Clinical factors associated with arrhythmia in obstructive sleep apnea-hypopnea syndrome: a retrospective cross-sectional study

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is frequently associated with cardiac arrhythmias; however, the clinical factors associated with concurrent arrhythmia in this population remain incompletely characterized. This study investigated factors associated with arrhythmia in patients with OSAHS, with particular focus on the monocyte-to-high-density lipoprotein cholesterol ratio (MHR). In this retrospective cross-sectional study, 451 patients with polysomnography (PSG)-confirmed OSAHS were enrolled and classified into arrhythmia and non-arrhythmia groups according to 24-hour Holter monitoring. Demographic characteristics, laboratory variables, PSG parameters, and echocardiographic indices were collected. Comparative analyses, correlation analyses, multivariable logistic regression, and receiver operating characteristic (ROC) curve analyses were performed. Arrhythmias, mainly premature atrial or ventricular contractions, were detected in 256 of 451 patients (56.8%, 256/451), and their prevalence differed significantly across OSAHS severity categories ( P = 0.014). Compared with patients without arrhythmia, patients with arrhythmia had higher MHR and neutrophil-to-lymphocyte ratio (NLR) values and lower high-density lipoprotein cholesterol (HDL-C) levels. Multivariable analysis showed that MHR, apnea-hypopnea index (AHI), and HDL-C were independently associated with concurrent arrhythmia. Among the individual variables evaluated, MHR showed weak standalone discriminatory performance, with an area under the curve (AUC) of 0.656. MHR is a blood-derived inflammatory and lipid-related index associated with concurrent arrhythmia in patients with OSAHS. Its standalone discriminatory performance was weak; therefore, MHR should be interpreted only as an adjunctive marker for cross-sectional characterization rather than as an independent screening tool.