Structural MRI identifies insomnia as a risk factor for Alzheimer’s

Going by structural MRI of the brain, older people under 80 who have normal cognitive function but poor sleep quality are at heightened risk of developing Alzheimer’s disease or amnestic mild cognitive impairment (aMCI).  

That’s according to researchers at the University of Miami in Florida who had their findings published online Dec. 12 in Sleep.

Radiology professor Noam Alperin, PhD, and colleagues first evaluated 74 volunteers ranging in age from around 64 to around 78. All the participants were cleared as cognitively normal in neuropsychological tests and clinical assessments.

The researchers then screened the group for sleep quality using two widely used indexes and excused five participants who presented with mild geriatric depression.

Of the remaining 69 subjects, 38 individuals (mean age, 70.7±7) were classified as poor sleepers and 31 (mean age, 69.6±6) as normal sleepers.

Next, using structural MRI and an open-source analysis tool for parceling the brain on MR images, Alperin and team measured regions known to be affected by aMCI in individuals diagnosed with it.  

They found that, compared with the normal sleepers, the poor sleepers had significantly less brain-matter volume and thickness across numerous regions than the normal sleepers.

Further, the fewer hours of sleep the poor sleepers got, the stronger the correlation with reduced volumes and thicknesses.

“Atrophy related to poor sleep quality impacted a number of regions implicated in aMCI and Alzheimer’s disease,” the authors concluded. “As such, interventions targeted towards improving sleep quality amongst the elderly may prove an effective tool for modulating the course of aMCI and Alzheimer’s disease.”