthDay News) — People who are overweight
and obese are usually given higher-than-normal doses of radiation in order
to obtain usable X-ray images, even though the long-term effects are
unknown, new research contends.

“You need to get a certain amount of X-rays to go through the body in
order to get an informative image, and excess weight impedes that,”
explained the study’s lead author, Jacquelyn C. Yanch, a professor at the
Massachusetts Institute of Technology in Boston. “And there are very few
ways around that problem, other than increasing an overweight patient’s
exposure to radiation to improve the image quality.”

“Americans have gotten larger on average over the last half-century,
and so as a result, our radiation dosages have gone up,” she added.
“Exposure can be sometimes 20, 30, even 40 times as much for an overweight
patient as for a lean person. And in general, we’re also getting more
exams and more intensive exams.”

“But even so, we don’t actually know the impact of such high doses over
time, or whether they’re dangerous, because we simply haven’t tracked the
effect,” Yanch said. “So, it’s very important for us to start monitoring
this exposure for each individual patient so we can get a handle on
it.”

X-rays account for the lion’s share of people’s exposure to radiation,
the researchers note.

To gauge how high radiation doses must be to get effective X-rays for
overweight and obese people, the researchers used computer simulations
that delivered X-ray beams at various strength levels to so-called
“phantom” patients representing five different fat tissue levels, from
lean to obese. Different body areas, including the chest and abdominal
regions, were X-rayed to see which entry points were most effective in
rendering high-quality images.

The researchers then compared the dosage levels, body position options
and body mass distribution numbers with the amount of radiation the
computer software indicated that each imaginary patient would have had to
absorb to get the desired image.

Overall, they found that directing an X-ray to the thickest part of a
person’s fat allowed delivery of a lower radiation dose than would be
needed if a different area were targeted.

Even so, the dosage needed to get an effective X-ray via the abdominal
region of a moderately overweight man was up to 10 times greater than for
a lean man, the study found. And for a more severely overweight or obese
person, the needed dosage was up to 40 times greater than for someone of
normal weight.

The findings are reported in the July issue of Radiology.

Yanch and her team pointed out, however, that the development of
adipose tissue cancer from radiation exposure has not been proven. In
fact, she said, the issue is not that the jury is still out but that it
has not even begun to deliberate.

“For some procedures, the standard doses are very low, and so even 20
times higher than that is likely still too low to be concerned about,” she
noted. “But for some procedures, the doses to a very overweight person
will be quite high. Yet the scientific field does not know what this all
means. We don’t know if this is anything to be concerned about yet. We
have models and prediction, but no real data.”

“The way to find out is to begin to pay close attention to what doses
are being given over time, patient by patient, and what the outcomes are,”
she added.

Dr. Levon Nazarian, a professor of radiology and vice chairman for
education at Thomas Jefferson University Hospital in Philadelphia, agreed
that the central question is how the risk for health problems goes up with
repeated exposure to high-dose radiation.

“It’s true that the dose from a typical X-ray is very, very small,” he
said. “So, yes, 40 times a very small dose is still small and probably
not dangerous. However, were you to do repeated X-rays at 40 times the
regular dose, eventually the additive effect could be dangerous because
your body never forgets an X-ray. It’s cumulative over time. So the more
you do over a lifetime, the more you have a chance of causing cancer due
to radiation exposure.”

Dr. Raul N. Uppot, a radiologist at Massachusetts General Hospital and
an assistant professor of radiology at Harvard Medical School, noted that
doctors dealing with overweight patients are caught between a rock and a
hard place because of the absence of definitive information about
long-term side effects of high-dose radiation.

“The image quality among obese patients is not sufficient unless
something is done to adjust exposure upwards to deal with the problem,” he
noted. “That is a bottom line. But, of course, we’re always trying to
balance what’s safe with what’s needed. So certainly I think, when you
have no other option but to increase dosage exposure, you do want to come
back and monitor these patients and see if their risk of cancer is any
higher. Ultimately, that’s the critical information needed to determine
what dosages are, in fact, safe.”

More information

The Radiological Society of North America has more on radiation exposure in X-rays.

