Untreated Sleep Apnea Linked to Doubled Parkinson's Risk

Untreated obstructive sleep apnea roughly doubles the risk of developing Parkinson's disease, according to a large observational study released in November 2025 ^[1].

This finding identifies a modifiable risk factor for a condition that has historically been viewed as largely inevitable for those genetically predisposed. By linking a treatable sleep disorder to neurodegeneration, the research suggests that early intervention could potentially prevent or delay the onset of Parkinson's symptoms.

Researchers led by Neilson et al., including investigators from the U.S. Department of Veterans Affairs, analyzed a national veteran health-care database ^[1]. The study population comprised approximately 11 million individuals ^[2]. The data indicated that the odds of developing Parkinson's disease were nearly doubled in patients with untreated sleep apnea ^[2].

Conversely, the study found that individuals using continuous positive airway pressure (CPAP) therapy had significantly lower odds of developing the condition ^[3]. This suggests that maintaining open airways during sleep may protect the brain from the damage associated with apnea.

Scientists hypothesize that the risk is driven by repeated nocturnal oxygen desaturation ^[1]. This process may cause neuro-inflammation and oxidative stress, which are believed to accelerate Parkinsonian neurodegeneration ^[1].

"The findings suggest that obstructive sleep apnea is a modifiable risk factor for Parkinson’s disease," Caroline Hopkins Legaspi said ^[4].

The scale of the veteran database provided a robust sample size for the researchers to observe these trends across a diverse population. While the study is observational, the stark difference between the untreated group and CPAP users highlights the potential impact of medical adherence to sleep therapy.