Shift Work Tied to Increased Multiple Sclerosis Risk

Working shifts for three or more years before age 20 tied to increased odds of developing MS

TUESDAY, Oct. 18 (HealthDay News) -- Working shifts, particularly before the age of 20 years, is associated with increased occurrence of multiple sclerosis (MS), according to a review published online Oct. 17 in the Annals of Neurology.

Anna Karin Hedström, M.D., from the Karolinska Institute in Stockholm, Sweden, and colleagues investigated the potential correlation between shift work and the risk of MS in two studies. One study involved 1,343 incident cases of MS and 2,900 controls, and the second included 5,129 prevalent cases and 4,509 controls. The occurrence of MS was compared in individuals who had been exposed to shift work at different ages, versus those who had never been exposed.

The investigators found that, in both studies, there was a significant correlation between shift work at a young age and the occurrence of MS (odds ratios [ORs], 1.6 in the incident study and 1.3 in the prevalence study). Compared with those who had never worked shifts, individuals who had worked shifts for three years or longer before the age of 20 years had an increased likelihood of developing MS (ORs, 2.0 in the incident study and 2.1 in the prevalence study).

"The observed association between shift work at a young age and occurrence of MS in two independent studies strengthens the notion of a true relationship," the authors write.

Two authors disclosed financial ties to the pharmaceutical industry.

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