515 Excessive daytime sleepiness: beyond the Epworth Sleepiness Scale results from a population-based study

Abstract Introduction Excessive daytime sleepiness (EDS) is a common symptom present in several clinical, mental and sleep disorders. However, its subjective metrics have been criticized in the literature due to lack of association with disorder severity, or disagreement with objective measures. Epworth Sleepiness Scale (ESS) is a widely used questionnaire to evaluate EDS, however it may not be sufficient as a sole measure to identify cases of somnolence in the general population. Study objectives: To investigate the association between EDS with socio-demographic, body composition and PSG measures in the general population of São Paulo, Brazil. Methods 1,042 participants from a population-based epidemiological study underwent full in-lab PSG, questionnaires (ESS, fatigue, quality of life, depression and anxiety scales), bio impedance, socio-demographic and anthropometric measures at baseline and in the follow-up 9 years later. A univariate linear regression analysis including the whole sample (baseline and follow-up) was performed to analyze predictors of EDS and ESS score in the follow-up was the dependent variable. All variables with a p-value <0.15 were included in an exploratory factor analysis (principal component analysis with Varimax rotation) to assess the factorial structure of EDS. Results The results supported a five-factorial structure associated with EDS as follows: Factor 1 - Quality of life (Physical and Psychological domains of WHOQOL), Factor 2 – Fatigue (questions from Chalder Fatigue Scale concerning weakness, tiredness, lack of energy and less strength in the muscles), Factor 3 – PSG – sleep duration (wake after sleep onset, sleep efficiency, total time spent awake), Factor 4 – PSG – sleep structure (arousal index, N1 and N3 duration), Factor 5 – Body composition (body mass index). PSG variables related to sleep disordered breathing and movement disorders were not associated with EDS. Conclusion EDS measured by ESS was associated with domains other than sleep disorders in the general population. ESS metrics was significantly associated with fatigue and sleep duration. Support (if any) Associação Fundo Incentivo à Pesquisa (AFIP), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES – Processo 88887.468428/2019-00).