Related Experiment Video
Updated: Jul 13, 2026

Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments
Published on: August 8, 2019
Disturbances in melatonin and core body temperature circadian rhythms after minimal invasive surgery
I Gögenur1, B Middleton, V B Kristiansen
1Department of Surgical Gastroenterology D, University of Copenhagen, Gentofte Hospital, Niels Andersens Vej 65, DK-2900 Hellerup, Denmark. ismgog01@gentoftehosp.kbhamt.dk
Background:
Sleep disturbances, fatigue and reduced general well-being frequently occur after minimal invasive surgery. The circadian rhythms of melatonin and core body temperature are central to the regulation of normal sleep. The aim of this study was to assess changes in these circadian rhythms after laparoscopic cholecystectomy.
Methods:
Twelve women were studied before and after laparoscopic cholecystectomy. The major urinary melatonin metabolite, 6-sulphatoxymelatonin (aMT6s), and the core body temperature were measured for 1 day before and 1 day after surgery. The basal and maximum secretion of aMT6s were determined, as well as the timing and amplitude of aMT6s and the temperature rhythm. The patients' rest-activity and calculated sleep parameters were assessed by actigraphy.
Results:
A significant delay in the timing of aMT6s rhythm was observed after surgery [median (range) peak time of aMT6s: after surgery, 05:49 h (02:57-08:23 h); before surgery, 04:32 h (02:18-06:49 h); P< or = 0.05]. The amplitude of the aMT6s rhythm was also significantly decreased after surgery [after surgery, 7.1 ng aMT6s/mg creatinine (1-15.9 ng); before surgery, 13.2 ng aMT6s/mg creatinine (2.9-22.7 ng); P< or = 0.005]. There was almost a 12-h phase delay of the core body temperature rhythm after surgery [peak time: before surgery, 17:39 h (15:17-22:06 h); after surgery, 05:14 h (03:24-21:43 h); P< or = 0.01].
Conclusions:
Following laparoscopic cholecystectomy, there was a delay in the timing of the aMT6s rhythm and a decreased evening decline in the temperature rhythm.
Related Concept Videos
Circadian Rhythms and Gene Regulation
Circadian Rhythms and Gene Regulation
Management of Insomnia
Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
Restless Leg Syndrome and Night Terrors
The exact cause of RLS is not fully understood, but it is believed to involve dopamine, a neurotransmitter that helps regulate muscle movement. Imbalances in dopamine levels...
Sedatives and Hypnotics Drugs: Miscellaneous Agents
Melatonin congeners like ramelteon (Rozerem) and tasimelteon (Hetlioz) selectively bind to melatonin receptors (MT1 and MT2) and thus mimic the actions of melatonin, a hormone that regulates sleep-wake cycles. Tasimelteon is primarily used for non-24-hour sleep-wake disorder, common in blind patients. They are also used to treat conditions like insomnia...
