Obstructive sleep apnea (OSA) is associated with a higher incidence of developing Parkinson’s disease (PD), but it may be a modifiable risk factor, according to research presented at the American Academy of Neurology (AAN) annual meeting.
Results of a large cohort study showed that individuals with OSA, who began CPAP within 2 years of their diagnosis, had a lower incidence of PD compared with those started later or not at all.
These findings have important implications for patients and clinicians, explained Isabella Montano, a clinical research assistant at the Portland VA Research Foundation, who presented the findings during the Contemporary Clinical Issues Plenary Session. “We can potentially intervene earlier and potentially see how that can alter the onset of Parkinson’s disease,” she said.
An estimated 6 million people are diagnosed with OSA in the US, and up to 30 million may be undiagnosed. In addition, about 20% of all military veterans have an OSA diagnosis, and the “gold standard” of treatment is with CPAP.
Previous studies have suggested a linkage between OSA and PD through increased hazard ratio, but the cohort was limited to Taiwanese and South Korean populations, Montano explained.
In the current study, Montano and colleagues evaluated the possibility of an increased risk of PD among veterans who have been diagnosed with OSA, and if CPAP use is able to mitigate it. They conducted an EHR-based retrospective study using a large national database that included over 20 million veterans. Within this population, their sample was comprised of 1.5 million with OSA and 9.6 million without OSA.
Those using CPAP were divided into two groups: those who initiated treatment within 2 years of an OSA diagnosis and those who began more than 2 years after diagnosis.
In their preliminary analysis, they found that there was an increased incidence of 1.8/1000 (p<0.001) of PD with a diagnosis of OSA.
When looking at the relationship of CPAP use to PD, they found that early use of CPAP decreased the incidence by 2.3/1000 (p<0.001).
While these data suggest that CPAP use can modify the risk of PD, Montano emphasized that much work still remains to be done. “It would be interesting to see how OSA severity could alter these results, and it would also be very interesting to see how adherence to CPAP could also alter these results,” she said.
Invited discussant Roneil Gopal Malkani, MD, an associate professor of neurology (sleep medicine) at Northwestern University, noted that prior research studies do show that an association between OSA and PD. “Several studies have looked at the prevalence and a recent meta-analysis found there was a 45% prevalence of OSA in PD,” he said.
Several papers have also looked at OSA as a risk factor for PD, and a meta analysis of 4 retrospective studies showed a correlation, with an adjusted hazard ratio of 1.59.
Data on the effect of OSA treatment on PD incidence is more limited. “A retrospective study on OSA surgery showed a lower risk of PD than with no OSA treatment,” he said. “That study, together with the data the researchers have shown us now, suggest that there may be a signal here, by which we can reduce risk of Parkinson’s disease with the treatment of sleep apnea.”
However, he emphasized that prospective studies and clinical trials are needed to further elucidate these findings, and to confirm if the risk of PD can be lowered.
PL4: Contemporary Clinical Issues Plenary Session
Obstructive Sleep Apnea is a Risk Factor for Parkinson’s Disease and CPAP Mitigates Risk of PD: An EHR-based Cohort Study in Military Veterans. Presented at: American Academy of Neurology Annual Meeting; April 5-9, 2025; San Diego.
Montano has no disclosures. Malkani has no relevant disclosures
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