A recent study has established a significant link between untreated sleep apnea and an increased risk of developing Parkinson’s disease. Researchers from the Oregon Health & Science University and the Portland VA Health Care System discovered that individuals who do not treat their obstructive sleep apnea face nearly double the likelihood of being diagnosed with Parkinson’s compared to those who utilize continuous positive airway pressure (CPAP) therapy.
Published on November 24, 2025, in the journal JAMA Neurology, the study analyzed electronic health records from over 11 million U.S. military veterans who received care through the Department of Veterans Affairs between 1999 and 2022. The findings suggest that untreated sleep apnea, which causes repeated interruptions in breathing and results in lower oxygen levels during sleep, may strain neurons over time, contributing to neurodegenerative conditions.
The study highlights the importance of sleep health, particularly as it relates to aging. Parkinson’s disease, a progressive neurological disorder, currently affects an estimated 1 million individuals in the United States, with the risk increasing steadily each year after the age of 60.
Researchers found a strong association between untreated sleep apnea and Parkinson’s, even after adjusting for key factors such as obesity, age, and high blood pressure. Among the veterans diagnosed with sleep apnea, those who did not use CPAP therapy were nearly twice as likely to receive a Parkinson’s diagnosis compared to those who adhered to treatment.
“It’s not at all a guarantee that you’re going to get Parkinson’s, but it significantly increases the chances,” noted Gregory Scott, M.D., Ph.D., assistant professor of pathology at the OHSU School of Medicine and a pathologist at the VA Portland.
Sleep apnea disrupts normal breathing patterns, preventing individuals from receiving adequate oxygen during sleep. “If you stop breathing and oxygen is not at a normal level, your neurons are probably not functioning at a normal level either,” explained Lee Neilson, M.D., assistant professor of neurology at OHSU and a staff neurologist at the Portland VA. “Add that up night after night, year after year, and it may explain why fixing the problem by using CPAP may build in some resilience against neurodegenerative conditions, including Parkinson’s.”
These findings could have significant implications for clinical practice. Neilson emphasized the need to prioritize sleep health for patients, especially given the elevated risk of Parkinson’s disease associated with untreated sleep apnea. “I think it will change my practice,” he stated.
Many veterans have reported positive experiences with CPAP therapy, which could encourage others to adopt the treatment. “The veterans who use their CPAP love it,” Scott remarked, adding that those who regularly use the device often feel better and less fatigued. He hopes that awareness of the potential reduction in Parkinson’s risk will motivate more individuals with sleep apnea to consider CPAP therapy.
The study involved multiple contributors, including co-authors Isabella Montano, Jasmin May, M.D., Ph.D., Jonathan Elliott, Ph.D., and Miranda Lim, M.D., Ph.D., all affiliated with OHSU and the Portland VA Health Care System, alongside Yeilim Cho, M.D., and Jeffrey Iliff, Ph.D., from the University of Washington and the VA Puget Sound Health Care System.
Funding for this research came from various sources, including the VA, the John and Tami Marick Family Foundation, the Collins Medical Trust, the National Institute on Aging of the National Institutes of Health, and the U.S. Army Medical Research Acquisition Activity. The authors clarified that their opinions and conclusions do not necessarily reflect those of the Department of Defense, the NIH, the VA, or other funding bodies.
As sleep health gains recognition for its impact on neurological conditions, this study may prompt further investigation into effective interventions for sleep apnea and its potential role in preventing diseases such as Parkinson’s.
