Monday, November 7, 2011

Babies on obesity path? New sign may offer answer (AP)

CHICAGO � Researchers say there's a new way to tell if infants are likely to become obese later on: Check to see if they've passed two key milestones on doctors' growth charts by age 2.

Babies who grew that quickly face double the risk of being obese at age 5, compared with peers who grew more slowly, their study found. Rapid growers were also more likely to be obese at age 10, and infants whose chart numbers climbed that much during their first 6 months faced the greatest risks.

That kind of rapid growth should be a red flag to doctors, and a sign to parents that babies might be overfed or spending too much time in strollers and not enough crawling around, said pediatrician Dr. Elsie Taveras, the study's lead author and an obesity researcher at Harvard Medical School.

Contrary to the idea that chubby babies are the picture of health, the study bolsters evidence that "bigger is not better" in infants, she said.

But skeptics say not so fast. Babies often grow in spurts and flagging the speediest growers could lead to putting infants on diets � a bad idea that could backfire in the long run, said Dr. Michelle Lampl, director of Emory University's Center for the Study of Human Health.

"It reads like a very handy rule and sounds like it would be very useful � and that's my concern," Lampl said. The guide would be easy to use to justify feeding infants less and to unfairly label them as fat. It could also prompt feeding patterns that could lead to obesity later, she said.

Lampl noted that many infants studied crossed at least two key points on growth charts; yet only 12 percent were obese at age 5 and slightly more at age 10. Nationally, about 10 percent of preschool-aged children are obese, versus about 19 percent of those aged 6 to 11.

Lampl and Edward Frongillo, an infant growth specialist at the University of South Carolina, voiced concern in an editorial accompanying the study in the journal Archives of Pediatrics & Adolescent Medicine, released online Monday. They argue that more research is needed to confirm whether the study's recommendation is really a useful way to flag infants for obesity.

"The potential to do more harm than good is actually very high," Frongillo said.

Taveras said the kind of rapid growth noted in the study should be used to raise awareness about potential risks but is not a reason to put babies on a diet.

The study involved 45,000 infants and children younger than age 11 who had routine growth measurements during doctor checkups in the Boston area from 1980 through 2008.

Growth charts help pediatricians plot weight, length in babies and height in older kids in relation to other children their same age and sex. Pediatricians sometimes combine an infant's measures to calculate weight-for-length � the equivalent of body-mass index, or BMI, a height-to-weight ratio used in older children and adults.

The charts are organized into percentiles. For example, infants at the 75th percentile for weight are heavier than 75 percent of their peers.

The study authors used seven major cutoffs on the charts � the 5th, 10th, 25th, 50th, 75th, 90th and 95th percentiles � to calculate growth pace. An infant whose weight-for-length jumped from the 19th percentile at 1 month to the 77th at 6 months crossed three major percentiles � the 25th, 50th and 75th � and would be at risk for obesity later in childhood, the authors said.

Larger infants were most at risk for obesity later on, but even smaller babies whose growth crossed at least two percentiles were at greater risk than those who grew more slowly.

About 40 percent of infants crossed at least two percentiles by age 6 months. An analysis of more than one-third of the study children found that 64 percent grew that rapidly by age 2.

Dr. Joanna Lewis, a pediatrician at Advocate Lutheran General Hospital in Park Ridge, Ill., said she supports the idea that infancy is not too young to start thinking about obesity.

Still, she emphasized that rapid growth in infancy doesn't mean babies are doomed to become obese. "It's not a life sentence," and there are steps parents can take to keep their babies at a healthy weight without restrictive diets, she said.

Lewis said many of her patients are large babies whose parents feed them juice or solid food despite guidelines recommending nothing but breast milk or formula in the first six months.

"The study reinforces what we try to tell parents already: Delay starting solids and don't put juice in a bottle," Lewis said.

Lewis also advises parents that when starting infants on solid food, have the whole family sit down and eat together. Research has shown that obesity is less common in children raised in families that have frequent meals together at home.

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Online:

Journal: http://www.archpediatrics.com

Growth charts: http://www.cdc.gov/growthcharts

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AP Medical Writer Lindsey Tanner can be reached at http://www.twitter.com/LindseyTanner



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Hit reset on cancer screening: 'Tests not perfect' (AP)

WASHINGTON � It turns out that catching cancer early isn't always as important as we thought.

