The Mediating Effect of Metabolic Score for Insulin Resistance on the Link Between Cardiometabolic Index and Obstructive Sleep Apnea

Background Although there is considerable evidence that obstructive sleep apnea (OSA) is associated with cardiovascular and metabolic risks, such as insulin resistance and visceral fat accumulation, limited studies have explored how these risks are mediated by specific metabolic markers. The purpose of this study was to explore the relationship between Cardiometabolic Index (CMI) and OSA, and to pay special attention to the mediating role of insulin resistance metabolic score (METS-IR). Methods Data from 12,703 participants aged 20 and above were analyzed from the National Health and Nutrition Examination Survey (NHANES). CMI was the primary exposure variable, METS-IR served as the mediating variable, and OSA was the outcome. Multivariate logistic regression models were used to adjust for confounders and assess the relationship between CMI and OSA. Mediation analysis determined the proportion of CMI’s effect on OSA explained by METS-IR. Results Among 12,703 subjects, the prevalence of OSA was 30.88%. CMI was significantly associated with increased OSA risk, and participants with the highest quartile of CMI were significantly more likely to have OSA (OR = 2.06, 95% CI : 1.70–2.49). Mediation analysis showed that METS-IR accounted for 89.8% of the association between CMI and OSA, highlighting the key role of insulin resistance in this pathway. Conclusions CMI is a key predictor of OSA risk, which is mainly mediated by its effect on insulin resistance, as shown by METS-IR. These findings highlight the importance of addressing metabolic dysfunction in the prevention and management of OSA, and CMI and METS-IR provide valuable insights into clinical risk assessment in high-risk populations.