NEW YORK— Being overweight or obese is a risk factor for developing type 2 diabetes, but it turns out that these heavier patients may have an advantage: people who are overweight when they are diagnosed with diabetes live longer than their thinner peers, reported TIME.
The so-called obesity paradox, in which being overweight appears to be protective against early death, has been seen before in heart failure and chronic kidney disease.
But, says study author Mercedes Carnethon, associate professor of preventive medicine at Northwestern University, that doesn’t necessarily mean that gaining excess weight is a healthy strategy; rather, it may be that people who are thin when they develop diabetes are already be vulnerable to worse health.
“We hypothesized that their diabetes may be different,” she says. “They may have developed diabetes for reasons unrelated to obesity."
Overall, about 85 percent of people with diabetes are heavy. Gaining too much weight is a major contributor to type 2 diabetes, since excess fat cells can affect the way the body breaks down glucose and produces insulin, but some normal weight individuals can develop the disease as well. The elderly and people of Asian descent are more likely to be at normal weight when diagnosed, for example.
For the new study, published in the Journal of the American Medical Association (JAMA), Carnethon and her team reviewed data on five previous studies that were tracking people for heart disease risk factors. The studies, which were conducted between 1990 and 2011, included 2,625 people who were recently diagnosed with diabetes, about 12 percent of whom were at normal weight.