Czech researchers claim that sleep quality, rather than sleep duration or timing, has a greater impact on quality of life (QoL).
Their study, published in the open-access journal PLOS ONE, is among the first to observe the impact of changes in sleep quality over the long term.
It is also the first study to investigate the potential effects on quality of life (QoL) of social jetlag—a mismatch between one’s own internal sleep rhythms and external demands.
Aleš Kudrn, Ph.D., and Michaela Kudrnáová of Charles University’s Faculty of Social Sciences served as the study’s principal authors., of the Institute of Sociology, Czech Academy of Sciences concluded:
“While the length and timing of our sleep are important, people who have better sleep also have a higher quality of life, regardless of the time and duration of their slumber. Additionally, we discovered that those whose sleep improved also had an improved quality of life after monitoring [4,523] people for three years.”
Inconclusive sleep and poor sleep quality have been linked to lower quality of life, according to prior research.
Defining Quality of Life
The Charles University researchers define the quality of life (QoL) as “an interplay between the perception of an internal state, such as the experience of happiness or feeling of good heath or satisfaction, and external events in the surrounding environment, which may include family and career.”
The criteria for well-being, life satisfaction, happiness, and purpose served as the foundation for their analysis. What exactly is social jetlag?
Social jetlag is the term used to describe the discrepancy between biological time, which is established by internal circadian rhythms, and social time, which is primarily established by the external environment. The increasing use of artificial light and nightwork is largely responsible for this pervasive “circadian misalignment”.
Given that a variety of physiological processes are regulated by the circadian clock, health professionals have connected social jetlag to adverse health effects. These include sleep issues, high blood pressure, cognitive impairment, mental health issues, and metabolic issues.
Data on Sleep Quality, Duration, Bedtime
Data from the Czech Household Panel Study (CHPS), with an emphasis on data gathered over a three-year period, were consulted by the Charles University team.
Every person in the sampled households was questioned for the survey. In each “wave” of data collection, the same members of the same households were asked to contribute.
2018 saw 5,132 self-administered questionnaires about work, health, and sleep patterns from Czech adults. 2,046 questionnaires received responses in 2019 and 2,161 in 2020.
Due to a requirement for blood draws, the sample size decreased between 2018 and 2019.
The experts looked at how sleep affected the dependent QoL variables that were previously mentioned.
For instance, they measured life satisfaction according to responses to the question “How content are you with your life overall, taking everything into account?” They gauged perceived happiness with responses to the question “What would you say your overall level of happiness is?”
The study also evaluated sleep duration, sleep quality as perceived, and social jetlag.
The reported responses regarding sleep and wake times on workdays and free days were used to calculate the amount of time spent sleeping. Perceived quality of sleep was based on answers to the question “What level would you give your sleep’s quality?”
The researchers calculated social jetlag “as the difference between the mid-sleep time on free days and workdays.”
Individual and Household Sleep Patterns
The Charles University team repeatedly measured the CHPS data for both individuals and households to test their hypotheses regarding the effects of sleep-related factors on QoL.
The length of sleep and social jetlag were discovered to be significant factors in explaining how people differ in terms of their quality of life. Longer sleep duration was linked to worse subjective health and lower levels of happiness, whereas social jetlag was linked to lower life satisfaction and increased work stress.
The most significant factor, however, was better sleep quality because it was linked to better results for all measures of quality of life, including greater life satisfaction, greater well-being, greater happiness, better subjective health, and lower levels of work stress.
Again, sleep quality emerged as the key factor when researchers focused on changes within individuals over the course of the study rather than comparing individuals. The QoL measures of the participants were unaffected by variations in sleep duration or social jetlag. On the other hand, better sleep quality was linked to higher levels of subjective health, happiness, and well-being.
This is consistent with earlier studies that found a strong correlation between sleep quality and quality of life.
Study Strengths and Limitations
Medical News Today discussed this study with Doctor David Cutler practices family medicine at Providence Saint John’s Health Center in Santa Monica, California. He wasn’t a part of this project.
Dr. Cutler told MNT that the findings were important, but their shortcomings made him hesitant to draw definitive conclusions:
“You might not be able to generalize the findings to all countries because all the data was gathered from one nation. Additionally, because the data collection took place during the longer summer months, the results might not be applicable to the entire year. Results were self-reported, so reporting bias may have existed. Additionally, selection bias might be present since not all questionnaires were returned.”
Dr. Cutler also mentioned that the study did not clarify causality:
“However, it is still unknown whether the extremes of sleep duration contributed to lower quality of life or if those with a lower quality of life were more likely to have either a shorter or longer sleep duration.”
The authors of the study also acknowledge that because the factors that contribute to social jet lag are rarely altered, their research timeframe might not have been sufficient to detect any potential effects.
The COVID pandemic in the spring of 2020 might have had an impact on some of the findings. As a result, the study might not have captured typical sleep patterns.
Tips for Better Sleep
Dr. Cutler shared several ways to improve sleep quality without prescription drugs or supplements:
- Stick to a consistent sleep schedule: Even on weekends, go to bed and get up at the same time each day. Your body’s natural sleep-wake cycle will be better controlled as a result.
- Create a bedtime routine: Create a relaxing routine before going to bed. Reading a book, taking a warm bath or shower, or listening to soothing music are some examples of this.
- Create a comfortable sleep environment: Make sure your bedroom is calm, dark, and quiet. Purchase cozy bedding, pillows, and mattresses.
- Limit exposure to screens: For at least two hours prior to going to bed, refrain from using electronic devices like laptops, tablets, and smartphones.
- Avoid caffeine, nicotine, and alcohol: These things make it more difficult to fall asleep and can disturb your sleep.
- Exercise regularly: Enhancing sleep quality through regular exercise is possible. Just remember to finish your workout at least a few hours before going to bed.
- Manage stress: Lack of sleep may be caused by stress. To help you relax, try yoga, deep breathing exercises, or relaxation techniques like meditation. The most effective method of treating insomnia is a consistent cognitive behavioral therapy regimen.
- Consider seeking medical advice: It’s crucial to speak with a healthcare provider if you consistently have sleep issues. They might suggest additional testing or alternative therapies.
