Bariatric Surgery Can Be Long-Term Type 2 Diabetes “Cure”
Many leading diabetes organizations — including the American Diabetes Association — often mention the goal of finding a cure for diabetes. This ambitious goal generally refers to some kind of treatment that doesn’t need to be taken indefinitely, and makes a person not have signs of diabetes in blood tests — meaning that their A1C (a measure of long-term blood glucose control), fasting glucose or oral glucose tolerance test (OGTT) results fall in the normal range.
Right now, there isn’t any such treatment that works for everyone with type 1 or type 2 diabetes. But there is a treatment that seems to fit this description for many people with type 2 — bariatric surgery, also often called weight-loss or metabolic surgery. While there are a few different kinds of surgery in this category, the most effective for diabetes reversal is widely believed to be gastric bypass, which involves surgically reducing the size of a person’s stomach to a small pouch.
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Studies have shown that in people with diabetes who undergo the procedure, gastric bypass leads to metabolic changes almost right away — before significant weight loss occurs. These findings suggest that type 2 diabetes, rather than being caused by excess body weight, is the result of metabolic abnormalities that also lead to obesity in many people. Once these metabolic abnormalities are resolved through surgery, both weight loss and diabetes resolution can occur.
Now, a new study confirms that bariatric surgery can be a long-term “cure” for type 2 diabetes, causing lasting resolution of detectable signs of diabetes.
Randomized trial with long-term follow-up
The study, published in the journal The Lancet, is notable because of its design as a randomized controlled trial. This means that it didn’t just observe people who had or didn’t have bariatric surgery, which is problematic as a study design because in the real world, there are often differences — in diabetes severity, obesity severity and more — between people who have the surgery and those who don’t. Instead, participants were randomly assigned to have bariatric surgery, or not to have it.
This study actually randomly assigned its 60 obese participants with type 2 diabetes to one of three interventions — normal medical treatment of diabetes, gastric bypass surgery, or biliopancreatic diversion (a procedure similar to gastric bypass that also bypasses part of the small intestine). The researchers were interested in seeing how many participants in each group were in diabetes remission two years later — defined as an A1C level below 6.5% and fasting glucose below 100 mg/dl without taking any diabetes medications for at least a year.
But the researchers also followed up after 10 years, looking at how lasting any diabetes remission as in 57 of the original 60 participants. Out of all 40 participants who received a surgical treatment, 15 (37.5%) maintained diabetes remission during the entire 10-year follow-up period. In comparison, only one person in the group that received normal medical treatment achieved diabetes remission — and that person underwent bariatric surgery after the original two-year follow-up period. Specifically, the 10-year remission rate was 50.0% for biliopancreatic diversion and 25.0% for gastric bypass.
Out of the 34 study participants who were in diabetes remission at two years, 20 (58.8%) had a relapse of high blood glucose during the next eight years. This number was higher in participants who underwent gastric bypass group than in those who had biliopancreatic diversion (66.7% versus 52.6%). But even among participants who had a diabetes relapse, everyone maintained adequate blood glucose control at the 10-year follow-up, even if they needed to take medications — with an average A1C level of 6.7%. Participants who underwent surgery were also far less likely to have diabetes complications than those in the standard medical therapy group, with only 7% the rate of complications compared with standard diabetes therapy.
Surgery effective for long-term diabetes control
The researchers concluded that even among participants who didn’t achieve diabetes remission — those who still needed to take diabetes medications — there were clear benefits from undergoing bariatric surgery, with a higher likelihood of maintaining adequate blood glucose control and a much lower likelihood of having diabetes complications. And for those who did achieve and maintain remission, the benefits speak for themselves — close-to-normal blood glucose levels without having to take any diabetes medications.
There were, however, more serious adverse events during the 10-year period — related to either diabetes or any surgery — among participants who underwent biliopancreatic diversion than those who had standard medical therapy, with 2.7 times the likelihood. But participants who had gastric bypass were actually less likely to experience serious adverse events than those who had standard therapy, with 0.7 times the likelihood. This indicates that any surgical risks from undergoing gastric bypass surgery are outweighed by a lower likelihood of serious events related to diabetes, such as severe hypoglycemia (low blood glucose).
If you believe you may be a candidate for bariatric surgery and are interested in it as a potential diabetes treatment, talk to your doctor about the risks and benefits.
Want to learn more about type 2 diabetes remission? Read “Type 2 Diabetes Remission Possible With Doable Weight Loss,” “Low-Carb Diets Lead to Greater Remission of Type 2 Diabetes” and “Reversing Type 2 Diabetes Through Weight Loss.”