The Effects of Laparoscopic Gastric Banding, a Weight Loss Surgery

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Laparoscopic gastric banding prevents type 2 diabetes and arterial hypertension and induces their remission in morbid obesity: a 4-year case-controlled study, by A.E. Pontiroli and colleagues. Diabetes Care 28:2703-2709, 2005.

What is the problem and what is known about it so far?

Obesity, or being seriously overweight, is a leading cause of type 2 diabetes, especially among people who have higher-than-normal blood glucose levels (or pre-diabetes). People who are obese are also at high risk for cardiovascular disease (heart-and-blood-vessel disease).

Why did the researchers do this particular study?

Research has shown that changes in lifestyle, like losing weight through diet and exercise, combined with medication therapy can help prevent type 2 diabetes in obese people with pre-diabetes. The researchers in this study wanted to look at the health effects of weight loss due to laparoscopic gastric banding, a type of stomach surgery, in severely obese people.

Laparoscopic gastric banding restricts the size of a person's stomach. The person then eats only small amounts of food at one time, which helps the person lose weight.

Who was studied?

A total of 122 people who were severely obese.

How was the study done?

Of the 122 patients, 73 chose to have the surgery; 49 refused, but these people took part in the study as a comparison group. The people who refused the surgery chose to try to lose weight through more conventional ways, like dieting. All patients underwent yearly check-ups for four years.

What did the researchers find?

The people who had the surgery were able to lose a lot of weight. The group who didn't have the surgery didn't lose or gain weight.

Among patients who had pre-diabetes when the study began, none of the patients who had the surgery developed type 2 diabetes. Five (of 29) patients who didn't have the surgery developed type 2 diabetes.

Among patients who had type 2 diabetes when the study began, 7 (of 17) patients who had the surgery were able to lower their blood glucose to below diabetic levels. Only 1 patient (of 20 patients) was able to lower blood glucose to a nondiabetic level.

Hypertension (high blood pressure) developed in only one of the patients who had the surgery and in 11 of the patients who didn't have the surgery. Fifteen patients who had the surgery and only one patient who didn't have the surgery were able to lower their blood pressure to healthy levels.

What were the limitations of the study?

This study was pretty small compared to other studies that looked at lifestyle changes, drug therapies, and dieting to treat obesity.

A lot of patients usually quit taking part in studies on obesity before the studies are over, but the drop-out rate for this study was pretty low.

The large differences between the results of the two groups could have been because of other factors, but the researchers don't think this was the case.

What are the implications of the study?

Laparoscopic gastric banding, a type of stomach surgery, can help severely obese people lose weight and keep it off. Losing weight and keeping it off for long periods of time can help seriously obese people prevent type 2 diabetes and hypertension.

There are various possible side effects associated with weight loss surgery, such as acid reflux and nutritional problems. People who are interested in this surgery should discuss the possible side effects with their doctors.

FOR MORE INFORMATION

Surgery to treat obesity. Forefront, Summer/Fall 2005, p. 23. (PDF)

101 Weight Loss Tips for Preventing and Controlling Diabetes, by Anne Daly, Linda M. Delahanty, and Judith Wylie-Rosett (Alexandria, Va., ADA, 2002).