influence of sleep deprivation on the 24-hour ghrelin secretion pattern

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 enzymelinked 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.