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BOSTON – Yes, he’s obsessed with grooming, and he occasionally barks at you, but in most ways Isaac is not your typical fitness instructor. He weighs in at 350, eats 16 pounds of food at a time and he’s only 9 years old. And he’s a seal.

Isaac is one of five northern fur seals to be featured in a new exhibit at the New England Aquarium that aims to entice an increasingly obese generation of kids to get moving.

The seals twist, stretch, leap out of the water, run on their flippers and shoot like missiles under and between the fiberglass rocks. Isaac even stands on his head. The “Move It!” program at the New Balance Foundation Marine Mammal Center, which opens Wednesday, uses the seals’ athleticism as an example for children.

“Those marine animals will do things that are jaw-dropping at times,” said Tony LaCasse, an aquarium spokesman. “We wanted kids to be inspired by them.”

The seals will dart around an open-air space in the $10 million center, built at the back of the aquarium on Boston Harbor.

The animals are rarely this close to the Atlantic. They live in the Pacific from Southern California to Japan, and north to the Bering Sea. Males grow to up to 7 feet long and 600 pounds, while females are about 5 feet and 110 pounds.

The seals are considered depleted under the Marine Mammal Protection Act, and a big reason is the hunters who pursued its pelt — two layers thick and stuffed with 300,000 hairs per square inch. The pelt demands constant grooming, and the seals attend to themselves in an endearing way, contorting their bodies so their long flippers can get the job done.

Kathy Streeter, the aquarium’s marine mammals curator, calls the northern fur seal a “Dr. Seuss animal” — a quirky combination of a sea otter and sea lion. It has ears, unlike the harbor seals common around Boston, has a distinctive bark and can prop itself up on its long flippers to look at visitors face to face.

That charisma, plus its story as a hunted and scarce animal, made it a good choice for a marine mammal center that seeks to help people relate to ocean life, Streeter said.

“They help give people a perspective on how the ocean affects everybody,” she said.

The center opening is a sign of health at the aquarium three years after it regained its accreditation after repairing shaky finances. The accreditation was pulled in 2003 by the Association of Zoos and Aquariums after financial struggles and layoffs followed two major expansions in the late 1990s.

The new center’s childhood fitness push comes as statistics from the Centers for Disease Control and Prevention estimate 32 percent of American kids ages 2 to 19 are overweight, including 17 percent who are obese.

Panels around the aquarium will show seal moves like stretching, jumping and swimming, explain the ways the moves are similar to humans and encourage kids to “Try It!”

A guide that visitors get with their tickets includes more exhortations to move like the seals, and also eat some of the healthy fish they devour. In the center itself, the seals will perform stretches and moves with trainers, and some kids will be allowed into the shallow end of the seals’ swimming area to exercise with them.

Paul Boyle, an environmental biologist and a vice president at the Association of Zoos and Aquariums, said that other institutions have pushed programs that get kids engaged outdoors, but that tying seal moves to kid fitness was unique and innovative. He added that the center has a strong draw in the sleek, engaging fur seals — though attendance will ultimately be a measure of just how strong.

Figuring out whether the seals can inspire fitness is a tougher task, but Boyle didn’t see it as much of a stretch.

“You can almost see a child in front of the exhibit, gyrating, trying to mimic the seal and saying, ‘Well this is pretty cool,’” he said. “Then they go home and they may roll around in the backyard and then they may start to, you know … run.”

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THURSDAY, June 25 (HealthDay News) — Despite having one of the
highest rates of obesity in America, the poor are less likely to undergo
weight loss surgery than obese people who are better off financially, new
research shows.

White women with higher incomes and private health insurance were the
most likely to have the surgery, according to a study to be presented
Wednesday at the American Society for Metabolic & Bariatric Surgery
(ASMBS) annual meeting, in Dallas.

Using data from the 2006 Nationwide Inpatient Sample, sponsored by the
U.S. Agency for Healthcare Research and Quality, researchers identified
88,000 morbidly obese adults who had bariatric surgery in the United
States in 2006.

