K. Sadeghniiat-Haghighi1, A. Najafi, A. Rahimi-Golkhandan, S. Akbarpour, M. Mohammadzade

Occupational Sleep Research Center, Baharloo Hospital,

Tehran University of Medical Sciences, Tehran, Iran, Islamic Republic of

Introduction: Obstructive Sleep Apnea (OSA) and Insomnia are two common sleep disorders. More than 40% of patients with OSA reported at least one insomnia symptom. Coexistence of OSA and insomnia will result in lower sleep quality, lower quality of life and lesser compliance to continuous Positive Airway Pressure (CPAP) therapy as the first line treatment for OSA. In this study we aimed to evaluate insomnia prevalence and its severity in Iranian sleep clinic patients who were suspicious to OSA.

Materials and methods: This cross-sectional study was conducted among 1771 participants referred to sleep clinic located in Baharloo hospital, Tehran, Iran from 2012 to 2018.Insomnia Severity Index (ISI) and Beck Depression Inventory (BDI- II) questionnaires were filled out by the sleep clinic patients who were suspicious to OSA. All the participants underwent one-night Polysomnography. Results: In current study, of 1771 subjects, 1242 (68%) were male. The mean age of patients was 47.18 ±13.65. Patients had mean RDI of 41.53 ± 31.98, mean ISI of 12.11 ± 5.99 and mean BDI score of and 12.88 ± 11.22. Moderate and severe insomnia (ISI score≥15) was reported by 639(36%) patients. Subjects with normal RDI had mean ISI score of 13.71±6.32, and patients with mild, moderate and severe OSA reported mean ISI scores of 12.76±5.96, 11.61±5.92 and 11.91±5.95, respectively (P value:0.001). The correlation between RDI and ISI score was 0.006 (P value: 0.8).

Conclusions: Evaluation of insomnia and depression in patients with OSA is recommended. There may be an association between respiratory parameters of PSG and symptoms of insomnia among patients with OSA.