RT Journal Article
SR Electronic
T1 Effect modification of the association between total cigarette smoking and ALS risk by intensity, duration and time-since-quitting: Euro-MOTOR
JF Journal of Neurology, Neurosurgery & Psychiatry
JO J Neurol Neurosurg Psychiatry
FD BMJ Publishing Group Ltd
SP 33
OP 39
DO 10.1136/jnnp-2019-320986
VO 91
IS 1
A1 Susan Peters
A1 Anne E Visser
A1 Fabrizio D'Ovidio
A1 Jelle Vlaanderen
A1 Lützen Portengen
A1 Ettore Beghi
A1 Adriano Chio
A1 Giancarlo Logroscino
A1 Orla Hardiman
A1 Elisabetta Pupillo
A1 Jan H Veldink
A1 Roel Vermeulen
A1 Leonard H van den Berg
A1 ,
YR 2020
UL http://jnnp.bmj.com/content/91/1/33.abstract
AB Background We investigated the association between cigarette smoking and risk of amyotrophic lateral sclerosis (ALS) in a pooled analysis of population-based case–control studies and explored the independent effects of intensity, duration and time-since-quitting.Methods ALS cases and controls, matched by age, sex and region, were recruited in the Netherlands, Italy and Ireland (*Euro-MOTOR project). Demographics and detailed lifetime smoking histories were collected through questionnaires. Effects of smoking status, intensity (cigarettes/day), duration (years), pack-years and time-since-quitting (years) on ALS risk were estimated using logistic regression models, adjusting for age, sex, alcohol, education and centre. We further investigated effect modification of the linear effects of pack-years by intensity, duration and time-since-quitting using excess OR (eOR) models.Results Analyses were performed on 1410 cases and 2616 controls. Pack-years were positively associated with ALS risk; OR=1.26 (95% CI: 1.03 to 1.54) for the highest quartile compared with never smokers. This association appeared to be predominantly driven by smoking duration (ptrend=0.001) rather than intensity (ptrend=0.86), although the trend for duration disappeared after adjustment for time-since-quitting. Time-since-quitting was inversely related to ALS (ptrend<0.0001). The eOR decreased with time-since-quitting smoking, until about 10 years prior to disease onset. High intensity smoking with shorter duration appeared more deleterious than lower intensity for a longer duration.Conclusions Our findings provide further support for the association between smoking and ALS. Pack-years alone may be insufficient to capture effects of different smoking patterns. Time-since-quitting appeared to be an important factor, suggesting that smoking may be an early disease trigger.