Oxygen desaturation index and fibrinogen: An independent association in sleep-disordered breathing - A retrospective cross-sectional study

Obstructive sleep apnea (OSA) elevates cardiovascular risk partly through coagulation dysregulation, in which fibrinogen (FIB) plays a central role. However, the independent association between oxygen desaturation index (ODI), rather than apnea-hypopnea index (AHI), and FIB requires robust validation amid challenges of confounding. To determine whether ODI is an independent and robust predictor of plasma fibrinogen levels in a clinical sleep-disordered population.

We conducted a retrospective analysis of 690 OSA patients who underwent sleep monitoring and FIB measurement. Missing data were handled using multiple imputation and then LASSO regression was performed to identify key predictors of FIB.

LASSO consistently selected ODI, diabetes, smoking, and alanine aminotransferase (ALT) as key predictors across all datasets (100% selection rate). In the adjusted model, ODI demonstrated a significant independent association with fibrinogen (β = 0.0039 per unit, 95% CI: 0.0025-0.0054, P < 0.001), corresponding to a 0.16 g/L increase across the interquartile range of ODI. This association remained stable after bootstrap validation, multiple imputation pooling (pooled β = 0.0041, P < 0.001).

ODI is a robust and independent predictor of fibrinogen levels in sleep-disordered breathing, with a clinically meaningful effect size comparable to established cardiovascular risk factors. These findings underscore the pivotal role of hypoxemic burden in the prothrombotic state of OSA and support its integration into cardiovascular risk assessment.