SLEEP 2026 | Current state of evidence on the association between obstructive sleep apnea and dementia

I think the way I look at it, you know, is like if we want to, if we start this normally, you know, the cross-sectional analysis shows evidence that there is an association, you know? But the challenges with cross-sectional analysis is the issue of temporality. If A will cause B, then A has to come before B, and then now we have longitudinal studies that actually show that obstructive sleep apnea onset can precede the onset of incident dementia, so there’s evidence that shows that. So that’s good. The issue of temporality is there. You look at the strength of association. So if something is, if there’s any relationship with, in terms of causality, then you expect that maybe the strength of association should be great, right? I think at best we see a mild to moderate effect size. Obstructive sleep apnea is a chronic medical condition. It’s heterogeneous, has lots of risk factors, and affects multiple organ systems, mental health, brain health, cardiovascular health. So we might not have that clear-cut causal stuff that we see with infectious disease, for example. Like, okay, this virus causes this. But there’s evidence with respect to at least mild to moderate effect size. When you look at pathology, so one of my thought processes is if, you know, there’s a risk factor, is it related to the pathophysiological processes that would cause a particular disease? And we have evidence to show that as well, that obstructive sleep apnea is related or associated with changes and is a longitudinal study of changes in Alzheimer’s disease biomarkers, including beta-amyloid pathology, including tau pathology that correlates more with symptomatology, you know? So we see that. The other thing is, does OSA modify, you know, the progression risk? We see evidence to that effect. So the presence and or absence of obstructive sleep apnea in people that are at risk, you know, varies depending on the presence of obstructive sleep apnea. So for example, obstructive sleep apnea, or generally sleep problems, they coexist a lot with cardiovascular comorbidities. So we’ve looked at obstructive sleep apnea co-occurring with hypertension. Hypertension is an established risk factor for dementia outcomes. And we’ve looked at the trajectory for a hypertensive individual without obstructive sleep apnea and a co-occurring hypertensive and OSA patient, right? And when you look at the trajectory, the individual that has the comorbidities has a steeper slope in terms of progression, in terms of the cognitive decline. We’ve also seen that even the established risk factor, APOE, when you look at amyloid pathology, we’ve looked at individuals that are said to be amyloid positive, meaning the amyloid levels pass a certain threshold. And then we’ve looked at people who have obstructive sleep apnea and have some level of amyloidopathy, so they have that amyloid positive, we’ve looked at people who are over obstructive sleep apnea only and then amyloid pathology only, and when you look at it, you see a synergistic effect between obstructive sleep apnea and amyloid pathology, so people who have some level of A-beta above that threshold that we’re looking at, and they have obstructive sleep apnea, their time to progression from normal to MCI or MCI to AD is shorter, you know, so there’s evidence that clear evidence that obstructive sleep apnea, you know, can modify the risk and trajectory for, you know, dementia outcomes. So, I mean, so generally, I think that what what is lacking, right, is the trials to treat obstructive sleep apnea and see how it can impact all of these outcomes I’ve talked about. Clinical outcomes, symptomatology in terms of cognitive trajectory, or altering biomarker progression, you know? So that’s what’s missing. There are anecdotal evidence showing that if you treat obstructive sleep apnea in AD or in certain dementia cases, you do have improvement in cognition. But these are anecdotal. So that’s where the challenge is. So that’s the state of the evidence so far.

This transcript is AI-generated. While we strive for accuracy, please verify this copy with the video.