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Kim K, Ko DS, Kim JW, Lee D, Son E, Kim HW, Song TJ, Kim YH. Association of smoking with amyotrophic lateral sclerosis: A systematic review, meta-analysis, and dose-response analysis. Tob Induc Dis 2024; 22:TID-22-13. [PMID: 38239315 PMCID: PMC10795623 DOI: 10.18332/tid/175731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 11/09/2023] [Accepted: 11/22/2023] [Indexed: 01/22/2024] Open
Abstract
INTRODUCTION Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder primarily affecting the voluntary motor nervous system. Several observational studies have provided conflicting results regarding the association between smoking and ALS. Therefore, our objective was to investigate this association through a systematic review, meta-analysis, and dose-response analysis. METHODS On 16 January 2023, we initially extracted records from medical databases, which included Medline, Embase, Web of Science, Scopus, and ScienceDirect. We included case-control and cohort studies as eligible studies. Subgroup analyses were performed based on sex, study design, and current smoking. Restricted cubic-spline analysis was utilized to assess the dose-response relationship between smoking (pack-years) and ALS. RESULTS Twenty-eight case-control and four cohort studies met the inclusion criteria. The unadjusted OR for the overall association between smoking and ALS was 1.14 (95% CI: 1.06-1.22, I2=44%, p<0.001), and the adjusted OR (AOR) was 1.12 (95% CI: 1.03-1.21, I2=49%, p=0.009). Subgroup analysis revealed a more pronounced association among current smokers, with an AOR of 1.28 (95% CI: 1.10-1.49, I2=66%, p<0.001) and AOR of 1.28 (95% CI: 1.10-1.48, I2=58%, p=0.001). In the dose-response analysis, the non-linear model revealed an inverted U-shaped curve. CONCLUSIONS Our study provides evidence of a positive relationship between smoking and the risk of ALS. To mitigate the risk of developing ALS, discontinuing smoking, which is a modifiable risk factor, may be crucial.TRIAL REGISTRATION: The study was registered in PROSPERO.IDENTIFIER: CRD42023388822.
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Affiliation(s)
- Kihun Kim
- Department of Biomedical Informatics, School of Medicine, Pusan National University, Yangsan, Republic of Korea
- Department of Anatomy, School of Medicine, Pusan National University, Yangsan, Republic of Korea
| | - Dai Sik Ko
- Division of Vascular Surgery, Department of General Surgery, Gachon University Gil Medical Center, Incheon, Republic of Korea
| | - Jin-Woo Kim
- Department of Oral and Maxillofacial Surgery, School of Medicine, Ewha Womans University Medical Center, Republic of Korea
| | - Dongjun Lee
- Department of Biomedical Informatics, School of Medicine, Pusan National University, Yangsan, Republic of Korea
| | - Eunjeong Son
- Division of Respiratory and Allergy, Department of Internal Medicine, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Hyun-Woo Kim
- Department of Neurology, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Tae-Jin Song
- Department of Neurology, Seoul Hospital, Ewha Womans University College of Medicine, Gangseo-gu, Republic of Korea
| | - Yun Hak Kim
- Department of Biomedical Informatics, School of Medicine, Pusan National University, Yangsan, Republic of Korea
- Department of Anatomy, School of Medicine, Pusan National University, Yangsan, Republic of Korea
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Vasta R, Chia R, Traynor BJ, Chiò A. Unraveling the complex interplay between genes, environment, and climate in ALS. EBioMedicine 2022; 75:103795. [PMID: 34974309 PMCID: PMC8728044 DOI: 10.1016/j.ebiom.2021.103795] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/03/2021] [Accepted: 12/16/2021] [Indexed: 12/11/2022] Open
Abstract
Various genetic and environmental risk factors have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). Despite this, the cause of most ALS cases remains obscure. In this review, we describe the current evidence implicating genetic and environmental factors in motor neuron degeneration. While the risk exerted by many environmental factors may appear small, their effect could be magnified by the presence of a genetic predisposition. We postulate that gene-environment interactions account for at least a portion of the unknown etiology in ALS. Climate underlies multiple environmental factors, some of which have been implied in ALS etiology, and the impact of global temperature increase on the gene-environment interactions should be carefully monitored. We describe the main concepts underlying such interactions. Although a lack of large cohorts with detailed genetic and environmental information hampers the search for gene-environment interactions, newer algorithms and machine learning approaches offer an opportunity to break this stalemate. Understanding how genetic and environmental factors interact to cause ALS may ultimately pave the way towards precision medicine becoming an integral part of ALS care.
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Affiliation(s)
- Rosario Vasta
- ALS Center, Department of Neuroscience "Rita Levi Montalcini", University of Turin, via Cherasco 15, Turin 1026, Italy; Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging (NIH), Bethesda, MD 20892, USA
| | - Ruth Chia
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging (NIH), Bethesda, MD 20892, USA
| | - Bryan J Traynor
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging (NIH), Bethesda, MD 20892, USA; Reta Lila Weston Institute, UCL Queen Square Institute of Neurology, University College London, London WC1N 1PJ, UK; Department of Neurology, Johns Hopkins University Medical Center, Baltimore, MD 21287, USA; National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA; ASO Rapid Development Laboratory, Therapeutics Development Branch, National Center for Advancing Translational Sciences, NIH, Rockville, MD, USA
| | - Adriano Chiò
- ALS Center, Department of Neuroscience "Rita Levi Montalcini", University of Turin, via Cherasco 15, Turin 1026, Italy; Institute of Cognitive Sciences and Technologies, C.N.R., Rome 00185, Italy; Neurology 1, AOU Città della Salute e della Scienza di Torino, Turin, Italy.
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Su WM, Cheng YF, Jiang Z, Duan QQ, Yang TM, Shang HF, Chen YP. Predictors of survival in patients with amyotrophic lateral sclerosis: A large meta-analysis. EBioMedicine 2021; 74:103732. [PMID: 34864363 PMCID: PMC8646173 DOI: 10.1016/j.ebiom.2021.103732] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/10/2021] [Accepted: 11/22/2021] [Indexed: 02/04/2023] Open
Abstract
Background The survival time of amyotrophic lateral sclerosis (ALS) is greatly variable and protective or risk effects of the potential survival predictors are controversial. Thus, we aim to undertake a comprehensive meta-analysis of studies investigating non-genetic prognostic and survival factors in patients with ALS. Methods A search of relevant literature from PubMed, Embase, Cochrane library and other citations from 1st January 1966 to 1st December 020 was conducted. Random-effects models were conducted to pool the multivariable or adjusted hazard ratios (HR) by Stata MP 16.0. PROSPERO registration number: CRD42021256923. Findings A total of 5717 reports were identified, with 115 studies meeting pre-designed inclusion criteria involving 55,169 ALS patients. Five dimensions, including demographic, environmental or lifestyle, clinical manifestations, biochemical index, therapeutic factors or comorbidities were investigated. Twenty-five prediction factors, including twenty non-intervenable and five intervenable factors, were associated with ALS survival. Among them, NFL (HR:3.70, 6.80, in serum and CSF, respectively), FTD (HR:2.98), ALSFRS-R change (HR:2.37), respiratory subtype (HR:2.20), executive dysfunction (HR:2.10) and age of onset (HR:1.03) were superior predictors for poor prognosis, but pLMN or pUMN (HR:0.32), baseline ALSFRS-R score (HR:0.95), duration (HR:0.96), diagnostic delay (HR:0.97) were superior predictors for a good prognosis. Our results did not support the involvement of gender, education level, diabetes, hypertension, NIV, gastrostomy, and statins in ALS survival. Interpretation Our study provided a comprehensive and quantitative index for assessing the prognosis for ALS patients, and the identified non-intervenable or intervenable factors will facilitate the development of treatment strategies for ALS. Funding This study was supported by the National Natural Science Fund of China (Grant No. 81971188), the 1.3.5 project for disciplines of excellence, West China Hospital, Sichuan University (Grant No. 2019HXFH046), and the Science and Technology Bureau Fund of Sichuan Province (No. 2019YFS0216).
