Occupation May Affect ALS Mortality Rate
Although known risks factors for ALS include age, male sex, and cigarette smoking, how occupations can influence ALS or other neurodegenerative diseases is less understood. A new study, however, finds that those who have high-status careers, often called white collar workers, face higher Amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD) mortality rates.
A research team reported on data of more than 12 million deaths from 30 U.S. states in a study titled “Mortality from Amyotrophic Lateral Sclerosis and Parkinson’s Disease Among Different Occupation Groups — United States, 1985–2011” and published in Morbidity and Mortality Weekly Report (MMWR).
To see how career choice affects ALS and PD mortality, the team examined data from CDC’s National Institute for Occupational Safety and Health (NIOSH) National Occupational Mortality Surveillance (NOMS), which contains data on 12,710,846 deaths that occurred between 1985–1999, 2003–2004, and 2007–2011 in 30 states.
The team defined ALS and PD deaths using the International Classification of Diseases, 9th Revision until 1998 and 10th Revision thereafter. Their study analysis included 26,917 ALS deaths and 115,262 PD deaths. The deceased’s usual occupation, which was recorded on death certificates in a text field, was assigned a U.S. Census 1990 or 2000 occupation code. Based on these occupation codes, the researchers were able to create 26 categories based on similar job duties and order these categories from high SES (e.g., management) to low SES (e.g., transportation and material moving).
They found a higher ALS mortality—proportionate mortality ratios (PMRs) higher than 1—in 14 occupation categories. Of those, four categories (computers/mathematics, architecture/engineering, legal, and education/training/library) featured a significantly higher ALS mortality rate (defined as greater than or equal to 1.50 PMR). For PD, the mortality was higher in high SES jobs including community/social services, education/training/library, and legal.
Overall, the team concluded that white collar workers tended to have higher ALS and PD mortality rates. “If the associations between higher SES occupations and ALS and Parkinson’s disease mortality are real, then the burdens of ALS and Parkinson’s disease mortality could also increase in the future because the U.S. workforce is increasing in the number and proportion of workers employed in higher SES occupations,” explained the authors.
Future studies focused on white collar workers may help to understand whether these individuals are exposed to specific agents or experiences. Importantly, confounding factors such as cigarette smoking and economic status will have to be excluded.
The authors noticed that their study examined mortality rather than ALS incidence. Therefore, it is possible that other workers also develop these conditions but die earlier of other causes.