Living in poorer communities linked to worse Parkinson’s symptoms
Patients from wealthier areas have higher rates of diagnoses; less severe disease
People with Parkinson’s disease who live in disadvantaged communities tend to have more severe motor symptoms and greater motor disability, according to a study that shows that social and environmental factors, many of which may be modifiable, can influence the severity of the disease.
“If environmental exposures or other social determinants of health in these communities are worsening [Parkinson’s] motor symptoms, programs to address these at the individual and community levels could improve quality of life, including motor outcomes,” the study’s researchers wrote. The study, “Community Disadvantage Is Associated With More Severe Motor Symptoms in Parkinson Disease,” was published in Neurology Clinical Practice.
Parkinson’s is caused by the progressive degeneration and death of certain nerve cells, which can lead to motor symptoms that include tremor, slowed movement, and difficulty walking. Nonmotor symptoms, such as cognitive impairment, are also common. Other movement disorders may include similar symptoms that are related to various causes. These are collectively referred to as parkinsonism, with those stemming from other conditions called atypical parkinsonism.
The disease’s underlying origins are still debated, but exposure to certain environmental toxins like pesticides may be a factor. Some studies in the U.S. have found higher rates of Parkinson’s diagnosis in well-resourced communities and among people with higher socioeconomic status, however. This is surprising, as socioeconomic status generally corresponds to more limited environmental exposures, according to the researchers.
Community disadvantage and disease severity
To investigate the potentially complicated relationship between social determinants of health and Parkinson’s, the researchers compared the relative severity of symptoms to community disadvantage. “We hypothesized that worse community disadvantage would be associated with worse motor symptom severity and worse cognition in [Parkinson’s] and atypical parkinsonisms,” they wrote.
The study included 458 participants with Parkinson’s who were a mean age of 68.2. All were part of an ongoing study at the University of Cincinnati and were drawn from several nearby regions. Nearly all (97.4%) were non-Hispanic white, and most (88%) lived in urban areas.
Using each participant’s address, the researchers calculated the Material Community Deprivation Index for their immediate neighborhood. “This composite index score goes beyond an individual’s socioeconomic markers (e.g., individual income or education level) and assesses the neighborhood for a broader environmental context,” they wrote.
Among those with Parkinson’s, they found a significant correlation between higher community disadvantage and more severe motor symptoms. People from more disadvantaged areas also had significantly greater disability. Neither of these correlations were statistically significant in the group with atypical parkinsonism.
“Considered with recent literature, our findings suggest that in the United States, those in well-resourced areas have higher rates of [Parkinson’s] diagnoses, but less severe [Parkinson’s] symptoms,” the researchers wrote.
This may be because people from wealthier areas are more likely to be diagnosed, while those in disadvantaged communities may not be diagnosed as often, but once they are, their symptoms are usually worse, making patients in underserved areas especially vulnerable.
Another possible reason for the higher number of Parkinson’s cases in wealthier areas is that the disease may be underdiagnosed in poorer communities, with transportation or cultural factors playing a role. “This means there may be aging individuals who are not receiving [Parkinson’s] care that would greatly improve quality of life,” wrote the researchers, who said further studies could assess these explanations more directly and that including more racially, ethnically, and geographically diverse groups may increase data quality. This study only included participants receiving care at one center, so it couldn’t capture differences in access to healthcare resources, and access may depend on a variety of factors and could influence symptom severity, they said.
Health interventions in low-resource communities could focus on reducing environmental exposures and other factors that may influence symptom severity in these areas, such as food insecurity and crime. “Determining the biologic effect of these exposures individually and in combination is important to develop strategies to mitigate their effect on [Parkinson’s]/parkinsonism severity,” the researchers wrote.
Increasing Parkinson’s screening in disadvantaged neighborhoods could help people get treatment earlier, which may allow for better motor outcomes.
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