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.

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Key information

Conditions

Obstructive Sleep Apnea (OSA) Apnea Dyssomnias Metabolic Dysfunction-Associated Steatotic Liver Disease Nervous System Diseases Respiration Disorders Respiratory Tract Diseases Sleep Apnea Syndromes Sleep Apnea, Obstructive Sleep Disorders, Intrinsic Sleep Wake Disorders

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Hisar Hospital Intercontinental

Istanbul, 34768, Turkey (Türkiye)

About this study

This is a single-center, retrospective observational study of adults aged 18-65 years who underwent diagnostic full-night polysomnography. Participants were classified according to the apnea-hypopnea index (AHI) as AHI <5 events/h, mild OSA (5-14.9 events/h), moderate OSA (15-29.9 events/h), or severe OSA (≥30 events/h).

Demographic, polysomnographic, hematologic, and biochemical data were obtained retrospectively from hospital records. Laboratory measurements closest to the polysomnography date within ±30 days were used. The FIB-4 index was calculated from age, aspartate aminotransferase, alanine aminotransferase, and platelet count.

FIB-4 was evaluated as a continuous variable and using clinically established risk thresholds. Associations between FIB-4 and polysomnographic measures, including AHI, oxygen desaturation index (ODI), and minimum peripheral oxygen saturation (SpO₂), were examined. The study also explored the relationship between FIB-4 and the neutrophil-to-lymphocyte ratio (NLR). No study-related intervention was administered.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Adults aged 18-65 years. Underwent technically adequate diagnostic full-night polysomnography. Sufficient demographic and clinical data available for OSA classification.

Exclusion criteria

Age <18 or >65 years. Technically inadequate polysomnography. Split-night or positive airway pressure (PAP) titration studies. Known advanced chronic liver disease or cirrhosis. Hematologic malignancy. Active infection. Clinically significant systemic inflammatory or autoimmune disease. Chemotherapy, radiotherapy, or immunosuppressive therapy. Pregnancy. Clinically significant alcohol use or alcohol-related liver disease. Missing laboratory components required for the relevant FIB-4 or NLR analysis.

Treatment and study plan

Primary outcomes

FIB-4 Index Across Obstructive Sleep Apnea Severity Groups

Time frame: Within 30 days before or after polysomnography

FIB-4 index was compared across four groups defined by the apnea-hypopnea index (AHI): AHI <5 events/hour, mild OSA (5-14.9 events/hour), moderate OSA (15-29.9 events/hour), and severe OSA (≥30 events/hour).
FIB-4 Index Across Obstructive Sleep Apnea Severity Groups

Time frame: Within ±30 days of polysomnography

FIB-4 index will be compared across four OSA severity groups defined by the apnea-hypopnea index (AHI): AHI <5 events/hour, mild OSA (5-14.9 events/hour), moderate OSA (15-29.9 events/hour), and severe OSA (≥30 events/hour). FIB-4 is calculated as age (years) × AST (U/L) / [platelet count (10⁹/L) × √ALT (U/L)].

Sponsors and collaborators

Lead sponsor

Hisar Intercontinental Hospital

Other

Registry information

Official study title

Association of the FIB-4 Index With Obstructive Sleep Apnea Severity and Nocturnal Hypoxemia: A Retrospective Polysomnographic Study

Acronym: FIB-4-OSA

Important dates

Study start: 2026
Primary completion: 2026
Study completion: 2026
First posted: Sep 1, 2026
Registry last updated: Sep 1, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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Completed