Thursday, February 05, 2009
re-visit - diabetes and weight loss surgery
If you listen to the TV, you will hear that weight loss surgery (either gastric bypass or lap band) "cures" diabetes. You will see happy patients less than 2 years post op dramatically throwing out their medication.
Remember TV is NOT the truth. Not even close.
We have two studies available which looked at diabetes and weight loss surgery.
The first was the Swedish Obesity Study. It compared weight loss surgery patients to people trying to diet. It was NOT randomized and as a matter of fact, those chosen to be in the NON patient group had MORE diabetes and MORE heart disease. The surgeries used in this study were gastric bypass and gastric banding.
At the two year point, they recorded a 73 percent remission in those patients with diabetes.
But at the 10 year point, only 36 percent of the patients remained "diabetes free". That means for most of them, the diabetes had returned. We have no longer term results than this.
Also this study did NOT look at the number of gastric bypass patients who got reactive hypoglycemia which is less treatable than diabetes (caused by the death of the islet cells of the pancreas). One 13 year post op recently remarked that "most gastric bypass patients eventually get this problem."
Finally the Swedish Obesity study found that at the 10 year point the "average" BMI among the weight loss surgery patients was 35. Still clinically obese.
SOURCE: New England Journal of Medicine: Volume 351:2683-2693 December 23, 2004 Number 26 Lifestyle, Diabetes, and Cardiovascular Risk Factors 10 Years after Bariatric Surgery Lars Sjostrom, M.D., Ph.D et al
graph showing percentage of patients in remission from diabetes at the 2 and 10 year points
The second study was the "Monash Study". This study was randomized sort of. It did not take any diabetics who were diagnosed more than 2 years before surgery. (and we all know that moderate lifestyle changes without weight loss can bring A1C back to "normal" in the first few years after diagnosis).
It did not study patients any more than two years post op. They found at the 2 year post op point, 73 percent of patients were in remission (and the researchers used remission and not cure!) which is the same that the Swedish Obesity study found.
Monash Melbourne study link
The TV ran with it. The Monash Study used adjustable lap band patients. And the word "remission". The TV said they were gastric bypass and used the word "cure".
I have heard some Weight Loss surgery surgeons use the word "cure" also and the ASBS is now trying to recommend gastric bypass for overweight patients with diabetes (i.e. BMI 30 or more). Those patients tend to fare badly post op. Somehow their bodies do not adapt as well as heavier patients.
Speaking of Weight Loss retention: The third study we should look at is the Utah study which found that 34 percent of patients whose start BMI was over 50, regained all or most of their weight within 10 years.
SOURCE: Annals of Surgery. 244(5):734-740, November 2006. Christou, Nicolas V. MD, PhD; Look, Didier MD; MacLean, Lloyd D. MD, PhD
Bottom line, weight loss surgery is not effective unless you diet, count calories and exercise (which will keep weight off without surgery) and it does NOT cure diabetes - no study ever found that and the only place reporting a diabetes "cure" is TV which is selling the surgery or some surgeons who are also selling the surgery.