Summary: Teenagers who suffer from insufficient or disturbed sleep may be at higher risk of developing multiple sclerosis later in life.
Insufficient and disrupted sleep during adolescence may increase later risk of multiple sclerosis (MS), suggests a case-control study published online in the Journal of Neurology Neurosurgery and Psychiatry.
According to researchers, accumulating enough hours of restful sleep during youth can help prevent the disease.
MS is influenced by both genetic and environmental factors, including smoking, adolescent weight (BMI), Epstein-Barr virus infection, sun exposure and vitamin D, the researchers note.
Shift work has also been linked to an increased risk of disease, particularly at a young age, but whether sleep patterns (duration, disruption of biological clock, and quality of sleep) might affect this risk n has not been fully evaluated, they add.
To investigate this further, the researchers relied on a population-based case-control study, the Epidemiological Survey of Multiple Sclerosis (EIMS), including Swedish residents between the ages of 16 and 70.
People with MS were recruited from hospitals and private neurology clinics and matched by age, sex and place of residence with two healthy people randomly selected from the national population registry between 2005 and 2013 and 2015 and 2018.
The researchers focused particularly on sleep patterns among 15 to 19-year-olds, and the final analysis included 2,075 people with MS and 3,164 without the disease in this age group when recruiting for the study.
Participants were asked about their sleep habits at different ages: sleep duration on work or school days, and on weekends or free days.
Short sleep was defined as less than 7 hours/night; sufficient sleep of 7 to 9 hours; and a long sleep of 10 hours or more.
Changes in sleep schedule between work/school days and weekends/free days were calculated over the teenage years 15-19 and categorized as less than 1 hour/night, 1 at 3 o’clock and more than 3 o’clock.
Study participants were also asked to rate sleep quality over different age periods using a 5-point scale, where 5 equals very good.
The average age at which MS was diagnosed was 34 years. Sleep duration and quality during adolescence were associated with the risk of MS diagnosis, which increased with fewer hours of sleep and poorer sleep quality.
Compared to sleeping 7-9 hours/night during adolescence, short sleep was associated with a 40% increased risk of later developing MS, after taking into account a range of potentially influential factors, including BMI at 20 and smoking.
But long sleep, including weekends or days off, was not associated with an increased risk of MS.
Similarly, subjectively rated poor sleep quality during this period was associated with a 50% increased risk of developing the disease.
Changes in sleep pattern between work/school days and weekends/free days did not seem to have an influence.
The results remained similar when those who worked shifts were excluded.
The researchers caution that their findings should be interpreted with caution due to possible reverse causation, whereby poor sleep could be a consequence of neurological damage rather than the reverse.
But they point out that insufficient and poor quality sleep is known to affect immune pathways and inflammatory signaling, while the biological clock is also involved in regulating the immune response.
And insufficient or disturbed sleep is common among adolescents, a phenomenon that is partly explained by physiological, psychological and social changes during this age group, they explain.
“Associations have also been shown between social media use and sleep patterns. The availability of technology and access to the Internet at all times contributes to sleep deprivation in adolescents and represents a significant public health problem,” they add.
“Educational interventions directed at adolescents and their parents regarding the negative health consequences of insufficient sleep are important.”
And they conclude: “Insufficient sleep and poor sleep quality during adolescence appear to increase the risk of later developing MS. Sufficient restful sleep, necessary for adequate immune function, may therefore be another preventive factor against MS.
About this sleep and multiple sclerosis research news
Author: Press office
Contact: Press office – BMJ
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Original research: Free access.
“Insufficient sleep during adolescence and risk of multiple sclerosis: results from a Swedish case-control study” by Anna Karin Hedström et al. Journal of Neurology Neurosurgery and Psychiatry
Insufficient sleep in adolescence and risk of multiple sclerosis: results of a Swedish case-control study
Shift work, which often leads to sleep deprivation and circadian desynchronization, has been associated with an increased risk of multiple sclerosis (MS). Our aim was to study the impact of sleep duration, circadian disturbances and sleep quality on the risk of MS.
We used a case-control study based on the Swedish population (2075 cases, 3164 controls). Aspects of sleep were associated with MS risk by calculating OR with 95% CIs using logistic regression models.
Compared to sleeping 7–9 hours/night during adolescence, short sleep (<7 hours/night) was associated with an increased risk of developing MS (OR 1.4, 95% OR 1.1–1 ,7). Similarly, poor subjective sleep quality during adolescence increased the risk of later developing MS (OR 1.5, 95% CI 1.3 to 1.9), whereas phase shift did not significantly influence risk. Our results remained similar when those who worked shifts were excluded.
Insufficient sleep and poor sleep quality during adolescence appear to increase the risk of later developing MS. Sufficient restful sleep at a young age, necessary for adequate immune function, can be a preventive factor against MS.