Jet lag is a disorder of circadian rhythms caused by the adaptation of the body after a flight through several time zones. It is manifested by malaise, nocturnal insomnia, daytime hypersomnia, deterioration of the ability to concentrate attention, decreased mood, dyspeptic phenomena. Diagnosis is carried out taking into account clinical data, polysomnography and actigraphy are performed to exclude sleep disorders. Methods that facilitate the course of the adaptation period include observing the daily routine, light therapy, taking melatonin pharmaceuticals, and, according to indications, the use of sleeping pills.
ICD 10
G47.2 Sleep and wake cycle disorders
General information
Jet lag is a newly emerged disease of civilization caused by massive transmeridian air travel. In the medical literature, there is a synonymous name — desynchronosis, reflecting the underlying disorder of the circadian rhythms. Jet lag is a physiological acclimatization to the conditions of the time zone change. In people who frequently make transmeridian flights, the syndrome can cause serious somnological disorders. The prevalence of jetlag is unknown, as many patients do not seek medical help.
Causes
The only etiofactor provoking the syndrome is air travel, which provides an excessively rapid change in time zones. Clinically significant jet lag occurs after the change of more than two time zones. The course of the syndrome depends on the direction of flight. Traveling to the west is associated with a later time of going to bed, it is easier to transfer. The flight to the east requires early falling asleep and waking up, adaptation is more difficult. Researchers have established a direct relationship between the duration of desynchronosis with the direction of flight and the number of crossed belts: each time zone in the eastern direction requires 1 day of adaptation, in the western direction — 1.5 days.
The risk group for the development of jet lag includes airline employees who make long flights (pilots, long-distance flight attendants), diplomats, businessmen, managers, translators, engineers, whose professional activities are associated with permanent business trips. Contributing factors are sleep deprivation, stress, excessive consumption of coffee, alcoholic beverages, overeating, the presence of decompensated somatic pathology, age over 50 years. The risk of jetlag depends on the chronotype of the traveler: “larks” are easier to tolerate West-east flights, “owls” — east-west.
Pathogenesis
The circadian sleep-wake mechanism (biological clock) is regulated by the suprachiasmal nucleus of the hypothalamus, coordinated with the daily rhythm of solar illumination. Certain retinal cells that perceive the effects of light send efferent impulses to suprachiasmal neurons. The result of regulatory actions is a decrease in the production of the epiphysis of the “sleep hormone” — melatonin. At night, the secretion of melatonin increases, its concentration in the blood serum increases by 30 times.
Due to the change of time zones, there is an inconsistency between the established biological clock and the solar day of the new location. Endogenous signals that promote falling asleep and waking up do not correspond to the local day/night rhythm. Such a situation entails a restructuring of the circadian mechanism, which requires a certain amount of time. The period of adaptation is associated with dissomnia caused by lack of sleep, mild cognitive disorders, and psychoemotional discomfort. Since the circadian rhythm subordinates the work of the gastrointestinal tract, jetlag is accompanied by symptoms of dyspepsia.
Classification
In clinical practice, the division of jet lag by severity has found application. Depending on the severity of insomnia (insomnia) and hypersomnia (drowsiness), the degree of deterioration of working capacity, difficulties in professional activity, there are mild, moderate and severe syndrome. According to the peculiarities of the course of the SSSP , it is classified into 3 main forms:
- Spicy. The duration of symptoms does not exceed 1 week. The syndrome resolves independently with the end of the adaptation period. Medical support is necessary for severe manifestations.
- Subacute. Lasts 7-90 days. It is observed after a 2-3-fold change of time zones. It passes independently, provided there are no further transmeridian flights.
- Chronic. Symptoms are observed for more than 3 months. The syndrome develops after multiple time zone changes. It requires medical treatment against the background of elimination of the etiological factor.
Symptoms
Jetlag manifests dissomnic disorders that occur on 2-3 days after the flight. Patients note problems falling asleep, frequent night awakenings, feel drowsy during the day, periodically “fall asleep on the go.” There may be episodes of irresistible sleep in an unsuitable environment. In the future, there is an alternation of periods of insomnia with normal sleep. Complaints of reduced daytime activity, deterioration of working capacity, headache, depressive mood background, feeling of discomfort are characteristic. Cognitive disorders are expressed mainly in difficulties of concentration of attention, which can provoke serious mistakes in professional activity.
