WEDNESDAY, Oct. 16, 2013 (HealthDay News) -- The presence of type 2 diabetes may be more important than body-mass index (BMI), a standard measure of body weight, in deciding who should have weight-loss surgery, a new study finds.
Researchers found that whether people have type 2 diabetes is actually a much bigger predictor than BMI of whether patients will die within the next 10 years. Therefore, the researchers said, diabetes should be a more important consideration when deciding who is eligible for gastric bypass or other weight-loss surgeries.
The research involved more than 15,000 obese people between 18 and 65 years of age with an average BMI of 36.2. The threshold for obesity is 30.
The study, published Oct. 16 in the journal JAMA Surgery, showed that a person's age and a diagnosis of type 2 diabetes were the most significant risk factors for death among these patients. Smoking also was a risk factor that could be used to estimate their 10-year risk of dying.
Meanwhile, the researchers said BMI was the least significant risk factor.
The research team, led by Dr. Raj Padwal, of the University of Alberta in Canada, wrote that since diabetes often eases after weight-loss surgery, "a strong case could be made for prioritizing it over BMI or other [illnesses]" when determining eligibility for weight-loss surgery.
One expert in bariatric surgery wasn't surprised by the findings.
"BMI is just a number and can be elevated by excess fat and even large amounts of muscle," said Dr. Mitchell Roslin, chief of obesity surgery at Lenox Hill Hospital in New York City. "Furthermore, it does not correlate well with the degree of medical impairment caused by weight. The distribution of where the excess fat is located is a far more important determinant of medical problems than the BMI number itself."
"My largest patients very rarely have significant diabetes," Roslin said. "Clearly, we still have much to learn about obesity, and which patients require the most aggressive treatments. Linking [insurance] coverage and care to only BMI is unfair and not consistent with medical facts."
The U.S. National Institutes of Health provides more information on weight-loss surgery.