Of those, 81 percent were women, 75 percent were white, 80 percent had
incomes at least two times the poverty level and 82 percent had private
health insurance.

Although government statistics show that blacks make up 18 percent of
morbidly obese adults, they represented only 11 percent of people getting
bariatric surgeries, the team noted.

“The socioeconomic differences we found were pretty striking,” said Dr.
Matthew J. Martin, an assistant professor of surgery at Madigan Army
Medical Center in Tacoma, Wash. “Income, race, insurance status, and even
your gender, are potential barriers to access to surgery.”

Morbid obesity was defined as having a body-mass index (BMI) over 40,
or a BMI of 35 to 40 with an obesity-related disease such as type 2
diabetes, heart disease or sleep apnea, criteria established by the U.S.
National Institutes of Health.

Despite a growing body of evidence that bariatric surgery is among the
most effective long-term treatments for severe obesity, few actually
undergo the procedure, which costs an average of between $17,000 to
$26,000, according to the ASMBS.

In fact, less than one-half of 1 percent of the more than 22 million
people in the U.S. who are medically eligible for bariatric surgery
actually go through with it, according to statistics derived using data
from the National Health and Nutrition Examination Survey (NHANES).

Socioeconomic disparities in health care are common in other types of
medical conditions, including cancer and cardiovascular treatments. Lack
of access to health care is one reason why the poor tend to have worse
health overall than the rest of the population, Martin said.

Obesity seems to strike lower-income people more than the more
affluent. About 35 percent of the morbidly obese had a household income
that was less than two times the poverty level, the study found, compared
to 28 percent of the general population.

About 15 percent of the morbidly obese had incomes below the poverty
level, a benchmark that varies depending on household size and geographic
region.

The morbidly obese were also more likely to have no insurance of be
underinsured, defined as having coverage from Medicaid or other
government-subsidized healthcare. About 20 percent of the morbidly obese
were underinsured, compared with 8 percent of the general population.

Women and blacks also made up a disproportionate amount of the morbidly
obese compared to their proportion of the population as a whole.

Nearly 30 percent of those who had bariatric surgery also had
diabetes, 52 percent had hypertension and 19 percent had chronic pulmonary
disease. The morbidly obese took twice as many sick days per year (5.4 vs.
2.8) and missed more work days (8 vs. 5).

“Increasing access and breaking down the socioeconomic barriers to
bariatric surgery among the underserved population has the potential to
significantly impact the health and well-being of millions of people
throughout the U.S,” Martin said.

While Medicaid and government-run medical plans do cover bariatric
surgery, patients often have long wait times for approval and often are
denied coverage for seemingly arbitrary reasons, added ASMBS President Dr.
Scott Shikora.

Even after a surgeon, mental health professional, dietician and
physician who specializes in obesity has determined the patient should
have bariatric surgery, the patient is told to try six months or a year of
additional, medically supervised weight loss attempts before trying
surgery, Shikora said.

“In our area, it’s difficult for patients with Medicaid to get approval
even if they meet all of the criteria,” said Shikora, director of Weight
and Wellness Center at Tufts Medical Center in Boston. “They seem to
arbitrarily reject applications, require lots of paperwork and take a long
time to approve anything.”

Another study also scheduled to be presented Wednesday found that
weight loss surgery may work just as well for older patients as it does
for younger ones. Researchers found that morbidly obese seniors age 65
and older who had laparoscopic gastric bypass surgery lost about 76
percent of their excess body weight and had no more complications than
younger patients.

“Bariatric surgery in the older population is underutilized because of
a misperception that old age alone puts patients at higher risk for
complications and mortality, said Dr. Joseph Kuhn, MD, study co-author and
director of General Surgical Research at Baylor University Medical Center
in Dallas. “We found seniors can benefit just as much as younger people
from bariatric surgery without taking on additional risk.”

Despite a higher prevalence of surgical risk factors such as sleep
apnea, type 2 diabetes and hypertension, 100 patients aged 65 to 77 with
an average BMI of 45 had hospital stays and complication rates that were
comparable to younger patients, the team found.

