Insomnia symptoms and subclinical myocardial injury: Data from the Nord-Trøndelag Health (HUNT) study

Incidence of adverse cardiovascular events in patients with insomnia: A systematic review and meta-analysis of real-world data

Insomnia is a prevalent sleeping disorder associated with increasing cardiovascular (CV) mortality and morbidity. However, data incorporating recent clinical studies evaluating these outcomes is scarce. Hence, we aimed to investigate the association of insomnia with CV mortality, myocardial infarction (MI), all-cause mortality, and incidence of CV disease by conducting the first-ever meta-analysis of real-world data evaluating these CV outcomes. MEDLINE and Scopus databases were queried till August 2022 to identify studies comparing prespecified outcomes in patients with and without insomnia. The primary outcomes were CV mortality and myocardial infarction, while secondary outcomes included all-cause mortality, and CV-disease incidence. All data were pooled using an inverse-variance weighted random-effects model, and results were reported as relative risks (RRs) and p-values. 21 studies were analyzed. Risks for CV mortality and MI were significantly higher in patients with insomnia (RR 1.53, p<0.01, and RR 1.48, p = 0.03, respectively). The risk for all-cause mortality and CV disease incidence was also significantly higher in insomnia patients (RR 1.14, p = 0.03, and RR 1.31, p<0.01, respectively). Individuals with insomnia experience a higher risk of long-term mortality, MI, and incidence of CV disease.

Novel oxygen desaturation parameters are associated with cardiac troponin I: Data from the Akershus Sleep Apnea Project

Novel diagnostic markers for obstructive sleep apnea beyond the apnea-hypopnea index (AHI) have been introduced. There are no studies on their association with markers of subclinical myocardial injury. We assessed the association between novel desaturation parameters and elevated cardiac troponin I and T. Participants with polysomnography (498) from the Akershus Sleep Apnea study were divided into normal and elevated biomarker groups based on sex-specific concentration thresholds (cardiac troponin I: ≥4 ng/L for women, ≥6 ng/L for men; and cardiac troponin T: ≥7 ng/L for women, ≥8 ng/L for men). Severity of obstructive sleep apnea was evaluated with the AHI, oxygen desaturation index, total sleep time with oxygen saturation below 90% (T90), lowest oxygen saturation (Min SpO₂ %), and novel oxygen desaturation parameters: desaturation duration and desaturation severity. How the AHI and novel desaturation parameters predicted elevated cardiac troponin I and cardiac troponin T levels was assessed by the area under the curve (AUC). Based on multivariable-adjusted linear regression, the AHI (β = 0.004, p = 0.012), desaturation duration (β = 0.007, p = 0.004), and desaturation severity (β = 0.147, p = 0.002) were associated with cardiac troponin I levels but not cardiac troponin T. T90 was associated with cardiac troponin I (β = 0.006, p = 0.009) and cardiac troponin T (β = 0.005, p = 0.007). The AUC for the AHI 0.592 (standard error 0.043) was not significantly different from the AUC of T90 (SD 0.640, p = 0.08), desaturation duration 0.609 (SD 0.044, p = 0.42) or desaturation severity 0.616 (SD 0.043, p = 0.26) in predicting myocardial injury as assessed by cardiac troponin I. Oxygen desaturation parameters and the AHI were associated with cardiac troponin I levels but not cardiac troponin T levels. Novel oxygen desaturation parameters did not improve the prediction of subclinical myocardial injury compared to the AHI.