Obesity paradox is the notion that people who are overweight or moderately obese have a lower risk of early death but a new study is debunking the phenomenon, at least for patients with Type 2 diabetes.
For the study, researchers examined people with diabetes from the Nurses' Health Study and Health Professionals Follow-up Study who were free of cardiovascular disease and cancer at the time of their diagnosis. Taking into account the subjects' body-mass index (BMI) and their smoking status, the researchers found that those who were overweight or obese when they were diagnosed with diabetes were up to 33 percent more likely to die than those who were at the higher end of normal weight at the time of their diagnosis.
"Smokers tend to be leaner, and that may attenuate the risk of obesity or even make it look protective," said study lead author Deirdre Tobias, a research fellow at the Harvard School of Public Health (HSPH). "But when we stratified the data by smoking status, we saw the relationship is truly linear, with mortality risk going up with BMI."
The researchers also found that the risk of death was worst among the heaviest subjects and those who were diagnosed before the age 65 as they gained weight.
"These data dispel the notion that being overweight or obese confers survival advantage among diabetic patients," said Frank Hu, professor of nutrition and epidemiology at HSPH and senior author of the study. "Clearly, weight management is an important therapeutic strategy for overweight or obese individuals with type 2 diabetes."
The study, published in the January 16 issue of the New England Journal of Medicine concludes that obesity paradox is a myth for those with Type 2 diabetes. "We found no evidence of lower mortality among patients with diabetes who were overweight or obese at diagnosis, as compared with their normal-weight counterparts, or of an obesity paradox," the researchers reported.
Tobias, however, said that the cause isn't necessarily closed. "But at this point, there is no reason to believe that being overweight or obese would be protective for people with diabetes," she said.
Susan Spratt, a diabetes researcher from the Duke University School of Medicine in Durham, North Carolina, agrees. "Losing weight is beneficial, and you may not have to lose a lot," she said. "But losing five percent or 10 percent of your body weight if you are obese can help so many issues, from joint pain and sleep apnea, to diabetes and diabetes complications."
