Background and Purpose: Objective ambulatory activity during daily living has not been characterized for people with Parkinson disease prior to initiation of dopaminergic medication. Our goal was to characterize ambulatory activity based on average daily step count and examine determinants of step count in nonexercising people with de novo Parkinson disease.
Methods: We analyzed baseline data from a randomized controlled trial, which excluded people performing regular endurance exercise. Of 128 eligible participants (mean ± SD = 64.3 ± 8.6 years), 113 had complete accelerometer data, which were used to determine daily step count. Multiple linear regression was used to identify factors associated with average daily step count over 10 days. Candidate explanatory variable categories were (1) demographics/anthropometrics, (2) Parkinson disease characteristics, (3) motor symptom severity, (4) nonmotor and behavioral characteristics, (5) comorbidities, and (6) cardiorespiratory fitness.
Results: Average daily step count was 5362 ± 2890 steps per day. Five factors explained 24% of daily step count variability, with higher step count associated with higher cardiorespiratory fitness (10%), no fear/worry of falling (5%), lower motor severity examination score (4%), more recent time since Parkinson disease diagnosis (3%), and the presence of a cardiovascular condition (2%).
Discussion and Conclusions: Daily step count in nonexercising people recruited for this intervention trial with de novo Parkinson disease approached sedentary lifestyle levels. Further study is warranted for elucidating factors explaining ambulatory activity, particularly cardiorespiratory fitness, and fear/worry of falling. Clinicians should consider the costs and benefits of exercise and activity behavior interventions immediately after diagnosis of Parkinson disease to attenuate the health consequences of low daily step count.
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Department of Physical Medicine and Rehabilitation (C.C., M.S.), Department of Neurology (B.K., B.B.), Division of Geriatric Medicine (W.K., T.W., E.M.), and Division of Endocrinology, Metabolism, and Diabetes (E.M.), University of Colorado School of Medicine, Aurora, Colorado; Geriatric Research Education and Clinical Center, VA Eastern Colorado Healthcare System, Denver, Colorado (C.C.); Dickson Advanced Analytics, Carolinas HealthCare System, Charlotte, North Carolina (C.M.); School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania (A.D., D.J.); Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois (D.H., C.C.); Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, Illinois (C.P., D.C.); Department of Physical Therapy, University of Illinois at Chicago, Chicago Illinois (J.R.); and Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (S.J.).
Correspondence: Cory L. Christiansen, PT, PhD, University of Colorado Anschutz Medical Campus, Mailstop C244, 13121 East 17th Avenue, Aurora, CO 80045 (firstname.lastname@example.org).
Dr Christiansen's effort was supported by NIH Grant Number K12 HD055931. Dr Schenkman receives royalties from Pearson Publications and Prentice Hall. Dr Hall receives research support from Pfizer and Neurocrine and receives grant support from Parkinson Disease Foundation and Shapiro Foundation. Dr Jain receives grant support from American Parkinson Disease Association. Dr Comella receives compensation/honoraria for services as a consultant or advisory committee member from Acorda Therapeutics, Allergan, Ipsen Biopharmaceuticals, Lundbeck, Medtronic, Merz Pharmaceuticals, Acadia Pharmaceuticals, Neurocrine Biosciences, Revance Therapeutic, and Ultragenyx Pharmaceuticals. Dr Corcos receives compensation/honoraria for services as a consultant for Temple University. For the remaining authors, none were declared. This work was supported by NIH Grant Number R01NS074343 (SPARX) and NIH/NCATS Colorado CTSA Grant Number UL1 TR001082. Contents are the authors' sole responsibility and do not necessarily represent official NIH views.
ClinicalTrials.gov registration number: NCT01506479
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