title: Diurnal intermittent fasting during Ramadan: the effects on leptin and ghrelin levels.
abstract: We aimed to assess the effect of Islamic intermittent fasting, during and outside of Ramadan, on plasma levels of leptin and ghrelin while controlling for several potential confounding variables. Eight healthy male volunteers with a mean age of 26.6±4.9 years reported to the sleep disorders center (SDC) at King Saud University on four occasions: 1) adaptation; 2) 4 weeks before Ramadan while performing Islamic fasting for 1 week (baseline fasting) (BLF); 3) 1 week before Ramadan (non-fasting baseline) (BL); and 4) during the second week of Ramadan while fasting. Plasma leptin and ghrelin levels were measured using enzyme-linked immunoassays at 22:00, 02:00, 04:00, 06:00, and 11:00. During BLF, there were significant reductions in plasma leptin concentrations at 22:00 and 02:00 compared with the baseline concentrations (at 22:00: 194.2±177.2 vs. 146.7±174.5; at 02:00: 203.8±189.5 vs. 168.1±178.1; p<0.05). During Ramadan, there was a significant reduction in plasma leptin levels at 22:00 (194.2±177.2 vs. 132.6±130.4, p<0.05). No significant difference in plasma ghrelin concentrations was detected during the BL, BLF, or Ramadan periods. Cosinor analyses of leptin and ghrelin plasma levels revealed no significant changes in the acrophases of the hormones during the three periods. The nocturnal reduction in plasma leptin levels during fasting may be the result of the changes in meal times during fasting.
authors.affiliation: Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia; National Plan for Science and Technology, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Alzoghaibi
authors.affiliation: Center for Healthful Behavior Change, Division of Health and Behavior, Department of Population Health, New York University Langone Medical Center, Clinical and Translational Research Institute, New York, New York, United States of America; Somnogen Canada Inc., Toronto, Ontario, Canada.
authors.forename: Seithikurippu R
authors.initials: SR
authors.lastname: Pandi-Perumal
authors.affiliation: The University Sleep Disorders Center, Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia; National Plan for Science and Technology, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Munir M
authors.initials: MM
authors.lastname: Sharif
authors.affiliation: The University Sleep Disorders Center, Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia; National Plan for Science and Technology, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Ahmed S
authors.initials: AS
authors.lastname: BaHammam
mesh_terms: D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D004734:Energy Metabolism; D005215:Fasting / Q000097:blood*; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D007514:Islam; D020738:Leptin / Q000097:blood*; D008297:Male; D012890:Sleep / Q000502:physiology; D055815:Young Adult
chemical_list: D054439:Ghrelin; D020738:Leptin