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Affiliation(s)
- Wei-Ming Su
- Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare disease center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yang-Fan Cheng
- Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare disease center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zheng Jiang
- Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare disease center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Qing-Qing Duan
- Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare disease center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Tian-Mi Yang
- Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare disease center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Hui-Fang Shang
- Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare disease center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| | - Yong-Ping Chen
- Department of Neurology, Laboratory of Neurodegenerative Disorders, Rare disease center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
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Abstract
Cigarette smoke (CS) has been consistently demonstrated to be an environmental risk factor for amyotrophic lateral sclerosis (ALS), although the molecular pathogenic mechanisms involved are yet to be elucidated. Here, we propose different mechanisms by which CS exposure can cause sporadic ALS pathogenesis. Oxidative stress and neuroinflammation are widely implicated in ALS pathogenesis, with blood–spinal cord barrier disruption also recognised to be involved in the disease process. In addition, immunometabolic, epigenetic and microbiome alterations have been implicated in ALS recently. Identification of the underlying pathophysiological mechanisms that underpin CS-associated ALS will drive future research to be conducted into new targets for treatment.
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Role of Oxidative Stress in the Pathogenesis of Amyotrophic Lateral Sclerosis: Antioxidant Metalloenzymes and Therapeutic Strategies. Biomolecules 2021; 11:biom11030437. [PMID: 33809730 PMCID: PMC8002298 DOI: 10.3390/biom11030437] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/12/2021] [Accepted: 03/12/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) affects motor neurons in the cerebral cortex, brainstem and spinal cord and leads to death due to respiratory failure within three to five years. Although the clinical symptoms of this disease were first described in 1869 and it is the most common motor neuron disease and the most common neurodegenerative disease in middle-aged individuals, the exact etiopathogenesis of ALS remains unclear and it remains incurable. However, free oxygen radicals (i.e., molecules containing one or more free electrons) are known to contribute to the pathogenesis of this disease as they very readily bind intracellular structures, leading to functional impairment. Antioxidant enzymes, which are often metalloenzymes, inactivate free oxygen radicals by converting them into a less harmful substance. One of the most important antioxidant enzymes is Cu2+Zn2+ superoxide dismutase (SOD1), which is mutated in 20% of cases of the familial form of ALS (fALS) and up to 7% of sporadic ALS (sALS) cases. In addition, the proper functioning of catalase and glutathione peroxidase (GPx) is essential for antioxidant protection. In this review article, we focus on the mechanisms through which these enzymes are involved in the antioxidant response to oxidative stress and thus the pathogenesis of ALS and their potential as therapeutic targets.
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Pereira M, Gromicho M, Henriques A, Pronto-Laborinho AC, Grosskreutz J, Kuźma-Kozakiewicz M, Petri S, Uysal H, Swash M, de Carvalho M. Cardiovascular comorbidities in amyotrophic lateral sclerosis. J Neurol Sci 2020; 421:117292. [PMID: 33423011 DOI: 10.1016/j.jns.2020.117292] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/18/2020] [Accepted: 12/22/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND The role of cardiovascular risk factors in amyotrophic lateral sclerosis (ALS) is controversial. A favourable profile has been found in ALS patients, but previous studies have not specifically considered the profile in different disease phenotypes. METHODS Demographic data, smoking habits, lifetime exercise, and medical history including diabetes mellitus, arterial hypertension, hypercholesterolemia, hypertriglyceridemia, stroke, and cardiac events, were analysed in ALS patients and in controls with other neurological disorders, utilising a standardized questionnaire applied by the same neurologist. In ALS patients the results were analysed according to their different phenotypes. Univariate analyses and multinomial logistic models were applied to estimate the odds ratios (ORs) and confidence intervals (CIs) for covariates, to test potential modifiers and their effects. RESULTS 500 consecutively assessed adult ALS patients (mean age 65.6, 47% women, and 136 bulbar-onset) and 327 age and gender-matched controls were studied. Patients with spinal-onset ALS took more exercise (p = 0.012), reported less hypertension (p = 0.002) and had fewer cardiac events (p = 0.012). Multinomial regression analysis showed that men without hypertension have a higher risk of having spinal-onset ALS (p < 0.001) while female with hypertension have a higher risk of having bulbar-onset ALS (p = 0.033). CONCLUSIONS Risk-factors in ALS can be influenced by gender and phenotype. This study suggests that men with spinal ALS are healthier, exercise more and have lower rate of hypertension, but females with bulbar-onset ALS are more prone to hypertension. The complex interplay between exercise, diet and comorbidities with ALS phenotype requires further investigation.
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Affiliation(s)
- Mariana Pereira
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Marta Gromicho
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
| | - Ana Henriques
- Departamento de Estatística e Investigação Operacional, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Ana Catarina Pronto-Laborinho
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | | | | | - Susanne Petri
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Hilmi Uysal
- Department of Neurology, Akdeniz University Faculty of Medicine, Antalya, Turkey
| | - Michael Swash
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal; Barts and the London School of Medicine, Queen Mary University of London, London, UK
| | - Mamede de Carvalho
- Instituto de Fisiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal; Departamento de Neurociências e Saúde Mental, Hospital de Santa Maria - Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
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7
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Opie-Martin S, Jones A, Iacoangeli A, Al-Khleifat A, Oumar M, Shaw PJ, Shaw CE, Morrison KE, Wootton RE, Davey-Smith G, Pearce N, Al-Chalabi A. UK case control study of smoking and risk of amyotrophic lateral sclerosis. Amyotroph Lateral Scler Frontotemporal Degener 2020; 21:222-227. [PMID: 32301340 PMCID: PMC7261396 DOI: 10.1080/21678421.2019.1706580] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Introduction: Susceptibility to amyotrophic lateral sclerosis (ALS) is associated with smoking in some studies, but it is not clear which aspect of smoking behavior is related. Using detailed records of lifetime smoking we investigated the relationship between smoking and ALS in a UK population. Methods: In this retrospective case-control study, smoking status was collected using environmental questionnaires from people diagnosed with ALS between 2008 and 2013 and from age, sex and geographically matched controls. Categorical measures of smoking behavior were: smoking at the time of survey and smoking initiation; continuous measures were intensity (cigarettes per day), duration (years from starting to stopping or time of survey), cigarette pack years, and comprehensive smoking index (CSI), a measure of lifetime smoking. We used logistic regression to assess the risk of ALS with different combinations of smoking variables adjusted for age at survey, gender, level of education, smoking status and alcohol initiation, selecting the best model using the Akaike Information Criterion. Results: There were 388 records with full smoking history. The best-fitting model used CSI and smoking status at the time of survey. We found a weak association between current smoking and risk of ALS, OR 3.63 (95% CI 1.02-13.9) p value 0.05. Increase in CSI score did not increase risk of ALS: OR 0.81 (95% CI 0.58-1.11) p value 0.2.Conclusion: There is weak evidence of a positive effect of current smoking on the risk of ALS which does not show dose-dependence with higher levels of lifetime smoking and maybe a false positive result.
