Doctor Attacks Effectiveness of Gastric Bubbles
A UC Irvine physician has concluded that the gastric bubble--a balloon-like device that is inflated inside the stomach to promote weight loss--is ineffective after he studied patients who lost the same amount of weight whether or not they had the bubble.
Dr. Hooshang Meshkinpour, an associate professor of gastroenterology, says the 21 patients in his six-month study had the bubble inserted for three months and then underwent a “sham” procedure and had no bubble for the next three months.
“Basically, there was no difference (in weight loss) between the two treatments. . . . Having the bubble did not really help,” Meshkinpour said Monday.
In fact, he said, the patients did not lose as much weight as they should have if they had been diligently following their prescribed diets.
Meshkinpour presented his findings last week in Chicago at the American Gastroenterological Assn. annual meeting, and the study has been published in the journal Gastroenterology.
He said four other studies on the gastric bubble were presented during the meeting and, although their goals and methods were different,they, too, questioned the effectiveness of the device.
The bubble, manufactured by American Edwards Laboratories of Irvine, is inserted through the mouth, then inflated in the stomach, as a temporary measure to curtail the appetite and help obese patients lose weight.
Under Meshkinpour’s study, 10 people had the bubbles inserted during the first three months, while 11 had a tube inserted down their throats and inflation was simulated. The groups were reversed for the second three months. The patients knew the switch would be made but did not know when the bubble was in or out.
During the three months they had the bubbles inserted, the patients lost an average of 11.88 pounds, and during the sham period, they lost an average of 11.44 pounds. The patients were placed on diets of 1,000 calories a day and underwent dietary counseling to encourage them to change their eating habits and to increase their activity, he said.
Didn’t Reduce Cheating
But it appears that the presence of the bubble--or even thinking that it was present--did not reduce cheating on the diet, he said.
“If they had faithfully followed the diet, they should have lost more than 12 pounds,” Meshkinpour said. “The presence of the bubble did not help them stick to the diet.”
Meshkinpour’s study, which was conducted with Dr. David Hsu and Dr. Sirus Fariear, used patients who were 21 to 53 years old and about 25% over their ideal weight.
Nationwide, more than 20,000 gastric bubbles have been inserted, Meshkinpour said.
The bubble was approved for use by the U.S. Food and Drug Administration in 1985, but late last year American Edwards mailed new labeling information to doctors trained to insert the device, warning them of new and more severe side effects than first reported. The new labeling information also recommended earlier removal of the balloon and limiting its use to more severely overweight patients. According to the advisory, the bubble can cause intestinal blockages and perforations and ulcers of the stomach.
15% of Stomach Capacity
The bubble occupies about 11% to 15% of the stomach’s capacity and theoretically reduces craving for food by producing an early feeling of fullness.
Meshkinpour said a “wide variety of reasons” might account for his study’s results.
“The bubble may be too small. We don’t know,” he said, adding that if a study was to be performed using larger balloons, “we might get different results.”
Another possibility, he said, is that the stomach may adjust to the bubble’s insertion. “The stomach is a very pliable organ” and can accommodate a large volume of food, he said.
What’s more, he said, the study calls into question one of the basic assumptions of the bubble’s use--that the bubble will produce a feeling of fullness more quickly because it takes up space in the stomach.
“The bubble is supposed to produce early satiety,” he said. But the near-identical weight-loss figures from people with and without the bubble discredits that assumption, he said.
Too ‘Preliminary’
A spokeswoman for American Edwards said that Meshkinpour’s study, along with others presented at the association’s meeting, were too “preliminary” to draw any long-term conclusions and that follow-up research is needed.
In addition, “crossover” studies such as Meshkinpour’s--in which one type of treatment is used and then switched to another type of treatment--may not be appropriate in weight loss because of the “cycle of weight loss,” said Signe Gotcher, product manager for American Edwards.
“Weight loss is not a continuous thing,” she said. The body changes and adjusts as time passes during a weight-loss regimen, she said. Comparing the first three months with the bubble against the second three months without “is a bit like comparing apples and oranges,” she said.
But Meshkinpour said he compared the weight loss between the bubble and sham groups during the first three months and made the same comparison during the latter half. He found that the “difference was not significant.”
Not Goal of Study
Gotcher also said that when patients use the gastric bubble, there is an interplay of three factors that could affect weight loss--diet, behavior modification and the bubble itself. To truly evaluate the effectiveness of the bubble, it needs to be tested in ways where diet and exercise cannot be factors in weight loss, she said. Meshkinpour’s study does not separate out those two factors, she said.
“That’s true, but that was not the goal of the study,” Meshkinpour responded.
There is a secret to weight loss, he said, that has been known for many years.
“The principle of weight reduction is based on reducing intake and increasing output. You have to reduce your caloric intake and do exercise. That is the best combination that can work. All other measures will fail,” he said. “Unfortunately, I don’t think there is an easy way to do it,” Meshkinpour said. “You have to pick a program that you can live with and stick with it for a long, long time.”
