Physical activity and amyotrophic lateral sclerosis: a European population-based case-control study.

OBJECTIVE: To assess whether physical activity is a risk factor for amyotrophic lateral sclerosis (ALS). METHODS: From February 2008 to April 2012, 652 patients with ALS from European population-based registries (France, Ireland, Italy, United Kingdom, Serbia) and 1,166 population controls (matched for age, sex, and residency) were assessed. Upon direct interview, data were collected on occupation and history of sport and leisure activities, physical activity, and accidental injuries. Physical exercise was defined as having spent time doing activities that caused an individual to breath hard at least once per month and was coded as none, job-related, and/or sport-related. Sport-related and work-related physical exercise were quantified using metabolic equivalents (METs). Risks were calculated using conditional logistic regression models (adjusting for age, country, trauma, and job-related physical activity) and expressed as odds ratios (ORs) and adjusted ORs (Adj ORs) with 95% confidence intervals (CIs). RESULTS: Overall physical activity was associated with reduced odds of having ALS (Adj OR=0.65, 95% CI=0.48-0.89) as were work-related physical activity (Adj OR=0.56, 95% CI=0.36-0.87) and organized sports (Adj OR=0.49, 95% CI=0.32-0.75). An inverse correlation was observed between ALS, the duration of physical activity (p=0.0041), and the cumulative MET scores, which became significant for the highest exposure (Adj OR=0.34, 95% CI=0.21-0.54). An inverse correlation between ALS and sport was found in women but not in men, and in subjects with repeated traumatic events. INTERPRETATION: Physical activity is not a risk factor for ALS and may eventually be protective against the disease.

Trauma and amyotrophic lateral sclerosis: a european population-based case-control study from the EURALS consortium.

OBJECTIVES: To assess the association between amyotrophic lateral sclerosis (ALS) and previous traumatic events, age of trauma, and site of injury. METHODS: A population-based case-control study was performed in five European countries (Italy, Ireland, France, United Kingdom, Serbia). Newly diagnosed ALS patients and matched controls were interviewed to collect relevant demographic factors and exposures. Key clinical features at diagnosis were collected in ALS patients. Trauma was any accidental event causing an injury. Injuries were dated and classified according to cause, severity, type, site, and complications. All exposures were censored five years before symptoms onset. Risks were computed as odds ratios (OR) with 95% confidence intervals (CI) using univariate and multivariate conditional logistic regression models. RESULTS: Five hundred and seventy-five ALS patients and 1150 controls were interviewed. Disabling traumatic events predominated in the cases (OR 1.54 (95% CI 1.24-1.92)) and maintained significance after adjustment, with a significant gradient. A history of 2 + head injuries was associated with an almost three-fold increased risk of ALS. The risk was almost two-fold when trauma occurred at age 35-54 years. Site of injury was uneventful. CONCLUSIONS: Traumatic events leading to functional disability or confined to the head are risk factors for ALS. Traumatic events experienced at age 35-54 years carry the highest risk.