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Affiliation(s)
- Sarah Opie-Martin
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, United Kingdom
| | - Ashley Jones
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, United Kingdom
| | - Alfredo Iacoangeli
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, United Kingdom
| | - Ahmad Al-Khleifat
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, United Kingdom
| | - Mohamed Oumar
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, United Kingdom
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Chris E Shaw
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, United Kingdom
| | - Karen E Morrison
- Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Robyn E Wootton
- MRC Integrative Epidemiology Unit at the University of Bristol, University of Bristol, Bristol, United Kingdom.,School of Psychological Science, University of Bristol, Bristol, United Kingdom.,NIHR Bristol Biomedical Research Centre, University Hospitals Bristol NHS Foundation Trust and University of Bristol, Bristol, United Kingdom
| | - George Davey-Smith
- MRC Integrative Epidemiology Unit at the University of Bristol, University of Bristol, Bristol, United Kingdom
| | - Neil Pearce
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ammar Al-Chalabi
- School of Psychological Science, University of Bristol, Bristol, United Kingdom
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Filippini T, Fiore M, Tesauro M, Malagoli C, Consonni M, Violi F, Arcolin E, Iacuzio L, Oliveri Conti G, Cristaldi A, Zuccarello P, Zucchi E, Mazzini L, Pisano F, Gagliardi I, Patti F, Mandrioli J, Ferrante M, Vinceti M. Clinical and Lifestyle Factors and Risk of Amyotrophic Lateral Sclerosis: A Population-Based Case-Control Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17030857. [PMID: 32019087 PMCID: PMC7037077 DOI: 10.3390/ijerph17030857] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/28/2020] [Accepted: 01/28/2020] [Indexed: 12/26/2022]
Abstract
Background: Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disease of the motor neurons. The etiology of ALS remains largely unknown, particularly with reference to the potential environmental determinants. Methods: We performed a population-based case-control study in four provinces from both Northern and Southern Italy in order to assess non-genetic ALS risk factors by collecting through tailored questionnaires information about clinical and lifestyle factors. We estimated ALS risk by calculating odds ratio (OR) with its 95% confidence interval (CI) using unconditional logistic regression models adjusted for sex, age and educational attainment. Results: We recruited 230 participants (95 cases and 135 controls). We found a possible positive association of ALS risk with trauma, particularly head trauma (OR = 2.61, 95% CI 1.19–5.72), electric shock (OR = 2.09, 95% CI 0.62–7.06), and some sports, although at a competitive level only. In addition, our results suggest an increased risk for subjects reporting use of private wells for drinking water (OR = 1.38, 95% CI 0.73–2.27) and for use of herbicides during gardening (OR = 1.95, 95% CI 0.88–2.27). Conversely, there was a suggestion of an inverse association with overall fish consumption (OR = 0.27, 95% CI 0.12–0.60), but with no dose-response relation. Consumption of some dietary supplements, namely those containing amino acids and, in the Southern Italy population, vitamins and minerals such as selenium, seemed associated with a statistically imprecise increased risk. Conclusions: Our results suggest a potential etiologic role a number of clinical and lifestyle factors with ALS risk. However, caution is needed due to some study limitations. These include the small sample size and the low number of exposed subjects, which affect statistical precision of risk estimates, the potential for exposure misclassification, and the uncertainties about mechanisms underpinning the possible association between these factors and disease risk.
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Affiliation(s)
- Tommaso Filippini
- CREAGEN—Environmental, Genetic and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (T.F.); (C.M.); (F.V.); (E.A.); (L.I.)
- Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Maria Fiore
- Department of Medical, Surgical Sciences and Advanced Technologies “G. F. Ingrassia”, Catania University, 95123 Catania, Italy; (M.F.); (G.O.C.); (A.C.); (P.Z.); (F.P.); (M.F.)
| | - Marina Tesauro
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, 20122 Milan, Italy; (M.T.); (M.C.)
| | - Carlotta Malagoli
- CREAGEN—Environmental, Genetic and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (T.F.); (C.M.); (F.V.); (E.A.); (L.I.)
| | - Michela Consonni
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, 20122 Milan, Italy; (M.T.); (M.C.)
| | - Federica Violi
- CREAGEN—Environmental, Genetic and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (T.F.); (C.M.); (F.V.); (E.A.); (L.I.)
- Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, 41125 Modena, Italy
- Azienda USL-IRCCS di Reggio Emilia, 42122 Reggio Emilia, Italy
| | - Elisa Arcolin
- CREAGEN—Environmental, Genetic and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (T.F.); (C.M.); (F.V.); (E.A.); (L.I.)
| | - Laura Iacuzio
- CREAGEN—Environmental, Genetic and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (T.F.); (C.M.); (F.V.); (E.A.); (L.I.)
- Department of Public Health, Local Health Unit, 41121 Modena, Italy
| | - Gea Oliveri Conti
- Department of Medical, Surgical Sciences and Advanced Technologies “G. F. Ingrassia”, Catania University, 95123 Catania, Italy; (M.F.); (G.O.C.); (A.C.); (P.Z.); (F.P.); (M.F.)
| | - Antonio Cristaldi
- Department of Medical, Surgical Sciences and Advanced Technologies “G. F. Ingrassia”, Catania University, 95123 Catania, Italy; (M.F.); (G.O.C.); (A.C.); (P.Z.); (F.P.); (M.F.)
| | - Pietro Zuccarello
- Department of Medical, Surgical Sciences and Advanced Technologies “G. F. Ingrassia”, Catania University, 95123 Catania, Italy; (M.F.); (G.O.C.); (A.C.); (P.Z.); (F.P.); (M.F.)
| | - Elisabetta Zucchi
- Neurology Unit, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy;
| | - Letizia Mazzini
- ALS Centre Department of Neurology, ‘Maggiore della Carità’ University Hospital, 28100 Novara, Italy; (L.M.); (I.G.)
| | - Fabrizio Pisano
- Neurological Rehabilitation Division, Policlinico San Marco di Zingonia, 24046 Zingonia (BG), Italy;
| | - Ileana Gagliardi
- ALS Centre Department of Neurology, ‘Maggiore della Carità’ University Hospital, 28100 Novara, Italy; (L.M.); (I.G.)
| | - Francesco Patti
- Department of Medical, Surgical Sciences and Advanced Technologies “G. F. Ingrassia”, Catania University, 95123 Catania, Italy; (M.F.); (G.O.C.); (A.C.); (P.Z.); (F.P.); (M.F.)
| | - Jessica Mandrioli
- Neurology Unit, Department of Neuroscience, S. Agostino Estense Hospital, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy;
| | - Margherita Ferrante
- Department of Medical, Surgical Sciences and Advanced Technologies “G. F. Ingrassia”, Catania University, 95123 Catania, Italy; (M.F.); (G.O.C.); (A.C.); (P.Z.); (F.P.); (M.F.)
| | - Marco Vinceti
- CREAGEN—Environmental, Genetic and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy; (T.F.); (C.M.); (F.V.); (E.A.); (L.I.)
- Department of Epidemiology, Boston University School of Public Health, Boston, MA 02118, USA
- Correspondence:
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Wei QQ, Chen Y, Chen X, Cao B, Ou R, Zhang L, Hou Y, Shang H. Clinical and prognostic features of ALS/MND in different phenotypes–data from a hospital-based registry. Brain Res Bull 2018; 142:403-408. [DOI: 10.1016/j.brainresbull.2018.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/03/2018] [Accepted: 09/11/2018] [Indexed: 10/28/2022]
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10
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Wang MD, Little J, Gomes J, Cashman NR, Krewski D. Identification of risk factors associated with onset and progression of amyotrophic lateral sclerosis using systematic review and meta-analysis. Neurotoxicology 2017; 61:101-130. [DOI: 10.1016/j.neuro.2016.06.015] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 06/29/2016] [Indexed: 12/11/2022]
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11
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Luna J, Logroscino G, Couratier P, Marin B. Current issues in ALS epidemiology: Variation of ALS occurrence between populations and physical activity as a risk factor. Rev Neurol (Paris) 2017; 173:244-253. [DOI: 10.1016/j.neurol.2017.03.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 03/29/2017] [Accepted: 03/31/2017] [Indexed: 11/16/2022]
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12
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Abstract
The causes of amyotrophic lateral sclerosis (ALS) are largely unknown, and may always be multiple, including environmental factors. Monogenetic determinants of ALS are involved in roughly 20% of all cases (including 10% familial cases). Less well understood multigenetic causes may contribute to another 20% to 80%. Environmental factors likely play a role in the development of ALS in susceptible individuals, but proved causation remains elusive. This article discusses the possible factors of male gender (males are selectively exposed to different influences, or genetically predisposed to be susceptible), smoking, military service, exercise, electrical exposure, heavy metals, agricultural chemicals, and geographic clusters.
