Cancer survivors who got radiation treatments as children have nearly twice the risk of developing diabetes as adults, U.S. researchers said on Monday.
They said children who were treated with total body radiation or abdominal radiation to fight off cancer appear to have higher diabetes risks later in life, regardless of whether they exercise regularly or maintain a normal weight.
The odds of surviving childhood cancer have improved with better therapies but several research teams have found that some treatments pose health risks later in life.
Dr. Lillian Meacham of Emory University in Atlanta and colleagues compared rates of diabetes in nearly 8,600 childhood cancer survivors diagnosed between 1970 and 1986, and nearly 3,000 of their siblings who did not have cancer.
After adjusting for other risk factors, including body mass index -- a ratio of height and weight -- they found the childhood cancer survivors overall were 1.8 times more likely to have diabetes.
And the more radiation that was used, the greater the diabetes risk. For those treated with total body radiation -- a treatment often used before bone marrow transplants to treat childhood leukemia -- the diabetes risk was more than seven times greater.
Cancer survivors already have higher risks of heart and kidney disease. A study last year found children who survive cancer while they are young are five to 10 times more likely than their healthy siblings to develop heart disease.
It is imperative that clinicians recognize this risk, screen for diabetes and pre-diabetes when appropriate, and approach survivors with aggressive risk-reducing strategies, the team wrote in the Archives of Internal Medicine.
They said more study was needed to understand how radiation could promote diabetes in cancer survivors.
Type 2 diabetes -- the most common form of diabetes -- develops when the body makes too much insulin and does not efficiently use the insulin it makes.