Melatonin Treatment for Eastward and Westward Travel Preparation

The article I chose was called “Melatonin Treatment for Eastward and Westward Travel Preparation.” The researchers of this article were Michel A. Paul, James C. Miller, Gary W. Gray, Ryan J. Love, Harris R. Lieberman & Josephine Arendt. The article stated that circadian misalignment can be induced by jet lag or shift work ultimately leading to adverse effects. Some adverse effects include fatigue and a reduction in alertness and performance.

The hormone melatonin is driven by the suprachiasmatic nucleus. The suprachiasmatic nucleus is located in the brain’s midline just above the optic chiasm, which is responsible for circadian rhythm control. This part of the brain also helps with different body functions in a 24-hour cycle. In this study, the researchers were hoping to determine, “in a group of subjects with a regular sleep wake cycle, the relative efficacy of three melatonin formulas.” One study looked at phase advanced and the second looked at phase delay. To measure melatonin a dim light melatonin onset (DLMO) was used. The researchers also wanted to quantify sleep time that was measured by a wrist activity monitor to determine regular sleep-wake cycles in each participant.

The participants that participated in this study were all healthy non-smoking males. In experiment one there were a total of 13 males who were in a double-blind and randomized order to compare three different levels of melatonin formulations. Participants were scheduled to come to the sleep lab for three days for a certain amount of hours then released. In experiment two there were 9 males who also participated in a double-blind, randomized and was repeated measures study using the same three melatonin formulations, but they were taken earlier in the day to achieve a phase delay.

The results indicated there were significant phase changes. In the study looking at phase advanced the participants were waken up an hour early after the administration of melatonin which contributed to phase advance. In study two, the participants remained in the sleep lab for an additional 3.5 hours later than their normal wake up times, which contributed to a phase delay. For those who were in the phase advanced group there were no differences that appeared during the slow or fast preparation of the study. However, for those who were in the phase delay group it was shown it was best to avoid the slow release of formulations. As a result this research shows if there is a use for travel it is best if a small dose of melatonin can be administered for optimal use.  

Source:

Paul, M. A., Miller, J. C., Gray, G. W., Love, R. J., Lieberman, H. R., & Arendt, J. (2010). Melatonin treatment for eastward and westward travel preparation. Psychopharmacology, 208(3), 377-386. doi:10.1007/s00213-009-1737-7