Association between METS-IR index and obstructive sleep apnea: evidence from NHANES

Insulin resistance (IR) is strongly associated with obstructive sleep apnea (OSA). Whereas, few studies have focused on the potential association between the Metabolic Score for Insulin Resistance (METS-IR), a novel non-insulin-dependent IR index, and OSA. Subjects from the National Health and Nutrition Examination Survey (NHANES) spanning 2005-2008 and 2015-2018 were recruited. The potential relationship between METS-IR and other IR indices with OSA was explored through three logistic regression analysis models and restricted cubic spline (RCS) curves. Receiver operating characteristic (ROC) curves were used to assess the diagnostic value of these indicators for OSA. On the basis of age, sex, race, body mass index (BMI), hypertension, diabetes， and cardiovascular disease (CVD), subgroup analyses were conducted to test the robustness of the METS-IR and OSA relationship. A total of 8,306 participants were enrolled, with an OSA prevalence of 30.69%. After adjusting for potential confounders, METS-IR, the triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio, the triglyceride glucose Index (TyG), and the homeostatic model assessment of insulin resistance (HOMA-IR) showed positive associations with OSA prevalence. In the highest tertile of METS-IR, TG/HDL-C, TyG index, and HOMA-IR, OSA prevalence was 2.96-fold, 1.42-fold, 1.29-fold, and 1.41-fold higher, respectively, compared to the lowest tertile (METS-IR: OR = 2.96, 95% CI: 2.50, 3.52, P < 0.0001; TG/HDL-C: OR = 1.42, 95% CI: 1.17, 1.73, P < 0.001; TyG index: OR = 1.29, 95% CI: 1.07, 1.55, P = 0.008; HOMA-IR: OR = 1.41, 95% CI: 1.18, 1.69, P < 0.001). ROC analysis revealed that METS-IR had the highest diagnostic accuracy for OSA (AUC = 0.652). The positive associations between these four IR indices and OSA remain stable across most cases (P for interaction > 0.05); however, all of them show significant interactions with diabetes (P for interaction < 0.05). The METS-IR index is positively associated with the prevalence of OSA and shows superior diagnostic accuracy compared to HOMA-IR, TG/HDL-C, and TyG index.