The purpose of this study is to evaluate the diagnostic accuracy of polysomnography indexes for diagnosis of sleep apnea in human subjects obstructive sleep apnea (OSA). This includes evaluation of polysomnography indexes (AHI; AI, arousal index; ODI, oxygen desaturation index) and heart rate variability (HRV) indexes.

This is a cross-sectional study collecting data from patients from the Sleep Institute of Itaperuna, Rio de Janeiro, Brazil. Polysomnography (PSG) monitoring and diagnosis was in accordance with American Society of Sleep Medicine (ASSM) standards. Standard baseline polysomnography is performed using a computerised system. The following extracted signals are measured: 2 electroencephalogram channels (O1-A2, O2-A1, C3-A2, C4-A1), 2 electrooculogram channels, electromyography (EMG, bilateral anterior tibialis), pulse oximetry (arterial oxygen saturation), nasal-oral airflow (thermistors), and electrocardiogram (ECG derivation DII). The polysomnograms are scored according to the criteria of Rechtschaffen and Kales.

Inclusion Criteria:

• Diagnosis of obstructive sleep apnea with an apnea-hypopnea index (AHI) > 5.

Exclusion Criteria:

• Subjects with a history or clinical examination suggestive of neuromuscular disease, hypertension or any surgical treatment were not considered in the study.

primary care clinic