A groundbreaking brain imaging study from Wake Forest University School of Medicine has validated an important step towards new Alzheimer's disease treatments. The research found that intranasal insulin, administered via a simple nasal spray, safely and effectively reaches critical memory regions in the brains of older adults. It also revealed that people with early cognitive decline absorb it differently.
Published in Alzheimer's & Dementia: Translational Research & Clinical Interventions, this study demonstrated through positron emission tomography (PET) imaging that intranasal insulin travels to 11 key brain regions linked to memory and cognition. Prior challenges in earlier trials were due to uncertainties about whether the treatment reached its intended targets.
Lead researcher Suzanne Craft, Ph.D., professor at Wake Forest University School of Medicine, highlighted: "This study addresses a crucial gap by showing that intranasal insulin can reach key brain targets." She noted that insulin resistance is a recognized risk factor for Alzheimer's disease. The study included 16 older adults with an average age of 72, among whom seven were cognitively normal and nine had mild cognitive impairment (MCI).
Using specialized radiotracers and a unique nasal spray system, participants underwent PET scans that revealed elevated insulin uptake in critical memory areas like the hippocampus, olfactory cortex, amygdala, and temporal lobe. The researchers observed different patterns of insulin absorption between cognitively normal individuals and those with MCI.
- Participants noted the nasal spray was "easy to use."
- Cognitively normal participants exhibited higher and distinct uptake patterns, while individuals with MCI showed rapid initial uptake followed by quicker clearance.
- In women, insulin uptake correlated strongly with cardiovascular health factors and decreased in regions where amyloid markers (indicative of Alzheimer's) were elevated.
- The procedure was well-tolerated, with only minor headaches reported by two participants, resolving within 24 hours.
"Confirming that intranasal delivery systems work effectively is a crucialstep before developing larger therapeutic trials," Craft said. This validation supports broader treatment approaches by addressing issues of drug efficacy and side effects in Alzheimer's therapy.
According to Craft, "Identifying effective ways to prevent and treat Alzheimer's dementia is urgent. These findings show we can now validate whether treatments reach their intended brain targets." The precision nasal delivery system used in the study was supplied by Aptar Pharma and could be adapted for other neurological therapies.
"The results validate our nasal delivery system, showing effective target delivery to specific brain regions," said Reenal Gandhi from Aptar Pharma. "This paves the way for improved therapeutic delivery to the central nervous system."
The Wake Forest team will now conduct larger studies within 12-18 months to explore vascular health, amyloid accumulation, and sex differences in brain insulin delivery.