Abstract
While polysomnography (PSG) is the gold standard for diagnosing obstructive sleep apnea (OSA), its limited availability means that many patients remain undiagnosed. This study seeks to evaluate whether CHI3L1-Ab could serve as a diagnostic biomarker for OSA. A total of 366 individuals, including 333 OSA patients and 33 healthy controls, were recruited for this study, all of whom underwent polysomnography. Enzyme-linked immunosorbent assay (ELISA) was used to measure CHI3L1-Ab levels, and clinical factors were analyzed to assess their relationship with CHI3L1-Ab expression. OSA patients exhibited significantly higher CHI3L1-Ab levels compared to healthy controls (P < 0.05), with an area under the curve (AUC) of 0.721. Subgroup analysis revealed the highest AUC of 0.735 (95% CI 0.637-0.832) in patients with severe OSA. Logistic regression analysis, which incorporated age, BMI and CHI3L1-Ab levels, demonstrated strong predictive performance with an AUC of 0.846 (95% CI 0.815-0.942). The corresponding nomogram allowed individualized risk estimation based on these predictors. The combination of CHI3L1-Ab levels, age and BMI demonstrated strong predictive accuracy in distinguishing OSA from healthy individuals. These findings also suggest that elevated CHI3L1-Ab levels could serve as an independent diagnostic biomarker for OSA.