June 9 (UPI) -- Older adults with osteoarthritis are at increased risk for developing Parkinson's disease later in life, according to a study published Wednesday by the journal Arthritis Care & Research.
Those with the most common form of arthritis are 41% more likely to develop the movement disorder than those without the condition, the data showed.
Although osteoarthritis can affect the hands, knees, hips and spine, those with the knee and hip forms have a higher risk for Parkinson's than those with other types of the condition, the researchers said.
"Coexisting osteoarthritis and Parkinson's disease can additively increase the risk of falling," study co-author Dr. Shin-Liang Pan said in a press release.
"Moreover, osteoarthritis-related mobility impairments may mask early motor symptoms of Parkinson's disease," said Pan, a physical medicine and rehabilitation specialist at National Taiwan University.
The findings are based on an analysis of health insurance claims data for nearly 67,000 adults in Taiwan age 50 to 64 over a four-year period.
Roughly half the participants had osteoarthritis, which occurs when the protective cartilage that cushions the ends of bones at the joints wears down over time, while the other half did not.
Participants with knee and hip osteoarthritis had a 55% higher risk for Parkinson's disease, a progressive brain disorder that causes shaking, stiffness and difficulty with walking, balance and coordination, the data showed.
Those with osteoarthritis affecting other joints were between 30% and 40% more likely to develop the brain disorder.
Nearly 33 million adults in the United States have osteoarthritis in at least one joint, with older adults at higher risk for the condition due to lifetime wear and tear, according to the Centers for Disease Control and Prevention.
About 60,000 people nationally are diagnosed with Parkinson's each year, the Parkinson's Foundation estimates, with older adults again at higher risk for the disorder.
Although the reasons for the links between osteoarthritis and Parkinson's disease are unclear, both conditions involve inflammation, Pan said.