No Association between Daily Walking and Knee Structural Changes in People at Risk of or with Mild Knee
Britt Elin Øiestad1, Emily Quinn2, Daniel White2
1From the Norwegian Research Center for Active Rehabilitation, Department of Orthopedics, Oslo University Hospital, Oslo, Norway; Clinical Epidemiology Research and Training Unit, and Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine; Data Coordinating Center, Boston University School of Public Health, Boston, Massachusetts; Department of Epidemiology and Biostatistics, University of California, San Francisco, California; Department of Physical Therapy, University of Delaware, Newark, Delaware; Department of Rehabilitation Medicine, University of Kansas, Kansas City, Kansas; Division of Preventive Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA; Department of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany; Arthritis Research UK Epidemiology Unit, University of Manchester, Manchester, UK.B.E. Øiestad, PT, PhD, Norwegian Research Center for Active Rehabilitation, Department of Orthopedics, Oslo University Hospital; E. Quinn, MSc, Data Coordinating Center, Boston University School of Public Health; D. White, PT, ScD, MSc, Department of Physical Therapy, University of Delaware, and Clinical Epidemiology Research and Training Unit, Boston University School of Medicine; F. Roemer, MD, PhD, Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, and Department of Radiology, University of Erlangen-Nuremberg; A. Guermazi, MD, PhD, Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine; M. Nevitt, PhD, Department of Epidemiology and Biostatistics, University of California; N.A. Segal, MD, MS, Department of Rehabilitation Medicine, University of Kansas; C.E. Lewis, MD, MSPH, Division of Preventive Medicine, University of Alabama at Birmingham; D.T. Felson, MD, MPH, Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, and Arthritis Research UK Epidemiology Unit, University of Manchester. Britt
Objective:
We investigated the association between objectively measured daily walking and knee structural change, defined either as radiographic worsening or as cartilage loss, in people at risk of or with knee osteoarthritis (OA).
Methods:
Participants from the Multicenter Osteoarthritis Study (MOST) with Kellgren-Lawrence grades 0-2 and daily walking (measured with the StepWatch) at the 60-month visit were included. Participants had fixed-flexion, weight-bearing radiographs and knee magnetic resonance images (MRI) at 60 and 84 months. Radiographic worsening was read in both knees using the Osteoarthritis Research Society International grading, and MRI were read for 1 knee using the Whole-Organ MRI Score semiquantitative scoring. OR and 95% CI were calculated comparing those in the middle tertile against the lowest and highest tertiles of daily walking using logistic regression models and generalized estimating equations. Data on walking with moderate to vigorous intensity (min with > 100 steps/min/day) were associated to structural change using multivariate and logistic regression models.
Results:
The 1179 study participants (59% women) were 67.0 years old (± 7.6), with a mean (± SD) body mass index of 29.8 kg/m(2) (± 5.3) who walked 6981 (± 2630) steps/day. After adjusting for confounders, we found no significant associations between daily walking and radiographic worsening or cartilage loss. More time spent walking at a moderate to vigorous intensity was not associated with either radiographic worsening or cartilage loss.
Conclusion:
Results from the MOST study indicated no association between daily walking and structural changes over 2 years in the knees of people at risk of or with mild knee OA.
