September 23 (HealthDay News) -- Nasally administered insulin won't protect children at high risk of developing type 1 diabetes from getting the illness, Finnish researchers say.

The study included 264 children with an increased genetic risk for type 1 diabetes who tested positive for two or more diabetes-associated autoantibodies in consecutive blood samples taken 3 month to 6 months apart.

The team gave nasally-administered insulin to 137 children for a median of 1.8 years, while 127 children received a placebo.

In the insulin group, 56 children eventually developed diabetes, compared to 53 children in the placebo group.

"Adminstration of nasal insulin did not delay or prevent type 1 diabetes in children with genetically conferred risk of disease, even when started soon after antibodies to the condition were detected," wrote Drs. Kirsti Nnt-Salonen and Olli Simell, of the University of Turku, and colleagues.

The study was published online and was expected to be in an upcoming print edition of The Lancet.

"As Nnt-Salonen and colleagues and others have shown, autoantibody seroconversion in the first 13 years of life may be a common prerequisite for development of type I diabetes, which would suggest that an early window of susceptibility exists, after which seroconversion and type I diabetes are much less likely," Dr. David B Dunger and Dr. John Todd, University of Cambridge, U.K., wrote in an accompanying editorial.

SOURCE: The Lancet, news release, Sept. 23, 2008