Intranasal Insulin and Type-1 Diabetes
Intranasal insulin appears safe and may stabilize beta-cell and immune function in individuals at risk for type-1 diabetes. Mucosal administration of insulin retarded the development of diabetes in the non-obese diabetic mouse, a model of autoimmune type-1 diabetes. However, such immune responses to potentially therapeutic self-antigens have not yet been documented in humans.
Researchers from The Walter and Eliza Hall Institute of Medical Research in Victoria, Australia, studied the safety and immune effects of intranasal insulin in 38 individuals at risk for type-1 diabetes. Six participants in each arm of the crossover study (intranasal insulin-first and placebo-first groups) developed diabetes after a median of 1.1 years from entry. Eleven of these participants had baseline first-phase insulin responses to intravenous glucose (a measure of beta-cell function) no higher than the first percentile.
During treatment, circulating insulin antibodies increased significantly. Intra-nasal insulin was also associated with significant decreases in T-cell proliferation to insulin.
