Tuesday, July 8, 2008

Kids and Cholesterol

In the past few years there's been a steady push to get kids with very high cholesterol on statins, the LDL-lowering drugs already found in the medicine cabinets of 13 million Americans. Now the American Academy of Pediatrics--the nation's most influential group of pediatricians--has gotten in on the act. On Monday it released new guidelines suggesting that docs should start testing overweight kids or those with a family history of heart disease for high cholesterol at age two--and that they should consider prescribing statins as early as age eight. Four of the drugs are already FDA-approved for use in kids. The new AAP recommendations are sure to be controversial, especially since the drugs' long-term effects on kids are unknown.

Newsweek's Mary Carmichael spoke with Peter Belamarich, a pediatrician at Children's Hospital at Montefiore Medical Center in New York City, who has prescribed statins to some kids but takes issue with the new guidelines. Excerpts:

pizza_art_160_20080528100812 You've written that "lifestyle modification is the cornerstone of cardiovascular prevention in childhood." Isn't that what the AAP should be focusing on? Are you worried that these guidelines will encourage doctors to prescribe drugs to kids with high cholesterol instead of changes in diet and exercise?
Dr. Peter Belamarich: No. If people read them carefully, they say that the statin medications should be targeted to very high-risk children. The kids who would qualify for drug treatment based on these guidelines are less than one percent of all children. Ninety-nine percent of children and adolescents still should be treated with what's called therapeutic lifestyle change: limiting animal fat, increasing physical activity to an hour a day.

So what is your problem with the AAP guidelines?
My criteria for what justifies medication are higher than the guidelines'. I tend not to start medication until after age ten. And I don't treat very high-risk girls as aggressively as I would treat very high-risk boys, for two reasons. One, women develop cardiovascular disease slightly later in life, so there's less urgency in initiating treatment in childhood. Two, there are data suggesting that statins can interfere with growth and development in utero, so we should not use them in anybody who might get pregnant unintentionally, and that would include adolescents.

What does "very high-risk" mean regarding children and heart disease? It's not like these kids are having heart attacks at 10.
I think the children who most deserve these meds, if anybody does, are children who have a direct family history of premature coronary heart disease in young relatives who are under 40 or 50. Often, those kids have very low HDL, or "good," cholesterol levels. So I tend to treat boys with low HDL, a positive family history, and "bad" LDL levels in the 190s [milligrams per deciliter]. What makes it tricky is that prescribing these drugs in kids requires a lot more clinical judgment than it does in adults. In adults, there are scores that put all the risk factors together--hypertension, age, smoking, diabetes, sex, LDL/HDL ratio--and in middle-aged men, you can predict the risk of heart attack in the following year using those scores. We don't have that kind of score for children. So we have to use our judgment.

Are there enough data to support the use of statins in kids?
There's unequivocal data that if you've had a heart attack you should be on statins. There's no question, this is a fantastic drug. It decreases your risk of another heart attack by 30 percent or more and it's very safe. But that's for middle-aged people at high risk. We need studies with a logical progression showing it's okay to treat young adults, then very high-risk adolescents, and then extremely high-risk children younger than that. And that data is not all there. Some people would say, look, we're in the midst of an epidemic and it's really unethical to wait to start treatment. And other people, such as myself, would say that we need to be absolutely sure that what we're doing is safe before we do it.

Predicting pregnancy odds

Stanford University researchers said they are one step closer to accurately predicting if in vitro fertilization will result in pregnancy, according to a study released Tuesday.

The study, published in the Public Library of Science journal, identifies factors that will indicate with 70 percent accuracy the chances of pregnancy after a single round of in vitro fertilization, or IVF.

In vitro fertilization is a process by which eggs and sperm are clinically combined to create viable embryos that are then transferred into the uterus. Nationally, anywhere from 18 percent to 45 percent of IVF treatments, on women using their own eggs, result in pregnancy, according to the Society for Assisted Reproductive Technology.

IVF_fertilization Stanford researchers isolated four factors out of 30 to better predict pregnancy outcomes: the total number of embryos developed during fertilization; both the number of fully developed and undeveloped embryos; and a hormone test.

But the scientists' method only tells parents who've already undergone one round of IVF if the treatment likely worked, said Dr. Mylene Yao, the lead researcher on the study and a Stanford assistant professor of obstetrics and gynecology. What the method doesn't predict is the parents' chances of a pregnancy should they try IVF again, assuming the first attempt failed.

The Stanford researchers analyzed 665 IVF trials conducted at the university in 2005.

The researchers are now analyzing a larger

set of birth data from another study. Both studies will help them develop a method that predicts the odds of a pregnancy, and hopefully a live birth, in subsequent IVF treatments, Yao said.

"Ultimately, we want to be able to give patients more personalized and evidence-based information to help them decide whether they want to have IVF treatment if their first (treatment) does not result in a baby," Yao said.

For the most part, scientists already know to look at both undeveloped and developed embryos, said Dr. Susan Willman, an endocrinologist with the Reproductive Science Center of the San Francisco Bay Area. What the study does is calculate an actual probability, the first time she had read of one.

The trend in endocrinology research is to develop tests that predict the likelihood of pregnancy before fertility treatments begin, Willman said. Research is also focused on determining which embryos are healthiest to transfer.

Yao emphasized the study is one more way scientists pinpoint when IVF is most likely to work.