Pacing Weight Loss

Health experts say about 65 percent of Americans are overweight. A recent survey by the Centers for Disease Control and Prevention (CDC) found 25.6 percent of Americans are rated as obese.

Generally, as weight increases, so do the health risks. People who are overweight or obese are more likely to have type 2 diabetes, heart disease, stroke, elevated cholesterol, high blood pressure, osteoarthritis, gallbladder disease, respiratory problems, sleep apnea and certain types of cancer. Being overweight in a society that values appearance can add emotional stress to a patient’s life. The CDC estimates, in 1998, the economic cost of obesity (in terms of direct care and lost productivity) was up to $78.5 billion.

Help with Weight Loss: VBLOC™
Weight gain is caused by taking in more calories than the body expends. Thus, the best way to lose weight is to balance the calories in the other direction (i.e., take in fewer calories and burn more energy). It’s not easy. Researchers estimate more than 55 percent of Americans are trying to lose weight. Some manage to lose a few pounds only to gain them back. Others are able to lose some weight, but get stuck in a weight loss plateau and are unable to lose any more weight. Many people turn to fad diets, weight loss centers, medications, gastric bypass or LAP-BAND® surgery.

Now there’s another treatment under investigation, called VBLOC™ Therapy. VBLOC attempts to stimulate weight loss by blocking signals from the vagus nerve, the main communication pathway from the brain to the digestive system. James Maher, M.D., a Surgeon with Virginia Commonwealth University, explains the vagus nerve has two important functions in digestion. First, the nerve controls the ability for the stomach to expand after eating. Second, it controls the rate at which the lower portion of the stomach grinds up food and allows it to empty into the small intestine.

Earlier studies found that when the vagus nerve was cut, patients lost weight. Without the nerve signals, the stomach couldn’t expand after eating, so patients felt full sooner. In addition, food doesn’t get processed and emptied as quickly so it stays in the stomach for a longer period of time, increasing the time until hunger starts to hit again.

Over time, however, patients who had vagus nerve cutting didn’t sustain the weight loss, presumably because the body learned how to accommodate the loss of signals from the vagus nerve. VBLOC therapy aims to block the vagus nerve signals intermittently rather than constantly. Maher says that prevents the body from adjusting to the temporary loss of signals.

VBLOC is delivered through a device called the Maestro™ System. Two implanted electrodes are attached to the vagus nerve. The other ends of the electrodes are attached to a generator placed under the skin in the chest wall. The external components are a battery powered programmable controller and a belted, flexible coil.

During the day, the coil is placed over the implanted generator. Maher says the controller emits signals that block the transmission of vagus nerve impulses for five out of every ten minutes. Hopefully, the treatment will provide some of the same weight loss benefits as cutting of the vagus nerve without completely disrupting normal signaling.

An early study found the treatment was well tolerated and led to decreased intake of calories, faster onset of fullness and suppression of hunger. On average the participants receiving VBLOC lost about 14 percent of their excess weight.

VBLOC therapy is currently in a new study, called the EMPOWER Clinical Trial: Vagal Blocking for Obesity Control. Two-thirds of patients will have active signaling and one-third will have placebo treatment. All patients will receive instruction on healthy eating. For information on the trial, log onto http://www.clinicaltrials.gov, then type the trial identification number in the search box: NCT00521079. Information is also available at: http://www.empowerstudy.com, or by calling (866) 291-9146, Mon.-Thu., 7 AM to 7 PM, or Fri. 7 AM to 6 PM, central time.

The study is taking place at the following locations:

Scottsdale Bariatric Center, Scottsdale, AZ
Scripps Clinic, La Jolla, CA
University of California, Irvine Medical Center, Orange, CA
Stanford University Medical Center, Stanford, CA
Cleveland Clinic- Florida, Weston, FL
Johns Hopkins, Baltimore, MD
Tufts New England Medical Center, Boston, MA
University of Minnesota, Minneapolis, MN
Mayo Clinic, Rochester, MN
Washington University School of Medicine, St. Louis, MO
Cleveland Clinic, Cleveland, OH
Oregon Health and Science University, Portland, OR
Virginia Commonwealth University, Richmond, VA

For information about the trial, log onto http://www.clinicaltrials.gov, then type the trial identification number in the search box: NCT00521079. Information is also available at: http://www.empowerstudy.com, http://www.vcu.edu/lesspainsurgery/obesity/empower/aboutstudy.htm , or by calling (866) 291-9146, Mon.-Thu., 7 AM to 7 PM, or Fri. 7 AM to 6 PM, central time.

For general information on obesity:
National Heart, Lung and Blood Institute, http://www.nhlbi.nih.gov
National Institute of Diabetes and Digestive and Kidney Diseases, http://www.niddk.nih.gov
The Obesity Society, http://www.obesity.org