Seasonal changes in students' sleep quality as predictors of «adaptation» insomnia

Background: Sleep disorders occur even at a young age and may result from environmental factors such as circannual fluctuations in hormonal background and social sleep restriction, leading to the development of insomnia. The aim of the study: To assess the quality of sleep in young people (medical students), living in the city of Vladikavkaz in the spring and autumn seasons of the year for identifying predictors of insomnia. Materials and methods: With the help of the Pittsburgh questionnaire to determine the indices of sleep quality, we conducted a survey of 435 2-3 year medical students of the North Ossetian State Medical Academy (age 20.1±0.08) in seasons with a multidirectional photoperiod trend. In the spring period, 270 students were surveyed, in the autumn – 165. C17 components were assessed from 0 to 3 points, in total they determined the overall sleep quality index (Global Score PSQI, (GS)). We analyzed the sleep time of students, the relationship with latency and sleep duration. Results: The total score (GS) in the spring season was 7.19 (boys – 6.07; girls – 7.51), in autumn – 5.69 (boys – 5.59; girls – 5.75). “Bad sleep” is noted by 66.7% of respondents in spring, and 46.4% in autumn. The main contribution to the proportion of students with poor sleep quality in the spring is made by girls – 71.4%, in autumn, the proportion of students with a good quality of sleep increases, both among girls and boys. In the overall negative assessment of the quality of sleep in the spring, the leading role is played by sleep latency (contribution of 21.5%), in addition, the time of going to bed in 69.7% of medical students shifts to a period after 24:00, provoking a violation of circadian rhythms organism. Conclusion: The overall sleep quality index and the components of the PSQI questionnaire during the survey of medical students have a seasonal dependence. In all the studied seasons, students had a “poor” quality of sleep (more than 5 points), but in autumn, sleep characteristics improved by 21% according to Global Score points. In both seasons, students have 3 groups of symptoms out of 5 main criteria for the diagnosis of insomnia syndrome, which allows us to regard violations of the main components of the sleep index as predictors of the development of adaptive (acute) insomnia.