Effects of 6 months of endurance exercise on motor function, exercise capacity, and autonomic function based on presence of autonomic dysfunction in individuals with early Parkinson's disease.

BackgroundEndurance exercise improves aerobic capacity (VO_2peak) and motor symptoms in people with early Parkinson's disease (PD). Some people with PD exhibit signs of chronotropic incompetence (CI), which may impact exercise-induced benefits.ObjectiveWe investigated whether CI in people with early PD influences the change in motor signs, VO_2peak, and peak heart rate (HR) following 6 months of endurance exercise.MethodsWe performed secondary analyses of the Study in Parkinson's Disease of Exercise (SPARX), which randomized people with early PD into a high-intensity endurance exercise [80-85% of peak HR], moderate-intensity endurance exercise [60-65% of peak HR], or usual care group. MDS-UDPRS Part 3 score, VO_2peak, and heart rate (HR) response to maximal cardiopulmonary exercise testing (CPET) were analyzed at baseline and following 6 months of exercise. Participants were divided into three groups: 1) normal chronotropic response at baseline, 2) CI at baseline, and 3) taking medications with a known negative chronotropic effect regardless of CI status.ResultsData from 119 individuals (64.0 ± 9.0 years, 57.1% male, 0.3 years since diagnosis [median]) were analyzed. There were no differences among the groups in change in MDS-UPDRS motor score (p = 0.953), VO_2peak (p = 0.965), or peak HR (p = 0.388). People randomized into the high-intensity group improved VO_2peak compared to usual care (p < 0.001_adj) regardless of CI status.ConclusionsBaseline CI did not alter responses to endurance exercise in those with early PD, suggesting that the beneficial effects of endurance exercise on disease progression and VO_2peak in people with early PD apply equally to people with CI.