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Affiliation(s)
- Björn Oskarsson
- UC Davis Multidisciplinary ALS Clinic, An ALS Association Certified Center of Excellence, University of California Davis Medical Center, 4860 Y Street, Suite 3700, Sacramento, CA 95817, USA.
| | - D Kevin Horton
- Division of Toxicology and Human Health Sciences, ATSDR/CDC, 4770 Buford Highway Northeast, Atlanta, GA 30341, USA
| | - Hiroshi Mitsumoto
- The Eleanor and Lou Gehrig MDA/ALS Research Center, The Neurological Institute, Columbia University Medical Center, 710 West 168th Street, Floor 9, New York, NY 10032, USA
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13
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Zufiría M, Gil-Bea FJ, Fernández-Torrón R, Poza JJ, Muñoz-Blanco JL, Rojas-García R, Riancho J, López de Munain A. ALS: A bucket of genes, environment, metabolism and unknown ingredients. Prog Neurobiol 2016; 142:104-129. [DOI: 10.1016/j.pneurobio.2016.05.004] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/22/2016] [Accepted: 05/09/2016] [Indexed: 12/11/2022]
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14
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Seals RM, Hansen J, Gredal O, Weisskopf MG. Physical Trauma and Amyotrophic Lateral Sclerosis: A Population-Based Study Using Danish National Registries. Am J Epidemiol 2016; 183:294-301. [PMID: 26825926 DOI: 10.1093/aje/kwv169] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 06/22/2015] [Indexed: 11/14/2022] Open
Abstract
Prior studies have suggested that physical trauma might be associated with the development of amyotrophic lateral sclerosis (ALS). We conducted a population-based, individually matched case-control study in Denmark to assess whether hospitalization for trauma is associated with a higher risk of developing ALS. There were 3,650 incident cases of ALS in the Danish National Patient Register from 1982 to 2009. We used risk-set sampling to match each case to 100 age- and sex-matched population controls alive on the date of the case's diagnosis. Odds ratios and 95% confidence intervals were calculated using a conditional logistic regression model. History of trauma diagnosis was also obtained from the Danish Patient Register. When traumas in the 5 years prior to the index date were excluded, there was a borderline association between any trauma and ALS (odds ratio (OR) = 1.09, 95% confidence interval (CI): 0.99, 1.19). A first trauma before age 55 years was associated with ALS (OR = 1.22, 95% CI: 1.08, 1.37), whereas first traumas at older ages were not (OR = 0.97, 95% CI: 0.85, 1.10). Our data suggest that physical trauma at earlier ages is associated with ALS risk. Age at first trauma could help explain discrepancies in results of past studies of trauma and ALS.
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Couratier P, Corcia P, Lautrette G, Nicol M, Preux PM, Marin B. Epidemiology of amyotrophic lateral sclerosis: A review of literature. Rev Neurol (Paris) 2015; 172:37-45. [PMID: 26727307 DOI: 10.1016/j.neurol.2015.11.002] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 11/10/2015] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease of motor neurons, resulting in worsening weakness of voluntary muscles until death occurs from respiratory failure. The incidence of ALS in European populations is two to three people per year per 100,000 of the general population. In Europe, crude prevalences range from 1.1/100,000 population in Yugoslavia to 8.2/100,000 in the Faroe Islands. Major advances have been made in our understanding of the genetic causes of ALS, whereas the contribution of environmental factors has been more difficult to assess and large-scale studies have not yet revealed a replicable, definitive environmental risk factor. The only established risk factors to date are older age, male gender and a family history of ALS. Median survival time from onset to death is usually 3 years from the first appearance of symptoms. Older age and bulbar onset are consistently reported to have poorer outcomes. However, there are conflicting data regarding gender, diagnostic delay and El Escorial criteria. The rate of symptom progression has been revealed to be an independent prognostic factor. Psychosocial factors and impaired cognitive function are negatively related to ALS outcome, while nutritional status and respiratory function are also related to ALS prognosis. The effect of enteral nutrition on survival is still unclear, although noninvasive positive pressure ventilation (NIPPV) has been found to improve survival. These findings have relevant implications for the design of future trials.
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Affiliation(s)
- P Couratier
- Centre de compétence SLA-fédération Tours-Limoges, CHU de Limoges, 2, avenue Martin-Luther-King, 87000 Limoges, France; Inserm UMR1094, neuroépidémiologie tropicale, université de Limoges, 2, rue du Dr.-Marcland, 87025 Limoges cedex, France.
| | - P Corcia
- Centre de compétence SLA-fédération Tours-Limoges, CHU de Tours, 37044 Tours cedex 9, France
| | - G Lautrette
- Centre de compétence SLA-fédération Tours-Limoges, CHU de Limoges, 2, avenue Martin-Luther-King, 87000 Limoges, France
| | - M Nicol
- Centre de compétence SLA-fédération Tours-Limoges, CHU de Limoges, 2, avenue Martin-Luther-King, 87000 Limoges, France
| | - P-M Preux
- Inserm UMR1094, neuroépidémiologie tropicale, université de Limoges, 2, rue du Dr.-Marcland, 87025 Limoges cedex, France
| | - B Marin
- Inserm UMR1094, neuroépidémiologie tropicale, université de Limoges, 2, rue du Dr.-Marcland, 87025 Limoges cedex, France
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Weisskopf MG, Cudkowicz ME, Johnson N. Military Service and Amyotrophic Lateral Sclerosis in a Population-based Cohort. Epidemiology 2015; 26:831-8. [PMID: 26414854 PMCID: PMC4604116 DOI: 10.1097/ede.0000000000000376] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2014] [Indexed: 11/26/2022]
Abstract
BACKGROUND Military service has been suggested to be associated with an increased risk of amyotrophic lateral sclerosis (ALS), but only one prospective study-of a volunteer cohort-has examined this question. METHODS We prospectively assessed the relation between service in the military and ALS mortality among participants in the National Longitudinal Mortality Study, a population-representative cohort of U.S. men and women surveyed from 1973 through 2002. Participant follow-up was conducted from 1979 through 2002 for ALS mortality. There were 696,743 men and 392,571 women who were 25 years old or more with military service data. In this group, there were 375 male ALS deaths and 96 female ALS deaths. Adjusted hazard ratios (HRs) were calculated using Cox proportional hazards. RESULTS Men who served in the military had an increased adjusted ALS death rate [HR: 1.23; 95% confidence interval (CI): 0.98, 1.53] compared with those who did not serve. An increase in ALS mortality was found among those who served during World War II (HR: 1.47; 95% CI: 1.13, 1.91) but not during other time periods. This pattern of results was similar for women, but with larger confidence intervals (HR for military service: 1.26; 95% CI: 0.29, 5.59; HR for service during World War II: 2.03; 95% CI: 0.45, 9.05). CONCLUSIONS Military personnel have an increased risk of ALS, which may be specific to certain service periods although there was no data on actual deployment. Because of the longer follow-up time for World War II veterans, we cannot rule out that increased risk for those who served during other periods would be seen with further follow-up.
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Affiliation(s)
- Marc G. Weisskopf
- From the Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA; Department of Neurology, Massachusetts General Hospital, Boston, MA; and Center for Administrative Records and Applications, US Bureau of the Census, Washington, DC
| | - Merit E. Cudkowicz
- From the Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA; Department of Neurology, Massachusetts General Hospital, Boston, MA; and Center for Administrative Records and Applications, US Bureau of the Census, Washington, DC
| | - Norman Johnson
- From the Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA; Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA; Department of Neurology, Massachusetts General Hospital, Boston, MA; and Center for Administrative Records and Applications, US Bureau of the Census, Washington, DC
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Abstract
Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. It is typically fatal within 2-5 years of symptom onset. The incidence of ALS is largely uniform across most parts of the world, but an increasing ALS incidence during the last decades has been suggested. Although recent genetic studies have substantially improved our understanding of the causes of ALS, especially familial ALS, an important role of non-genetic factors in ALS is recognized and needs further study. In this review, we briefly discuss several major genetic contributors to ALS identified to date, followed by a more focused discussion on the most commonly examined non-genetic risk factors for ALS. We first review factors related to lifestyle choices, including smoking, intake of antioxidants, physical fitness, body mass index, and physical exercise, followed by factors related to occupational and environmental exposures, including electromagnetic fields, metals, pesticides, β-methylamino-L-alanine, and viral infection. Potential links between ALS and other medical conditions, including head trauma, metabolic diseases, cancer, and inflammatory diseases, are also discussed. Finally, we outline several future directions aiming to more efficiently examine the role of non-genetic risk factors in ALS.
