- 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 modify their risk.
- A recent study found that not getting enough sleep and low sleep quality in adolescence may increase the risk of developing multiple sclerosis later in life.
Sleep is essential to health, helping the body maintain its normal 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 & Psychiatry found that poor sleep in adolescence may increase the risk of developing multiple sclerosis (MS).
People with multiple sclerosis can experience a wide range
It is unclear why certain people develop multiple sclerosis. It could be related to a response by the body’s immune system. People with a family member with multiple sclerosis may have increased susceptibility to developing the disorder.
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 the 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 duration into three categories:
- less than seven hours each night (short sleep)
- between seven and nine hours each 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 free days. Finally, researchers asked participants about sleep quality, ranging from very bad to very good.
The study found that sleeping less than seven hours at night during adolescence was associated with an increased risk of developing multiple sclerosis. Low sleep quality offered a similar associated risk. They found that the sleep timing differences between weekends and school days did not significantly impact a person’s risk for multiple sclerosis.
Study author and researcher with the Karolinska Institute, Dr. Anna Hedström, explained to MNT:
“We set out to explore whether habitual sleep patterns at [a] young age affect the risk of later developing MS. Both insufficient [and] poor sleep negatively affects the immune system in several ways and has been associated with an increased risk of other inflammatory diseases. We found that sleeping too little or experiencing poor sleep quality increased the risk of later developing MS up 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’s also worth noting that the study’s findings remained similar when those who worked shifts were excluded, which is an important consideration as shift work is often associated with sleep deprivation and circadian desynchrony and these are known as risk factors for MS.”
The study did have some limitations. First, the study cannot prove that poor sleep causes multiple sclerosis. The authors admit that reverse causation, recall bias, selection bias, and residual confounding are possible.
Researchers also relied on data from questionnaires completed by participants, which can run the risk of inaccuracies. They also admit that they may have been components they didn’t adjust to, like 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 may 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 a few 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 this study provides important insights into the association between sleep and MS risk, it is just 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.”
The study adds to the evidence that adequate sleep is essential during the teen years and that inadequate sleep can be detrimental to health. The authors note that educating parents and teens about the potential consequences of insufficient sleep is critical. Dr. Hedstrom noted to MNT:
“Adequate sleep is necessary for optimal immune functioning and especially among adolescents, [but] insufficient sleep is common. Patients with MS who have children often ask whether they can somehow reduce the risk of their children developing the disease. Our study indicates that adequate sleep during teenage [years] could contribute to reduce[ing] the risk of later developing MS.”