Influence of Sleep Deprivation on the 24-Hour Ghrelin Secretion Pattern

Abstract

Background: Blood concentration of many hormones fluctuates during a 24-hour period and sleep deprivation affects this circadian rhythm. The ghrelin hormone is secreted from gastric cells and stimulates hunger. There are a few studies regarding the 24-hour ghrelin secretion pattern in normal subjects, but no studies have addressed the effects of sleep deprivation on this pattern. Objectives: To assess the 24-hour ghrelin secretion pattern and the effect of sleep deprivation on this pattern. Methods: This work was conducted on 16 young soldiers (age: 19 - 23 years old) who served in AJA University of Medical Sciences. The participants were divided into two groups. The first group had regular sleep-wake cycle (n = 8). The second group did not have normal arousal cycle (n = 8). Six blood samples were taken from each subject within 24 hours. The samples were centrifuged and serum was frozen to -20°C until the various assays were performed. Serum cortisol and ghrelin levels were measured by the enzyme-linked immunosorbent assay (ELISA). Results: Cortisol showed a diurnal rhythm with a peak at 06.00 A.M. in the normal and disrupted sleep subjects. However, ghrelin did not show a significant diurnal rhythm in neither group. Sleep deprivation did not have a significant effect on the time pattern of the cortisol and ghrelin secretion. Conclusions: It seems that in real life, ghrelin does not show a circadian rhythm and sleep deprivation does not impact this rhythm.