Lower birth weight accelerates onset of type 1 diabetes
Researchers at the University of Colorado Denver, along with colleagues at five other study sites nationwide, recently tested the “accelerator hypothesis,” which predicts that childhood obesity or higher body mass index levels are associated with a younger age at onset of type 1 diabetes. Surprisingly, it appeared that BMI level was a contributing factor only in cases with severe onset, while lower birth weight seemed to contribute to a younger or earlier diagnosis in almost all subjects. The study appears in the February issue of Diabetes Care.
“ The findings were somewhat surprising, given that obesity has been clearly connected to type 2 diabetes for a long time,” said Dana Dabelea, MD, PhD, assistant professor of preventive medicine and biometrics at the CU School of Medicine, lead author of the study and principal investigator of the Colorado site at UCD. “Type 1 diabetes is an autoimmune disease, and the obesity accelerator hypothesis did not hold true except in cases where a severe onset occurred and there was a substantial impairment of pancreatic insulin secretion. Low birth weight seemed to be a stronger contributing factor, which suggests that factors operating during the intrauterine life of a fetus may need to be more closely examined.
“ While not all higher BMI levels were associated with an earlier onset of type 1 diabetes, it was clear there was a relationship in cases where the production of insulin by the pancreas was severely damaged. The increasing prevalence of childhood obesity may substantially account for the younger age at onset of type 1 diabetes in these populations. Clearly, it is a contributor that needs to be addressed,” said Dabelea.
The study, funded by the Centers for Disease Control and Prevention and the National Institutes of Health, looked at 449 youths who were younger than 20 years old at the time they were diagnosed with type 1 diabetes. The diagnosis of type 1 diabetes was based on presence of autoimmunity. The researchers looked at relationships between age at diagnosis and BMI level, as well as reported birth weight for each participant. Data for the study came from the SEARCH for Diabetes in Youth study, a six-center, population-based study focusing on physician-diagnosed diabetes in children and youth in the United States.
" SEARCH is the first population-based study to look at diabetes in our youth," said Dr. Janet Collins, PhD, director of the CDC’s National Center for Chronic Disease Prevention and Health Promotion. "This type of research helps us better understand how to prevent and control diabetes among young people, and is critical to continued improvement of clinical and public health approaches to diabetes."
