Effects of Endurance Training on Motor Signs of Parkinson's Disease: A Systematic Review and Meta-Analysis.

Abstract

Evidence has demonstrated that endurance training (ET) reduces the motor signs of Parkinson's disease (PD). However, there has not been a comprehensive meta-analysis of studies to date. The aim of this study was to compare the effect of ET versus nonactive and active control conditions on motor signs as assessed by either the Unified Parkinson's Disease Rating Scale part III (UPDRS-III) or Movement Disorder Society-UPDRS-III (MDS-UPDRS-III). A random-effect meta-analysis model using standardized mean differences (Hedges' g) determined treatment effects. Moderators (e.g., combined endurance and physical therapy training [CEPTT]) and meta-regressors (e.g., number of sessions) were used for sub-analyses. Methodological quality was assessed by the Physiotherapy Evidence Database. Twenty-seven randomized controlled trials (RCTs) met inclusion criteria (1152 participants). ET is effective in decreasing UPDRS-III scores when compared with nonactive and active control conditions (g = - 0.68 and g = - 0.33, respectively). This decrease was greater (within- and between-groups average of - 8.0 and - 6.8 point reduction on UPDRS-III scores, respectively) than the moderate range of clinically important changes to UPDRS-III scores (- 4.5 to - 6.7 points) suggested for PD. Although considerable heterogeneity was observed between RCTs (I2 = 74%), some moderators that increased the effect of ET on motor signs decreased the heterogeneity of the analyses, such as CEPTT (I2 = 21%), intensity based on treadmill speed (I2 = 0%), self-perceived exertion rate (I2 = 33%), and studies composed of individuals with PD and freezing of gait (I2 = 0%). Meta-regression did not produce significant relationships between ET dosage and UPDRS-III scores. ET is effective in decreasing UPDRS-III scores. Questions remain about the dose-response relationship between ET and reduction in motor signs.