Weight-Loss Surgery May Improve Diabetes-Related Kidney Damage

WEDNESDAY, June 20 (HealthDay News) -- Weight-loss surgery may reduce the risk of kidney disease in obese people with diabetes, according to a small study.

The study included 52 patients, mostly female, who were obese and had type 2 diabetes. Nearly 40 percent of the patients had diabetic nephropathy, a form of kidney damage that can require dialysis and lead to kidney failure.

All of the patients underwent bariatric surgery, intended to help people lose weight. Most had a type of bariatric surgery known as gastric bypass, in which the stomach is stapled to make it smaller, and the small intestine is rerouted to the smaller pouch.

Five years after surgery, nearly 60 percent of the patients who'd had diabetic nephropathy no longer had the condition, the researchers said.

They also found that only 25 percent of those who did not have diabetic nephropathy at the time of surgery eventually developed the condition. That's about 50 percent less than the occurrence rate in people with diabetes who don't have bariatric surgery.

The five-year diabetes remission and improvement rates for patients in the study were 44 percent and 33 percent, respectively.

The study is scheduled to be presented at the annual meeting of the American Society for Metabolic & Bariatric Surgery in San Diego.

"When we started this study, we thought bariatric surgery may just halt the progression of diabetic nephropathy," lead author Dr. Helen Heneghan, a bariatric surgery fellow at the Cleveland Clinic Bariatric and Metabolic Institute, said in a society news release. "Instead, over half the patients who had diabetic nephropathy prior to undergoing bariatric surgery experienced remission. This is a remarkable finding that warrants greater consideration of bariatric surgery in this patient population."

About 90 percent of people with type 2 diabetes worldwide are overweight or obese, according to the World Health Organization.

In the study, patients' average body-mass index -- a measure of body fat based on height and weight -- was 49 at the time of the surgery. A body-mass index of 30 or higher is considered obese.

Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal. Experts also note that although the study found an association between weight-loss surgery and less kidney damage, researchers did not prove that the surgery was responsible for the decreased kidney disease.