Abstract
Background: Ramadan fasting and its associated lifestyle changes have been linked to changes in sleep and daytime sleepiness. This study was designed to assess the effects of Ramadan fasting on patterns of sleep and daytime sleepiness. Methods: The SenseWear Pro Armband T was used to assess the duration and distribution of sleep in eight Muslim and eight non-Muslim volunteers during the last week of Shaaban [baseline (BL) and the first (R1) and second (R2) weeks of Ramadan (1430 H)]. OPTALERT T was used to assess daytime drowsiness objectively using the John Drowsiness Scale (JDS) to assess sleepiness, and a visual reaction time test was used to assess mean reaction time (MRT). Results: The mean ages of Muslims and non-Muslims were 36.25 +/- 4.46 and 34.75 +/- 3.33 years, respectively. Although the start of work was delayed for Muslims from 0730 to 1000 hours, there was no change in working hours for non-Muslims. During Ramadan, bedtime and wake-up time were delayed, and there was a significant reduction in total sleep time for Muslims (5.91 +/- 1.36 hours, 4.95 +/- 1.46 hours, and 4.78 +/- 1.36 hours during BL, R1, and R2, respectively, P < 0.001), but not for non-Muslims. JDS values in both Muslims and non-Muslims were normal at BL (1.70 +/- 1.16 and 1.68 +/- 1.07, respectively), and no changes occurred during Ramadan (R1 or R2), indicating no increase in daytime sleepiness. There were no significant changes in MRT during R1 and R2 from BL in either group. Conclusion: Although the sleep cycle of the studied sample shifted during Ramadan among fast observers, there was no objective evidence for increased sleepiness during fasting.