Community Disadvantage Is Associated With More Severe Motor Symptoms in Parkinson Disease

The relationship between socioeconomic factors and Parkinson disease (PD) is unclear. Previous literature suggests a potential disconnect between the effect of socioeconomic status (SES) on PD risk and severity. A recent study found that people with PD in the United States were more likely to come from well-resourced communities. Multiple possible explanations were proposed, including that lower SES could be protective against PD risk. Other studies have found worsened PD symptoms and outcomes associated with lower individual SES. If environmental factors associated with lower SES influence PD biology in a way that worsens symptoms, those processes should also increase PD risk. We set out to determine whether community disadvantage, rather than individual SES, is associated with motor or cognitive symptom severity in PD and atypical parkinsonisms.

Community disadvantage was defined using the Material Community Deprivation Index, a compound score of multiple poverty markers. In our Cincinnati Cohort Biomarkers Program, a cohort that includes PD and atypical parkinsonisms, we tested for associations between community disadvantage and motor symptom severity (Movement Disorders Society Unified PD Rating Scale part III; MDS-UPDRS III), motor disability (Hoehn and Yahr stage [HY]), and cognition (Montreal Cognitive Assessment [MoCA]). We considered age, sex, disease duration, levodopa equivalent daily dose, education years, and race as covariates in multiple regression analyses.

A total of 565 people with PD or atypical parkinsonisms were included (458 idiopathic PD and 107 atypical parkinsonisms). Their mean age was 69 years, and 65% were men. The mean disease duration was 7 years, and the mean MDS-UPDRS III score was 30. The majority (75%) were HY stage 2, and the mean cognitive screening score was nondemented (MoCA 25/30). Worse community disadvantage was significantly associated with worse MDS-UPDRS III score (β 1.58, p = 0.01; adjusted for age, sex, and disease duration) and HY stage (OR 1.27, p = 0.04, adjusted for age, sex, disease duration, and education years). Community disadvantage was not significantly associated with MoCA score (p = 0.45).

Community disadvantage was associated with worse motor symptom severity and motor disability in PD, suggesting that there are modifiable social and environmental factors that can affect parkinsonian symptom severity.