Publication

Intranasal insulin improves memory in humans: superiority of insulin aspart

Journal Paper/Review - Jan 1, 2007

Units
PubMed
Doi

Citation
Benedict C, Hallschmid M, Schmitz K, Schultes B, Ratter F, Fehm H, Born J, Kern W. Intranasal insulin improves memory in humans: superiority of insulin aspart. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology 2007; 32:239-43.
Type
Journal Paper/Review (English)
Journal
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology 2007; 32
Publication Date
Jan 1, 2007
Issn Print
0893-133X
Pages
239-43
Brief description/objective

There is compelling evidence that intranasal administration of regular human insulin (RH-I) improves memory in humans. Owing to the reduced tendency of its molecules to form hexamers, the rapid-acting insulin analog insulin aspart (ASP-I) is more rapidly absorbed than RH-I after subcutaneous administration. Since after intranasal insulin administration, ASP-I may also be expected to access the brain, we examined whether intranasal ASP-I has stronger beneficial effects on declarative memory than RH-I in humans. Acute (40 IU) and long-term (4 x 40 IU/day over 8 weeks) effects of intranasally administered ASP-I, RH-I, and placebo on declarative memory (word lists) were assessed in 36 healthy men in a between-subject design. Plasma insulin and glucose levels were not affected. After 8 weeks of treatment, however, word list recall was improved compared to placebo in both the ASP-I (p<0.01) and the RH-I groups (p<0.05). ASP-I-treated subjects performed even better than those of the RH-I-treated group (p<0.05). Our results indicate that insulin-induced memory improvement can be enhanced by using ASP-I. This finding may be especially relevant for a potential clinical administration of intranasal insulin in the treatment of memory disorders like Alzheimer's disease.