Women working in fields that include teaching, healthcare, and — especially — social work “defined broadly” may be at a higher risk of Parkinson’s disease, a large observational study has found.
The study, “Occupation and Parkinson disease in the Women’s Health Initiative Observational Study,” was published in the American Journal of Industrial Medicine.
An individual’s risk of developing Parkinson’s is influenced by a variety of factors. Among these are workplace exposures, the most obvious being pesticides and other chemicals used in a job and linked to Parkinson’s risk.
Most studies into workplace-related risks for Parkinson’s involve men, and these data do not necessarily hold for other populations, both due to biological differences and because of differences among people drawn to specific fields.
Researchers used data from the Women’s Health Initiative Observational Study (WHI-OS) to assess Parkinson’s risk as a factor of career choice in 80,646 postmenopausal (ages 50 to 79) female workers in the United States who were followed for an average of 11 years after enrollment.
After adjusting for possible confounding factors like smoking history, income or ethnicity, they divided participants into broad career categories, like teaching (preschool through post-secondary), sales, counseling and social work, cleaning and maintenance, top executives, nurses, doctors and other healthcare professionals, etc.
They then determined whether any of these categories were significantly linked to Parkinson’s by calculating relative risk (RR; a value that is significantly higher or lower than 1 suggests an increased or decreased risk, respectively).
In total, 2,590 women (3.21%) in the study had Parkinson’s; 186 cases at its start and the rest diagnosed over the course of study follow-up.
There was a statistically significant increase in Parkinson’s risk among “counselors, social workers, and other community and social service specialists,” with a relative risk of 1.18, the researchers wrote, calling it an “excess risk.”
“Resonating with our findings, social work, defined broadly, has been associated with PD in studies of diverse designs, including an excess risk among white female religious workers,” the study said. “[A]lso there is evidence that women with PD are more likely to have a history of work that requires complex interpersonal interactions.”
Trends toward a higher Parkinson’s risk was found among “top executives” (RR of 1.18), “postsecondary teachers” (RR of 1.17), and workers in “building and grounds cleaning and maintenance” (RR of 1.21). But none of these associations reached statistical significance.
There was also a non-significant trend toward a lower Parkinson’s risk among people in sales, particularly “retail salespersons” (RR 0.87).
Researchers also looked at these risks broken down by how long participants had worked in these fields. For “counselors, social workers, and other community and social service specialists,” Parkinson’s risk increased with longer time spent on the job (from RR of 1.09 at 1–5 years of work to RR of 1.27 with 20 or more years). There was no consistent trend for time spent on the job for other career categories.
Based on 39 cases, they also noted evidence of an excessive risk among “health technologists and technicians” with more than 20 years of employment (RR of 1.46).
“Our findings paint a largely reassuring picture of occupational risks for PD [Parkinson’s disease] among U.S. women,” the researchers concluded.
They propose that future studies more closely examine the identified career paths to more specifically determine what factors might be influencing Parkinson’s risk for people in these fields.
As this study focused on older individuals, it may not be reflective of risks encountered by younger workers, particularly in fields with rapidly changing technology like healthcare, the researchers added.