Subclinical myocardial injury in patients with insomnia symptoms and obstructive sleep apnea: A cross-sectional study

INTRODUCTION: Obstructive sleep apnea (OSA) is associated with cardiovascular disease (CVD). Emerging evidence suggests that OSA can lead to subclinical myocardial injury even in the absence of established CVD. We aimed to evaluate the burden of subclinical myocardial injury in patients with OSA and insomnia symptoms compared to patients with OSA only. METHODS: Consecutive newly diagnosed patients with OSA and without pre-existing CVD were included in the study. All patients underwent polysomnography and completed the Athens Insomnia Scale (AIS). High- sensitivity troponin T (hs-cTnT) in the serum was measured in all participants for the evaluation of subclinical myocardial injury. RESULTS: A total of 110 patients diagnosed with OSA (aged 54.9 ± 11.4 years) were divided into two groups according to the AIS score. Group A included 50 patients without insomnia symptoms (AIS score<6) and group B included 60 patients with insomnia symptoms (AIS score≥6). The two groups had similar OSA severity (apnea hypopnea index: 40.5 ± 24.2 for group A vs 38.9 ± 24.4 for group B; p = 0.721). Serum hs-cTnT levels were significantly elevated in group B compared to group A (11.1 ± 4.7 vs. 8.2 ± 4.7 pg/mL, respectively; p = 0.001). In linear regression analysis, serum hs-cTnT levels were associated with AIS score (β = 0.456, p = 0.001) and average nocturnal oxygen saturation (β = -0.807, p = 0.006). CONCLUSIONS: The present study revealed that patients with OSA and insomnia symptoms have a greater burden of subclinical myocardial injury compared to patients with OSA only.