Inadequate and disturbed sleep during the teen years may increase the risk of developing multiple sclerosis (MS), according to a case-control study published online in Journal of Neurosurgery and Psychiatry.
Researchers have suggested that getting enough restorative sleep while young may help ward off the condition.
Researchers note that MS is influenced by both genetic and environmental factors, including smoking, adolescent weight (BMI), Epstein-Barr virus infection, sun exposure, and vitamin D.
Shift work has also been linked to an increased risk of developing the condition, especially at an early age, but whether sleep patterns-; Duration, body clock disruption, and sleep quality—may affect this risk—it hasn’t been fully evaluated, they add.
To explore this further, the researchers relied on a population-based case-control study, the Epidemiological Investigation of Multiple Sclerosis (EIMS), which included Swedish residents between the ages of 16 and 70.
Subjects with MS were recruited from privately run hospitals and neurological clinics and matched for age, sex and residential area with two healthy individuals randomly selected from the national population registry between 2005 and 2013 and 2015 and 2018.
The researchers focused specifically on sleep patterns during ages 15 to 19, and the final analysis included 2,075 people with MS and 3,164 people without the condition in this age group when they were recruited into the study.
Participants were asked about their sleep patterns at different ages: the duration of sleep on work or school days, on weekends or on free days.
Short sleep was defined as less than 7 hours/night; adequate sleep for 7-9 hours; and sleep for 10 hours or more.
Changes in sleep timing between work/school days and weekend/leisure days during adolescent years 15–19 were calculated and categorized as less than 1 hour/night, 1–3 hours, and more than 3 hours.
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. Sleep duration and quality during adolescence was associated with the risk of an MS diagnosis, which increased along with fewer hours of sleep and poorer quality.
Compared to sleeping 7-9 hours/night during the teenage years, short sleep was associated with a 40% increased risk of developing multiple sclerosis after accounting for a range of confounding factors, including body mass index at age 20 and smoking.
But prolonged sleep, including on weekends or on empty days, was not associated with an increased risk of multiple sclerosis.
Similarly, poor sleep quality self-assessed during this period was associated with a 50% increased risk of developing the condition.
Changes in sleep timing between work/school days and weekends/free days did not appear to be significant.
Results remained similar when those who worked shifts were excluded.
The researchers caution that their findings should be interpreted with caution at the expense of possible reverse causation; Where lack of sleep can be the result of neurological damage, not the other way around.
But they note that poor sleep and poor sleep quality are known to affect immune pathways and inflammatory signaling, while the body clock is also involved in regulating the immune response.
They explain that insufficient or disturbed sleep is common among adolescents, a phenomenon that is explained in part by physiological, psychological and social changes during this age period.
They add: “The association between social media use and sleep patterns has also been demonstrated. The availability of technology and access to the Internet at any time contributes to insufficient sleep among adolescents and is an important public health problem.”
“Educational interventions directed at adolescents and their parents regarding the negative health consequences of inadequate sleep are of importance.”
They concluded: “Inadequate sleep and reduced sleep quality during adolescence appear to increase the risk of developing MS later. Thus adequate restorative sleep, required for adequate immune function, may be another protective factor against MS.”
Akerstedt, T., et al. (2023) Poor sleep during adolescence and the risk of developing multiple sclerosis: results of a Swedish case-control study. Journal of Neurosurgery and Psychiatry. doi.org/10.1136/jnnp-2022-330123.