Abstract
Background and Objectives: Obstructive sleep apnea (OSA) is a clinically relevant comorbidity in both alcoholic fatty liver disease (AFLD) and non-alcoholic fatty liver disease (NAFLD). However, whether its impact differs between these etiologies remains unclear. This study directly compared OSA risk in patients with AFLD and NAFLD to elucidate its role in disease progression. Materials and Methods: We conducted a retrospective cohort study using the TriNetX research network. Adults aged ≥ 20 years with newly diagnosed AFLD or NAFLD between 2006 and 2020 were included. Propensity score matching was applied to balance demographic and clinical covariates. The primary endpoint was incident OSA, assessed at 1-, 2-, 3-, and 5-year intervals, and cumulatively through 28 September 2025. Effect estimates were expressed as relative risk, odds ratio and hazard ratio (HR). Results: Before matching, 896,302 NAFLD and 12,694 AFLD patients were identified; after 1:1 PSM, 11,583 patients remained in each group with balanced baseline characteristics. NAFLD patients consistently demonstrated higher OSA risk. Post-matching, OSA incidence became significantly elevated from year 2 onward (HR at 2 years = 1.764) and persisted at 3 years (HR = 2.078), 5 years (HR = 1.950), and cumulative follow-up (HR = 1.940). Conclusions: NAFLD confers nearly double the long-term OSA risk compared with AFLD. These findings support longitudinal OSA screening and targeted risk reduction strategies in NAFLD populations.