Interaction Between Exercise Intensity and Sedentary Behavior on VO 2 max Change in Patients with De Novo Parkinson Disease: The Study in Parkinson Disease of Exercise (SPARX) Phase 2 Randomized Clinical Trial
Interaction Between Exercise Intensity and Sedentary Behavior on VO 2 max Change in Patients with De Novo Parkinson Disease: The Study in Parkinson Disease of Exercise (SPARX) Phase 2 Randomized Clinical Trial
Where did the research take place?
The study site has not been established. Author addresses may differ from where the research occurred.
Atlanta, US · Author affiliation
Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USALocation evidence
Chicago, US · Author affiliation
Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, USALocation evidence
Pittsburgh, US · Author affiliation
Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, USALocation evidence
US · Author affiliation · country only
Physical Therapy Program, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USALocation evidence
Publication status: preprint
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Original abstract
Abstract Background Parkinson disease (PD) is associated with increased sedentary time and reduced cardiorespiratory fitness, making exercise an important component of disease management. Although exercise improves cardiorespiratory fitness, individuals with PD vary substantially in their response to exercise. Sedentary time may contribute to this variability, yet whether sedentary time modifies the response to intervention and varying exercise intensities within an intervention is unknown. We examined whether sedentary time interacted with 6 months of moderate-intensity or high- intensity aerobic exercise on maximal oxygen consumption (VO₂max) in individuals with PD. Methods This secondary analysis used data from the SPARX phase 2 randomized clinical trial including 128 de novo PD patients assigned to high- or moderate-intensity treadmill exercise, or usual care for 6 months. Interactions between randomized group and post-randomization 6-months average sedentary time were assessed for associations with 6-month change in VO 2 max by using linear regression models corresponding to Analysis of Covariance (ANCOVA) models with interaction. Results The interaction between exercise intensity and sedentary behavior on 6-month change in VO 2 max in the moderate-intensity group compared with usual care was not significant (β: -1.78, 95% CI: -3.76 to 0.20, p-value: 0.08), although the sensitivity analysis restricted to complete cases showed a significant interaction where each 10% increase in 6-months average sedentary time was associated with a 2.51 mL/kg/min decrease in VO 2 max change in the moderate-intensity group compared with usual care (β: -2.51, 95% CI: -4.53 to -0.48, p-value: 0.02). There was no significant interaction between exercise intensity and sedentary behavior on 6-month change in VO 2 max in the high-intensity group compared with usual care (β: -1.46, 95% CI: -4.74 to 1.83, p-value: 0.38). The sensitivity analysis showed similar results. Conclusions These hypothesis-generating, preliminary findings suggest that sedentary time may modify the response to exercise among individuals participating in moderate-intensity aerobic exercise. Future adequately powered randomized controlled trials are needed to confirm these findings and determine whether sedentary behavior should be considered when prescribing exercise for individuals with PD.