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Affiliation(s)
- Caroline Ingre
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Per M Roos
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Fredrik Piehl
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Freya Kamel
- Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Fang Fang
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
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18
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The disease intersection of susceptibility and exposure: Chemical exposures and neurodegenerative disease risk. Alzheimers Dement 2014; 10:S213-25. [DOI: 10.1016/j.jalz.2014.04.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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D’Amico E, Factor-Litvak P, Santella RM, Mitsumoto H. Clinical perspective on oxidative stress in sporadic amyotrophic lateral sclerosis. Free Radic Biol Med 2013; 65:509-527. [PMID: 23797033 PMCID: PMC3859834 DOI: 10.1016/j.freeradbiomed.2013.06.029] [Citation(s) in RCA: 216] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 06/14/2013] [Accepted: 06/14/2013] [Indexed: 12/12/2022]
Abstract
Sporadic amyotrophic lateral sclerosis (ALS) is one of the most devastating neurological diseases; most patients die within 3 to 4 years after symptom onset. Oxidative stress is a disturbance in the pro-oxidative/antioxidative balance favoring the pro-oxidative state. Autopsy and laboratory studies in ALS indicate that oxidative stress plays a major role in motor neuron degeneration and astrocyte dysfunction. Oxidative stress biomarkers in cerebrospinal fluid, plasma, and urine are elevated, suggesting that abnormal oxidative stress is generated outside of the central nervous system. Our review indicates that agricultural chemicals, heavy metals, military service, professional sports, excessive physical exertion, chronic head trauma, and certain foods might be modestly associated with ALS risk, with a stronger association between risk and smoking. At the cellular level, these factors are all involved in generating oxidative stress. Experimental studies indicate that a combination of insults that induce modest oxidative stress can exert additive deleterious effects on motor neurons, suggesting that multiple exposures in real-world environments are important. As the disease progresses, nutritional deficiency, cachexia, psychological stress, and impending respiratory failure may further increase oxidative stress. Moreover, accumulating evidence suggests that ALS is possibly a systemic disease. Laboratory, pathologic, and epidemiologic evidence clearly supports the hypothesis that oxidative stress is central in the pathogenic process, particularly in genetically susceptive individuals. If we are to improve ALS treatment, well-designed biochemical and genetic epidemiological studies, combined with a multidisciplinary research approach, are needed and will provide knowledge crucial to our understanding of ALS etiology, pathophysiology, and prognosis.
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Affiliation(s)
- Emanuele D’Amico
- Eleanor and Lou Gehrig MDA/ALS Research Center, The Neurological Institute of New York, Columbia University Medical Center, 710 West 168th Street (NI-9), New York, NY 10032, ;
| | - Pam Factor-Litvak
- Department of Epidemiology, Mailman School of Public Health, Columbia University Medical Center, 722 West 168th Street, New York, NY 10032,
| | - Regina M. Santella
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University Medical Center, 722 West 168th Street, New York, NY 10032,
| | - Hiroshi Mitsumoto
- Eleanor and Lou Gehrig MDA/ALS Research Center, The Neurological Institute of New York, Columbia University Medical Center, 710 West 168th Street (NI-9), New York, NY 10032
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20
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Trojsi F, Monsurrò MR, Tedeschi G. Exposure to environmental toxicants and pathogenesis of amyotrophic lateral sclerosis: state of the art and research perspectives. Int J Mol Sci 2013; 14:15286-311. [PMID: 23887652 PMCID: PMC3759860 DOI: 10.3390/ijms140815286] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 07/05/2013] [Accepted: 07/08/2013] [Indexed: 12/12/2022] Open
Abstract
There is a broad scientific consensus that amyotrophic lateral sclerosis (ALS), a fatal neuromuscular disease, is caused by gene--environment interactions. In fact, given that only about 10% of all ALS diagnosis has a genetic basis, gene-environmental interaction may give account for the remaining percentage of cases. However, relatively little attention has been paid to environmental and lifestyle factors that may trigger the cascade of motor neuron degeneration leading to ALS, although exposure to chemicals--including lead and pesticides-agricultural environments, smoking, intense physical activity, trauma and electromagnetic fields have been associated with an increased risk of ALS. This review provides an overview of our current knowledge of potential toxic etiologies of ALS with emphasis on the role of cyanobacteria, heavy metals and pesticides as potential risk factors for developing ALS. We will summarize the most recent evidence from epidemiological studies and experimental findings from animal and cellular models, revealing that potential causal links between environmental toxicants and ALS pathogenesis have not been fully ascertained, thus justifying the need for further research.
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Affiliation(s)
- Francesca Trojsi
- Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Second University of Naples, Piazza Miraglia 2, Naples 80138, Italy; E-Mails: (M.R.M.); (G.T.)
- Neurological Institute for Diagnosis and Care “Hermitage Capodimonte”, Via Cupa delle Tozzole 2, Naples 80131, Italy
| | - Maria Rosaria Monsurrò
- Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Second University of Naples, Piazza Miraglia 2, Naples 80138, Italy; E-Mails: (M.R.M.); (G.T.)
- Neurological Institute for Diagnosis and Care “Hermitage Capodimonte”, Via Cupa delle Tozzole 2, Naples 80131, Italy
| | - Gioacchino Tedeschi
- Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Second University of Naples, Piazza Miraglia 2, Naples 80138, Italy; E-Mails: (M.R.M.); (G.T.)
- Neurological Institute for Diagnosis and Care “Hermitage Capodimonte”, Via Cupa delle Tozzole 2, Naples 80131, Italy
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21
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Factor-Litvak P, Al-Chalabi A, Ascherio A, Bradley W, Chío A, Garruto R, Hardiman O, Kamel F, Kasarskis E, McKee A, Nakano I, Nelson LM, Eisen A. Current pathways for epidemiological research in amyotrophic lateral sclerosis. Amyotroph Lateral Scler Frontotemporal Degener 2013; 14 Suppl 1:33-43. [PMID: 23678878 PMCID: PMC5434707 DOI: 10.3109/21678421.2013.778565] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease. The current status of the epidemiology, challenges to its study, and novel study design options are discussed in this paper. We focus on recent results from large-scale population based prospective studies, case-control studies and population based registries, risk factors, and neuropathologic findings in chronic traumatic encephalomyelopathy. We identify areas of interest for future research, including time-trends in the incidence and prevalence of ALS; the meaning of lifetime risk; the phenotypic description of ALS; the definition of familial versus sporadic ALS, syndromic aspects of ALS; specific risk factors such as military service, life style factors such as smoking, the use of statins, and the presence of β-N-methylamino-L-alanine (BMAA), an excitotoxic amino acid derivative possibly produced by cyanobacteria found in almost every terrestrial and aquatic habitat; the emergence and disappearance of an endemic ALS in areas of the Pacific; and gene-environment interactions in the etiology of ALS. To move the epidemiology forward, we suggest using well-characterized cohorts of newly diagnosed ALS patients to identify risk and prognostic factors; storing biological material for future studies; building on the National ALS Registry as a resource of future studies; working in multidisciplinary consortia; and addressing the possible early life etiology of ALS.
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Affiliation(s)
- Pam Factor-Litvak
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, USA.