More information

There’s more on bariatric surgery at the U.S. National Institute of Diabetes and Digestive and Kidney
Diseases.

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PARIS (AFP) –
Weight-loss surgery that curbs food intake by stitching up parts of the stomach or small intestine reduces the risk of cancer in obese women by more than 40 percent, according to a study released Thursday.

But so-called bariatric surgery, which does not include fat removal through liposuction, did not appear to have the same cancer-beating impact on men, said the study in the The Lancet Oncology, a leading British medical journal.

Recent research has shown obesity to be the second most preventable cause of cancer after smoking. In the US, 14 percent of cancer deaths in men and 20 percent in women are attributed to being overweight or obese.

Until now, however, it was not known whether surgical treatment to reduce obesity lowered incidence of the disease.

A team of researchers in Sweden led by Lars Sjostrom of Gothenberg University anaylsed data from an ongoing health survey to compare cancer rates in obese patients who had weight-loss surgery, and those who did not.

Starting in 1987, they tracked 2,010 obese men and women who underwent bariatric procedures, and 2,037 obese patients who received other forms of conventional treatment. Subjects were tracked over a period averaging nearly 11 years.

The group who went under the knife lost, on average, nearly 20 kilos (44 pounds) over 10 years, while the control group put on an extra 1.3 kilos (2.9 pounds).

The number of first time cancers in the surgery group was 117, compared to 169 in the non-surgery group. But the benefits only showed up in women, who showed a 42 percent reduction in the onset of new cancers.

The researchers say the disparity may reflect a statistical distortion due to the far smaller number of men in the study.

A more likely explanation, however, could be the impact of treatment on post-menopausal breast and uterine cancers, noted Andrew Renehan of the University of Manchester in a commentary, also in The Lancet Oncology.

Surprisingly, there was no direct relationship between the amount of weight loss and reduction in cancers, suggesting that the anti-cancer benefits may be due to some mechanism other than shedding kilos or reduced calorie intake.

More research is needed to find out it this is true, the researchers said.

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TUESDAY, June 23 (HealthDay News) — Being overweight or obese as
a young adult increases the risk for pancreatic cancer, and obesity in
middle age is linked with poorer survival from the disease, a new study
finds.

Pancreatic cancer is the fourth leading cause of cancer-related death
for men and women in the United States. As the number of people who are
overweight and obese has increased in the past two decades, evidence has
grown that excess body weight is a risk factor for pancreatic cancer.

“The stronger association of excess body weight at earlier adulthood
with risk of pancreatic cancer suggests that weight control at younger age
should be the primary preventive strategy to reduce the risk of pancreatic
cancer,” said study researcher, Donghui Li, an associate professor in
gastrointestinal medical oncology at the University of Texas M. D.
Anderson Cancer Center in Houston.

The report is published in the June 24 issue of the Journal of the
American Medical Association.

Li’s group collected data on 841 people with pancreatic cancer and 754
healthy people.

They found that people who were overweight between ages 14 and 39 or
who were obese between ages 20 and 49 had an increased risk for pancreatic
cancer. The association was stronger in men than in women, the researchers
noted. Those who were overweight or obese and also smoked had an even
greater risk.

“For example, in your 30s, overweight was associated with 60 percent
increased risk of pancreatic cancer and obesity was associated with a two-
to threefold higher risk of pancreatic cancer,” Li said.

The risk of cancer leveled off for those who started to become
overweight or obese at age 40, and the risk became nonsignificant for
those whose excessive weight gain did not start until after age 50, Li
added.

In addition, people who were overweight or obese when they were 20 to
49 years old developed pancreatic cancer two to six years earlier than
people of normal weight, the study found.

“The median age of cancer diagnosis was 64 years for those with normal
[body-mass index], but was 61 years for overweight patients and 59 years
for obese patients,” Li said.

The study also found that obesity later in life — especially within
the year before a cancer diagnosis — was associated with reduced overall
survival time for people with pancreatic cancer, Li said.

“For example, the median survival time was 18 months for patients with
normal body weights during the year prior to cancer diagnosis, but the
median survival time was reduced to 13 months for overweight or obese
patients,” he said.

