Qom University of Medical Sciences Journal

Introduction
Sleep is a complex biological process with high effects on mental and physical health. It is considered one of the basic human needs and is essential for maintaining health, good quality of life (QoL), and proper functioning during the day. Studies in all age groups have shown that inadequate sleep plays an important role in increasing the risk of heart and metabolic diseases and reducing the quality of life and functions.
Like any other creatures, humans show circadian rhythms in many biological and behavioral variables that are influenced by external and internal factors; in an environment where environmental symptoms have been removed, an automatic 24-hour system manages their activities, the system that normally adjusts to the 24-hour cycle of darkness and light. However, there are interpersonal differences in sleep time known as morningness-eveningness preferences or chronotypes. People morningness chronotype are very active during the day and tend to sleep earlier at night. For people with eveningness chronotype, it is difficult to wake up early in the morning and they are usually much more active in the second half of the day than in the first half. They are called “owl”.
Despite many studies, sleep problems and their serious health consequences have received less attention from experts in Iran. In recent years, attention to the sleep problems in childhood has increased, but more research is still needed in this area. This study aims to investigate the sleep-wake pattern in adolescents living in Sistan & Baluchestan province, Iran.
Methods
This study was conducted on high school students in the Makran region of Sistan & Baluchestan province (Saravan, Iranshahr, and Chabahar cities). Inclusion criteria were age 13-19 years, no attention deficit/hyperactivity disorder, no any chronic disease, and not using any drugs that can affect sleep (e.g., Psychostimulants, anticonvulsants and antihistamines). Exclusion criteria were unwillingness to continue participation, and return of incomplete questionnaire. Sample size was calculated 384 by using Cochran formula and assuming the first type error of 0.05, P=0.5, and d=0.05. Considering a 15% sample drop, it increased to 441. Since a cluster sampling was used, the final sample size was determined 530. For this purpose, 177 students from each of the three cities in the Makran region were selected. Participants entered the study after signing the consent form. All participants were assured that their personal information would be kept confidential.
The data collection tool was the morningness-eveningness questionnaire (MEQ). This questionnaire has 19 items and three subscales of preferring to be awake (7 items), preferring to sleep (4 items) and preferring to have peak performance (4 items). The scores ranges from 16 to 86; A higher score indicates to be more morning type, and a lower score indicates to be more evening type. Individuals are categorized into five groups based on the MEQ scores: Definitely evening type (score 16-30), relatively evening type (score 31-41), moderate (score 42-58), relatively morning type (score 59-69), and definitely morning type (score 70-86). T-test and ANOVA were used to compare the sleep-wake pattern of male and female adolescents at different cities of Makran region. The significance level was set at 0.05.
Result
Participants were 504 high school students. Most of students had 17 years of age (20.8%); 53% were girls, and the rest were boys; 45.2% were in the first-grade high school (7-9th grade) and 49% in the second-grade high school (10-12th grade), and the educational level of 5.8% were unknown. The mean score of MEQ in overall was 56.7±8.9, indicating a moderate level of morningness/eveningness. In girls, the MEQ score (55.9±9.4) was less than in boys (57.7±8.3).
According to the findings, most of students preferred sleep pattern compared to other patterns, which was higher in boys than in girls, and this difference was statistically significant (P=0.009). Therefore, boys were more morning-oriented than girls. However, there was no significant difference between boys and girls regarding the wake pattern and peak performance preference (P>0.05).
Discussion
It can be concluded that the sleep-wake pattern of high school students in the Makran region of Sistan & Baluchestan province is at a moderate level, and all students prefer the sleep pattern over other patterns. Boys are more morning-oriented than girls. It is necessary to examine the circadian rhythms in adolescent students and take necessary measures to inform parents. It is recommended to localize the MEQ and find its cut-off point for the Iranian population to accurately evaluate their sleep-wake pattern. On the other hand, the officials of the education departments should design and implement a more desirable plan for the school start time based on the morningness/eveningness of students in different regions to increase their peak performance
Ethical Considerations
Compliance with ethical guidelines
This research was approved by the ethics committee of Iran University of Medical Sciences (ethics code IR.IUMS.FMD.REC.1398.164).
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Authors contributions
All authors contributed equally in preparing all parts of the research.
Conflicts of interest
The authors declared no conflict of interest.
Acknowledgements
The high school students of Makran region of Sistan and Baluchistan province who participated in the study and the education officials are appreciated and thanked.