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22
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Das K, Nag C, Ghosh M. Familial, environmental, and occupational risk factors in development of amyotrophic lateral sclerosis. NORTH AMERICAN JOURNAL OF MEDICAL SCIENCES 2012; 4:350-5. [PMID: 22912943 PMCID: PMC3421913 DOI: 10.4103/1947-2714.99517] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Background: Definite etiology of amyotrophic lateral sclerosis (ALS) is still a matter of debate. Aims: The study was designed to evaluate the role of environmental, occupational, and familial risk factors in development of ALS. Materials and Methods: This was a case control study of 110 cases of definite ALS with 240 age and sex matched controls. Investigations were done on the following aspects- family history, occupation, living place, source of drinking water, exposure to industrial, chemical, agricultural toxins and heavy metals, physical and electrical injury, working under magnetic field for more than 10 years in both the groups. Clinical examinations, electrophysiological, and neuroimaging studies were done in every patient. Chi square test, logistic regression analysis, and calculation of odds ratio were used to analyze the data. Results: Rural livings (odds ratio = 1.99), smoking (odds ratio = 1.88), insecticides, and pesticides exposures (odds ratio = 1.61), electrical injury (odds ratio = 6.2) were detected as the associated factors in development amyotrophic lateral sclerosis. Conclusions: The study expressed the need of extensive research globally in molecular and genetic levels to detect the associated factors in etiopathogenesis of ALS for better understanding the etiology and for remedial aspects.
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Affiliation(s)
- Kamalesh Das
- Department of Neurology, Burdwan Medical College and Hospital,Burdwan, West Bengal, India
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23
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de Jong SW, Huisman MHB, Sutedja NA, van der Kooi AJ, de Visser M, Schelhaas HJ, Fischer K, Veldink JH, van den Berg LH. Smoking, alcohol consumption, and the risk of amyotrophic lateral sclerosis: a population-based study. Am J Epidemiol 2012; 176:233-9. [PMID: 22791740 DOI: 10.1093/aje/kws015] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Smoking has been posited as a possible risk factor for amyotrophic lateral sclerosis (ALS), but large population-based studies of patients with incident disease are still needed. The authors performed a population-based case-control study in the Netherlands between 2006 and 2009, including 494 patients with incident ALS and 1,599 controls. To prove the relevance of population-based incidence cohorts in case-control studies, the authors compared results with those from cohorts including patients with prevalent ALS and referral patients. Subjects were sent a questionnaire. Multivariate analyses showed an increased risk of ALS among current smokers (odds ratio = 1.38, 95% confidence interval (CI): 1.02, 1.88) in the incident patient group only. Cox regression models showed that current smoking was also independently associated with shorter survival (hazard ratio = 1.51, 95% CI: 1.07, 2.15), explaining the lack of association in the prevalent and referral patient groups. Current alcohol consumption was associated with a reduced risk of ALS (incident patient group: odds ratio = 0.52, 95% CI: 0.40, 0.75). These findings indicate that current smoking is associated with an increased risk of ALS, as well as a worse prognosis, and alcohol consumption is associated with a reduced risk of ALS, further corroborating the role of lifestyle factors in the pathogenesis of ALS. The importance of population-based incident patient cohorts in identifying risk factors is highlighted by this study.
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Affiliation(s)
- Sonja W de Jong
- Department of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, the Netherlands
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Pamphlett R, Ward EC. Smoking is not a risk factor for sporadic amyotrophic lateral sclerosis in an Australian population. Neuroepidemiology 2012; 38:106-13. [PMID: 22377752 DOI: 10.1159/000336013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 12/12/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Controversy persists as to whether smoking is a risk factor for sporadic amyotrophic lateral sclerosis (SALS), the most common form of sporadic motor neuron disease (SMND). We therefore undertook a large case-control study of smoking and SALS in Australia. METHODS Cases and controls were recruited Australia-wide over a 10-year period. SALS and the other subgroups of SMND were categorised on the basis of neurologists' reports. Controls were partners or friends of SMND patients or community volunteers. Individuals filled in a questionnaire regarding smoking habits. A total of 809 patients with SMND (631 with SALS) and 779 controls were included in the study. SALS males and females were analysed separately. RESULTS No differences between SALS patients and control groups were found with regard to (1) the odds ratios of ever-smokers, ex-smokers or current smokers compared to never-smokers, (2) the means of numbers of cigarettes per day, years of smoking, pack years or age smoking began or (3) the proportions of their parents who had ever smoked. The proportion of ever-smokers and mean pack years did not differ between the clinical subgroups of SMND or between different sites of SALS onset. Partner smoking did not increase the risk of SMND. CONCLUSION This Australian case-control study does not support a link between cigarette smoking and any form of SMND.
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Affiliation(s)
- Roger Pamphlett
- Department of Pathology, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.
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25
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Bastos AF, Orsini M, Machado D, Mello MP, Nader S, Silva JG, da Silva Catharino AM, de Freitas MRG, Pereira A, Pessoa LL, Sztajnbok FR, Leite MA, Nascimento OJM, Bastos VH. Amyotrophic lateral sclerosis: one or multiple causes? Neurol Int 2011; 3:e4. [PMID: 21785676 PMCID: PMC3141115 DOI: 10.4081/ni.2011.e4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 04/02/2011] [Indexed: 12/11/2022] Open
Abstract
The Amyotrophic lateral sclerosis (ALS) is the most common form of motor neuron disease in the adulthood, and it is characterized by rapid and progressive compromise of the upper and lower motor neurons. The majority of the cases of ALS are classified as sporadic and, until now, a specific cause for these cases still is unknown. To present the different hypotheses on the etiology of ALS. It was carried out a search in the databases: Bireme, Scielo and Pubmed, in the period of 1987 to 2011, using the following keywords: Amyotrophic lateral sclerosis, motor neuron disease, etiology, causes and epidemiology and its similar in Portuguese and Spanish. It did not have consensus as regards the etiology of ALS. Researches demonstrates evidences as regards intoxication by heavy metals, environmental and occupational causes, genetic mutations (superoxide dismutase 1), certain viral infections and the accomplishment of vigorous physical activity for the development of the disease. There is still no consensus regarding the involved factors in the etiology of ALS. In this way, new research about these etiologies are necessary, for a better approach of the patients, promoting preventive programs for the disease and improving the quality of life of the patients.
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26
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Wang H, O'Reilly ÉJ, Weisskopf MG, Logroscino G, McCullough ML, Thun MJ, Schatzkin A, Kolonel LN, Ascherio A. Smoking and risk of amyotrophic lateral sclerosis: a pooled analysis of 5 prospective cohorts. ACTA ACUST UNITED AC 2011; 68:207-13. [PMID: 21320987 DOI: 10.1001/archneurol.2010.367] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Cigarette smoking has been proposed as a risk factor for amyotrophic lateral sclerosis (ALS), but epidemiological studies supporting this hypothesis have been small and mostly retrospective. OBJECTIVE To prospectively examine the relation between smoking and ALS in 5 well-established large cohorts. DESIGN Five prospective cohorts with study-specific follow-up ranging from 7 to 28 years. SETTING Academic research. PATIENTS Participants in the Nurses' Health Study, the Health Professionals Follow-up Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort, and the National Institutes of Health-AARP (formerly known as the American Association of Retired Persons) Diet and Health Study. MAIN OUTCOME MEASURES Amyotrophic lateral sclerosis deaths identified through the National Death Index. In the Nurses' Health Study and the Health Professionals Follow-up Study, confirmed nonfatal incident ALS was also included. RESULTS A total of 832 participants with ALS were documented among 562,804 men and 556,276 women. Smokers had a higher risk of ALS than never smokers, with age- and sex-adjusted relative risks of 1.44 (95% confidence interval, 1.23-1.68; P < .001) for former smokers and 1.42 (95% confidence interval, 1.07-1.88; P = .02) for current smokers. Although the risk of ALS was positively associated with pack-years smoked (P < .001), duration of smoking (9% increase for each 10 years of smoking, P = .006), and the number of cigarettes smoked per day (10% increase for each increment of 10 cigarettes smoked per day, P < .001), these associations did not persist when never smokers were excluded. However, among ever smokers, the risk of ALS increased as age at smoking initiation decreased (P = .03). CONCLUSIONS Results of this large longitudinal study support the hypothesis that cigarette smoking increases the risk of ALS. The potential importance of age at smoking initiation and the lack of a dose response deserve further investigation.
