Bariatric surgery can result in sustained reversal of obesity, type 2 diabetes: Study

Johns Hopkins University School of MedicineAug 17 2010

Results of a large national study show that nearly three-quarters of obese patients with type 2 diabetes who undergo weight-loss surgery are able to stop insulin and other antidiabetes drugs within six months.

In the Johns Hopkins study of insured, obese, diabetic patients, researchers also found that in the third year following surgery, average annual health care costs per patient decreased by more than 70 percent. The study is published in the Archives of Surgery this month.

"The cost to care for the average obese diabetic person in America is $10,000 a year, which could be cut to $1,800 with a very safe operation that eliminates more than 80 percent of the medications these individuals have depended on," says Marty Makary, M.D., M.P.H., an associate professor of surgery at the Johns Hopkins University School of Medicine and the study's leader. "The results show that bariatric surgery has huge implications for public health and control of health care costs."

Makary and his colleagues studied 2,235 adults with Blue Cross/Blue Shield insurance from throughout the United States who had type 2 diabetes and underwent bariatric surgery during a four-year period from January 1, 2002 to December 31, 2005. The average age of those in the study was 48 years old and 74.5 percent were women. More than 23 percent of participants were insulin dependent while more than 50 percent took metformin hydrochloride to keep their diabetes in check.

Makary and his colleagues found that within one year following surgery, the number of patients dependent on insulin dropped from 524 (23.4 percent) to 101 (5.5 percent). Those on metformin dropped from 1,129 (50.5 percent) to 156 (8.4 percent).

Bariatric surgery, at an average cost of $30,000, reduces stomach capacity, typically by stapling off the stomach and creating a much smaller pouch. Studies show it results in long-term weight loss, improved lifestyle and decreased mortality in some populations. Its use has increased 200 percent during the last five years, the authors note.

The risk of mortality from bariatric surgery is .3 percent. Makary points out that the health risks associated with diabetes and obesity are much greater.

Makary says more obese diabetic people should be offered a surgical weight-loss option, but notes that insurance coverage of the procedure is not universal, even for appropriate patients. Some private insurers may not cover it and people with Medicaid do not have equal and uniform access to the operation. "Our results suggest that insurance companies would do well to more readily cover bariatric surgery because it improves health and cuts health care costs," he says.

Makary says that while bariatric surgery has been shown to result in long-term weight loss, improved lifestyle and decreased mortality in many patients, its impact on diabetes has not been widely studied.

The weight loss that results from the surgery is one explanation for why diabetes symptoms subside, but for some patients, markers of the disease disappear even before significant amounts of weight are lost. One theory is that stomach hormones are somehow altered by the surgery and those changes allow for better natural control of blood glucose levels almost immediately.

"Until a successful nonsurgical means for preventing and reversing obesity is developed, bariatric surgery appears to be the only intervention that can result in a sustained reversal of both obesity and type 2 diabetes in most patients receiving it," Makary says.