Smoking is an important risk factor for MS. We therefore did a updated meta-analysis of all studies published on the topic. Our results confirm that smoking is associated with MS susceptibility and increases the risk of getting MS by ~50% (conservative: risk ratio (RR) 1.48, 95% confidence interval (CI) 1.35-1.63, p < 10⁻¹⁵; non-conservative: RR 1.52, 95% CI 1.39-1.66, p < 10⁻¹⁹). We also analysed 4 studies reporting the risk of developing secondary progressive MS; this fell just short of being statistical significance(RR 1.88, 95% CI 0.98-3.61, p = 0.06), but suggests that people with MS should probably stop smoking. "The million dollar question is how does smoking increase susceptibility to MS? We need to answer this to explain the MS causal pathway. We can't leave any stone unturned."
PLEASE COMPLETE THE MINI SMOKING SURVEY ON THE RIGHT, THANKS!
Handel et al. PLoS One. 2011 Jan 13;6(1):e16149.
COI: This work was done by our group.