Daily Walking and the Risk of Incident Functional Limitation in Knee Osteoarthritis: An Observational Study1. Issue 9 (September 2014)

• Record Type: Journal Article
• Authors: White, Daniel K.; Tudor‐Locke, Catrine; Zhang, Yuqing; Fielding, Roger; LaValley, Michael; Felson, David T.; Gross, K. Douglas; Nevitt, Michael C.; Lewis, Cora E.; Torner, James; Neogi, Tuhina
• Is Part Of: Arthritis care & research. Volume 66:Issue 9(2014:Sep.)
• Page Start: 1328
• Page End: 1336
• Publication Date: 2014-09
• Subjects: Arthritis -- Periodicals; Rheumatism -- Periodicals; 616.72
• DOI: 10.1002/acr.22362
• Languages: English
• ISSNs: 2151-464X

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="acr22362-sec-0001" sec-type="section"> <title>Objective</title> <p>Physical activity is recommended to mitigate functional limitations associated with knee osteoarthritis (OA). However, it is unclear whether walking on its own protects against the development of functional limitation.</p> </sec> <sec id="acr22362-sec-0002" sec-type="section"> <title>Methods</title> <p>Walking over 7 days was objectively measured as steps/day within a cohort of people with or at risk of knee OA from the Multicenter Osteoarthritis Study. Incident functional limitation over 2 years was defined by performance‐based (gait speed <1.0 meter/second) and self‐report (Western Ontario and McMaster Universities Osteoarthritis Index physical function score >28 of 68) measures. We evaluated the association of steps/day at baseline with developing functional limitation 2 years later by calculating risk ratios adjusted for potential confounders. The number of steps/day that best distinguished risk for developing functional limitation was estimated from the maximum distance from chance on receiver operating characteristic curves.</p> </sec> <sec id="acr22362-sec-0003" sec-type="section"> <title>Results</title> <p>Among 1, 788 participants (mean age 67 years, mean body mass index 31 kg/m<sup>2</sup>, 60% women), each additional 1, 000 steps/day was associated with a 16% and 18% reduction in incident functional limitation by performance‐based and self‐report measures, respectively. Walking <6, 000 and <5, 900 steps/day were the best thresholds to distinguish incident functional limitation by performance‐based (sensitivity 67.3%, specificity 71.8%) and self‐report (sensitivity 58.7%, specificity 68.9%) measures, respectively.</p> </sec> <sec id="acr22362-sec-0004" sec-type="section"> <title>Conclusion</title> <p>More walking was associated with less risk of functional limitation over 2 years. Walking >6, 000 steps/day provides a preliminary estimate of the level of walking activity to protect against developing functional limitation in people with or at risk of knee OA.</p> </sec> </abstract>