Dr. Robert R. McWilliams, an oncologist at the Mayo Clinic and
co-author of an accompanying journal editorial, said that if the findings
are correct, overweight and obesity have a negative impact on all facets
of pancreatic cancer.

“What’s notable about this study is that higher BMI has implications
throughout the course of pancreatic cancer — from development to worsened
survival,” he said.

“This represents another negative impact of rising obesity in our
country,” McWilliams said.

And it is yet another reason, he said, to maintain a healthy weight,
especially for those at higher risk for pancreatic cancer, such as people
with a family history of the disease.

“In addition, something associated with obesity apparently drives
pancreatic cancer,” McWilliams said. “As a scientific community, we need
to understand the underlying mechanism. Hopefully, this can lead to future
treatment strategies.”

More information

The American Cancer Society has more on pancreatic cancer.

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LONDON – Women who have their stomachs stapled not only lose weight, they also may reduce their cancer risk by up to 40 percent, new research says. In a study of more than 2,000 obese people who had surgery to reduce the size of their stomachs, Swedish researchers found women who had the procedure were less likely to get cancer than those who did not.

But for some reason, the surgery didn’t have the same effect in men; there was virtually no difference in the cancer rates in men who had the surgery and those who did not.

The research was published online Wednesday in the medical journal, Lancet Oncology.

A previous study has shown that stomach stapling surgery can prolong the lives of men and women by up to 10 years compared to those who don’t have it. Two other studies have suggested women in particular benefit from a lower cancer risk after getting the weight-loss operation.

Scientists have long thought obese people have a higher cancer risk, possibly because fat cells produce hormones that might lead to the disease. But doctors haven’t been able to prove that losing weight in other ways, including dieting, reduces that risk.

“This is one more piece of evidence in a complex puzzle,” said Dr. Len Lichtenfeld of the American Cancer Society, who was not linked to the Lancet Oncology study. “There seems to be a relationship between weight and cancer, but there is a missing link we don’t understand.”

Swedish researchers followed 2,010 obese patients from 1987 after they had their stomachs stapled, for about 10 years. Men and women were considered obese if they had a body mass index above 34 and 38 respectively. Experts say that a normal body mass index ranges from 19 to 25.

Researchers also tracked 2,037 obese people who did not have the surgery. For patients who got their stomachs stapled, most lost about 20 kilograms (44 pounds). In people who did not have the surgery, most gained a little over 1 kilogram (2 pounds, 3 ounces).

Of the women who had the surgery, 79 got cancer. In the non-surgery group, 130 women got cancer. Various types were seen, including breast, skin and blood cancer.

Among the men, 38 of the men who had the surgery got cancer versus 39 men in the non-surgery group.

The study was paid for by the Swedish Research Council and others, including drug makers Hoffman La Roche, Astrazeneca and Sanofi-Aventis, whose products include diet drugs.

Experts were baffled why only women appeared to have a lower cancer risk after the weight-loss surgery.

Lars Sjostrom of Sahlgrenska University Hospital in Sweden and the paper’s lead author, said it was possible there weren’t enough men in the study to see an effect — men only made up about a quarter of the participants.

Sjostrom and colleagues also found that neither weight loss without surgery or reduced calorie intake appeared to affect cancer rates among either men or women. He added that other possibilities to explain the smaller cancer risk, including genetics, were now being considered. “There is an unknown factor behind this effect, but we have no idea what it is,” he said.

Lichtenfeld hypothesized that the stomach surgeries might have different effects on hormones or some other substance in the body that ultimately reduced the chances of developing cancer.

____

On the Net: http://www.lancet.com

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CHICAGO (Reuters) –
Weight-loss surgery may help obese women lower their risk of developing cancer, Swedish researchers said on Tuesday.

They found women who had weight-loss surgery were 42 percent less likely to develop cancer during a 10-year study published in the journal Lancet Oncology.

Men in the study did not benefit, possibly because many cancers are driven by female hormones such as estrogen, they said, or simply because fewer men get weight-loss surgery.

Obesity has long been known to raise the risk of cancer, and the evidence continues to mount.

