White DK, et al. – Incident functional limitation was assessed in people with or at high risk of knee osteoarthritis without baseline functional limitation, after 2 years of replacing sedentary time with light intensity activity. Findings highlighted the potential of this strategy in attenuating the risk of performance–based functional limitation in this patient population. Moderate to vigorous physical activity rather than light provided stronger risk reduction and light activity was recommended over being sedentary when moderate to vigorous physical activity is not an option.

Methods

• Researchers gathered data from the Osteoarthritis Initiative between August 2008 and July 2010 to include in the present study people with or at high risk of knee osteoarthritis without baseline functional limitation.
• They analyzed data between May 2016 and August 2016 for time in sedentary, light, and moderate to vigorous physical activity from accelerometer monitoring.
• Incident functional limitation was defined as (1) slow gait speed <1.0 meters/second during a 20-meter walk, (2) Western Ontario and McMasters University Osteoarthritis Index physical function ≥28, or (3) Short Form 12 Physical Component scale <40.

Results

• Findings reported that inclusion criteria were met by 1,873 people (mean age=65.0 [SD=9.0] years, mean BMI=28.4 [SD=4.7] kg/m²).
• Researchers observed that replacing 60 minutes/day of sedentary time with 60 minutes/day of light activity was associated with a 17% reduced risk for incident slow gait speed 2 years later (Hazard Ratio=0.83, 95% CI=0.70, 0.99) after adjustment.
• They also observed that approximately 5 minutes/day of moderate to vigorous physical activity would be necessary to receive the equivalent benefit of 60 minutes/day of light activity.
• Data showed that effects in secondary patient-reported outcomes did not reach statistical significance.