Smoking as a risk factor for multiple sclerosis

Abstract

This is an accepted version of a paper published in Multiple Sclerosis. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination.Citation for the published paper: Salzer, J., Hallmans, G., Nyström, M., Stenlund, H., Wadell, G. et al. (2012) Objective: To investigate the effects of laboratory defined tobacco use on the risk for multiple sclerosis using prospectively collected biobank blood samples.Methods: Levels of cotinine were measured in n=192 cases, and n=384 matched controls, using an immunoassay. The risk for multiple sclerosis was estimated using matched logistic regression.Results: Elevated cotinine levels (≥10 ng/ml) were associated with a significantly increased risk for multiple sclerosis, (OR 1.5, 95% CI 1.0-2.1). This association was only present in young individuals (below median age at blood sampling, <26.4 years), (OR 2.2, 95% CI 1.3- 3.8).Conclusions: This study confirms that smoking is a risk factor for multiple sclerosis. It has the advantage of using analyses of cotinine levels in samples that were collected several years before disease onset, thus excluding any risk for recall bias and minimising the risk for reversed causation. Our results also suggest that the smoking related immunological events that contribute to the development of multiple sclerosis occur early in life.

Comparative study of adenosine deaminase activity, insulin resistance and lipoprotein(a) among smokers and healthy non-smokers

“…It has a direct effect on diseases like ischemic heart disease and lung cancer and also involved in the pathogenesis of diseases like rheumatoid arthritis, diabetes mellitus and inflammatory bowel disease and immune function. [12][13][14] Studies demonstrated change in ADA activities in pleural fluid of patients with COPD which are more commonly associated with smoking.…”

Miljøets betydning ved multippel sklerose

“…Øknin-gen i sykdomsrisiko er også bekreftet ved at forhøyede nivåer av kotinin (en surrogatmarkør for nikotin) ble målt i blodprøver tatt før utvikling av multippel sklerose (27). Nikotin per se er imidlertid neppe en viktig patogen faktor, da bruk av snus ikke ser ut til å øke risikoen (28) og fordi nikotin beskytter mot utvikling av multippel sklerose-liknende sykdom hos mus (29).…”

“…Sårbarhetspe-rioden for røyking er ikke avklart. I en studie var det ingen alderspåvirkning (26), mens en (27).…”

Timing of cigarette smoking as a risk factor for multiple sclerosis

“…We have recently reported the findings of a nested case-control study where levels of cotinine, a recognized biomarker for tobacco use, were measured in biobank blood samples collected median 9 years prior to disease onset [Salzer et al 2012a]. Elevated levels of cotinine suggestive of smoking (≥10 ng/ml) [Vineis et al 2005] were associated with a 50% increased risk of MS when analyzing the entire cohort.…”