- Multiple sclerosis is a chronic condition that affects the central nervous system.
- The exact cause of multiple sclerosis is unknown, and researchers are working to understand its risk factors and how people can change their risk.
- A recent study found that not getting enough sleep and poor sleep quality in adolescence may increase the risk of developing multiple sclerosis later in life.
Sleep is essential for health, helping the body maintain its typical functions. But researchers are still working to understand the health benefits of sleep and the dangers of poor sleep. One area of interest is the importance of sleep during adolescence.
A recent study published in the Journal of Neurology, Neurosurgery and Psychiatry found that poor sleep in adolescence may increase the risk of developing multiple sclerosis (MS).
People with multiple sclerosis may experience a wide
It is unclear why certain people develop multiple sclerosis. This may be related to a reaction by the body’s immune system. People with a family member with multiple sclerosis may have an increased susceptibility to developing the disease.
Non-study author, neurologist and multiple sclerosis specialist, Dr. Achillefs Ntranos, explained to MNT:
“There are a number of known risk factors for MS [multiple sclerosis], including genetics, gender (women are 3 times more likely to develop MS than men), and environmental factors such as low vitamin D levels or exposure to viruses, such as Epstein-Barr virus. Recent research has also suggested that certain lifestyle factors, such as smoking or obesity, may play a role in the development of MS.”
Researchers are still working to understand the level of risk posed by modifiable factors and how people can reduce their risk of developing multiple sclerosis.
This particular study was a case-control study in Sweden. Researchers included 2,075 participants who had multiple sclerosis and 3,164 controls. Researchers asked participants about sleep quality and duration during their teenage years. They divided sleep time into three categories:
- less than seven hours each night (short sleep)
- between seven and nine o’clock every night
- 10 or more hours each night (long sleep)
Researchers further asked participants about the difference between when they slept on work days or school days and when they slept on weekends and days off. Finally, researchers asked participants about sleep quality, ranging from very bad to very good.
The study found that sleeping less than seven hours a night during adolescence was associated with an increased risk of developing multiple sclerosis. Low sleep quality presented a similar associated risk. They found that the sleep time differences between weekends and school days did not significantly affect a person’s risk for multiple sclerosis.
Study author and researcher at the Karolinska Institute, Dr. Anna Hedström, explains MNT:
“We tried to investigate whether usual sleeping patterns at [a] young age affects the risk of developing MS later. Both insufficient [and] poor sleep negatively affects the immune system in several ways and has been associated with increased risk of other inflammatory diseases. We found that too little sleep or poor sleep quality increases the risk of later developing MS to 50%.”
Dr. Ntranos further commented on the study:
“[Getting] enough restorative sleep at a young age may be important for maintaining adequate immune function and may be a preventive factor against MS. It is also worth noting that the study’s findings remained similar when those who worked shifts were excluded, which is an important consideration since shift work is often associated with sleep deprivation and circadian dyssynchrony and these are known risk factors for MS.
The study did have certain limitations. First, the study cannot prove that poor sleep causes multiple sclerosis. The authors acknowledge that reverse causation, recall bias, selection bias, and residual confounding are possible.
Researchers also relied on data from questionnaires completed by participants, which may be at risk of inaccuracies. They also admit that it may have been components that they did not adjust for, such as stress and dietary habits. The study was conducted in one country, possibly indicating the need for more diverse population studies in the future.
Dr. Hedström noted the following components of further research:
“Previous studies have shown that insufficient sleep can contribute to low-grade inflammation, oxidative stress and disruption of the blood-brain barrier. Further studies are needed to investigate the exact mechanisms behind our findings.”
Dr. Ntranos also offered some words of caution:
“As with any observational study, it is important to keep in mind that the findings do not establish causality, and more research is needed to understand the underlying mechanisms and to confirm the findings… Overall, while these study provides important insights into the link between sleep and MS risk, it is only one piece of the puzzle. Further research is needed to fully understand the complex interplay of genetic, environmental and lifestyle factors that contribute to MS risk.”
Gain
The study adds to evidence that adequate sleep is essential during the teenage years and that insufficient sleep can be detrimental to health. The authors note that educating parents and teens about the potential consequences of insufficient sleep is critical. Dr. Hedström noted MNT:
“Sufficient sleep is necessary for optimal immune functioning and especially among adolescents, [but] insufficient sleep is common. Patients with MS who have children often ask if there is some way they can reduce the risk of their children developing the disease. Our study indicates that adequate sleep during teenage years [years] can contribute to reduction[ing] the risk of later developing MS.”
