Updated 17 October 2013

Diabetes better predictor of death than BMI

A new diabetes study shows that the presence of type 2 diabetes may be more important than weight in deciding who should have weight-loss surgery.

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.

They said, therefore, that diabetes should be a more important consideration when deciding who was eligible for gastric bypass or other weight-loss surgeries.

The research involved more than 15 000 obese people between the ages of 18 and 65 with an average BMI of 36.2. The threshold for obesity is 30.


The study 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.

Excess fat

"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."

More information

The US National Institute of Health provides more information on weight-loss surgery.

Photo about diabetes testing kit from Shutterstock


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Dr. May currently works as a fulltime endocrinologist and has been in private practice since 2004. He has a variety of interests, predominantly obesity and diabetes, but also sees patients with osteoporosis, thyroid disorders, men's health disorders, pituitary and adrenal disorders, polycystic ovaries, and disorders of growth. He is a leading member of several obesity and diabetes societies and runs a trial centre for new drugs.

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