Some tumors are too slow-growing to ever threaten your life. Some are so aggressive that finding them early doesn't make much difference. And today's treatments are much better for those somewhere in the middle.

Those complexities are changing the longtime mantra that cancer screening will save your life. In reality, it depends on the type of cancer, the test and who gets checked when.

"We can find cancer early. We can reduce the burden of the disease. But along the way, we're learning our tests are not as perfect as we'd like," says the American Cancer Society's Dr. Len Lichtenfeld, a longtime screening proponent. "We're learning that we're now finding cancer that would in fact never cause harm."

Now cancer specialists are struggling to find a new balance: to quit over-promising the power of early detection and to help people understand that the tests themselves have risks � while not scaring away those who really need it.

Least controversial are cervical and colorectal cancer screenings. They can spot pre-cancerous growths that are fairly easy to remove, although even some of those tests can be used too frequently. More serious questions surround other cancers � like which men, if any, should get a PSA blood test to check for prostate cancer, and whether women should start mammograms in their 40s or wait until they're 50.

Also in question is whether doctors will be able to head off another looming controversy: Just which smokers and ex-smokers should get a pricey CT scan that can detect lung cancer but also is prone to false alarms? A recent study found the scans could save some lives. But guidelines aren't due out until early next year that would decide who is at enough risk to outweigh the test's potential harm � such as a risky, invasive biopsy to tell if a suspicious spot is cancer or just an old smoking scar.

Yet already people like 80-year-old Fred Voss of Sunderland, Md., are seeking out the tests.

"It was a big relief, and it gave me something to watch," says Voss, who participated in the CT study but wanted to get tested again to make sure nothing had changed.

Today, guidelines for how to handle some of the most common cancer screenings conflict. And, they're written for the average patient when many people may need a more customized decision, says Dr. Jeanne Mandelblatt of Georgetown University. She has studied breast cancer risk for a government panel that recommends most women not begin screening for the disease until age 50.

Consider this, she says: The average woman has a 3 percent lifetime risk of dying of breast cancer, a low risk for a disease that women find so scary. But the chances of getting breast cancer do gradually increase with age and other circumstances.

So if you're 40 and have several risk factors � like dense breasts and close relatives with the disease � then you have the same risk as an average 50-year-old, not an average 40-year-old, and might consider earlier mammograms, Mandelblatt says. Few primary-care doctors have the time to go into that kind of detail.

Adding to the confusion are testimonials from cancer survivors that a screening saved their lives. Dartmouth researchers recently studied how often that's true for mammograms, and estimated that about 13 percent of women in their 50s whose breast cancer is detected by the tests survive as a result.

What else plays a role? Treatments have dramatically improved in recent years, saving more lives. Also, increasingly powerful mammograms are detecting more low-risk tumors, the kind that probably wouldn't have threatened a woman's life in the first place.

Still, mammograms are "not perfect, but they're the best we have," cautions Mandelblatt. She thinks the Dartmouth estimate is somewhat low.

PSA tests for prostate cancer are a much tougher call. Last month, a government panel recommended an end to routine PSA screenings, a step further than other major medical groups that urge men to weigh the pros and cons and decide for themselves. But the U.S. Preventive Services Task Force found limited, if any, evidence that screening average men improves survival. That's largely because so many men are diagnosed with slow-growing tumors that never would have killed them; still, they have treatments that can cause incontinence, impotence or even lead to death.

"We really � underline the word `really' � have to pull back the messaging on prostate cancer," says the cancer society's Lichtenfeld, who himself isn't sure of the test's net worth. PSA testing took off on the basis of "blind faith" that they would work, not science, he says.

What really worries Lichtenfeld is that ever more powerful cancer screenings are being developed, before doctors have a way to tell exactly which early tumors should be removed.

"We have cells in our body that are abnormal all the time, and our bodies deal with it," he says. "Our technology takes us further and further down the early-detection path, and we need to sort through all this."

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EDITOR'S NOTE � Lauran Neergaard covers health and medical issues for The Associated Press.



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