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Affiliation(s)
- Hao Wang
- Department of Nutrition, Harvard School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
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Lee PN. Summary of the epidemiological evidence relating snus to health. Regul Toxicol Pharmacol 2010; 59:197-214. [PMID: 21163315 DOI: 10.1016/j.yrtph.2010.12.002] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 12/06/2010] [Accepted: 12/06/2010] [Indexed: 02/06/2023]
Abstract
Interest in snus (Swedish-type moist snuff) as a smoking alternative has increased. This wide-ranging review summarizes evidence relating snus to health and to initiation and cessation of smoking. Meta-analyses are included. After smoking adjustment, snus is unassociated with cancer of the oropharynx (meta-analysis RR 0.97, 95% CI 0.68-1.37), oesophagus (1.10, 0.92-1.33), stomach (0.98, 0.82-1.17), pancreas (1.20, 0.66-2.20), lung (0.71, 0.66-0.76) or other sites, or with heart disease (1.01, 0.91-1.12) or stroke (1.05, 0.95-1.15). No clear associations are evident in never smokers, any possible risk from snus being much less than from smoking. "Snuff-dipper's lesion" does not predict oral cancer. Snus users have increased weight, but diabetes and chronic hypertension seem unaffected. Notwithstanding unconfirmed reports of associations with reduced birthweight, and some other conditions, the evidence provides scant support for any major adverse health effect of snus. Although some claims that snus reduces initiation or encourages quitting are unsoundly based, snus seems not to increase initiation, as indicated by few smokers using snus before starting and current snus use being unassociated with smoking in adults (the association in children probably being due to uncontrolled confounding), and there are no reports that snus discourages quitting.
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Affiliation(s)
- Peter N Lee
- PN Lee Statistics and Computing Ltd., Sutton, Surrey, UK.
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Alonso A, Logroscino G, Jick SS, Hernán MA. Association of smoking with amyotrophic lateral sclerosis risk and survival in men and women: a prospective study. BMC Neurol 2010; 10:6. [PMID: 20074360 PMCID: PMC2820482 DOI: 10.1186/1471-2377-10-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Accepted: 01/14/2010] [Indexed: 12/13/2022] Open
Abstract
Background Previous epidemiologic studies have examined the association of smoking with amyotrophic lateral sclerosis (ALS) incidence, but their results have been inconsistent. Moreover, limited information exists on the association between smoking and survival in ALS patients. We evaluated the association of smoking with ALS incidence and survival in a population-based cohort. Methods We conducted a case-control study nested in the General Practice Research Database, a computerized clinical database in the United Kingdom. Cases were 1143 individuals with a diagnosis of ALS; 11,371 matched controls were selected among GPRD participants free of ALS. Predictors of survival were determined in the ALS cases. Smoking information was obtained from the computer database. Results Smoking was not associated with the risk of ALS in this population. The rate ratio (RR) of ALS comparing ever versus never smokers was 1.04, 95% confidence interval (CI) 0.80-1.34. In analysis stratified by gender, however, ever smoking was associated with ALS in women (RR 1.53, 95% CI 1.04-2.23) but not in men (RR 0.75, 95% CI 0.53-1.06). Mortality was 71% after 2.1 average years of follow-up. Old age and female sex were associated with lower survival. Smoking was a predictor of mortality only in women. Comparing ever versus never smokers, RR (95% CI) of death was 1.31 (1.04-1.65) in women, and 0.90 (0.72-1.11) in men. Conclusion In this large population-based study, smoking was associated with ALS risk and worse survival in women but not in men.
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Affiliation(s)
- Alvaro Alonso
- Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, USA.
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Perry JJP, Shin DS, Tainer JA. Amyotrophic lateral sclerosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 685:9-20. [PMID: 20687491 DOI: 10.1007/978-1-4419-6448-9_2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a common neurological disorder that results in loss of motor neurons, leading to a rapidly progressive form of muscle paralysis that is fatal. There is no available cure and current therapies only provide minimal benefit at best. The disease is predominantly sporadic and until very recently only the Cu,Zn superoxide dismutase (Cu,ZnSOD), which is involved in a small number of sporadic cases and a larger component of familial ones, have been analyzed in any detail. Here we describe the clinical aspects of ALS and highlight the genetics and molecular mechanisms behind the disease. We discuss the current understanding and controversies of how mutations in Cu,ZnSOD may cause the disease. We also focus on the recent discovery that mutations in either TDP-43 or FUS/TLS, which are both involved in DNA/RNA synthesis, are likely the cause behind many cases of ALS that are not linked to Cu,ZnSOD.
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Affiliation(s)
- J Jefferson P Perry
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
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Harwood CA, McDermott CJ, Shaw PJ. Physical activity as an exogenous risk factor in motor neuron disease (MND): A review of the evidence. ACTA ACUST UNITED AC 2009; 10:191-204. [DOI: 10.1080/17482960802549739] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Abstract
OBJECTIVES A 2003 evidence-based review of exogenous risk factors for sporadic amyotrophic lateral sclerosis (ALS) identified smoking as the only risk factor that attained "probable" (more likely than not) status, based on 2 class II studies. The purpose of the current, evidence-based, update was to see if the conclusion of the previous review needed to be modified, based on studies published since. METHODS A Medline literature search was conducted for the period between 2003 and April 2009 using the search terms smoking and (ALS or "amyotrophic lateral sclerosis" or MND or "motor neuron disease"). The references of primary articles and reviews were checked to assure completeness of the search. Primary articles published since the previous review were classified as before. RESULTS Twenty-eight titles were identified, but only 7 articles met inclusion criteria. Of these, 1 provided class II evidence, and 1 class III evidence: both showed increased risk of ALS with smoking. The class II study showed a dose-response effect, and risk decreasing with number of years since quitting smoking. Five articles provided class IV or V evidence, which may not be relied upon to draw conclusions. CONCLUSIONS Smoking may be considered an established risk factor for sporadic amyotrophic lateral sclerosis (ALS) (level A rating; 3 class II studies, 1 class III study). Evidence-based analysis of epidemiologic data shows concordance among results of better-designed studies linking smoking to ALS, and lets those results drive the conclusions.
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Affiliation(s)
- Carmel Armon
- Division of Neurology, Tufts University School of Medicine/Baystate Medical Center, Springfield, MA 01199, USA.
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Fang F, Quinlan P, Ye W, Barber MK, Umbach DM, Sandler DP, Kamel F. Workplace exposures and the risk of amyotrophic lateral sclerosis. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:1387-92. [PMID: 19750102 PMCID: PMC2737014 DOI: 10.1289/ehp.0900580] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 05/11/2009] [Indexed: 05/11/2023]
Abstract
BACKGROUND Occupation has been suggested to play a role in amyotrophic lateral sclerosis (ALS) etiology, but detailed information on the importance of specific workplace exposures is lacking. OBJECTIVES Our aim was to assess the relationship between workplace exposures and the risk of ALS and to evaluate potential interactions between these exposures and smoking. METHODS We conducted a case-control study in New England between 1993 and 1996, comprising 109 cases and 253 controls who completed a structured interview covering occupations and workplace exposures. Unconditional logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for ALS. Analyses were conducted among the entire study population and after stratification by smoking. RESULTS We observed a higher risk of ALS for construction workers excluding supervisors (OR = 2.9; 95% CI, 1.2-7.2) and precision metal workers (OR = 3.5; 95% CI, 1.2-10.5). Self-reported exposures to paint strippers; cutting, cooling, or lubricating oils; antifreeze or coolants; mineral or white spirits; and dry cleaning agents each appeared to be associated with a 60-90% higher risk. Specific chemicals related to a > 50% increase in risk of ALS included aliphatic chlorinated hydrocarbons, glycols, glycol ethers, and hexane. Relative risks associated with these workplace exposures and chemicals were greater among nonsmokers and persisted in mutually adjusted models. CONCLUSIONS Our data suggest that certain occupations and workplace exposures may be associated with increased risk of ALS. These results need to be confirmed in independent populations.
