Liraglutide treatment leveled learning
The results showed that the learning rate was significantly lower in the subgroup with impaired insulin sensitivity, compared with those with normal insulin sensitivity following treatment with a placebo injection. This indicates a decreased adaptation of learning to predictability variations in individuals with impaired insulin sensitivity.
In contrast, treatment with a single dose of liraglutide significantly enhanced the learning rate in the group with impaired insulin sensitivity but significantly reduced the learning rate in the group with normal insulin sensitivity. Liraglutide’s effect was twice as large in the group with impaired insulin sensitivity than in the group with normal insulin sensitivity, and these opposing effects of liraglutide resulted in a convergence of the two groups’ adaptive learning rates so that there wasn’t any significant between-group difference following liraglutide treatment.
After analyzing the functional MRI data along with the learning results, the researchers concluded that liraglutide normalized learning in individuals with impaired insulin sensitivity by enhancing adaptive prediction error encoding in the brain’s ventral striatum and mesocortical projection sites.
This apparent ability of GLP-1 analogues to correct this learning deficit in people with impaired insulin sensitivity and obesity has implications regarding potential benefit for people with other pathologies characterized by impaired dopaminergic function and associated with metabolic impairments, such as psychosis, Parkinson’s disease, and depression, the researchers say.
“The fascinating thing about GLP-1 receptor agonists is that they have an additional mechanism that relates to anti-inflammatory effects, especially for alleviating cell stress,” said Dr. Tittgemeyer. “Many ongoing clinical trials are assessing their effects in neuropsychiatric diseases,” he noted.
The study received no commercial funding. Dr. Tittgemyer and most of his coauthors had no disclosures. One coauthor had several disclosures, which are detailed in the report. Dr. Kroemer had no disclosures.
A version of this article first appeared on Medscape.com.