Association of Slow Gait Speed With Trajectories of Worsening Depressive Symptoms in Knee Osteoarthritis: An Observational Study.

OBJECTIVE: To investigate the association of slow gait speed, defined as walking slower than is necessary for the community, with trajectories of depressive symptoms over 7 years among people with or at high risk of knee OA.
METHODS: Using data from the Osteoarthritis Initiative, we described trajectories of depressive symptoms measured annually with the Center for Epidemiologic Studies Depression Scale. We categorized speed during a 20-meter walk of <1.2 meters/second as slow gait speed. We used a group-based method to agnostically identify homogeneous clusters of depressive symptom trajectories. We then examined the association of slow gait speed with depressive symptom trajectories, using multinomial logistic regression adjusted for potential confounders.
RESULTS: From the 3,939 participants included (mean ± SD age 61.4 ± 9.2 years, body mass index 28.4 ± 4.7, 58% women, and 63% with a college degree), we identified 5 trajectories. The first 3 were stable over time and included 74% of the sample. The remainder had worsening depressive symptoms over time. Slow gait speed was associated with 2.1 times the odds of having the worst depressive symptoms trajectory compared to those without slow gait speed.
CONCLUSION: Slow gait speed may represent an important risk factor for worsening depressive symptoms over time in people with or at high risk of knee OA, and may signal the need for rehabilitation.