new research suggested.
Investigators drew on 10-year data from primary care registry to compare almost 110,000 patients who developed anxiety after the age of 50 years with close to 900,000 matched controls without anxiety.
After adjusting for a variety of sociodemographic, lifestyle, psychiatric, and neurological factors, they found that the risk of developing Parkinson’s disease was double in those with anxiety, compared with controls.
“Anxiety is known to be a feature of the early stages of Parkinson’s disease, but prior to our study, the prospective risk of Parkinson’s in those over the age of 50 with new-onset anxiety was unknown,” colead author Juan Bazo Alvarez, a senior research fellow in the Division of Epidemiology and Health at University College London, London, England, said in a news release.
The study was published online in the British Journal of General Practice.
The presence of anxiety is increased in prodromal Parkinson’s disease, but the prospective risk for Parkinson’s disease in those aged 50 years or older with new-onset anxiety was largely unknown.
Investigators analyzed data from a large UK primary care dataset that includes all people aged between 50 and 99 years who were registered with a participating practice from Jan. 1, 2008, to Dec. 31, 2018.
They identified 109,435 people (35% men) with more than one anxiety record in the database but no previous record of anxiety for 1 year or more and 878,256 people (37% men) with no history of anxiety (control group).
Features of Parkinson’s disease such as sleep problems, depression, tremor, and impaired balance were then tracked from the point of the anxiety diagnosis until 1 year before the Parkinson’s disease diagnosis.
Among those with anxiety, 331 developed Parkinson’s disease during the follow-up period, with a median time to diagnosis of 4.9 years after the first recorded episode of anxiety.
The incidence of Parkinson’s disease was 1.2 per 1000 person-years (95% CI, 0.92-1.13) in those with anxiety versus 0.49 (95% CI, 0.47-0.52) in those without anxiety.
After adjustment for age, sex, social deprivation, lifestyle factors, severe mental illness, head trauma, and dementia, the risk for Parkinson’s disease was double in those with anxiety, compared with the non-anxiety group (hazard ratio, 2.1; 95% CI, 1.9-2.4).
Individuals without anxiety also developed Parkinson’s disease later than those with anxiety.
The researchers identified specific symptoms that were associated with later development of Parkinson’s disease in those with anxiety, including depression, sleep disturbance, fatigue, and cognitive impairment, among other symptoms.
“The results suggest that there is a strong association between anxiety and diagnosis of Parkinson’s disease in patients aged over 50 years who present with a new diagnosis of anxiety,” the authors wrote. “This provides evidence for anxiety as a prodromal presentation of Parkinson’s disease.”
Future research “should explore anxiety in relation to other prodromal symptoms and how this symptom complex is associated with the incidence of Parkinson’s disease,” the researchers wrote. Doing so “may lead to earlier diagnosis and better management of Parkinson’s disease.”
This study was funded by the European Union. Specific authors received funding from the National Institute for Health and Care Research and the Alzheimer’s Society Clinical Training Fellowship program. The authors declared no relevant financial relationships.
A version of this article first appeared on Medscape.com.