Jobs associated with higher economic status appear to be risk factors for these neurologic disorders.
Higher Socioeconomic Status (SES) Occupation: New Risk Factor for ALS and PD? . PD and ALS affect > 1 million Americans . Known ALS risk factors include older age, male sex, smoking . Known PD risk factors include older age, male sex, pesticide exposure Smoking, caffeine associated with decreased PD risk . Past studies on occupation and neurological disease have focused on exposure to toxins in jobs associated with lower socioeconomic status (SES)
CDC Study of Occupation, PD, and ALS . Data from CDC national surveillance data Over 12.1 million deaths from 30 states between 1985-2011 26,917 ALS deaths 115,262 PD deaths Used proportionate mortality ratios (PMRs) to estimate associations between cause of death and occupation
Increased PD Mortality with Higher SES Jobs 13 occupation categories had PMRs significantly over 1.00 (increased risk) None had PMR ≥1.50 Highest: Community and social services (PMR 1.48 [1.41-1.56])
Increased ALS Mortality with Higher SES Jobs 14 occupation categories had PMRs significantly over 1.00 (increased risk) Four categories had PMRs ≥1.50: Computer and mathematical (PMR 1.66 [1.43-1.91]) Architecture and engineering (PMR 1.55 [1.45-1.66]) Legal (PMR 1.62 [1.39-1.87]) Education, training and library (PMR 1.67 [1.58-1.76])
Limitations Occupation came from death certificate, which could be incorrect Occupation categories could have diluted the association: Some farmers (higher insecticide exposure) may have been grouped with fishing and forestry (lower insecticide exposure) Some confounders like smoking not included PMRs have inherent limitations
What it Could Mean “The shifts in the US workforce toward older ages and higher SES occupations highlight the importance of understanding this finding, which will require studies with designs that provide evidence for causality, detailed exposure assessment, and adjustment for additional potential confounders,” first author John Beard, PhD, Epidemic Intelligence Service, CDC (Atlanta, Georgia), and colleagues.
Take Home Points . CDC study of deaths from 1985-2011 identified higher SES occupation as a potential new risk factor for ALS and PD . Reasons unknown, future studies needed to confirm and explore these findings