Objective To assess the determinants of amyotrophic lateral sclerosis (ALS) phenotypes in a population-based cohort. Methods The study population included 2,839 patients with ALS diagnosed in Piemonte, Italy (1995–2015). Patients were classified according to motor (classic, bulbar, flail arm, flail leg, predominantly upper motor neuron [PUMN], respiratory) and cognitive phenotypes (normal, ALS with cognitive impairment [ALSci], ALS with behavioral impairment [ALSbi], ALSci and ALSbi combined [ALScbi], ALS–frontotemporal dementia [FTD]). Binary logistic regression analysis was adjusted for sex, age, and genetics. Results Bulbar phenotype correlated with older age (p < 0.0001), women were more affected than men at increasing age (p < 0.0001), classic with younger age (p = 0.029), men were more affected than women at increasing age (p < 0.0001), PUMN with younger age (p < 0.0001), flail arm with male sex (p < 0.0001) and younger age (p = 0.04), flail leg with male sex with increasing age (p = 0.008), and respiratory with male sex (p < 0.0001). C9orf72 expansions correlated with bulbar phenotype (p < 0.0001), and were less frequent in PUMN (p = 0.041); SOD1 mutations correlated with flail leg phenotype (p < 0.0001), and were less frequent in bulbar (p < 0.0001). ALS-FTD correlated with C9orf72 (p < 0.0001) and bulbar phenotype (p = 0.008), ALScbi with PUMN (p = 0.014), and ALSci with older age (p = 0.008). Conclusions Our data suggest that the spatial–temporal combination of motor and cognitive events leading to the onset and progression of ALS is characterized by a differential susceptibility to the pathologic process of motor and prefrontal cortices and lower motor neurons, and is influenced by age, sex, and gene variants. The identification of those factors that regulate ALS phenotype will allow us to reclassify patients into pathologically homogenous subgroups, responsive to targeted personalized therapies.

Objectives To assess the role of body mass index (BMI) and of the rate of weight loss as prognostic factors in amyotrophic lateral sclerosis (ALS) and to explore the clinical correlates of weight loss in the early phases of the disease. Methods The study cohort included all ALS patients in Piemonte/Valle d’Aosta in the 2007–2011 period. Overall survival and the probability of death/tracheostomy at 18 months (logistic regression model) were calculated. Results Of the 712 patients, 620 (87.1%) were included in the study. Patients ’ survival was related to the mean monthly percentage of weight loss at diagnosis (p<0.0001), but not to pre-morbid BMI or BMI at diagnosis. Spinal onset patients with dysphagia at diagnosis had a median survival similar to bulbar onset patients. About 20% of spinal onset patients without dysphagia at diagnosis had severe weight loss and initial respiratory impairment, and had a median survival time similar to bulbar onset patients. Conclusions The rate of weight loss from onset to diagnosis was found to be a strong and independent prognostic factor in ALS. Weight loss was mainly due to the reduction of nutritional intake related to dysphagia, but a subgroup of spinal onset patients without dysphagia at diagnosis had a severe weight loss and an outcome similar to bulbar patients. According to our findings, we recommend that in clinical trials patients should be stratified according to the presence of dysphagia at the time of enrolment and not by site of onset of symptoms.

Objective: To investigate the role of hormonal risk factors for amyotrophic lateral sclerosis (ALS) among women from 3 European countries. Methods: ALS cases and matched controls were recruited over 4 years in Ireland, Italy, and the Netherlands. Hormonal exposures, including reproductive history, breastfeeding, contraceptive use, hormonal replacement therapy, and gynecologic surgical history, were recorded with a validated questionnaire. Logistic regression models adjusted for age, education, study site, smoking, alcohol, and physical activity were used to determine the association between female hormones and ALS risk. Results: We included 653 patients and 1,217 controls. Oral contraceptive use was higher among controls (odds ratio [OR] 0.65, 95% confidence interval [CI] 0.51–0.84), and a dose-response effect was apparent. Hormone replacement therapy (HRT) was associated with a reduced risk of ALS only in the Netherlands (OR = 0.57, 95% CI 0.37–0.85). These findings were robust to sensitivity analysis, but there was some heterogeneity across study sites. Conclusions: This large case-control study across 3 different countries has demonstrated an association between exogenous estrogens and progestogens and reduced odds of ALS in women. These results are at variance with previous findings, which may be partly explained by differential regulatory, social, and cultural attitudes toward pregnancy, birth control, and HRT across the countries included. Our results indicate that hormonal factors may be important etiologic factors in ALS; however, a full understanding requires further investigation.

Objective: To investigate the association between physical activity (PA) and amyotrophic lateral sclerosis (ALS) in population-based case–control studies in three European countries using a validated and harmonised questionnaire.Methods: Patients with incident ALS and controls were recruited from five population-based registers in The Netherlands, Ireland and Italy. Demographic and data regarding educational level, smoking, alcohol habits and lifetime PA levels in both leisure and work time were gathered by questionnaire, and quantified using metabolic equivalent of task scores. Logistic regression models adjusting for PA-related factors were used to determine the association between PA and ALS risk, and forest plots were used to visualise heterogeneity between regions.Results: 1557 patients and 2922 controls were included. We found a linear association between ALS and PA in leisure time (OR 1.07, P=0.01) and occupational activities (OR 1.06, P<0.001), and all activities combined (OR 1.06, P<0.001), with some heterogeneity between regions: the most evident association was seen in the Irish and Italian cohorts. After adjustment for other occupational exposures or exclusion of patients with a C9orf72 mutation, the ORs remained similar.Conclusion: We provide new class I evidence for a positive association between PA and risk of ALS in a large multicentre study using harmonised methodology to objectively quantify PA levels, with some suggestions for population differences.