TIPOLOGIA CIRCADIANA DE ADULTOS JOVENS: DIFERENÇAS DE GÊNERO

Abstract

Objective: To analyze circadian typology (diurnal preference) and gender differences in a university student population from Southern Brazil. Methods: Seven hundred and thirty six university student volunteers, with an age range 17- 49 yr, filled the Brazilian version of the Chronotype Questionnaire (CQ), the portuguese translation of the Horne and Östberg s Morningness-Eveningness Questionnaire (MEQ). Central and dispersion tendencies measures and CQ scores distribution curve (Kolmogorov-Smirnov) were calculated according to gender (Student t), age, birth season, and daylight-saving time discomfort (quisquare), with significance level of p<0.05. Results: Six hundred and fourty eight individuals (36% men; 64% women) were included in this study, with 12% of losses due to incorrect questionnaires. CQ score distribution was correlated to the normal curve (range=18-77; mean=46.6; s.d.=10.8). In this sample, 32% were evening-types; 54% were intermediate-types, and 14% were morning-types. CQ means were significatively different (p=0.003) when males (44.9±10.8) were compared to females (47.5±10.7), and 70% of those born during spring and summer were evening-types (p=0.015).There was no gender-by-season association. Conclusions: Men, and Individuals born in spring-summer, presented eveningness preference, without gender-birth season interaction. Our results are also in agreement with studies performed in the Northern Hemisphere, which showed an association between birth season and diurnal preference