The role of serum C-Fos and glial fibriller acidic protein levels in detecting the severity of obstructive sleep apnea.

Purpose: Hypoxia and sleep fragmentations that develop during sleep cause central nervous system damage in patients with obstructive sleep apnea (OSA). This study investigates the relationship between OSA severity and glial fibrillary acidic protein (GFAP) and c-Fos, which are considered indicators of neuronal damage.

Methods: The study included 84 participants (70 patients with OSA and 14 healthy individuals). All participants were evaluated with the Epworth Sleepiness Scale (ESS) before polysomnography (PSG), and serum GFAP and c-Fos values were measured after PSG. All participants were grouped according to the apnea-hypopnea index (AHI) score (control: AHI < 5, Mild OSA: 5 ≤ AHI < 15; moderate OSA: 15 ≤ AHI < 30; severe OSA: AHI ≥ 30).

Results: The average age of the participants was 48.5 ± 11.4 years. According to AHI scoring, 14 healthy individuals (16.7%) were in the control group, and 70 patients (83.3%) were in OSA groups. The serum GFAP levels and c-Fos levels were increased in the OSA groups (7.1 ± 5.7 ng/mL and 7.9 ± 7.5 pg/mL respectively) compared to the control group (1.3 ± 0.4 ng/mL and 2.7 ± 1.4 pg/mL p < 0.001 and p < 0.01, respectively). There was a significant positive correlation between AHI and oxygen desaturation index (ODI) values, which indicate disease severity, and serum c-Fos (r: 0.381 and r:0.931, p < 0.01, respectively) and GFAP (r: 0.793 and r:0.745, p < 0.01, respectively) values.

Conclusion: Serum GFAP and c-Fos values, which are considered indicators of neuronal damage, can be used as a serum marker to determine disease severity in OSA.