Air pollution linked to higher risk of Parkinson’s, dyskinesia in study
Measures to reduce air pollution may help decrease risk, worsening of disease
Exposure to air pollutants, such as fine particulate matter and nitrogen dioxide, may increase the risk of developing Parkinson’s disease and dyskinesia, or involuntary movements, according to a study using data from the Rochester Epidemiology Project.
These findings add to growing evidence that breathing polluted air is a risk factor for Parkinson’s. Setting measures to reduce the levels of air pollution could be an important step toward decreasing the risk of developing the disease or experiencing worse symptoms, researchers note.
The study, “Air Pollution and Parkinson Disease in a Population-Based Study,” was published in JAMA Network Open.
Parkinson’s believed to be driven by genetic, environmental factors
While its exact causes are unknown, Parkinson’s is believed to be driven by a combination of genetic and environmental factors. Growing evidence suggests that breathing polluted air could increase the risk of developing the disease.
Now, a team of researchers in the U.S. looked at whether exposure to fine particulate matter, which are tiny solid particles and liquid droplets known as PM2.5, and nitrogen dioxide affect the risk of developing Parkinson’s and change how the disease progresses.
The study included 346 people with a diagnosis of Parkinson’s and a median age of 72 years, and 4,813 age-matched individuals without the disease from a population database called the Rochester Epidemiology Project. The time period for the study ranged from 1998 to 2015 for PM2.5, and 2000 to 2014 for nitrogen dioxide.
People exposed to higher levels of PM2.5 had a significantly higher risk of developing Parkinson’s, with those who were in the top 20% of exposure having a 14% higher risk of developing Parkinson’s than those in the bottom 20%.
The risk of developing Parkinson’s was even greater, by up to 23%, for people who lived in large cities or metropolitan areas, which typically have more polluted air. Most people with Parkinson’s lived in metropolitan areas compared with nearly one-third of controls (79.5% vs. 32.7%).
Higher PM2.5 levels linked to form of Parkinson’s called akinetic rigid subtype
In addition to increasing the risk of Parkinson’s, exposure to higher levels of PM2.5 was linked to a form of Parkinson’s, called the akinetic rigid subtype, that causes stiffness and difficulty moving rather than tremor. People with this form of Parkinson’s may experience faster decline of motor skills.
Higher exposure to nitrogen dioxide was also associated with an increased risk of developing Parkinson’s, with people in the top 20% of exposure showing a 13% higher risk of developing the disease compared with those in the lowest 20%.
Among people with Parkinson’s, exposure to higher levels of PM2.5 or nitrogen dioxide was linked to an increased risk of dyskinesia, a side effect of Parkinson’s treatments that causes involuntary movements.
This means that air pollution may contribute to a worsening of symptoms in people who have already been diagnosed with Parkinson’s. However, unlike findings from earlier studies, exposure to air pollutants was not linked to an increased risk of death.
“These findings suggest that reducing air pollution may reduce risk of [Parkinson’s], modify the [Parkinson’s] phenotype [disease characteristics], and reduce risk of dyskinesia,” the researchers concluded.
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