A gas-filled gastric balloon may promote weight loss more effectively than does its water-filled cousin, according to data from a randomized study that was presented during a teleconference in advance of the annual Digestive Disease Week. A water-filled version of the device is on the market already.
The study enrolled 387 people aged 22 to 64 years old with a body mass index (BMI) from 30 to 40 kg/m2 at 15 different sites. People were randomized to the Obalon Balloon System or to a sham control group. People in the treatment group were asked to swallow three capsules: one every 3 weeks until week 12.
The balloon is contained within the capsule, and after swallowing each balloon was filled with 250 cubic centimeters (slightly more than 1 cup) of a nitrogen-based gas via a small catheter. The control group also swallowed sugar-filled capsules (sham treatment).
A total of 366 patients swallowed at least two capsules and were included in the per protocol analysis: 185 in the treatment group and 181 in the control group. All patients saw a registered dietitian every 3 weeks and also followed diet, exercise, and behavior modification lifestyle changes. Obalon balloons were removed endoscopically at week 24, when participants’ weight was assessed.
The balloon-treated group had a mean weight loss of 6.8%, compared with 3.59% in the control group. At least 5% of body weight loss was achieved by 64.3% of the balloon-treated group, compared with 32% of the control group. The balloon treatment group, but not controls, showed improvements in levels of systolic blood pressure, LDL cholesterol, and triglycerides.
The finding that obese participants who swallowed the Obalon 6-Month Balloon System lost nearly 7% of their body weight and experienced improvements in other health indicators “is important because weight loss is quite difficult to achieve and a significant number of people are not successful in achieving their weight loss goals with diet changes and exercise,” said lead author Dr. Shelby Sullivan, who presented the findings.
Adverse events were mostly mild and included diarrhea, cramping, and nausea in nine patients. No hospitalizations were required for these events. One patient with a pre-existing bleeding ulcer experienced a serious adverse event, which the investigators classified as being possibly related to treatment.
“This patient had an orthopedic procedure and was taking high doses of NSAIDs. That should have been excluded in the trial,” said Dr. Sullivan of Washington University, St. Louis.
“Treatment over time, and even with the initial swallowing of the balloon capsule is quite well tolerated, with only mild symptoms compared with other balloon systems,” she said. “Anecdotally, my impression is that patients liked the therapy because it allowed them to follow lifestyle therapy as well.”
The Obalon balloon is given in stages, giving patients’ stomachs time to adjust to the balloon. Unlike liquid-filled balloons, the gas floats up in the stomach and may cause fewer symptoms than liquid-filled balloons, she suggested.
Dr. Sullivan believes that when the Obalon system is used in the real world, it may lead to even greater weight loss. “This has been seen in other sham-controlled trials,” she noted.
Patients enrolled in the trial are being followed longitudinally and those in the sham control group are allowed to cross over to the Obalon balloons on an open-label basis.
“More than 640 million people globally have obesity, and at this time, there are more overweight than underweight people in the world. Some treatments that are alternatives to diet and exercise may be risky. Obalon swallowable balloon is a new treatment option that can help patients lose almost twice as much weight compared with lifestyle changes alone,” she said.
Dr. Sullivan received funding for this study from Obalon Therapeutics.