Nasal Insulin May Boost Brain Power in People with Type 2 Diabetes

Enhancement of vasoreactivity and cognition by intranasal insulin in type 2 diabetes. By Novak and colleagues. Diabetes Care 2014;37:751–759

What is the problem and what is known about it so far?

People with type 2 diabetes are at an increased risk of developing vascular dementia, which is caused by clogged blood vessels leading to the brain, and Alzheimer’s disease. Evidence suggests that high blood glucose levels damage brain blood vessels, making it more difficult for the blood vessels to expand and contract—a quality called vasoreactivity. Poor vasoreactivity may lead to a reduction in brain function, making it more difficult for people to perform the daily tasks of living. Insulin is a potent signal in the brain and may affect neural networks. People with type 2 diabetes may have a shortage of insulin in their brains, making them more susceptible to brain disease.

Why did the researchers do this particular study?

Ther researchers wanted to test whether insulin delivered via the nasal cavity could penetrate the blood brain barrier to improve vasoreactivity and cognition in people with type 2 diabetes.

Who was studied?

The study included 15 adults with type 2 diabetes and 14 people without the disease.

How was the study done?

Participants inhaled a solution of either insulin or a placebo through their noses, delivered with a ViaNase electronic atomizer. Then, on the same day, researchers monitored the vasoreactivity of the blood vessels in the brains of the participants with magnetic resonance imaging (MRI). The researchers also performed a variety of medical tests on the participants, including glucose measurements, heart health assessments, and tests that checked verbal and other cognitive skills.

What did the researchers find?

The researchers found that intranasal insulin was safe and did not affect blood glucose levels. In people with type 2 diabetes, nasal insulin increased vasoreactivity and cognitive skills.

What were the limitations of the study?

This was a study with a small number of participants. Larger studies are needed to prove the benefits of nasal insulin.

What are the implications of the study?

Getting adequate amounts of insulin in the brain via the nasal cavity may help protect people with type 2 diabetes from dementia and Alzheimer's disease. 

  • Last Reviewed: April 2, 2014
  • Last Edited: April 17, 2014

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