Epidemiological study: chronotype and daytime sleepiness before and during Ramadan.

Few epidemiological data have been reported on the relation between Ramadan fasting, life habits (meal frequency, sleep habits) and daytime sleepiness during Ramadan. This paper presents the results of a detailed study of the chronotype and daytime sleepiness before and during Ramadan. It was conducted on a sample of 264 subjects aged between 20 and 30 years. Results have revealed a significant decrease in the meal frequency during Ramadan compared with the control period. Before Ramadan, the majority of subjects woke up between 6 and 7 a.m. and went to sleep between 10 and 11 p.m. however, during Ramadan fasting, they woke up after 8 a.m. and preferred to go to sleep later (after midnight). Chronotype as evaluated by the Horne and Ostberg scale was changed significantly during Ramadan: an increase of the evening type and a decrease in the morning type of subjects was observed. Daytime sleepiness as evaluated by the Epworth Sleepiness Scale was significantly increased.