Researchers report dose-response association for physical activity, all-cause PD mortality

Physical activity and all-cause mortality in Parkinson’s disease may have a dose-response association, according to results of a nationwide population-based cohort study published in JAMA Neurology.

“Various exercises, including treadmill training, dance and tai chi, have shown beneficial outcomes against PD progression; however, which exercise type or intensity is more beneficial for preventing PD progression requires further investigation,” Seo Yeon Yoon, MD, PhD, of the department of physical medicine and rehabilitation at Korea University Guro Hospital, and colleagues wrote. “Moreover, there have been few reports on the associations of [physical activity] with mortality in PD.”

The researchers aimed to investigate the link between physical activity and mortality among people with PD and to determine how the amount and maintenance of physical activity affected this link. They used data on 10,699 individuals with PD (46% men; mean age, 69.2 years) included in the Korean National Health Insurance System between January 2010 and December 2013, with follow-up until Dec. 31, 2017. Further, they selected based on ICD-10 criteria individuals with new diagnoses of PD who underwent health checkups within 2 years before and after the diagnosis. They excluded those aged younger than 40 years or those who had missing data. Participants provided physical activity levels via self-reported questionnaires.

Results showed 1,823 deaths (17%) during the 8-year follow-up period. Those who were physically active had a lower mortality rate compared with those who were inactive at all physical activity intensities ([vigorous, HR = 0.8; 95% CI, 0.69-0.93]; [moderate, HR = 0.66; 95% CI, 0.55-0.78]; [light, HR = 0.81; 95% CI, 0.73-0.9]). Yoon and colleagues noted a significant inverse dose-response association between the total amount of physical activity and mortality. Physical activity maintenance correlated with the mortality rate. Participants with PD who were physically active before and after being diagnosed exhibited the greatest reduction in mortality rate across all intensities of physical activity.

There was a significant inverse dose-response association between the total amount of physical activity and mortality (HRs: vigorous, 0.8 [95% CI, 0.69-0.93]; moderate, 0.66 [95% CI,0.55-0.78]; light, 0.81 [95% CI, 0.73-0.90). Moreover, maintenance of physical activity was associated with the mortality rate. Individuals with PD who were physically active both before and after the PD diagnosis had the greatest reduction in mortality rate across all physical activity intensities ([vigorous, HR = 0.66; 95% CI, 0.5-0.88]; [moderate, HR = 0.49; 95% CI, 0.32-0.75]; [light, HR = 0.76; 95% CI, 0.66-0.89]). Those who started physical activity following the diagnosis had a lower mortality rate vs. those who remained physically inactive ([vigorous, HR = 0.82; 95% CI, 0.7-0.97;] [moderate, HR = 0.69; 95% CI, 0.57-0.83]; [light, HR = 0.86; 95% CI, 0.78-0.98]).

“Activity modification to increase and maintain [physical activity] would be beneficial for PD management, and future prospective randomized clinical trials to elucidate causal associations between [physical activity] and mortality in PD are warranted,” Yoon and colleagues wrote.

In a related editorial, Nienke M. de Vries, PhD, of the department of neurology at Radboud University Medical Center, the Netherlands, and colleagues commented on the study.

“One main advantage of the prospective, observational design used in this study, compared with clinical trials, is the large number of participants who could be followed up over a long interval,” de Vries and colleagues wrote. “Moreover, participants were sampled from a medical claims database that is representative of the study’s source population regarding the distribution of age, sex, disease severity and comorbidities. By contrast, clinical trials are often restricted to specific subgroups of patients.”