Article In Brief
New findings from JAMA Neurology reported that physical activity, regardless of intensity, is associated with reduced all-cause mortality among individuals with Parkinson's disease. Those who began to exercise after their diagnosis also had lower all-cause mortality than those who did not do physical activity.
A greater amount of physical activity, regardless of the intensity of exercise, is associated with reduced all-cause mortality among individuals with Parkinson's disease (PD), according to a report published online November 1 in JAMA Neurology.
The report found that physical activity—whether light, moderate, or intense—was associated with reduced all-cause mortality, with an inverse dose-response association between the total amount of physical activity and mortality. Participants who performed physical activity before and after the PD diagnosis had the lowest mortality risk, but those who took up exercise after their diagnosis also had lower all-cause mortality than those who did not.
“Individuals with PD who maintained PA [physical activity] before and after receiving the PD diagnosis showed the greatest decrease in mortality rate reduction (up to 50%),” wrote the lead author Seo Yeon Yoon, MD, PhD, of the department of physical medicine and rehabilitation at Korea University Guro Hospital in Seoul, and his colleagues. “However, among individuals with PD who discontinued PA after receiving their PD diagnosis, PA showed a weaker association with mortality risk. This finding suggests that recent PA levels were more important than past PA levels in terms of mortality reduction and PA maintenance could be encouraged in individuals with PD.”
The authors and experts who reviewed the report for Neurology Today agreed the results suggest neurologists should encourage patients to exercise more and more regularly—rather than more intensely. “Leisure time exercise or regular walking is less expensive and might be more applicable to individuals with PD than structured and intensive physical therapy programs,” the study authors wrote.
Using data from the Korean National Health Insurance System, Dr. Yoon and colleagues analyzed data on 10,699 individuals newly diagnosed with PD between January 1, 2010, and December 31, 2013. The cohort had to have attended health checkups within two years before and after receiving the PD diagnosis to evaluate the association between physical activity maintenance and mortality. The researchers excluded individuals younger than 40 years and those with missing data.
The research team collected the data on physical activity using self-reported structured questionnaires, similar to the International Physical Activity Questionnaire-Short form, in which participants were asked how many days per week they spent performing each activity by intensity level. High-intensity physical activity, such as running, aerobics, fast biking, and climbing, for more than 20 minutes was defined as vigorous activity. Activities such as fast walking, riding a bicycle at a normal speed, and doubles tennis, for more than 30 minutes were defined as moderate intensity; walking to and from work or for leisure, for more than 30 minutes was considered to be light-intensity activity.
A total of 1,823 of 10,699 individuals with PD died who were followed up for up to eight years. After adjustment for confounding variables, a significantly reduced mortality risk was observed in individuals with PD who were physically active compared with those who were physically inactive for all levels of intensity. Individuals with PD who were physically active both before and after the PD diagnosis showed the greatest reduction in mortality rate for all PA intensities: those maintaining vigorous physical activity had a hazard ratio (HR) for all-cause mortality of 0.66, while those doing moderate-intensity exercise had an HR of 0.76.
Individuals who started exercise after receiving the PD diagnosis had a lower mortality rate than those who remained physically inactive. Moreover, those who became inactive after receiving their PD diagnosis did not have a significantly better survival rate than individuals with PD who were continuously inactive, despite being physically active before receiving the diagnosis.
In an editorial accompanying the report, Nienke M. de Vries, PhD, and colleagues of the Donders Institute for Brain, Cognition and Behavior in the department of neurology at Radboud University Medical Center in Nijmegen, the Netherlands, said the report shows that the sheer amount or volume of physical activity makes a difference.
“This benefit was reflected here by a reduced mortality risk, and it remains to be determined whether this also translates into tangible health benefits during life for persons with PD,” they wrote. “Should this be demonstrated in further studies, then this would practically mean that people with PD should not necessarily be encouraged to reach high-intensity exercise levels, but that achieving a higher volume of physical activities—for instance, by simply taking longer daily walks—would also confer symptomatic improvement. Practically speaking, this could bring the positive associations of physical activity within reach of more people with PD around the world, including the many who now find it difficult to engage in truly high-intensity aerobic exercise.”
Experts who reviewed the report for Neurology Today agreed. “There are several limitations to large retrospective cohort studies like this, mainly that many confounding variables cannot be accounted for, but the strength of the study is its large sample size and generalizability,” said Mitra Afshari, MD, MPH, assistant professor in the department of neurological sciences at Rush University in Chicago.
“The results show that those PD patients who have been physically active their whole lives and can maintain that activity despite their diagnose fend the best, but those who pick up exercise after their diagnosis also do well with respect to survival. And those who became inactive despite being ‘athletes’ previously did just as poorly as the ‘non-athletes.’ This tells me how important it is to encourage our PD patients to pick up exercise even if they are not ‘athletes.’ We should be giving our PD patients, no matter where they are in their disease, a ‘prescription’ to exercise.”
Dr. Afshari is also site-principal investigator of the recent large NIH-funded Phase 3 SPARX3 (Study in Parkinson Disease of Exercise). She noted that movement disorder neurologists have traditionally thought of exercise as the one treatment for PD that has the potential to slow the progression of the disease.
“The question of the ‘dose,’ type, and maintenance level of exercise that is most beneficial for PD patients still remains unanswered, but we are getting closer with the series of SPARX treadmill-based exercise studies,” she told Neurology Today. (The principal investigator for the study is Daniel Corcos, PhD, of Northwestern University.)
Dr. Afshari said the results of the JAMA Neurology study suggest that moderate-intensity exercise may be just as good, if not better, than high-intensity exercise for survival. “Perhaps moderate-intensity exercise, which one would think is better tolerated and associated with greater maintenance, could be the right ‘prescription’ for our PD patients, with infinite refills.”
Kelvin L. Chou, MD, FAAN, clinical professor of neurology at the University of Michigan, agreed. “The findings are elegant, showing an inverse dose-response association between amount of physical activity and mortality in both men and women and PD,” he said. “While there are studies suggesting a relationship between physical activity and decreased PD risk or improved motor and cognitive symptoms, I am not aware of any other studies that have shown an association between physical activity and longer survival in PD.”
“There are several limitations to large retrospective cohort studies like this, mainly that many confounding variables cannot be accounted for, but the strength of the study is its large sample size and generalizability.”—DR. MITRA AFSHARI
He added, “Many different types of physical activity have been shown to be beneficial for PD patients, including bicycling, boxing, treadmill exercise, strength training, and tai chi among others. None of these modalities have really been compared in head-to-head fashion, so my message to patients is that they should adopt an exercise program using a type exercise or activity that they are likely to do. They should aim for 150 minutes of moderate intensity exercise per week, but even if they aren't there yet, some exercise is better than none.
“Bottom line: all neurologists should be encouraging their PD patients to engage in physical activity. Even some light activity is better than none,” Dr. Chou said.
Dr Yoon reported grant funding from the National Research Foundation of Korea (funded by the Korean government) during the conduct of the study. Dr. Chou received fees from Abbott, Amneal, Avon Pharmaceuticals, and Neurocrine. Dr. Afshari had no disclosures.