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Affiliation(s)
- Fang Fang
- Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Patricia Quinlan
- Department of Medicine, Division of Occupational and Environmental Medicine, University of California, San Francisco, California, USA
| | - Weimin Ye
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | | | - David M. Umbach
- Biostatistics Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Dale P. Sandler
- Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Freya Kamel
- Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
- Address correspondence to F. Kamel, Epidemiology Branch, National Institute of Environmental Health Sciences, P.O. Box 12233, Mail Drop A3-05, Research Triangle Park, NC 27709 USA. Telephone: (919) 541-1581. Fax: (919) 541-2511. E-mail:
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Soriani MH, Desnuelle C. Épidémiologie de la SLA. Rev Neurol (Paris) 2009; 165:627-40. [DOI: 10.1016/j.neurol.2009.04.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 04/02/2009] [Accepted: 04/13/2009] [Indexed: 12/11/2022]
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Gallo V, Bueno-De-Mesquita HB, Vermeulen R, Andersen PM, Kyrozis A, Linseisen J, Kaaks R, Allen NE, Roddam AW, Boshuizen HC, Peeters PH, Palli D, Mattiello A, Sieri S, Tumino R, Jiménez-Martín JM, Díaz MJT, Suarez LR, Trichopoulou A, Agudo A, Arriola L, Barricante-Gurrea A, Bingham S, Khaw KT, Manjer J, Lindkvist B, Overvad K, Bach FW, Tjønneland A, Olsen A, Bergmann MM, Boeing H, Clavel-Chapelon F, Lund E, Hallmans G, Middleton L, Vineis P, Riboli E. Smoking and risk for amyotrophic lateral sclerosis: analysis of the EPIC cohort. Ann Neurol 2009; 65:378-85. [PMID: 19399866 DOI: 10.1002/ana.21653] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Cigarette smoking has been reported as "probable" risk factor for Amyotrophic Lateral Sclerosis (ALS), a poorly understood disease in terms of aetiology. The extensive longitudinal data of the European Prospective Investigation into Cancer and Nutrition (EPIC) were used to evaluate age-specific mortality rates from ALS and the role of cigarette smoking on the risk of dying from ALS. METHODS A total of 517,890 healthy subjects were included, resulting in 4,591,325 person-years. ALS cases were ascertained through death certificates. Cox hazard models were built to investigate the role of smoking on the risk of ALS, using packs/years and smoking duration to study dose-response. RESULTS A total of 118 subjects died from ALS, resulting in a crude mortality rate of 2.69 per 100,000/year. Current smokers at recruitment had an almost two-fold increased risk of dying from ALS compared to never smokers (HR = 1.89, 95% C.I. 1.14-3.14), while former smokers at the time of enrollment had a 50% increased risk (HR = 1.48, 95% C.I. 0.94-2.32). The number of years spent smoking increased the risk of ALS (p for trend = 0.002). Those who smoked more than 33 years had more than a two-fold increased risk of ALS compared with never smokers (HR = 2.16, 95% C.I. 1.33-3.53). Conversely, the number of years since quitting smoking was associated with a decreased risk of ALS compared with continuing smoking. INTERPRETATION These results strongly support the hypothesis of a role of cigarette smoking in aetiology of ALS. We hypothesize that this could occur through lipid peroxidation via formaldehyde exposure.
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Affiliation(s)
- Valentina Gallo
- Division of Epidemiology, Public Health and Primary Care, Imperial College London, United Kingdom.
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Weisskopf MG, Ascherio A. Cigarettes and amyotrophic lateral sclerosis: only smoke or also fire? Ann Neurol 2009; 65:361-2. [PMID: 19399854 DOI: 10.1002/ana.21700] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterised by progressive muscular paralysis reflecting degeneration of motor neurones in the primary motor cortex, corticospinal tracts, brainstem and spinal cord. Incidence (average 1.89 per 100,000/year) and prevalence (average 5.2 per 100,000) are relatively uniform in Western countries, although foci of higher frequency occur in the Western Pacific. The mean age of onset for sporadic ALS is about 60 years. Overall, there is a slight male prevalence (M:F ratio approximately 1.5:1). Approximately two thirds of patients with typical ALS have a spinal form of the disease (limb onset) and present with symptoms related to focal muscle weakness and wasting, where the symptoms may start either distally or proximally in the upper and lower limbs. Gradually, spasticity may develop in the weakened atrophic limbs, affecting manual dexterity and gait. Patients with bulbar onset ALS usually present with dysarthria and dysphagia for solid or liquids, and limbs symptoms can develop almost simultaneously with bulbar symptoms, and in the vast majority of cases will occur within 1-2 years. Paralysis is progressive and leads to death due to respiratory failure within 2-3 years for bulbar onset cases and 3-5 years for limb onset ALS cases. Most ALS cases are sporadic but 5-10% of cases are familial, and of these 20% have a mutation of the SOD1 gene and about 2-5% have mutations of the TARDBP (TDP-43) gene. Two percent of apparently sporadic patients have SOD1 mutations, and TARDBP mutations also occur in sporadic cases. The diagnosis is based on clinical history, examination, electromyography, and exclusion of 'ALS-mimics' (e.g. cervical spondylotic myelopathies, multifocal motor neuropathy, Kennedy's disease) by appropriate investigations. The pathological hallmarks comprise loss of motor neurones with intraneuronal ubiquitin-immunoreactive inclusions in upper motor neurones and TDP-43 immunoreactive inclusions in degenerating lower motor neurones. Signs of upper motor neurone and lower motor neurone damage not explained by any other disease process are suggestive of ALS. The management of ALS is supportive, palliative, and multidisciplinary. Non-invasive ventilation prolongs survival and improves quality of life. Riluzole is the only drug that has been shown to extend survival.
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Affiliation(s)
- Lokesh C Wijesekera
- MRC centre for Neurodegeneration Research, Department of Clinical Neuroscience, Box 41, Institute of Psychiatry, Kings College London, London, SE5 8AF, UK
| | - P Nigel Leigh
- MRC centre for Neurodegeneration Research, Department of Clinical Neuroscience, Box 41, Institute of Psychiatry, Kings College London, London, SE5 8AF, UK
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Abstract
The latest reviews of the literature devoted to the epidemiology of ALS all agree that exogenic risk factors play a role in sporadic ALS. Nevertheless, there is no convincing evidence demonstrating in a reproducible manner an association between an environmental risk factor and ALS. This discordance is mainly explained by methodological skews. Over the last ten years, exogenic factors have been analyzed within the framework of specific lifestyle factors such as place of residence, smoking or not, or certain eating practices. The most recent work suggests that interactions between genetic and environmental factors depend on the age at exposure and the duration of exposure. The objectives of this general review is: to analyze the principal case-control studies, historical cohort studies or mortality studies which looked at the associations between an environmental factor and ALS, to present main results of studies having analyzed lifestyles in relation to one or more exogenic factors, and to discuss the limitations of epidemiologic studies on ALS.
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Gouveia LO, de Carvalho M. Young-onset sporadic amyotrophic lateral sclerosis: a distinct nosological entity? ACTA ACUST UNITED AC 2007; 8:323-7. [PMID: 17852021 DOI: 10.1080/17482960701553956] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
There are few reports describing young-onset amyotrophic lateral sclerosis (ALS). Age at onset is a prognostic factor in ALS, and thus it is relevant to investigate the clinical features of very young ALS patients. We describe three young-onset ALS cases and review the literature. SOD1 mutations were not identified. Our cases and 24 others from the literature indicate that young-onset ALS is characterized by slowly progressive symmetrical weakness; nevertheless, progression is variable. Young-onset ALS seems to be a distinct clinical syndrome but its aetiological background is largely unknown.
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