June 25 -- WEDNESDAY, June 24 (HealthDay News) -- Not only does one of the largest studies on bariatric surgery find the procedure to be as safe as other routine surgeries, two other studies confirm that it also appears to stave off diabetes for the long term.
Researchers from Duke University Medical Center analyzed data from nearly 58,000 patients included in the Bariatric Outcomes Longitudinal Database (BOLD), the largest repository of medical information on people who've undergone the weight-loss surgery.
Only about 10 percent had complications, according to the study, which was to be presented Wednesday at the annual meeting of the American Society for Metabolic and Bariatric Surgery, in Grapevine, Texas.
The most common complaint was nausea or vomiting, though researchers said they had not yet completed their analysis. Total mortality was less than 1 percent.
"This is further evidence, using the world's largest collection of information about bariatric surgery, to support that it is a safe and valuable treatment option for patients who suffer from morbid obesity," said lead study author Dr. Eric J. DeMaria, vice chair of the department of surgery at Duke.
Morbid obesity is defined as a body mass index (BMI, a ratio of weight to height) over 40, or a BMI of 35 to 40 plus an obesity-related disease such as type 2 diabetes, heart disease or sleep apnea, according to criteria set by the U.S. National Institutes of Health.
Two other studies also to be presented Wednesday found that weight-loss surgery can lead to the long-term remission of diabetes.
Researchers from Virginia Commonwealth University examined 177 morbidly obese patients with type 2 diabetes who underwent gastric bypass surgery, the most common weight-loss procedure, between 1993 and 2003.
Nearly 90 percent of the patients experienced a return to normal blood sugar levels within the first year. And about 60 percent were still diabetes-free five to 16 years later, according to the study.
Those most likely to have their diabetes return were those who were insulin dependent at the time of the surgery, meaning their disease was more severe.
About 75 percent of patients able to control their diabetes with diet or oral medications remained diabetes-free, compared to only 30 percent of those who were insulin dependent at the time of the surgery, the study found.
"The big thing we got from this study was the earlier you got these patients for gastric bypass and the earlier they were referred during the course of their diabetes, the better their chance for diabetes control," said senior author Dr. James W. Maher, a Virginia Commonwealth University professor of surgery.
A second study on the impact of bariatric surgery on diabetes looked at gastric banding, another common weight-loss procedure.
Researchers from New York University School of Medicine examined 95 patients who had laparoscopic gastric banding between January 2002 and January 2004. About 88 percent were taking oral diabetes medication and 15 percent were on insulin.
After five years, about 40 percent of patients were in remission and about 43 percent had improved blood sugar levels. The average fasting glucose level decreased from 146 to 118.5 and the average HbA1c (a measurement of glucose levels over time) decreased from about 7.5 percent to around 6.6 percent, the researchers said in a meeting news release.
"Our study contributes to mounting evidence that demonstrates gastric banding can have a sustained and meaningful effect on diabetes and morbid obesity and that the two diseases are interrelated," senior study author Dr. Christine Ren, an associate professor of surgery at New York University School of Medicine, said in the news release.
The patients also lost substantial weight -- their mean BMI dropped from 46 to 35. Study participants had diabetes an average of 6.5 years prior to surgery, the researchers said.
Studies such as these are good news for people with morbid obesity, many of whom have tried and failed to lose weight without surgery, said Dr. Scott Shikora, president of the American Society for Metabolic and Bariatric Surgery.
"For people who have type 2 diabetes related to their weight, other than bariatric surgery, there are no other treatments that put diabetes into remission," Shikora said.
Yet some patients, their families and even physicians fear bariatric surgery, remembering some highly publicized complications and deaths during the procedure's early days, Shikora said.
"The field has dramatically improved and is much more advanced than it was 20 years ago," Shikora said.
Shikora and DeMaria lay credit for that improvement on the American Society for Metabolic and Bariatric Surgery Centers of Excellence program, which sets standards for training and patient care at the 350 hospitals and for the 650 surgeons granted the status.
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more on bariatric surgery.
SOURCES: Eric J. DeMaria, M.D., vice chair, Department of Surgery, Duke University Medical Center, Durham, N.C.; James W. Maher, M.D., professor of surgery, Virginia Commonwealth University, Richmond, Va.; Scott Shikora, M.D., president, American Society for Metabolic and Bariatric Surgery, Gainesville, Fla.; June 24, 2009, study presentations, American Society for Metabolic and Bariatric Surgery annual meeting, Grapevine, Texas