title: Analysis of factors that modify susceptibility and rate of progression in amyotrophic lateral sclerosis (ALS).
abstract: We conducted case-control and prospective longitudinal studies to examine risk factors and predictors of disease progression for ALS. Ninety-five subjects with ALS and 106 healthy control subjects were enrolled. All subjects completed a risk factor questionnaire at enrollment. The ALS subjects were prospectively followed for one year to define factors that influence the rate of disease progression, measured by rate of change in percent predicted forced vital capacity (%FVC) and the ALS functional rating scale (ALSFRS) score. The association of each potential risk factor with ALS was determined using univariate logistic regression. A random slope model was used to determine the association of each risk factor with disease progression. The demographic characteristics of ALS subjects and controls at enrollment did not differ. Significant risk factors for ALS included reported exposure to lead (p = 0.02) and pesticides (p = 0.03). Disease progression was faster in the ALS subjects having bulbar onset and a shorter time period between onset of symptoms and diagnosis. Pertinent variables not associated with either causation or progression of ALS included physical activity, cigarette smoking and a history of physical trauma or other clinical disorders.
authors.affiliation: Neurology Clinical Trials Unit, Massachusetts General Hospital, Charlestown, MA 02129, USA.
authors.forename: M Muddasir
authors.initials: MM
authors.lastname: Qureshi
authors.forename: Douglas
authors.initials: D
authors.lastname: Hayden
authors.forename: Leo
authors.initials: L
authors.lastname: Urbinelli
authors.forename: Kimberly
authors.initials: K
authors.lastname: Ferrante
authors.forename: Kristyn
authors.initials: K
authors.lastname: Newhall
authors.forename: Daniela
authors.initials: D
authors.lastname: Myers
authors.forename: Sarah
authors.initials: S
authors.lastname: Hilgenberg
authors.forename: Ryan
authors.initials: R
authors.lastname: Smart
authors.forename: Robert H
authors.initials: RH
authors.lastname: Brown
authors.forename: Merit E
authors.initials: ME
authors.lastname: Cudkowicz
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology / Q000503:physiopathology*; D016022:Case-Control Studies; D015331:Cohort Studies; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors