Bottom Line: A daily insulin pill did not delay or prevent the development of type 1 diabetes among relatives of people with type 1 diabetes at increased risk of this disease.
Why The Research Is Interesting: A previous trial of oral insulin to prevent Type 1 diabetes hinted that in a group of relatives with insulin antibodies, oral insulin might prevent or delay the disease. Prevention or delay of diabetes would have major clinical ramifications.
Who: Children and adults with normal glucose tolerance who were relatives of patients with type 1 diabetes and had an increased risk for the disease because they had at least two autoantibodies, including insulin autoantibodies.
When: Participants were enrolled in the trial March 2007 through December 2015.
How (Study Design): This was a randomized clinical trial. Participants (n=560) were randomized to 7.5 mg oral insulin or placebo.
What (Study Measures): The time from randomization to the development of type 1 diabetes.
Authors: Jeffrey P. Krischer, Ph.D., of the University of South Florida College of Medicine, Tampa, and coauthors with the Writing Committee for the Type 1 Diabetes TrialNet Oral Insulin Study Group
Results: During a median follow-up of 2.7 years, diabetes was diagnosed in 58 participants (28.5 percent) in the insulin pill group and 62 (33 percent) in the placebo group. Time to diabetes was not significantly different between the two groups.
Study Limitations: There are likely many reasons and mechanisms by which type 1 diabetes develops, and the trial assumed that all participants were similar in those characteristics and in their potential response to oral insulin.
Study Conclusions: Among autoantibody-positive relatives of patients with type 1 diabetes, a 7.5 mg insulin pill daily compared with placebo did not delay or prevent the development of type 1 diabetes. These findings do not support oral insulin as used in this study for diabetes prevention.
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For more details and to read the full study, please visit the For The Media website.
(doi:10.1001/jama.2017.17070)
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
JAMA