(Jan. 5, 2008) Michael Savage, DDS, is professor and chair of the Division of Oral Surgery at the University of Colorado Denver School of Dental Medicine, and is a diabetic. For more than 10 years, he has been participating in a diabetes study at the Barbara Davis Center for Childhood Diabetes on the Anschutz Medical Campus that looks at the prevalence of diabetes in identical twins. Savage has an identical twin brother named Patrick and they both have type 1 diabetes. The brothers are 61-years old; Michael’s brother was diagnosed with type 1 diabetes more than 30 years ago when they were both 27 but Michael was more recently diagnosed four years ago at age 57 — three decades after his brother’s diagnosis.
“When Patrick was first diagnosed with diabetes, I knew it was just a matter of time before I would be diagnosed too,” said Michael. “Back then, there were conflicting reports about twins and diabetes; some said I had a 30 percent chance and others said it was closer to 100 percent. I wasn’t sure which report was correct but I always knew in my heart that it was inevitable.”
Researchers at the Barbara Davis Center have been following 83 sets of identical twins for more than 40 years. In each set of twins at least one of them had been diagnosed with diabetes before they became participants in the study. Overall, the study found that in identical twins, if one is diagnosed with diabetes, it is just a matter of time before the other will be diagnosed too.
In following the 83 sets of identical twins the researchers found that by 60 years of age, the cumulative incidence of diabetes between the identical twins was 65 percent and autoantibodies, or markers indicating a prediabetic condition, had developed in 78 percent of the twins. Among 32 of the twins who were autoantibody-positive, or at high risk, the risk of diabetes was 89 percent within 16 years after the first positive antibody test.
The researchers indicate that the next steps would include identifying specific genes associated with type 1 diabetes; other research with diabetes and identical twins might look at how one twin develops diabetes while the other might not develop clinical symptoms for years or even decades.
Photo: Pat, left, and Mike Savage are identical twins with diabetes.