JET LAG SYNDROME: CURRENT INSIGHT AND REVIEW OF THE SCIENTIFIC LITERATURE

Abstract

The jet lag syndrome is a phenomenon of modern social life that occurs due to a mismatch between the body's natural circadian rhythm and the external environment due to rapid travel across multiple time zones. Jet lag syndrome symptoms are primarily related to sleep disturbance, interfering with travellers' social life and vocational performance. The symptoms usually last for a few days but can be for a week depending upon the changes in time zones. During the jet lag, abrupt shifts in the environmental light-dark cycle temporarily desynchronize the suprachiasmatic nucleus (SCN) of the hypothalamus downstream oscillatory networks from each other, resulting in increased sleepiness and impaired daytime functioning. Eastward travel is associated with a longer duration of jet lag than westward travel. Polysomnographic data show that jet lag results in changes in sleep-wake timing and different aspects of sleep architecture. This circadian misalignment can lead to a cluster of symptoms, including signicant metabolic, cardiovascular, psychiatric, and neurological impairments.[1] Light is the major entrainment factor for the circadian clock, and timed bright light exposure at the appropriate portion of the light-dark cycle is the principal non-pharmacological approach. Nutraceuticals and pharmacological therapies include melatonin, melatonin receptor analogues (agonists), non-benzodiazepine hypnotic agents, caffeine, diphenhydramine (e.g., Benadryl, McNeil; Aler-Dryl, Reese), and armodanil. The awareness about the jet lag syndrome, planned sleep schedule before departure and phase resetting by exposure to light or medication can help travellers overcome this condition. New research suggests that modication of clock function via genetic manipulation may one day have clinical applications.[2] The current perspective of the COVID-19 pandemic resulted in many countries imposing a lockdown, reducing sunlight exposure and altering daily social schedules. Therefore, it essentially leads to changing 'time zones' without actually travelling across time zones, causing social jet lag.[3]