Author(s): Mills R.J.; Young C.A.; Tennant A.
Source: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration; 2018; vol. 19 ; p. 183-184
Publication Date: 2018
Publication Type(s): Conference Abstract
Abstract:Background: Cellular oxidative stress is thought to be important in the pathogenesis of motor neurone disease (MND) in susceptible individuals (1). Smoking promotes oxidative stress and in a metanalysis of case-control studies, smoking has been established as a risk factor for developing MND (2). A smoking history is also linked with shorter survival time (3). Objective(s): To explore whether a history of smoking affects age of onset in patients with an established diagnosis of MND. Method(s): Subject demographics and disease data as well as detailed smoking history were collected through a questionnaire pack for self-completion, in the ongoing longitudinal Trajectories of Outcomes in Neurological Conditions (TONiC) study in the UK. Comparisons were made by T test or one way ANOVA (alpha 0.05). Result(s): 327 records with smoking history data were available for analysis. 61% were male; mean age of 65 years, median disease duration 8 months. Mean age of disease onset was 63.5 years. 172 subjects had never smoked, 126 had previously smoked and 29 were current smokers. ANOVA revealed a significant difference in the age of onset between groups with a mean difference of 6.1 years (p=0.07). Duncan’s post hoc test revealed that never smokers and former smokers were an homogenous subgroup and that the difference was therefore between these (mean age onset 64 years) and current smokers (mean age onset 57.9 years). Discussion and conclusions: Subjects who continued to smoke developed MND, on average, 6.1 years before those who were previous or never smokers. Further work is required to determine the minimum tobacco exposure necessary to produce this effect and the minimum length of time required for smoking cessation to mitigate the effect. The study provides another reason for smoking avoidance in the general population and suggests smoking cessation advice should be imperative for individuals thought to be at higher risk of developing MND.