Manufactured insulin delivered via a simple nasal spray could help improve mild cognitive impairment brought on by Alzheimer's disease.

Older adults with either amnesic mild cognitive impairment (MCI) or mild to moderate Alzheimer's dementia (AD) who were given the treatment for 21 days showed significant improvement in their short-term ability to retain and process verbal and visual information, Wake Forest Baptist Medical Center reported. The patients who received 40 international unit (IU) doses of the drug, dubbed insulin detemir, as opposed to 20 showed more significant improvements.

Additionally, patients who received 40 IU of the drug who had the Alzheimer's-linked gene APOE-e4 had significantly higher memory scores than those who received a lower dosage or a placebo.

"The study provides preliminary evidence that insulin detemir can provide effective treatment for people diagnosed with mild cognitive impairment and Alzheimer's-related dementia similar to our previous work with regular insulin," said Suzanne Craft, professor of gerontology and geriatric medicine at Wake Forest Baptist and lead author of the study, which is published online in advance of the February issue of the Journal of Alzheimer's Disease. "We are also 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."

The researchers found only minor adverse reactions to the insulin treatment, indicating further research should be conducted in order to test the potential of the drug. The researchers noted previous trials had shown promising results of nasally-administered insulin among patients with these conditions, but this was the first to look at longer-lasting insulin detemir.

"Alzheimer's is a devastating illness, for which even small therapeutic gains have the potential to improve quality of life and significantly reduce the overall burden for patients, families and society," Craft said. "Future studies are warranted to examine the safety and efficacy of this promising treatment."