"These patients have compromised pancreatic beta cell function and can no longer compensate for the additional metabolic demands associated with higher body mass index."

"Whether the reduced beta cell function is solely due to an autoimmune-mediated attack or whether non-autoimmune factors also contribute is a distinction that we are unable to make in this study," the researchers said.

The researchers also found that low birth weight may also be a factor in accelerating the onset of type 1 diabetes, which is now considered an autoimmune disorder, in which the body's own defenses turn on it.

As birth weight decreased, the age at which type 1 diabetes appeared advanced. The study was part of the Search for Diabetes in Youth, and involved 449 participants who were under 20 at the time of the diagnosis.

Search for Diabetes in Youth is trying to determine the prevalence and incidence of childhood diabetes and document how much childhood diabetes is type 1, how much is type 2, and how much is due to other rare causes.