A diagnosis of type 1 diabetes often seems to come out of the blue. But German researchers say they can predict who will likely develop the chronic disease.
Blood samples taken from children at increased genetic risk of type 1 diabetes reveal significant "preclinical" clues, the researchers found. The strongest predictor is the presence of two diabetes-related autoantibodies, they reported in the June 18 issue of the Journal of the American Medical Association.
"If you have two or more autoantibodies, it's nearly inevitable that you will develop the disease. Most people -- even physicians -- don't appreciate this risk," said Dr Jay Skyler, deputy director for clinical research at the Diabetes Research Institute and a professor at the University of Miami Miller School of Medicine. Skyler was not involved in the research.
Nearly 70% of youngsters with two diabetes-related autoantibodies developed type 1 diabetes over a 10-year period compared to less than 15% of kids with just one autoantibody, the researchers found.
Skyler, co-author of an accompanying journal editorial, said this study highlights the need for effective prevention strategies for type 1 diabetes.
Type 1 diabetes is believed to be an autoimmune disease in which the body's immune system mistakenly destroys the insulin-producing beta cells in the pancreas. Insulin is a hormone needed to turn the carbohydrates from food into fuel for the body.
To survive, people with type 1 diabetes must monitor their food intake and replace the lost insulin through injections or an insulin pump.
Type 1 diabetes can occur at any age, and there's currently no known way to prevent or cure it, according to the JDRF (formerly the Juvenile Diabetes Research Association). And unlike its more common counterpart, type 2 diabetes, the development of type 1 diabetes isn't linked to lifestyle choices.
The current study included children from Colorado, Finland and Germany who were followed from birth for up to 15 years. Children in the Colorado and Finland study groups were included in the study if they had a specific genotype that indicated a genetic predisposition to developing type 1 diabetes. Children in the German study had to have a parent with type 1 diabetes to be included in the study.
Majority remained healthy
More than 13 000 youngsters were recruited in all. During the study follow-up, the researchers found that nearly 1 100 children -- or about 8% of the total group -- developed one or more autoantibodies, which are markers for the destruction of the insulin-producing beta cells in the pancreas.
The vast majority of the children, despite their higher risk, remained free of type 1 diabetes and free of signs that the disease might develop.
"Autoantibodies are a marker for the risk of diabetes. [But] they are just markers; they are not causing the disease," said Dr Joel Zonszein, director of the Clinical Diabetes Center at Montefiore Medical Center in New York City.
Of the children who developed autoantibodies, 585 developed two or more. The remaining 474 children had just one autoantibody, according to the study.
In children with multiple autoantibodies, 43.5% developed type 1 diabetes within five years, about 70% had diabetes after 10 years and about 84% had the condition after 15 years. At the 10-year mark, just 14.5% of children with a single autoantibody had developed type 1 diabetes.
The researchers also found that children who had multiple autoantibodies before age 3 were more likely to quickly develop type 1 diabetes. Children with certain genotypes -- the HLA genotype DR3/DR4-DQ8 -- were more likely to develop type 1 diabetes faster. And girls were more likely to progress to type 1 diabetes faster than boys if they had multiple autoantibodies, according to the study.
"Findings from this study suggest there should be a greater emphasis for [people with multiple autoantibodies] to be enrolled in studies that could delay or prevent type 1 diabetes," Skyler said.
Zonszein said these findings can help better predict who is at high risk for type 1 diabetes. "[However], we're still a long way from stopping the development of type 1 diabetes," he added.
He also noted that the children in the studies were almost all white, so these findings might not translate to other population groups, such as blacks or Hispanics.
Learn more about type 1 diabetes from the Diabetes Research Institute.