Association between ambient air pollution and obstructive sleep apnea risk: A population-based cross-sectional study

Obstructive sleep apnea (OSA) is a common sleep disorder associated with poor cardiometabolic and neurocognitive outcomes; however, the role of ambient air pollution in OSA remains unclear. We investigated the association between ambient air pollution exposure and OSA risk in Korean adults using individual-level exposure estimates.

We analyzed data from 4235 adults aged ≥40 years in the 2019 Korea National Health and Nutrition Examination Survey. The OSA risk was assessed using the STOP-Bang questionnaire. Individual exposure to air pollutants-particulate matter (PM) ≤2.5 µm (PM_2.5) and ≤10 µm (PM₁₀), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), carbon monoxide (CO), and ozone (O₃)-was estimated using geocoded residential data. Regression models and threshold-based analyses were used to assess associations across various exposure windows, adjusting for major sociodemographic, lifestyle, and clinical covariates.

An increase in the interquartile range of PM_2.5 (8.9 µg/m³) at a 30-day average was associated with a higher risk of OSA (adjusted odds ratio [OR]: 1.140, 95% confidence interval [CI]: 1.00-1.29). PM₁₀ exposure showed consistent associations with intermediate OSA risk (STOP-Bang 3-4), with the strongest effects observed at 90 days (OR: 1.340, 95% CI: 1.05-1.69). CO exposure above the 480 ppb threshold was associated with a higher risk of OSA at 90 days (OR: 1.337, 95% CI: 1.00-1.77) and 180 days (OR: 1.495, 95% CI: 1.12-2.00). NO₂, SO₂, and O₃ showed no associations with OSA risk after adjustment.

Mid-term (1-6 months) exposure to PM and CO was associated with a modestly increased screening-defined OSA risk.