with Ali Aminian, MD, and J. Michael Gonzalez-Campoy, MD, PhD

When you have diabetes with obesity, bariatric surgery leads to significant benefits including reducing heart disease events and improving diabetes outcomes. But is it the right choice for you?

Bariatric surgery not only helps people with type 2 diabetes and obesity reduce weight substantially, but these procedures also lead to improved heart health and better control of blood sugar,¹ according findings published in the Journal of the American Medical Association (JAMA).

Researchers from the Cleveland Clinic evaluated the experiences of nearly 2,300 patients who had weight loss surgery and compared them to patients who had similar medical conditions but received standard medical care as well as no gastric surgery.¹

Cleveland Clinic researchers show the value of weight loss surgery as an effective method of reducing risks of heart disease and type 2 diabetes, even lowering rates of death. Photo: 123rf

Assessing 4 Types of Gastric Surgery for Differences in Health Benefits

Weight loss surgery—also called bariatric surgery, gastric bypass, or gastric sleeve— ”is associated with significant reductions in cardiovascular disease (CVD) complications, specifically a reduction in the risks associated with heart disease, stroke, and heart failure as well as kidney failure and atrial fibrillation [abnormal heart rhythm],” says Ali Aminian, MD, FACS, lead author of the study and associate professor of surgery at the Cleveland Clinic in Ohio. Overall, the median follow up of these patients was nearly 4 years (half longer, half less).

Those who had surgery were also less likely to die during the study period. “The risk of dying dropped by 41% in 8 years of follow-up,” says Dr. Aminian.¹

Dr. Aminian and his team compared the results of individuals who did and did not have the weight loss surgery. The patients had one of 4 types of weight loss surgery—gastric banding, sleeve gastrectomy, adjustable gastric banding or duodenal switch.

The median age of the patients in the surgery group was 52 years and nearly the same, 55 years, in the nonsurgical treatment group. The median body mass index (BMI) at the start of the study was similar across both groups: 45 kg/m² in the surgery group and nearly 43 in the non-surgical treatment group.¹

The researchers looked at how likely the individuals in each group were to develop one of five major disease complications associated with having obesity and diabetes during the study period:

• Coronary artery events
• Cerebrovascular events such as a stroke
• Heart failure
• Atrial fibrillation
• Kidney disease
• Or to die

Not only was there a 41% reduction in the risk of death during the cumulative 8-year follow up among those who had any form of surgery, these individuals were also less likely to develop any of the other disease-related complications. While about 31% of those in the surgery group had one of the associated health consequences studied, nearly 48% of those in the non-surgery treatment group developed at least one of the 5 most problematic diseases. That difference is considered significant.¹

Are All Types of Weight Loss Surgery Equally Beneficial?

The researchers did not formally look at the subgroups of patients by type of surgery, Dr. Aminian says. However, ”95% of our patients had a gastric bypass procedure or the sleeve gastrectomy,” he says. Those are two of the most commonly performed procedures, he says.

Each bariatric surgical approach has pros and cons, he tells EndocrineWeb. Gastric bypass patients usually lose more weight compared to those who undergo the sleeve gastrectomy but the overall complication rate for bypass surgery is a bit higher. “In effect, the bypass procedure is a bit more effective, and the sleeve technique is a bit more safe,” says Dr. Aminian.

“However, overall, the two procedures are similar,” he adds.

While this study examined the risk of death and rates of heart disease related events, the researchers also took note of weight loss. “At the end, those receiving surgery achieved an average weight loss of about 64 pounds (29 kilograms),” Dr. Aminian says, resulting in an average of 15% greater weight loss and lower blood sugar levels than those opting for standard medical management.¹

The individuals who elected to have gastric surgery also needed less diabetes medications, including insulin, and were able to reduce their reliance on medications to manage their cardiovascular disease, (ie, blood pressure, blood cholesterol, heart failure, blood clots). 

What Have We Learned about Gastric Surgery in People with Diabetes?

“Before this study, we knew these procedures were safe, and effective for losing weight and improving diabetes,” Dr. Aminian says. However, much less was known about the direct impact on the factors related to heart disease.

Now, he says, our research shows that “when we do the surgery not only do patients lose substantial weight and their diabetes gets better, but also the need for cardiovascular and diabetes medicines is reduced significantly, survival rates improve and the risk of having any of these major cardiovascular disease events drops significantly—from 60 to 40%.”

While the higher levels of weight loss may explain the better results in the individuals who had surgery, the improved outcomes also be due to beneficial metabolic and hormonal changes that occur following after gastric surgery, which is independent of the weight loss,¹ Dr. Aminian says.

Treating Diabetes Must Incorporate Sustained Weight Loss

“This is not the first report to document a cardiovascular or mortality benefit from bariatric surgery as compared with conventional medical treatment,” says J. Michael Gonzalez-Campoy, MD, PhD, FACE, medical director and CEO of the Minnesota Center for Obesity, Metabolism and Endocrinology, who reviewed the data for EndocrineWeb.

But the study contributes some valuable data from large numbers at a major medical care center, Dr. Gonzalez-Campoy says. For patients, the message is that you ”should know that treatment of your diabetes, high blood pressure, and high cholesterol should also be accompanied by effective treatment of overweight.”   

Dr. Gonzalez-Campoy cautions that while bariatric surgery is one way to accomplish critical weight loss, “obesity is a life-long disease so surgery does not cure obesity, it only treats it.” And, he says, it is certainly not the only reasonable option.

After all, it’s important to note that this study that compares who did and did not have the surgery has some limitations, Dr. Gonzalez-Campoy tells EndocrineWeb. Among them—less than 10% of the patients who did not have surgery were given the newer diabetes medications, such as the GLP-1RA (glucagon-like peptide-1 receptor agonists) or sodium glucose cotransporter-2 inhibitors (SGLT-2i), and these are also linked with substantial cardiovascular benefits.^2,3

In addition, he says, if patients choose to stick with an effective weight loss program while also receiving consistent medical management of your diabetes, you may expect to do better than the patients who were in the non-surgery group at the Cleveland Clinic study.

Treat Both Diabetes, Weight to Improve Overall Health  

For those with diabetes and obesity, the message Dr. Gonzalez-Campoy is: “If you have diabetes, it should be treated to goal. If you have obesity, it should be also be treated with the aim to lose at least 10% of your starting weight over the first 6-12 months, and then to continue to effectively achieve meaningful weight loss.”

In an editorial accompanying the study, Edward H. Livingston, MD, deputy editor of JAMA, writes that the study results should be interpreted cautiously due to some weakness in the research design. One key problem is the ”imprecise matching” of the study groups; and a second is that those who had surgery had a higher body mass index to start with. Even so, he writes, bariatric surgery should be the preferred treatment option for patients who are motivated and aren’t able to lose weight in other ways.⁴

Medtronic partially funded the study with an unrestricted grant, and had no role in the study execution or reporting. Dr. Gonzalez- Campoy has no relevant financial disclosures.  

Last updated on 09/12/2019