Association of daytime sleepiness with obstructive sleep apnoea and comorbidities varies by sleepiness definition in a population cohort of men

Background and objective: To determine correlates of excessive daytime sleepiness (EDS) identified with the Epworth Sleepiness Scale (ESS) and a more broad definition, while accounting for obstructive sleep apnoea (OSA) in community dwelling men. Methods: Participants of the Men Androgens Inflammation Lifestyle Environment and Stress (MAILES) Study (n = 837, ≥ 40 years) without a prior OSA diagnosis, underwent in-home full unattended polysomnography (PSG, Embletta X100), completed the ESS, STOP questionnaire and Pittsburgh Sleep Quality Index in 2010–2011. In 2007–2010, questionnaires and biomedical assessment (in South Australian public hospital-based clinics) identified medical conditions. An alternate EDS definition (EDS_Alt) consisted of ≥ 2 of 3 problems (feeling sleepy sitting quietly; feeling tired/fatigued/sleepy; trouble staying awake). Results: EDS_Alt (30.4%, n = 253), but not ESS ≥ 11 (EDS_ESS, 12.6%, n = 104), increased significantly across OSA severity and body mass index categories. In adjusted analyses, EDS_ESS was significantly associated with depression: odds ratio (OR), 95%CI: 2.2 (1.3–3.8) and nocturia: 2.0 (1.3–3.2). EDS_Alt was associated with depression, financial stress, relationship, work-life balance problems and associations with nocturia and diabetes were borderline. After excluding men with EDS_ESS, EDS_Alt was associated with oxygen desaturation index (3%) ≥ 16 and the highest arousal index quartile but not with comorbidities. Conclusion: Sleepiness not necessarily leading to dozing, but not ESS ≥ 11, was related to sleep disordered breathing. Clinicians should be alert to (1) differing perspectives of sleepiness for investigation and treatment of OSA, and (2) the presence of depression and nocturia in men presenting with significant Epworth sleepiness regardless of the presence of OSA.