The results of a small Phase 2 clinical trial offers promising signs that daily doses of an insulin nasal spray could be used to slow age-related cognitive decline. Over the last couple of decades an intriguing hypothesis has emerged suggesting insulin resistance in the brain may play a role in age-related cognitive and functional decline. Prior human trials with intranasal insulin have delivered mixed results.
The participants were divided into four groups: a diabetes group given placebo, a diabetes group given intranasal insulin, a healthy group given placebo and a healthy group given intranasal insulin.
“At baseline, participants with diabetes walked slower and had worse cognition than the participants without diabetes, who served as a clinical reference for normal aging population.” At the end of the study period the researchers found those diabetics who were taking the intranasal insulin improved their gait speed and performed better on cognitive tests than those diabetics in the placebo group.
The non-diabetic group receiving the intranasal insulin also displayed improvements on decision making and verbal memory tests compared to non-diabetics in the placebo group.
From a safety perspective the researchers found intranasal insulin generated no adverse effects after 24 weeks.
Intranasal insulin did not affect or disrupt subcutaneous insulin treatment in those type 2 diabetic subjects receiving ongoing glucose-lowering therapy.
The results are certainly fascinating but the researchers are cautious to stress there are still lots of questions to answer before some kind of intranasal insulin spray for brain health is available to the elderly.
“INI-treated diabetic participants had faster walking speed, increased cerebral blood flow and less insulin resistance, while INI-treated controls performed better on executive function and verbal memory tasks,” the researchers concluded in the new study.