title: Circadian pattern of sleep, energy expenditure, and body temperature of young healthy men during the intermittent fasting of Ramadan.
abstract: We hypothesize that factors other than a sudden shift in eating habits contribute to delay of circadian rhythms during Ramadan. We assessed circadian changes during a baseline period (BL, 1 week before Ramadan), the first week (R1), and the second week (R2), of Ramadan, in six healthy Muslim young adults using portable armband physiological and activity sensor devices. All participants lived in an unconstrained environment and showed delayed sleep phase syndrome, so that they normally slept during the day and ate at night. During Ramadan, there was a further delay in the acrophase of skin temperature during Ramadan, indicating a shift in the circadian pattern of body temperature. Additionally, there was a delay in the peak of energy expenditure during R1 and R2. These results support our hypothesis that in addition to sudden shift in meal times, other factors may affect the sleep pattern and circadian rhythms during Ramadan.
authors.affiliation: The University Sleep Disorders Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia. ashammam2@gmail.com
authors.forename: Ahmed
authors.initials: A
authors.lastname: BaHammam
authors.forename: Mohammad
authors.initials: M
authors.lastname: Alrajeh
authors.forename: Mohammad
authors.initials: M
authors.lastname: Albabtain
authors.forename: Salman
authors.initials: S
authors.lastname: Bahammam
authors.forename: Munir
authors.initials: M
authors.lastname: Sharif
mesh_terms: D000293:Adolescent; D001831:Body Temperature / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005215:Fasting / Q000502:physiology*; D006801:Humans; D007514:Islam; D008297:Male; D008991:Monitoring, Physiologic; D017286:Polysomnography; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology; D055815:Young Adult