Among the somatic manifestations, the leading symptoms are gastrointestinal dysfunction: anorexia, diarrhea, constipation, discomfort in the epigastric region, nausea. In women, menstrual cycle failure is possible. As they adapt to the conditions of the new time zone, there is a decrease in the severity of these manifestations. The chronization of the process is associated with numerous flights, manifested by the presence of symptoms of jet lag in the inter-flight period.
Complications
Against the background of deterioration of well-being, episodes of pronounced drowsiness in the wrong place, jet lag syndrome can be complicated by depression, subjective distress. The feeling of psychological exhaustion is dangerous by the formation of suicidal thoughts. The condition is aggravated when trying to overcome jetlag by taking large doses of caffeine, energy drinks, alcohol. In patients with mental disorders, there is a possibility of exacerbation. In manic-depressive psychosis, a transmeridian flight in the east-west direction provokes a depressive phase of the disease, in the west-east direction — a manic one. In women who repeatedly change time zones, the syndrome can be complicated by a violation of the menstrual cycle, since the production of female sex hormones is carried out in accordance with the circadian rhythm.
Diagnostics
Jetlag rarely becomes a reason to go to the doctors. Most patients undergo an adaptation period on their own. Diagnosis is carried out by a therapist, neurologist, somnologist according to characteristic complaints, anamnestic data. Instrumental studies are required mainly in cases of subacute, chronic course of the syndrome, include:
- Polysomnography. Polysomnographic examination is performed in a dream, makes it possible to evaluate its effectiveness, identify violations, and conduct a differential diagnosis of somnological disorders. Jetlag is characterized by a decrease in sleep efficiency by 10%, the presence of micro-arousals.
- Actigraphy of sleep. Monitoring of the sleep-wake rhythm is carried out for several days with a device attached to the patient’s wrist. Actigraphy allows you to detect a violation of circadian rhythmicity.
The diagnosis is established provided that the observed clinical syndrome is not a consequence of a mental or somatic disease. It is necessary to differentiate the jet lag syndrome with road fatigue caused by dehydration, inactivity, inhalation of dry air in an airplane. Road fatigue occurs during any long-term air travel, regardless of the change of time zones. With an adequate regimen and diet, the duration of symptoms is limited to a couple of days.
Treatment
The severity of jetlag decreases over time. The reconfiguration of the biological clock occurs at a speed of 60 minutes / day for west-east air travel, 90 minutes / day — for a similar journey to the west. Treatment allows you to speed up adaptation, relieve symptoms. There are a number of therapeutic techniques used in various combinations. The recommended methods of treatment are:
- Taking melatonin. The drug promotes falling asleep, normalization of the circadian cycle, has an adaptogenic effect. Taking the remedy in the evening before the endogenous hormone secretion phase turns the biological clock back, facilitates adaptation in a more eastern time zone. When flying to the west, taking a small dose of the drug at night allows you to reorient the biological clock forward.
- Sleep mode monitoring. Along with light therapy, it is the most important aspect of setting up the circadian rhythm. It is recommended to start the gradual shift of the regime for rapprochement with that in the arrival region before the planned trip. If you stay in a different time zone for a short time, if circumstances allow, you can keep the “home” rhythm. In the first few days, a little daytime sleep is useful. Do not allow too long sleep during the day, which can provoke problems falling asleep in the evening.
- Light therapy. Purposeful exposure to light at a certain time of day helps to adapt faster. After a flight to the west, stimulation with bright light is necessary in the evening, after a flight in the opposite direction — in the morning.
- The appointment of sleeping pills. The indication is pronounced insomnia. Sleeping pills can improve the quality of night sleep. Monotherapy with a short-acting drug is recommended. The combination of pharmaceuticals, the use of sleeping pills with a long period of action contributes to the occurrence of daytime drowsiness.
- The use of caffeine. Caffeinated drinks potentiate a feeling of cheerfulness. Since caffeine often provokes increased insomnia, taking such drinks is recommended in the morning.
Prognosis and prevention
In the vast majority of cases, jetlag passes on its own. Chronization is rarely observed, it is associated with the peculiarities of professional activity. The best prevention of jet lag is to prepare for a change in the time zone by a corresponding shift of the day mode, light stimulation. Additional preventive measures are the refusal to drink alcohol, the deliberate use of caffeinated, hypnotic drugs, a balanced diet. Patients with mental disorders, severe diseases of internal organs are recommended to avoid trans-Meridian air travel, to move by slower modes of transport, allowing them to gradually adapt to changing time zones.