More research urged on treating childhood obesity

Although the U.S. Preventive Services Task Force in July concluded that insufficient science exists to indicate the use of body mass index to track childhood obesity, some medical groups are urging physicians to do exactly that.

This disconnect is representative of the uncertainties that have led many physicians and childhood obesity experts to call for studies to determine the effectiveness of BMI screening in this population and what can be done after a doctor determines that weight could be an issue.

"What this means is we don't have the evidence that we ought to," said Virginia Moyer, MD, MPH, a member of the USPSTF and professor of pediatrics at the University of Texas, Houston. "This is a call to action."

For now, though, several medical societies are recommending that children be routinely screened for weight problems using BMI. The American Medical Association, for instance, adopted such policy at its Annual Meeting in June.

"Screening for overweight using BMI has a possible substantial benefit and little if any risk," said AMA Trustee Ronald M. Davis, MD.

The USPSTF, however, issued its recommendation last month, saying it could not endorse such efforts. The position reflected the panel's finding that evidence in support of BMI screening in this age group was imperfect because it does not always give clear-cut answers about whether an intervention is required.

"It's a terrible problem, and doctors need to be thinking about it," Dr. Moyer said. "Unfortunately, there's no evidence for an intervention that works in a primary care setting, and there's no evidence that screening itself makes a difference."

But authors of the most recent task force recommendation say their conclusion is not necessarily a reason to stop measuring children's BMI. Rather, it highlights a significant gap between medical practice and scientific evidence. The paper also suggests that it might be time to consider whether energy might be better used to change the environment rather than the individual child.

"When we counsel patients, are we wasting our breath?" Dr. Moyer asked. "Maybe we ought to be putting our efforts into changing the community."

The AMA policy, in line with that of other medical societies, calls on doctors to be advocates for changes that could make communities less conducive to obesity.

Meanwhile, physicians responded that the BMI remained a useful tool, particularly since it is a relatively benign test, cheap and easy to administer. Also, a lack of evidence is not an indication that it is not effective but rather an indication that more research is needed.

Waiting for answers

"By no means should physicians not provide advice and measure BMI," said Scott Gee, MD, a pediatrician and medical director for prevention and health information at Kaiser Permanente Northern California. "With overweight, we are kind of where we were 20 years ago with tobacco, when we didn't know a lot about physicians providing advice to quit. I think the evidence will come with time."

Physicians say the need for this research is particularly acute, not just because of the growth in the number of children who are overweight, but also growth in the size of individual overweight kids. Many doctors report they have at least a handful of pre-pubescent patients who top 300 pounds and have accompanying comorbid conditions. This situation was unheard of just a few years ago.

"Their weight is off the growth curve, and their height is not doing the same," said Thomas Tryon, MD, a pediatrician from Joplin, Mo.

Also, the first guidelines for bariatric surgery in adolescents were published in July of last year, and an increasing number of institutions are offering bariatric surgery to those younger than 18. For example, a study published in the July-August Health Affairs analyzing data from the Agency for Healthcare Research and Quality's nationwide inpatient sample database found that the number of bariatric surgeries in all age groups increased 400% from 1998 to 2002. The number for 12- to 17-year-olds went from being too small to count in 1998 to approximately 178 in 2002. And many experts suspect this may be an undercount.

"That tells you how big the problem is," said Paul Ehrmann, DO, a family physician in Royal Oak, Mich., and the director and founder of the Children's Health Initiative Pilot Program, an initiative attempting to address obesity in this community.

Research related to bariatric surgery in those younger than 18, however, also is lacking. To address this situation, the National Institutes of Health funded two projects at Cincinnati Children's Hospital Medical Center. One will look at the quality of life in adolescents before and after the surgery.

The other will explore the impact of this kind of surgery on type 2 diabetes. This study has been launched in part because surgeons have observed that those who have not lived as long with obesity and accompanying metabolic problems tend to do better, but many patients wait until they're in their 40s or older to have it done.

"Adults are usually coming in at a point when they've already lost a lot of ground," said Thomas Inge, MD, PhD, one of the study leaders and Surgical Director of the Comprehensive Weight Management Program. "We will be looking at the metabolic response and comparing adolescents to adults to understand whether it may be better to have the surgery early rather than later."