Andrew Varga, MD: How Sleep Apnea Affects Elderly Spatial Orientation

A new study from investigators at the Icahn School of Medicine at Mount Sinai showed that mild obstructive sleep apnea (OSA) in cognitively normal older adults is associated with significantly atypical morning spatial navigation performance—an early symptom of Alzheimer disease (AD).

Previous trials have already evidenced an association between OSA and possible AD progression.

In an interview with MD Magazine® following the presentation of data at the American Thoracic Society (ATS) 2019 International Meeting in Dallas, TX, this week, lead study author Andrew Varga, MD, assistant professor of Medicine, Critical Care, and Sleep Medicine at Icahn, explained the most cognitively-affected OSA patient population, and expanded on the association between sleep apnea and psychiatric conditions.

What was the OSA patient population whose morning spatial navigation were affected?

Varga: This was a group of older people, average age was around 68 years old. One of the really interesting things is that these were people that were recruited from the community and didn't intrinsically have any sleep complaints. So they were not necessarily complaining that they had snoring or any other breathing issues with sleep apnea. They were not complaining of any cognitive complaints, were not complaining of any sleepiness.

We showed that, when we recruited this population, that sleep apnea is enormously prevalent. And prior studies have shown that sleep apnea in an elderly population its president around the rate of 50%. So it's extraordinarily prevalent and we were seeing essentially the same thing—about 50% of our population had sleep apnea. And what was really interesting was that, even though these people are not complaining about anything per se—not complaining of snoring, not complaining of other cognitive issues—we saw that we’ve identified a population that had apnea. And when we kind of pushed the system and really tested them on this ability to remember space and spatial navigation, there was a deficit—even though they didn't have any other issues.

Could sleep apnea patients be suffering any adverse psychiatric effects due to their therapy?

I think that's the next obvious question is, ‘Is this kind of deficit something that's fixable? Is it reversible? If you treat people, does it get better?’

We'd like to think that that's likely to be the case, but I think that remains to be seen, and therapy runs the gamut from CPAP to oral appliances to positional therapy—upper airway stimulation. I think, by and large, they all work well in people and they're effective, and we can show that with treated people's number of events per hour go down to close to 0 and. We really need to figure out whether or not that ends up impacting these cognitive outcomes.

The study, "Effects of Obstructive Sleep Apnea on Human Spatial Navigational Memory Processing in Cognitively Normal Older Individuals," was presented at ATS 2019.