Obstructive sleep apnea, insulin resistance and long-term cardiovascular outcomes in acute coronary syndrome

Background Insulin resistance (IR) is a critical modifiable risk factor in acute coronary syndrome (ACS). Obstructive sleep apnea (OSA), prevalent in ACS, is associated with adverse outcomes and may also affect IR. We elucidated the relationship between IR and long-term cardiovascular outcomes in ACS patients with or without OSA. Methods This study enrolled ACS patients who underwent portable sleep monitoring from June 2015 to January 2020. OSA was defined as an apnea hypopnea index ≥15 events/hour. IR status was assessed using the Triglyceride glucose index (TyG), the Triglyceride glucose-waist circumference (TyGWC), and triglyceride glucose-waist to height ratio (TyGWHtR). The relationships between IR and major adverse cardiovascular and cerebrovascular events were analyzed. Results A total of 1662 patients in the analysis, 873 patients (52.5%) were diagnosed with OSA. At a median follow-up of 3.6 years, OSA was independently associated with increased MACCE risk in patients with TyG>8.94 (adjusted HR=1.351, 95%CI=1.035-1.763, P=0.027), TyG-WC>892.31 (adjusted HR=1.344, 95%CI=1.023-1.766, P=0.034), and TyG-WHtR>5.26 (adjusted HR=1.330, 95%CI=1.016-1.739, P=0.038), but not in those with TyG level ≤median (HR 1.139, 95% CI 0.889-1.460, P= 0.303), TyG-WC level ≤median (HR 1.137, 95% CI 0.885-1.460, P= 0.316) and TyG-WHtR level ≤median (HR 1.112, 95% CI 0.859-1.440, P= 0.419). Baseline data showed that higher TyG derivatives were associated with more metabolic abnormalities and severe OSA-related characteristics. There were consistently increases of HRs for MACCE in the OSA group with insulin resistance indicators risin. Conclusions TyG and its derivatives (TyG-WC, TyG-WHtR) modify the association between OSA and long-term cardiovascular outcomes in ACS patients. These IR surrogate markers can effectively identify high-risk subgroups of OSA patients who may benefit from targeted interventions.