Could Bad Sleep in Teen Years Raise Risks for MS?

In the current study, Torbjörn Åkerstedt and colleagues (2023) aimed to investigate the influence of sleep duration, circadian disruption, and sleep quality on MS risk. Multiple sclerosis (MS) is a disease that is believed to be caused by a combination of genetic and environmental factors. These factors include smoking, adolescent body mass index (BMI), Epstein-Barr virus infection, sun exposure, and vitamin D. However, one factor that has not been extensively studied in relation to MS is shift work.

Shift work can disrupt the body's natural sleep-wake patterns, leading to restricted sleep duration, which can affect immune pathways and increase the risk of inflammatory chronic diseases. Additionally, shift work can disrupt the body's natural circadian rhythms, which can lead to disturbed melatonin secretion and immune dysfunction. Previous studies have found that shift work may be associated with an increased risk of MS, particularly when the exposure occurs at a young age.

Both human and animal studies have suggested that insufficient sleep may contribute to the risk of inflammatory chronic diseases and neurodegenerative processes. However, the possible link between sleep patterns and MS risk has not been previously investigated.

The study is a population-based case-control study that includes the Swedish general population aged 16-70 years. Cases were recruited from hospital-based and privately run neurology units and diagnosed according to the McDonald criteria by local neurologists. For each case, two controls were randomly selected from the national population register and matched by age in 5-year age groups, sex, and residential area. A standardized questionnaire was used to collect information on lifestyle factors and different exposures. Complementary questions, including questions about sleep habits, were sent to all participants who had answered the questionnaire during the previous period. Participants with disease onset before the age of 20 and those who were unable to answer the questions about sleep habits were excluded. Therefore, the study includes 2075 cases and 3164 controls.

From the results of the study, the researchers found that individuals who have a history of short sleep duration and low sleep quality during adolescence may have an increased risk of developing multiple sclerosis (MS) later in life. The study suggests that there is a link between sleep habits and MS risk, and that insufficient sleep may contribute to the risk of inflammatory chronic diseases and neurodegenerative processes. However, the study also notes that these findings should be interpreted with caution due to the potential for reverse causation, and that further research is needed to confirm the association and understand the underlying mechanisms. The study also highlights that insufficient sleep is a common problem among adolescents, and that educational interventions addressing this issue may be important for preventing MS and other health problems.

References:

Åkerstedt, T., Olsson, T., Alfredsson, L., et al. (2023). Insufficient sleep during adolescence and risk of multiple sclerosis: results from a Swedish case-control study. Journal of Neurology, Neurosurgery & Psychiatry. doi: 10.1136/jnnp-2022-330123.