A "Dose" of Obesity

Type 2 diabetes risk increases with degree and duration of obesity

(RxWiki News) Being obese is already known to raise the risk for type 2 diabetes. Now, it seems that the "dose" of obesity - the amount of excess weight a person carries and for how long - has an effect on that person's risk.

The amount of excess weight and the time a person carries that excess weight are both important risk factors for developing type 2 diabetes.

"Get rid of excess weight at an early age."

This study shows that the link between weight and type 2 diabetes is similar to the link between smoking and lung cancer risk, says the study's lead author Joyce Lee, M.D., M.P.H., a pediatric endocrinologist at the University of Michigan's C.S. Mott Children's Hospital.

A person's risk for diabetes can increase significantly, she explains, depending on the amount of excess weight and number of years that person carries that weight.

Currently, there is a childhood obesity epidemic in the United States, which means that many young Americans are getting heavier earlier in their lives and carrying that excess weight for longer stretches of their lifetimes, says Dr. Lee. These new findings suggest that the rates of diabetes may grow to even larger levels than was previously thought.

From their study, Dr. Lee and colleagues found that measuring both amount and duration of excess weight was a better way to predict the risk of type 2 diabetes, compared to measuring only amount of weight. More specifically, they calculated the risk for diabetes using the number of years body mass index (BMI) - a measure of weight and height - was 25 or higher.

The researchers found this measure to be a better predictor of diabetes than BMI alone.

After looking at about 8,000 teenagers and young adults, the researchers found that blacks and Hispanics had a higher risk for diabetes than whites who had the same amount of excess weight over a period of time. For example, Hispanics with a BMI of 35 (10 points above a healthy weight and five points above the obesity mark) were two times more likely to develop diabetes compared to whites with the same BMI. Blacks with a BMI of 35 were 1.5 times more likely to get diabetes than whites.

Dr. Lee says that these results show the need for stronger efforts to prevent and treat obesity in adolescents and young adults, especially within racial minority groups.

She also believes that measuring this "dose" of excess BMI could help doctors and their patients better understand their risk of developing diabetes in the future. 

The study is published in the Archives of Pediatric Adolescent Medicine.

Review Date: 
September 6, 2011