Bariatric Surgery: Surgery to Promote Weight
Loss
When
bariatric surgery is performed in people with type 2 diabetes, 60 percent or more have normal blood glucose
levels without medications, and the others can use fewer medications. There is also improvement in the lipid
profile, blood pressure, and sleep apnea. The National Institutes of Health recommend that bariatric surgery is
one option that should be considered if a person has extreme obesity (BMI greater than 40) or if a person has
diabetes and a BMI greater than 35.
There are two kinds of
bariatric surgeries that are performed for weight loss:
-
In restrictive surgery the size of
the stomach is reduced by using an adjustable gastric band, cinched around the stomach like a
belt.
-
In malabsorptive surgery the food is
diverted so that it does not get absorbed as effectively. The Roux-en-Y gastric bypass procedure is
currently the most popular procedure—a small stomach pouch is created and separated from the rest of
the stomach, and the outlet of this newly created pouch empties into the lower part of the small
intestine and so causes malabsorption.
A year after the Roux-en-Y
gastric bypass procedure, patients have lost over 75 percent of their excess weight. There is some regaining of
the weight, but the weight loss is still 50 to 60 percent of excess weight at ten years or more. The adjustable
gastric banding procedure initially results in less weight loss. During the course of a three-year study, most
patients had lost an average of 36 percent of their excess weight.
Clearly, bariatric surgery is
the most effective therapy we have for type 2 diabetes. The surgery is now done with laparoscopes, and the risk
of death is less than 1 percent. However, there are a number of side effects. The adjustable gastric banding
can cause nausea and vomiting, heartburn, and abdominal pain. The band can slip, so some people may need a
second surgery. The Roux-en-Y gastric bypass operation impairs absorption of nutrients. Impaired absorption of
iron and vitamin 12
can cause anemia, and impaired
calcium absorption can cause bone loss. Therefore, people who have this procedure must take iron, calcium, and
vitamin supplements. Some people can also get a “dumping syndrome” due to the rapid emptying of the stomach
contents into the intestine, causing nausea, sweating, faintness, and diarrhea after eating. This can be quite
disabling. Occasionally, they can get reactive hypoglycemia, with glucose levels in the 30s to 40s after a
carbohydrate-rich meal.
|