Prior research has suggested that weight-loss surgery might help people rid themselves of type 2 diabetes, and a new study finds that the effect might be long-lasting.
"This is a very important study because it's the first randomized trial comparing bariatric surgery to medical treatment of diabetes with five years of follow-up," said Dr. Philip Schauer, who directs the Bariatric and Metabolic Institute at the Cleveland Clinic.
Schauer was not involved in the new British study, which was led by Dr. Francesco Rubino of King's College London. Rubino's team tracked five-year outcomes for 53 obese patients with type 2 diabetes.
The patients were randomly selected to undergo either one of two types of weight-loss surgery, or just to continue with conventional drug therapy to help control their diabetes.
The study found that half of the 38 weight-loss surgery patients maintained diabetes remission, compared with none of the 15 patients in the drug treatment group.
And regardless of whether or not their diabetes went into full remission, patients who underwent surgery still tended to have lower blood sugar levels than those treated with drugs, the researchers reported Sept. 3 in The Lancet.
The patients in the surgery group also used far fewer diabetes and heart medications, the research team added.
"The ability of surgery to greatly reduce the need for insulin and other [diabetes] drugs suggests that surgical therapy is a cost-effective approach to treating type 2 diabetes," Rubino said in a news release from the college, where he is chair of bariatric and metabolic surgery.
The new study backs up findings from previous research. For example, a study published in July in JAMA Surgery, of 61 obese people with type 2 diabetes, found that weight-loss surgery was better at keeping the disease at bay compared to diet and exercise alone.
And in 2014, another study from King's College London, published in The Lancet Diabetes & Endocrinology, found that obese people who underwent the surgery had a lower risk of developing type 2 diabetes.
The new study is among the first to suggest that these benefits last over time, Rubino's team said.
This study also found that, over five years, the heart risk of people who'd undergone weight-loss surgery was about half that of those in the drug treatment group.
Also, patients who had weight-loss surgery were less likely to have diabetes-related complications such as heart attack, stroke and kidney disease.
None of the patients in the surgery group died or had long-term complications.
The researchers noted that while people in the bariatric surgery groups lost more weight than people treated with drug therapy, weight loss alone didn't predict whether or not diabetes would recede.
That suggests that the benefits of surgery in curbing type 2 diabetes may rely on more than just shedding excess pounds, the British team said.
The two methods of weight-loss surgery included in the study were gastric bypass or biliopancreatic diversion.
According to the study authors, the former involves a shrinking of the size of the stomach and a rerouting of part of the small intestine, while the latter involves a more extensive intestinal bypass.
There were pros and cons to each method, the team found: More people saw their diabetes go into remission with biliopancreatic diversion, but patients who got gastric bypass had fewer nutritional side effects and had better quality of life overall.
In assessing the effectiveness of surgical and drug therapy, the British team looked at outcomes such as blood sugar control, the need for diabetes and heart medications, cholesterol levels, complications from diabetes or the bariatric surgery, and overall quality of life.
The researchers stressed that this was a relatively small trial and a much larger trial is warranted before firm conclusions can be drawn.
Nevertheless, the trial "shows that surgery is quite durable in the long term -- for at least five years," Schauer said. "And, that the procedure is relatively safe with a very low complication rate."
However, like any invasive procedure, weight-loss surgery comes with risks and recovery time, and it can be expensive.
The cost of weight-loss surgery varies, but the U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) estimates the cost is generally between $20,000 and $25,000. Insurance coverage for the procedure depends on the insurance company.
Schauer hopes the new findings might help widen access to the surgeries.
"Physicians should strongly consider surgery as an important option for long-term control of diabetes," he said. "In addition, insurance companies and third-party payers should consider reviewing the coverage of bariatric surgery in their standard insurance policy."