Who Reverses Diabetes with Bariatric Surgery

David Mendosa Health Guide June 21, 2012
  • People who have diabetes and are severely overweight are deciding more and more often that bariatric surgery is just the thing for them. Although it is expensive and like any surgery it can have complications, the amount of weight that they lose is usually dramatic and their diabetes often completely disappears.

    Some people, including a couple of my friends, have had wonderful results from bariatric surgery. But not everybody benefits.

    If you are morbidly obese, I’m sure that you have considering bariatric surgery. But how can you tell what the chances are that it will work for you?

    A study presented yesterday at the annual meeting of the American Society for Metabolic and Bariatric Surgery can help you decide. Richard A. Perugini, M.D., a bariatric surgeon at the University of Massachusetts Medical Center in Worcester, was the lead study author and presented the findings of his team at the annual meeting. The abstract of the study, “Predictors for Remission of Type 2 Diabetes Mellitus Following Roux En Y Gastric Bypass,” is online.

    Graphic of a Roux-en-Y gastric bypass connection

    Roux-en-Y is the name of the most commonly performed bariatric surgery in the United States. About 80 percent of the weight loss surgeries here are this hard-to-pronounce operation.

    Dr. Perugini and his colleagues studied what happened to 139 consecutive people with type 2 diabetes who had the Roux-en-Y operation. The researchers particularly wanted to find out who experienced remission of their diabetes. They defined remission as “adequate glycemic control without diabetic medication.”

    “Individuals who achieve ‘remission’ by my definition had an average Hgb-A1c of 5.7 one year following gastric bypass,” Dr. Perugini wrote me. “Individuals not achieving remission, who were still on medications, had a Hgb-A1c of 6.3 at one year post-op.”

    People who weren’t using insulin and whose pancreatic beta cells were working better were much more likely to get remission of their diabetes. The study found that overall 67 percent of these gastric bypass patients achieved remission one year after surgery, but that number grew to 96 percent when they weren’t on insulin and didn’t have severely reduced pancreatic function.

    They measured how well the beta cells were working by using something they call the “glucose disposition index.” If the patients had a GDI of 30 percent of normal or less, they were less likely to achieve remission.

    What didn’t make a difference in remission rates was how much the patient weighed before surgery and whether they had lost any weight after six weeks or after one year.

    “The study shows beta cell function -- the cells in the pancreas that produce insulin -- and insulin dependence, not initial weight or subsequent weight loss, are the greatest predictors of potential diabetes remission after gastric bypass,” Dr. Perugini says. “The study further confirms type 2 diabetes becomes more difficult to manage as it progresses.”

    Knowing this can help. But I don’t think that it’s quite as straightforward as it might seem.

    Dr. Perugini’s remark about diabetes progression relates to the old strategy of countering the typical high-carbohydrate diet with more and more diabetes drugs culminating in insulin. But nowadays more and more doctors start us off on insulin. Using insulin therapy as a surrogate for the degree of diabetes control makes sense some of the time -- but not always.

    What the study does make clear is that if you are going to have bariatric surgery, it’s better not to wait until your diabetes has become completely unmanageable. Even then,  you need to consider the many different types of bariatric surgery, where to have the surgery, the possible complications, and how much it costs.

    While Roux-en-Y gastric bypass is the most common bariatric surgery, different hospitals use different techniques, including less invasive laparoscopic surgery. Other common procedures include gastric banding, one of the least invasive surgeries, and the relatively new sleeve gastrectomy.  

    Hospitals have different degrees of experience and success with bariatric surgery. Hospitals and individual surgeons who have more experience with bariatric surgery do better, according to an Agency for Healthcare Research and Quality study.

    Generally, about 2.5 percent of people who have bariatric surgery have serious complications, according to a study last year in Annals of Surgery. The inpatient death rate from bariatric surgery went way down from 0.89 to 0.19 between 1998 and 2004, according to another report from the Agency for Healthcare Research and Quality.

    A recent and comprehensive review in The New England Journal of Medicine shows somewhat worse statistics. Within 30 days after surgery 0.3 percent of the patients had died. And 4.1 percent of them suffered serious complications.

    If you have health insurance, your provider might pay for bariatric surgery. But if not, you will need deep pockets. It’s getting a little less expensive, but the mean cost to all payers in 2004 was $10,385, the Agency for Healthcare Research and Quality says.

    Whenever people have asked me about bariatric surgery for weight loss, I have always suggested that they consider it only as a last resort. Surgery is still serious business, but so is diabetes. The proportion of people whose diabetes goes into remission after this surgery is impressive, particularly when people with diabetes don’t wait until they have only a few working beta cells.

    While lifestyle changes like following a very low-carb diet can put diabetes into remission for some of us, others can’t afford to wait to lose weight without surgery. If you are in that group, now may be the time of last resort.