The aim of our study was to assess the levels of inflammatory biomarkers in a large sample of OSA patients and to investigate any correlation between these markers with clinical and polysomnographic (PSG) parameters.

Subjects undergone a PSG for OSA diagnosis were recruited. Patients with known comorbidities were excluded from the study. Included patients were grouped according to apnea-hypopnea index (AHI) as mild, moderate and severe. Patients with AHI < 5 served as control group. Demographic, PSG data, serum levels of hs-C-reactive protein (hs-CRP), fibrinogen, erythrocyte sedimentation rate (ESR) and Uric Acid (UA) were measured and compared between groups.

Systemic inflammation is important in obstructive sleep apnea (OSA) pathophysiology and its comorbidity. The objective of this study was to investigate how early biomarkers of inflammation may be altered in OSA patients. To complete this goal the investigators assessed the circulating levels of four inflammatory markers, hs-C-reactive protein (hs-CRP), Fibrinogen, erythrocyte sedimentation rate (ESR) and Uric Acid (UA) in a representative population of consecutively enrolled, untreated and otherwise healthy subjects with a clinical suspicion of obstructive sleep apnea. A secondary objective was to investigate any correlation between these markers with clinical and polysomnographic (PSG) parameters of these subjects.Subjects who had undergone a PSG for OSA diagnosis were recruited. Patients with known comorbidities were excluded from the study. Included patients were grouped according to apnea-hypopnea index (AHI) as mild, moderate and severe. Patients with AHI < 5 served as control group. Demographic, PSG data, serum levels of hs-CRP, fibrinogen, ESR and UA were measured and compared between groups.

Inclusion Criteria:

• newly diagnosed, untreated, and otherwise healthy obstructive sleep apnea (OSA) patients
• healthy subjects (without OSA)

Exclusion Criteria:

• refusal to participate,
• previous OSA diagnosis and treatment
• known comorbidities,
• pregnancy,
• history of narcolepsy or restless leg syndrome.
• Subjects younger than 18 years,
• Central sleep apnea syndrome (CSAS) diagnosed with PSG,

Consecutive patients, who were admitted to the Sleep Disorders Center, Department of Thoracic Medicine, University of Crete Medical School, for evaluation of suspected sleep-disordered breathing, were considered as potential recruits for this study.