LYON, FRANCE—Smoking is associated with an increased risk for
multiple sclerosis (MS), according to Jonathan Salzer, MD, from
the Department of Neurology at Umeå University in Sweden, and
colleagues, who reported their study findings at the 28th
Congress of the European Committee for Treatment and Research in
Multiple Sclerosis (ECTRIMS). They found that elevated cotinine
levels in serum and plasma samples drawn a median of nine years
prior to disease onset were associated with a 50% increased risk
for MS. The effect was only evident in those under a median age
of 26.4. The association, the researchers said, became slightly
stronger when excluding users of smokeless tobacco. Dr. Salzer
and colleagues sought to investigate the effects of laboratory-
defined tobacco use on the risk for MS using prospectively
collected biobank blood samples. Their nested case-control study
was performed in northern Sweden, and used two population-based
biobank cohorts to identify blood samples collected before MS
onset. Levels of