The use of 7.5 mg/day oral insulin does not appear to delay the onset of type 1 diabetes compared with placebo among autoantibody-positive relatives of patients with type 1 diabetes, according to a study published in JAMA.
Patients who tested positive for microinsulin autoantibodies were randomly assigned to receive either 7.5 mg/day oral insulin (n=283) or placebo (n=277). In the main study group, a total of 203 patients received oral insulin vs 186 patients who received placebo. Time to type 1 diabetes onset made up the primary outcome in the main study group.
At a median follow-up period of 2.7 years, type 1 diabetes was diagnosed in 28.5% (n=58) of participants receiving oral insulin vs 33% (n=62) of patients receiving placebo. According to the researchers, there was no significant difference between the 2 groups in regard to the time to diabetes onset (hazard ratio [HR], 0.87; 95% CI, 0-1.2; P =.21).
Among 55 patients included in secondary stratum 1, a total of 13 patients receiving oral insulin developed diabetes vs 19 patients receiving placebo. In this analysis, the time to diabetes onset was longer among those receiving oral insulin vs placebo (HR, 0.45; 95% CI, 0-0.82; P =.006). There was no statistically significant difference for the entire patient cohort in regard to the primary outcome (HR, 0.83; 95% CI, 0-1.07; P =.11).
In addition to cautioning against using oral insulin as a preventative for type 1 diabetes in at-risk patients, the investigators of this study suggest the study emphasizes “the feasibility of identifying and treating individuals early in the type 1 diabetes disease process.”
Writing Committee for the Type 1 Diabetes TrialNet Oral Insulin Study Group. Effect of oral insulin on prevention of diabetes in relatives of patients with type 1 diabetes: a randomized clinical trial. JAMA. 2017;318:1891-1902.