This is the final post in a three-week series on gastric surgery.
When you’re overweight with type 2 diabetes losing weight isn’t just a desire—it’s part of your recommended care. Insulin resistance increases with your BMI, so slimming down and getting rid of the fat tucked away between the organs of your abdomen is vital to your health.
But how should you go about getting to that trimmer, healthier you? Calorie restriction diets and exercise programs work for some, but others have tried to no avail. And surgery has been proven successful, but many are squeamish about going under the knife. So which path is right for you? And which is more successful?
That’s what researchers at Joslin have been taking a look at over the last year and a half. In their SLIMM-T2D trial Joslin’s Allison Goldfine, M.D., and Brigham and Women’s David Lautz, M.D., are comparing bariatric surgery to Joslin’s intensive lifestyle-modification program called Why WAIT.
“Over the long-run, are they equivalent? Is the weight loss alone all that’s important?” asks Dr. Goldfine. “If you lose weight but don’t have cardiovascular benefits from it, what’s the trade-off?”
Why WAIT, created in 2005 by Osama Hamdy, M.D., Ph.D., brings patients in to Joslin once per week for 12 weeks for exercise, nutrition and diabetes self-management education, and medical care. Since the participants are learning how to live healthfully, rather than simply following a strict diet, they can apply the lessons to their real lives with lasting benefits.
A 2008 study showed that by the end of the 12 weeks participants had lost an average of 9.8 percent of their initial body weight—about 23 pounds per person. They also showed cardiovascular improvements such as reduced blood pressure, lower cholesterol levels and fewer inflammation markers. On top of all that, their diabetes medications were scaled back significantly—some were taken off medication altogether.
Since Why WAIT is a fairly new concept there haven’t been many studies on what this type of program can offer. Bariatric surgery, however, has been around for decades and has had plenty of time to be scrutinized. Evaluation and surgical techniques have been refined since the early days and as procedures get better researchers continue to test their efficacy.
A Swedish Obesity Society study published in 2004 in the New England Journal of Medicine detailed a trial in which patients got one of three types of bariatric surgery procedures, either gastric banding, vertical banded gastroplasty, or gastric bypass surgery. A control group got no surgery at all.
The researchers monitored the patients for 10 years, recording everything from their initial drop in weight to any weight regained over time. At the end of the 10 years, the subjects who got the surgeries lost (and more-or-less maintained) an average of 23 percent of their initial body weight. The controls gained 1.6 percent.
That same study showed reduction in death by 30 percent. Other studies have shown death from heart disease reduced by 50 percent, from cancer reduced by 50 percent, and from diabetes down by 90 percent.
And a number of studies, including two published this March in the New England Journal of Medicine, have shown that after bariatric surgery patients either have reduced their diabetes medications or are off drugs all together.
So why are these two separate approaches—intensive lifestyle adjustments versus bariatric surgery—both so successful in improving type 2 diabetes health?
Bariatric surgery promotes weight loss, which improves insulin sensitivity. The procedures shrink your stomach so that you feel full while eating significantly fewer calories than your body burns. Once your body uses up the calories you eat, it turns to calories stored in white fat, shrinking those cells.
But it may also be about the hormonal changes. Some of the surgeries reconfigure your bowels so nutrients hit the end portion of your intestine earlier, which triggers a decrease in the hormone that tells you you’re hungry and an increase in the hormone that tells you you’re full. Other hormones may improve insulin secretion.
These hormone changes, particularly when combined, lead to rapid weight loss. Just the fact that your body is carrying less weight increases your cells’ sensitivity to insulin.
Lifestyle changes, on the other hand, also may have a few more things at play. Weight loss is important, for sure. But exercise, one of the key components of the Why WAIT program, is a huge boost to insulin sensitivity. Cardio also decreases the amount of fat between the organs of your belly. So even if you only lose a small amount of weight through lifestyle changes you still see enormous diabetes benefits.
“We know that it’s probably why minimal weight loss through lifestyle changes tends to have a lot of health rewards and health benefits. We are trying to determine how these two approaches, lifestyle and medical diabetes and weight managemen or bariatric surgery, compare to treat patients with type 2 diabetes,” says Dr. Goldfine.
Surgery as a diabetes treatment is currently only considered after lifestyle changes have failed. But research suggests that full type 2 reversal is more likely the shorter the duration of the disease at the time of surgery. “So it begins to ask the question maybe we shouldn’t be using it as a last resort 10 years down the road,” says Dr. Goldfine.
If surgery proves to have as much consistent and long-term benefit as lifestyle changes, perhaps more patients will be visiting the OR earlier in the course of their diabetes.
“That’s what we’re asking in this particular project,” says Dr. Goldfine, “because I think it could really be fundamentally changing how we think about diabetes care and surgery.”