A study released on Tuesday in the Journal of the American Medical Association found people who were obese as young adults had twice the risk of developing pancreatic cancer, an especially aggressive kind.

Weight-loss operations — in which doctors change the digestive system’s anatomy to cut the volume of food a person can eat — have been shown to reverse diabetes and reduce the risks of dying from heart disease.

The Swedish study, led by Lars Sjostrom of Sahlgrenska University Hospital in Gothenburg, compared 2,010 obese patients who had weight-loss surgery with 2,037 obese patients who got standard diet and exercise treatment.

Overall, they found the surgery helped people maintain an average weight loss of 19.9 kg or about 43 pounds over 10 years. People in the diet and exercise group gained an average of 1.3 kg or nearly 3 pounds during the study period.

The surgery cut the rates of cancer by a third, but women enjoyed most of that benefit. Among women, there were 79 first-time cancers in the surgery group, and 130 among those who got standard treatment.

Dr. Andrew Renehan of the University of Manchester in the United Kingdom said in a commentary the absence of a benefit in men could simply reflect the number of men who were in the study.

He said for women, the greatest cancer prevention effects were likely to be post-menopausal breast and endometrial cancers — cancers sensitive to hormone levels.

Renehan said the effects of weight-loss surgery may take longer to show up in men, who are more prone to colon, rectal and kidney cancers, which take longer to become apparent.

Dr. Leena Khaitan, a bariatric surgeon at University Hospitals Case Medical Center in Cleveland, said the fact that men did not benefit likely reflected who gets the surgery.

“We know 80 percent of patients who undergo weight-loss surgery tend to be women. I suspect if we had larger numbers of men, we would probably see a difference,” Khaitan said.

She said the study and others like it suggested bariatric, or weight-loss, surgery may be an important way to prevent costly, chronic diseases like cancer.

“It’s a strong argument for preventive medicine.”

She said many patients who qualify for the surgery do not get it because of problems with insurance coverage, but that may be short-sighted.

A study last year in the American Journal of Managed Care funded by Johnson & Johnson, a maker of bariatric surgery instruments, found insurers recoup the costs of weight-loss surgery within two to four years as obese patients become healthier and have fewer medical problems.

(Editing by Peter Cooney)

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NEW YORK (Reuters Health) –
In a study of urban-living mostly African American adolescents, nearly 40 percent were overweight or obese, and 27 percent of these youngsters underestimated their weight, researchers report.

Of the 448 students in grades 5 to 8, more than 62 percent of the overweight boys and nearly 31 percent of the overweight girls listed their weight as normal or underweight, Dr. Youfa Wang, at Johns Hopkins University in Baltimore and colleagues found. The participants attended one of four Chicago Public Schools.

Compared with boys and girls not trying to lose weight, those who said they were trying to lose weight were not eating a healthier diet or increasing their physical activities, Wang and colleagues report in BMC Public Health, a journal published by BioMed Central.

Wang’s team assessed the association between actual and perceived body weight, body dissatisfaction, and intended weight control among a subset of 196 boys and 252 girls who were an average of nearly 12 years old.

Measurements of body mass index – the ratio of height to weight — showed that 40 percent of these students were overweight or obese. As noted, 27 percent of these youngsters (36 percent of the boys and 21 percent of the girls) underestimated their weight.

Still, the researchers found about 24 percent of the study group, and twice as many girls as boys, indicated dissatisfaction with their weight.

Forty-three percent of the students they were trying to lose weight. Yet, again Wang’s group did not find a greater vegetable and fruit consumption or level of physical activity this group compared with those not trying to lose weight.

“In fact,” Wang and colleagues report, “boys who reported trying to lose weight still spent more time watching TV than those who did not.”

These findings emphasize the need for improved guidance for youngsters trying to lose weight.

Data showing gender differences in weight perception and common miscalculation of body weight, also indicate these children need a better understanding of what a healthy body weight is, Wang and colleagues note.

SOURCE: BMC Public Health, June 12, 2009.

