FIB-4 Index, Sleep Apnea Severity, and Nocturnal Hypoxemia

This retrospective study evaluates whether the Fibrosis-4 (FIB-4) index is associated with the severity of obstructive sleep apnea (OSA) and nighttime oxygen desaturation. Adults who underwent full-night polysomnography were grouped according to apnea-hypopnea index (AHI) as no OSA, mild OSA, moderate OSA, or severe OSA. Routine clinical, laboratory, and sleep-study data were reviewed. The main aim is to compare FIB-4 values across OSA severity groups and to examine whether FIB-4 is related to AHI, oxygen desaturation index (ODI), and minimum oxygen saturation during sleep. The study also evaluates the proportion of patients with FIB-4 values at or above 1.30, a commonly used threshold for identifying individuals who may need further liver fibrosis assessment. FIB-4 is used in this study as a noninvasive liver fibrosis risk marker and not as a diagnosis of liver fibrosis.