Liver steatosis mediates the association between metabolic score for insulin resistance and obstructive sleep apnea.

Obstructive sleep apnea (OSA) is associated with metabolic disorders such as insulin resistance and liver fat accumulation. However, the specific mediating role of liver-related metabolic indicators in this association has not been fully studied. The purpose of this study was to investigate the relationship between Metabolic Score for Insulin Resistance (METS-IR) and OSA, focusing on the mediating effects of liver fat percentage (PLF) and hepatic steatosis index (HSI). Understanding these mechanisms may provide insights into targeted interventions for OSA. A total of 12,655 participants from the National Health and Nutrition Examination Survey (NHANES) were included in this analysis. Obstructive sleep apnea (OSA) was assessed using the NHANES questionnaire. Weighted multivariate logistic regression was employed to assess the relationship between METS-IR and OSA, with a mediation model constructed to explore the mediating roles of key liver and metabolic markers, including PLF, HSI, SII and OBS. Among 12,655 subjects, 31.04% had OSA. METS-IR was closely related to the increased risk of OSA, and the highest quartile group of METS-IR had a significantly increased risk of OSA (OR = 2.36, 95% CI 1.73-3.23). Mediating effect analysis showed that PLF and HSI mediated 6.95% and 17.87% of the effects, respectively, while systemic immunity-inflammation index (SII) and oxidative balance score (OBS) had no significant mediating effect. METS-IR is an important predictor of OSA risk, primarily mediated by hepatic lipid accumulation. Addressing insulin resistance and hepatic metabolic health is crucial for the effective management of OSA and provides valuable guidance for clinical risk assessment in susceptible populations.