Shift work influences multiple sclerosis risk

• Published in: Multiple sclerosis Vol. 21; no. 9; pp. 1195 - 1199
• Main Authors: Hedström, AK, Åkerstedt, T, Olsson, T, Alfredsson, L
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.08.2015; Sage Publications Ltd
• Subjects: Adolescence; Adolescent; Adult; Age Factors; Aged; Case-Control Studies; circadian rhythm; Female; Humans; immunology; Incidence; Male; Middle Aged; multiple sclerosis; Multiple Sclerosis - epidemiology; Odds Ratio; Risk Factors; shift work; sleep deprivation; work schedule; Work Schedule Tolerance; Young Adult; Adolescence; shift work; risk factors; sleep deprivation; multiple sclerosis; circadian rhythm; work schedule; immunology
• ISSN: 1352-4585; 1477-0970; 1477-0970
• DOI: 10.1177/1352458514563592

Background: An association between working shift at a young age and subsequent risk for multiple sclerosis (MS) has been observed. Objective: To investigate whether this finding could be replicated, and to further explore the influence of age at first exposure to shift work. Methods: Using a Swedish population-based, case-control study (2337 cases and 4904 controls), the incidence of MS among subjects whom had worked shifts was compared with that of those whom had not, by calculating odds ratios (ORs) with 95% confidence intervals (CIs) by means of logistic regression. Results: The OR of developing MS was 1.5 (95% CI 1.2–1.8) among those whom started working shifts before age 20, whereas a less pronounced association was observed among those whom started working shifts at age 20 or later (OR 1.2; 95% CI 1.1–1.4). The effect of shift work was more pronounced among subjects whom had been exposed at a young age, regardless of the duration between the start of shift work and disease onset. Conclusion: Some aspects of adolescence seem to be of great importance, regarding the impact of shift work on MS risk. Circadian disruption and sleep deprivation may contribute towards explaining the association; however, the exact mechanisms behind our observations remain to be elucidated.