A range of comorbidities, such as epilepsy and hearing loss, were encountered in primary care settings prior to the onset of Parkinson disease (PD) in ethnically diverse populations, according to a nested case-control study published in JAMA Neurology.
Most research on PD has been conducted among individuals with Northern European ancestry. As few studies have focused on PD among more diverse populations, it remains unclear whether these individuals differ for early signs and symptoms of disease. The objective of the current study was to investigate the link between risk factors and early presentations of PD in an ethnically diverse population living in areas of high social deprivation but with access to universal health care in the UK.
Data for this study were sourced from Egton Medical Information Systems which has collected patient records in East London since 1990. All individuals (n=1055) who were diagnosed with PD were evaluated for potential signifiers of PD compared with control individuals (n=1,009,523) who had no neurological diagnoses. During the ten years before a PD diagnosis, cases and controls were assessed for 24 variables. A confirmatory analysis was performed using data from the UK Biobank among 110 cases and 1100 control individuals at less than 2 years, 274 cases and 2740 control individuals at 2 to less than 5 years, and 1074 cases and 10740 control individuals at 5-10 years before PD diagnosis.
Cases and control individuals were aged mean 72.9 (standard deviation [SD], 11.3) and 40.3 (SD, 15.2) years, 40.1% and 48.8% were women, 50.9% and 43.7% were White, 19.7% and 21.5% South Asian, 15.7% and 13.3% Black, and 44.7% and 44.9% had the most deprived level, respectively.
Using a subset of ten age-matched control individuals (n=10,550) for every PD case, significant predictors for PD included epilepsy, head injury, being underweight, having hypotension, constipation, depression, anxiety, insomnia, fatigue, dizziness, memory symptoms, hearing loss, shoulder pain, tremor, rigidity, and balance difficulties at less than 2 years before PD.
At 2 to less than 5 years, patients received health care for epilepsy, hypotension, constipation, insomnia, dizziness, memory symptoms, hearing loss, shoulder pain, tremor, and balance difficulties.
The most distant symptoms (5-10 years) included epilepsy, type two diabetes, hypertension, constipation, erectile dysfunction, depression, anxiety, dizziness, tremor, rigidity, and balance difficulties.
Overall, smoking (adjusted odds ratio [aOR], 0.74; 95% CI, 0.64-0.85) and drinking (aOR, 0.8; 95% CI, 0.68-0.93) were observed to be inversely related with eventual PD.
Stratified by ethnicity, most trends were similar, however, Black and South Asian patients did not present with rigidity prior to PD.
Using data from the UK Biobank, the researchers validated the relationship between PD and epilepsy at less than 2 years (aOR, 3.17; 95% CI, 1.13-7.72), hearing loss (aOR, 1.29; 95% CI, 1.05-1.65) and epilepsy (aOR, 2.71; 95% CI, 1.27-5.31) at 2 to less than 5 years, and hearing loss (aOR, 1.18; 95% CI, 1.04-1.33) and epilepsy (aOR, 2.31; 95% CI, 1.55-3.34) at 5-10 years.
This study may have underestimated the prevalence of PD, as data suggests that some minorities have atypical PD presentations which may have been mislabeled as vascular mimics of neurodegenerative disease.
“Tremor and memory symptoms occurring up to 10 and 5 years, respectively, before diagnosis had the highest level of associations with subsequent PD,” the researchers noted. “Further research is needed to explore the associations between epilepsy and PD as well as hearing loss and PD.”
Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.
Simonet C, Bestwick J, Jitlal M, et al. Assessment of Risk Factors and Early Presentations of Parkinson Disease in Primary Care in a Diverse UK Population. JAMA Neurol. 2022;e220003. doi:10.1001/jamaneurol.2022.0003