People with Parkinson’s disease have a higher risk of bad falls and hip fractures as early as 26 years before diagnosis, partly because of a poorer sense of balance that might be an early sign of the illness, according to a study published in the journal PLOS Medicine and titled “Risk of Injurious Fall and Hip Fracture up to 26 y before the Diagnosis of Parkinson Disease: Nested Case–Control Studies in a Nationwide Cohort.”
Parkinson’s disease (PD) is a progressive neurological disorder caused by the gradual loss of the nerve cells that usually produce dopamine, a neurotransmitter that regulates the body’s motor functions. Evidence from studies has shown that low muscle strength in late adolescence is linked with PD diagnosed 30 years later.
To investigate if such lower muscle strength may also translate into increased risks of falls and fractures before a PD diagnosis, researchers looked at 24,412 adults — a cohort taken from the Swedish National Patient Register — diagnosed with PD between 1988 and 2012. All patients were matched with up to 10 controls. During an average study period of 20 years prior to a PD diagnosis, 18 percent of PD patients, and 11.5 percent of controls, had at least one fall that caused an injury that required emergency care.
The results revealed reduced muscular strength in the arms could be detected, on average, 30 years before a PD diagnosis. Moreover, this reduced muscular strength could also be associated with an increased risk of hip fractures more than 15 years before PD diagnosis, and injuring falls up to 10 years before diagnosis. Signs of gradual dysfunction in balance reactions and impaired mobility were also present at an early stage.
These findings suggest that clinically relevant neurodegenerative impairment could be present many years before the clinical onset of the disease. “We asked ourselves if fall-related injuries at an early age could be a warning sign of the deteriorating balance that is characteristic to Parkinson’s disease,” Helena Nyström, a doctoral student at the Department of Community Medicine and Rehabilitation and co-author of the article, said in a news release. “By investigating health data from registers, we could see a correlation between individuals who were later diagnosed with Parkinson’s and who were more often involved in injurious falls. It was also shown that the higher risk of hip fractures could be measured more than two decades before the diagnosis.”