The significance of environmental and lifestyle factors for the onset and course of multiple sclerosis.

Multiple sclerosis (MS) is the leading cause of non-traumatic neurological disability in young adults in Europe. The etiology is unclear. Twin studies suggest that environment and/or lifestyle play a crucial etiological role.

We have initiated a population-based case-control study, called EIMS, where individual and environmental factors for the first time are investigated systematically with concomitant genetic information.

Newly diagnosed cases of MS and randomly chosen controls are identified and asked about e.g. socio-demographic factors, lifestyle/environmental factors, sunlight exposure, oral contraceptive/hormonal factors, vaccinations, infections, atopic disease, trauma, various work related exposures and psychosocial factors.

For both cases and controls blood samples are taken for analysis of putative risk genes since environmental exposure probably contribute to disease only in individuals with certain genotypes. Cases are followed regarding course of disease.

Today, data from 3700 cases and 7000 controls have been gathered and so far very interesting and important findings have emerged.

If environmental and/or lifestyle factors can be identified as contributing causes to MS, this will enable preventive measures, which can lead to important gains with regard to health, working life and economics, both on the individual and societal level.

Such knowledge could potentially also lead to improved understanding of disease mechanisms for chronic disease in general.