Playing with the Band

As millions of us try to lose the weight we gained over the holidays, the Food and Drug Administration is due to make a decision with implications for those tipping the scales into obesity: whether to approve gastric lap bands for people who are just slightly obese. These devices are now approved only for dangerously obese adults, with a body mass index of at least 35.

Like gastric bypass surgery, a lap band reduces the size of the stomach so that eating a large meal is impossible. As a result, patients sometimes lose 100 pounds or more within a year, and that weight often stays off at least another year.

The surgery is more effective for most people than diet, exercise or diet pills. And since lap bands are less invasive, expensive and risky than gastric bypass, it is reasonable to ask whether the F.D.A. should approve the product for people seeking less drastic weight loss. Last month, an advisory panel said it should.

If the agency bases its decision on science rather than sympathy, however, it will reject the recommendation — because there is no research proving that a lap band provides slightly obese patients with long-term health benefits that are greater than its risks.

Some experts, including most bariatric surgeons, say the benefits are obvious even if the research is skimpy. And although most of them have financial ties to the lap-band industry, they also have an important fact on their side: weight loss during the first year after the procedure is often impressive.

But what matters for most patients is whether a lap band is more effective than diet and exercise for years and years after the surgery — and unfortunately we don’t know if it is.

Under the proposed change, lap bands would be approved, for example, for a 5-foot-6-inch woman weighing 186 pounds (a body mass index of 30) who does not have diabetes or heart disease but does have joint pain that might be relieved by weight loss. Under the current rules, this woman could get a lap band only if she was willing to pay $12,000 to $30,000 for the 30-minute surgery. Because the procedure does not have F.D.A. approval, insurance plans and Medicare usually do not cover it.

Theoretically, lap bands could save lives and billions of health care dollars that would otherwise be spent to treat diabetes or heart disease, replace hip or knee joints or pay for often-ineffective weight loss strategies. But potential benefits are not the same as proven ones. And the reality is, we don’t know how safe and effective lap-band surgery is for most people, whether they are 30 or 300 pounds overweight.

How could we lack such basic information? The F.D.A. approved Inamed’s Lap-Band for the dangerously obese almost 10 years ago. But it did so based on the company’s study of fewer than 200 very obese patients who had lap bands for three years. As a condition of approval, the agency required a follow-up study, but in 2006 Inamed was bought by Allergan, and the study was not completed. Last year, when Allergan asked the F.D.A. to expand approval to the not-so-obese (essentially doubling the potential patient pool), the request was based on a clinical trial of only 149 patients who had lap bands for one to two years.

In this study, the operations were done by carefully selected surgeons on relatively healthy patients, all under the age of 55 — which gave the study its best chance of producing favorable results. Even so, there were many adverse reactions. The most common were vomiting, difficulty swallowing, pain and gastroesophageal reflux. Five percent of subjects required additional surgery one to nine months after getting their lap bands, and in most cases this meant permanent removal. One of the devices that was removed had already eroded — raising concern about how long lap bands last. And unlike the initial surgery, often an outpatient procedure, the revisions and removals meant hospitalizations lasting up to a week.

The men in the Allergan study had worse outcomes than the women; 20 percent had their devices removed in the first year. This is not surprising, given an earlier report by the Agency for Healthcare Research and Quality that men were almost three times as likely as women to die from bariatric surgery. But the poor outcome for men needs further investigation, because the Allergan trial included only 14 men.

What’s more, there were only two Asians, 14 African-Americans and 16 Hispanics among all the men and women in the study. Clearly, more research is needed on more people of both sexes and all ages and races.

Most important, we need studies of people who have had lap bands for longer than a few years to learn if the weight loss is lasting, if patients will tolerate the devices in the long run and what risks may accrue from living with one inside the body. The earlier three-year study of very obese patients found that one in four had their lap bands removed and not replaced.

The F.D.A.’s job is to make sure that the lap band is safe and effective, but it cannot do this without long-term data on a more diverse group of patients. Moreover, if the F.D.A. approves the lap band for people who are only 30 or 40 pounds overweight, taxpayers may soon be paying billions of Medicare dollars for these procedures, and for fixing the potential complications. Health insurance companies would be pressured to follow Medicare’s lead, which could add to the cost of insurance for all of us.

Obesity can kill, but when people are not at immediate risk of fatal illness, the F.D.A. does them no favors by giving its approval to an implanted medical device before it has been adequately tested.

Diana Zuckerman is the president of the National Center for Health Research and its Cancer Prevention and Treatment Fund.

Read this op-ed at the New York Times website.