Summary: A large analysis of more than 11 million medical records shows that people with untreated obstructive sleep apnea (OSA) face a substantially higher long-term risk of developing Parkinson’s disease. After adjusting for factors such as age, obesity and cardiovascular conditions, veterans who did not use continuous positive airway pressure (CPAP) were nearly twice as likely to be diagnosed with Parkinson’s compared with those who treated their apnea.
The findings point to repeated nighttime oxygen drops as a plausible mechanism that increases the brain’s vulnerability over time. Researchers say the results emphasize the importance of improving sleep quality and encouraging adherence to CPAP as possible measures to reduce neurodegenerative risk.
Key Facts:
- Higher Risk: Untreated obstructive sleep apnea was associated with a markedly increased risk of developing Parkinson’s disease in long-term follow-up.
- Protective CPAP: Consistent CPAP therapy was linked to a significantly lower likelihood of a later Parkinson’s diagnosis.
- Oxygen Stress: Chronic intermittent oxygen deprivation during sleep may make neurons more susceptible to degeneration over years.
Source: Oregon Health and Science University
Overview
New research published in JAMA Neurology analyzed electronic health records from more than 11 million U.S. veterans who received care through the Department of Veterans Affairs between 1999 and 2022. Led by investigators at Oregon Health & Science University (OHSU) and the Portland VA Health Care System, the study explored whether obstructive sleep apnea (OSA) is associated with an increased risk of developing Parkinson’s disease (PD) and whether CPAP treatment modifies that risk.
Parkinson’s disease is a progressive neurodegenerative disorder that affects movement and can involve cognitive and autonomic symptoms. The prevalence of PD increases with age, affecting an estimated 1 million Americans. This large EHR-based cohort provides one of the most extensive assessments to date of the relationship between OSA, CPAP use, and subsequent PD incidence.
After excluding veterans who already had Parkinson’s at the time of exposure or who had incomplete records, the researchers included 11,310,411 veterans (mean age 60.5 years). Among them, 1,552,505 (13.7%) had a diagnosis code for obstructive sleep apnea. The analysis adjusted for competing risk of death and balanced for age, race, sex and smoking status. Additional models also accounted for body mass index, vascular comorbidities, psychiatric diagnoses, and medications.
Results showed that veterans with OSA had a higher cumulative incidence of Parkinson’s over time. At six years from OSA diagnosis, there were approximately 1.61 additional cases of Parkinson’s per 1,000 people compared with veterans without OSA (point estimate; 95% CI, 1.13–2.09). The association remained after multiple adjustments and appeared stronger in female veterans. Importantly, veterans who used CPAP early and consistently had a substantially reduced number of subsequent PD cases.
Clinical implications
OSA causes repeated interruptions in breathing during sleep, producing intermittent hypoxia (low oxygen levels) and sleep fragmentation. Lead author Lee Neilson, M.D., notes that when oxygen delivery falls repeatedly, neuronal function can be impaired night after night. Over years, that chronic stress may increase neuronal vulnerability and the risk of neurodegeneration. Early and consistent CPAP use helps restore airflow and oxygenation, which researchers propose could build resilience against progressive brain disorders such as Parkinson’s.
Co-author Gregory Scott, M.D., Ph.D., emphasized that an elevated risk does not mean a diagnosis is inevitable, but that addressing sleep-disordered breathing may be a meaningful, modifiable factor. Clinicians and health systems may consider stronger screening for OSA and strategies to improve CPAP adherence as part of brain-health prevention efforts.
Study team
The study was conducted by researchers from OHSU and the Portland VA Health Care System and included co-authors Isabella Montano, B.A.; Jasmin May, M.D., Ph.D.; Jonathan Elliott, Ph.D.; Miranda Lim, M.D., Ph.D.; Yeilim Cho, M.D.; and Jeffrey Iliff, Ph.D., among others.
Funding and disclosures
This research received support from the U.S. Department of Veterans Affairs (grants BX005760, CX00253, I01RX004822, I01RX005371, CX002022, BX006155 and Bx006155), the John and Tami Marick Family Foundation, the Collins Medical Trust, the National Institute on Aging (award P30AG066518), and the U.S. Army Medical Research Acquisition Activity (award numbers HT9425-24-1-0774 and HT9425-24-1-0775). Opinions, interpretations and conclusions expressed by the authors are their own and do not necessarily reflect the views of funding agencies or government organizations.
Key Questions Answered
Q: Does untreated sleep apnea increase the risk of Parkinson’s disease?
A: Yes. In this large veterans cohort, untreated OSA was associated with a significantly higher long-term risk of PD.
Q: Can CPAP therapy lower this Parkinson’s risk?
A: The data indicate that consistent CPAP use was associated with a reduced incidence of PD compared with untreated OSA.
Q: Why might sleep apnea contribute to neurodegeneration?
A: Recurrent oxygen desaturation and sleep fragmentation can stress neurons over years, potentially increasing vulnerability to degenerative processes.
Editorial Notes
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full by editorial staff.
- Additional context was provided by the newsroom team to aid reader understanding.
About this research
Author: Erik Robinson
Source: Oregon Health and Science University
Contact: Erik Robinson, Oregon Health and Science University
Image credit: Neuroscience News
Original Research: “Obstructive Sleep Apnea, Positive Airway Pressure, and Implications of Early Treatment in Parkinson Disease” by Gregory Scott et al., published in JAMA Neurology. (Closed access)
Abstract (condensed)
Importance: Obstructive sleep apnea is linked to several adverse health outcomes, including cognitive decline and earlier mortality. Previous epidemiological findings on the relationship between OSA and Parkinson’s disease have been inconsistent, and the potential protective role of CPAP has not been well studied.
Objective: To assess the association between OSA and incident Parkinson’s disease among U.S. veterans and to evaluate whether CPAP use modifies PD risk.
Design, setting, and participants: An electronic health record–based cohort study including veterans seen in the VA system between January 1, 1999, and December 30, 2022, with mean follow-up of approximately 4.9 years. Veterans with preexisting PD or incomplete records were excluded.
Exposure: OSA identified via administrative diagnosis codes; CPAP usage determined from clinical documentation fields.
Main outcomes and measures: Cumulative incidence of Parkinson’s disease, calculated with adjustment for competing risk of death and balanced for demographic and behavioral covariates.
Results: Of 11,310,411 veterans included, 1,552,505 had OSA. Veterans with OSA showed an increased cumulative incidence of PD over time, with an additional 1.61 cases per 1,000 people at six years compared with veterans without OSA. Adjusted analyses confirmed the association and indicated a reduced case count among those treated with CPAP early in the disease course.
Conclusions and relevance: In this large EHR-based cohort, obstructive sleep apnea was associated with an elevated risk of later Parkinson’s disease, and early CPAP treatment appeared to modify that risk. Improved screening for OSA and interventions to support CPAP adherence could have meaningful benefits for long-term brain health.