Nasal spray of a man-made form of insulin, a hormone that regulates the amount of glucose in the blood, may improve working memory in adults with mild cognitive impairment and Alzheimer's disease, new research has found.
The researchers administered insulin detemir, a manufactured form of the hormone, on 60 adults diagnosed with amnesic mild cognitive impairment (MCI) or mild to moderate Alzheimer's dementia (AD).
"The study provides preliminary evidence that insulin detemir can provide effective treatment for people diagnosed with mild cognitive impairment and Alzheimer's-related dementia," said lead author of the study Suzanne Craft, professor of gerontology and geriatric medicine at Wake Forest Baptist Medical Center in the US.
Previous trials had shown promising effects of nasally-administered insulin for adults with AD and MCI, but this study was the first to use insulin detemir, the researchers noted.
The study participants who received nasally-administered 40 international unit (IU) doses of insulin detemir for 21 days showed significant improvement in their short-term ability to retain and process verbal and visual information compared with those who received 20 IU does or a placebo.
Additionally, the recipients of 40 IU doses carrying the APOE-e4 gene - which is known to increase the risk for Alzheimer's - recorded significantly higher memory scores than those who received the loser dosage or placebo.
The non-carriers of the gene across all three groups posted significantly lower scores.
"We are especially encouraged that we were able to improve memory for adults with MCI who have the APOE-e4 gene, as these patients are notoriously resistant to other therapies and interventions," Craft noted.
The study was published online in the Journal of Alzheimer's Disease.