Source

WASHINGTON (AFP) –
Obesity during early adulthood raises the chances that a person will be diagnosed with pancreatic cancer, according to a study released Tuesday.

“This is the first study to explore at which ages excess body weight predisposes an individual to pancreatic cancer,” said Donghui Li, professor of medicine at the University of Texas Anderson Department.

“With our epidemiological research, we aimed to demonstrate the relationship between BMI (body mass index) and risk of pancreatic cancer across a patient’s life span and determine if there was a time period that specifically predisposes an individual to the disease,” he added.

Li said the study also examined the link between BMI, which is calculated according to a person’s weight and height, cancer occurrence and the chances of survival among patients.

The researchers found that obese youths between the age of 14 and 19 years old had a 60 percent higher chance of developing pancreatic cancer than their less overweight peers.

Obese individuals between the age of 20 and 40 were two to three times more likely to develop pancreatic cancer, but the risk levelled off for those who gained the weight in their 40s and was statistically insignificant for those 50 and above.

The study also found that obese or overweight individuals were more likely to develop pancreatic cancer earlier on their lives.

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MONDAY, June 22 (HealthDay News) — Obesity is already linked to
heart disease, diabetes and high blood pressure, but new research finds
those extra pounds can also significantly increase a woman’s risk of
developing endometrial cancer, especially if she experiences early
menopause.

Published in the July issue of Obstetrics & Gynecology, the
study found that women with a body-mass index (BMI) greater than 35 who
were under 45 at the time of their last menstrual period had a 22 times
higher risk of developing endometrial cancers than their normal-weight
peers.

“In this young population, the risk of endometrial cancer increased
dramatically if they had a BMI greater than 25,” said study author Cheryll
C. Thomas, an epidemiologist at the U.S. Centers for Disease Control and
Prevention.

Body-mass index is a measurement used to estimate one’s body fat. A BMI
between 18.5 and 24.9 is considered normal, according to the CDC.
Twenty-five to 29.9 is overweight, and anything 30 or over is considered
obese.

Although obesity is a known risk factor for endometrial cancer in
pre-menopausal and postmenopausal women, little research has focused on
younger women, according to background information in the current study.

Thomas and her colleagues reviewed data from the CDC’s Cancer and
Steroid Hormone Study, a multi-center, population-based study done in the
1980s. They found 421 women between the ages of 20 and 54 who had been
diagnosed with endometrial cancer, and they also recruited a randomly
selected control group of 3,159 women from the same areas of the country.

Women who were younger than 45 when they had their last period and had
a BMI above 35 had a 21.7 times greater risk of developing endometrial
cancer than a woman of normal weight. In women older than 45 at their last
menstrual period, those with BMIs above 35 had 3.7 times greater odds of
developing endometrial cancer than their normal-weight peers.

Women who had BMIs of at least 25 who were also under 45 at the age of
their last menstrual period had about a sixfold increase in risk vs. their
normal-weight counterparts.

The researchers suspect that a hormonal imbalance, specifically a lack
of progesterone, is likely to blame for the increased risk, Thomas
said.

Dr. Diane Yamada, section chief for gynecologic oncology at the
University of Chicago Medical Center, said she suspects the “unopposed
estrogen” causes the increased risk. Fat tissue, she explained, plays a
role in producing estrogen. “People think about estrogen as only coming
from the ovaries, but if you have a lot of adipose tissue, you’ll have
more estrogen.”

Whatever the cause, Thomas said these findings highlight the importance
of maintaining a healthy weight.

Both doctors said that weight loss can help reduce the risk of
endometrial cancer.

“People have to be very aware that obesity not only puts you at risk
for heart disease, diabetes, high blood pressure, but also for cancer,”
said Yamada. “Endometrial cancer is just one of multiple reasons to try to
get healthier.”

Any woman, overweight or not, who experiences significant changes in
her menstrual periods — such as a period that lasts longer or a heavier
flow than usual — should discuss these changes with her doctor. And,
Yamada advised that any postmenopausal woman who develops bleeding should
call her doctor right away, because these could be signs of cancer.

More information

To learn more about endometrial cancer, visit the National Cancer Institute.

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