This week in the medical journals
By Peggy Peck
Medpage Today Senior Editor
Editor's Note: CNN.com has a business partnership with MedPageToday.com, which provides custom health content. A medical journal roundup from MedPage Today appears each Thursday.
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The thick and thin of health
Size and shape were pinpointed in the big medical journals this week. The major focus, of course, was on the dangers of obesity, but thinness didn't get off scot-free.
Thin apparently throws a monkey wrench into current wisdom about hormone replacement therapy, according to researchers from Oxford University in England, who reported their findings in The Lancet.
Hormone replacement therapy has been a bad news story since three years ago when U.S. researchers announced that it did not reduce heart attacks or strokes. Instead, it increased the risk of breast cancer. The one positive finding was that a combination of estrogen and progestin reduced the risk of endometrial cancer.
The researchers at Oxford University reported that not all women will reduce their risk of endometrial cancer if they are taking a combination of estrogen and progestin.
Researchers for the Britain's Million Women Study found that thin postmenopausal women who take a combination of estrogen and progestin for hormone replacement actually increase their risk of developing endometrial cancer.
The endometrial cancer protection, they said, is limited to overweight women who use hormone combinations like Prempro.
On the breast-cancer front, the Oxford researchers agreed with their American cousins that the use of the hormones, which are prescribed to relieve menopause symptoms such as hot flashes, increases the risk of breast cancer in postmenopausal women of every size and shape.
HRT endometrial cancer risk greater for thin women
While the hormone replacement study reported a risk for thin women, the rest of the week's "size and shape" news favored the svelte.
Researchers at the Kaiser Permanente Northern California Medical Groups analyzed data from more than 10,000 men and women and came up with this chilling prediction: Obesity in middle age greatly increases the risk of dementia in old age.
Writing in the British Medical Journal, the researchers reported that compared with normal weight subjects, people who are obese during middle age have a 74 percent increased risk of dementia by ages 60 to 79. Just being overweight in their 40s increased the participants' risk for dementia in their 60s and 70s by 35 percent.
Arterial stiffening -- or hardening of the arteries as it was once known -- is also influenced by obesity. Researchers from the University of Colorado in Boulder sounded the alarm about the need for women to stay fit after menopause -- a difficult task for women who fight "shifting body mass" and a slowing metabolism when their bodies stop producing estrogen.
Writing in Hypertension, Journal of the American Heart Association, the researchers reported that a sedentary lifestyle at menopause contributes to increased abdominal fat and higher concentrations of LDL -- the so-called bad cholesterol -- in the blood.
These factors, they said, increase a factor called oxidative stress that stiffens arteries. The solution, they reported, is exercise, weight control and close monitoring of cholesterol levels.
Final analysis: Size matters.
Middle-age obesity predicts old-age dementia
Sedentary postmenopausal women at more risk for arterial stiffening
A new look at some old procedures
Just in time for Mother's Day, the Journal of the American Medical Association reported that too many American women undergo a surgical procedure called episiotomy during normal vaginal births.
The procedure, which is done in about 35 percent of vaginal deliveries, was once thought to make childbirth easier by widening the vagina with a small surgical incision, but researchers from the University of North Carolina said the opposite is true.
After analyzing data from 26 episiotomy studies, they concluded that episiotomy actually increases the risk for injury to women.
The surgery, they said, should be used only when it will prevent harm to the baby -- a situation that occurs in probably less than 10 percent of vaginal deliveries.
A second study appearing in JAMA questioned the role of the ancient Chinese practice of acupuncture in relieving the pain and frequency of migraine headaches.
In a random trial that compared acupuncture with "sham acupuncture," the winner was the placebo effect. There was a benefit, but it was not the way the traditional acupuncturists would have liked to see it.
There was no difference in relief whether the acupuncture needles were inserted in strictly prescribed places, a la the Chinese traditionalists, or simply placing them hither and yon in the body, as was done with the sham procedure.
Both made patients improve, unlike patients for whom nothing was done, said researchers at the Center for Complementary Medicine Research at Technische Universität in Munich, Germany.
Message from both studies: Evidence trumps tradition.
No evidence found to support routine episiotomy
Surprise finding on acupuncture for migraine
Mom is still right: Eat your veggies
A team of Stanford researchers had these words of caution about low-fat diets: They are not created equal.
Writing in the Annals of Internal Medicine, the researchers reported that an experimental diet that is rich in fruits, vegetables, whole grains and beans is twice as effective at lowering LDL (the so-called bad cholesterol) as a standard low-fat diet.
That's bad news for low-fat fans who rely on pre-packaged low fat items, said the researchers, although it might seem a no-brainer that a plate of raw carrots and broccoli can deliver more cholesterol-fighting punch than a package of low-fat chocolate chip cookies.
Take home from the grocery store message: It's the veggies.
Plant-based diet beats packaged low-fat diet in LDL reduction
More painful news on painkillers
Following an FDA public health advisory on April 7 warning about heart risks associated with use of all nonsteroidal anti-inflammatory drugs, or NSAIDs, for pain, with the exception of aspirin, came a report about lung risks associated with Tylenol, or acetaminophen, as it is known generically.
Tylenol is not an NSAID, so it was not included in the FDA's action. But now an international team of researchers from the United States, England, and the Netherlands that analyzed data from a survey of 13,000 Americans reported that frequent use of Tylenol is associated with an increased risk of asthma, chronic obstructive pulmonary disease and overall decreased lung function.
Daily Tylenol users had a 75 percent greater risk of asthma than nonusers, and their risk for the disease was 72 percent greater than nonusers, the researchers reported in the American Journal of Respiratory and Critical Care Medicine.
Bottom line: There are no painless painkillers.
What a pain! Now it's Tylenol troubles