Magnetocardiographic characteristics in patients with varying severity of obstructive sleep apnea syndrome

Background Obstructive sleep apnea syndrome (OSAS) is an established risk factor for cardiovascular disease. Magnetocardiography (MCG) is an emerging non-invasive electrophysiological technique with potential value in cardiovascular assessment; however, its utility in evaluating OSAS severity remains unclear. This study aimed to characterize MCG features across different severities of OSAS and to evaluate their predictive performance for moderate-to-severe disease. Methods This retrospective study enrolled OSAS patients between June 2023 and October 2024, all of whom underwent MCG examination. Patients were stratified by OSAS severity, and MCG parameters were compared between the normal-to-mild and moderate-to-severe groups. Baseline data, complete blood count, serum biochemical indicators, and MCG parameters were collected along with relevant clinical and laboratory data. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of moderate-to-severe OSAS, and receiver operating characteristic (ROC) curves were constructed to evaluate the predictive performance of each parameter and the combined model. Results Group comparisons revealed significant differences in traditional OSAS severity risk factors (sex, body mass index, etc.). Diastolic function indicators, including E/A ratio and left atrial size, also showed marked differences between groups, with the moderate-to-severe subgroup exhibiting larger left atria and a higher proportion of E/A ratio values below 1. Univariate analysis identified 35 MCG parameters that differed between groups, while multivariate regression retained four independent predictors (htrt, tmdf, RS-didma, and qr_rela_dist_neg_mode). ROC analysis indicated that T-wave- and QRS-wave-related indices had moderate predictive value; a combined model incorporating htrt, tmdf, and RS-didma showed superior area under the curve compared to any single parameter. Conclusion MCG parameters demonstrate distinct characteristics across OSAS severity levels and yield favorable predictive performance for moderate-to-severe OSAS, positioning MCG as a promising non-invasive tool for early diagnosis. The observed changes in diastolic function markers may suggest underlying coronary microcirculatory alterations in patients with moderate-to-severe OSAS. Rigorously designed prospective studies are warranted to validate MCG as a standardized diagnostic modality for OSAS-related coronary microcirculation disorder.