Abstract
BACKGROUND: The primary aim of this study was to longitudinally examine the impact of diabetes mellitus (DM) on physical performance measures including Gait Speed and Chair Stand tests over 8 years of follow-up in people with or at risk of knee osteoarthritis (OA). DESIGN: A prospective longitudinal study. SETTING: Multisite community based. POPULATION: This study included participants with or at risk of knee OA aged from 45 to 79 years from the Osteoarthritis Initiative from baseline to 96 months follow-up. METHODS: The participants performed physical performance measures using a 20 m Walk Test for Gait Speed and 5 Times Sit To Stand for repeated chair stand test time at baseline and during follow-up visits. Participants were asked about the presence of diabetes mellitus (DM) at baseline and categorized into with or without DM. Generalized estimating equations were utilized with 2 models, one for DM and Gait Speed and the other for DM and Repeated Chair Stand Test after controlling for covariates including age, sex, education, Body Mass Index (BMI), depressive symptoms, physical activity level, baseline number of comorbidities, and baseline Kellgren and Lawrence grades for OA grading for each knee. RESULTS: A total of 4796 participants were included and categorized into those with DM (N.=362) and without DM (N.=4311) at baseline. Participants with DM at baseline showed significantly declined gait speed (B=-0.048, 95% Confidence Interval [95% CI]: [-0.07, -0.02], P<0.001) and significantly an increased time for repeated chair stand test (B=0.49, 95% CI: [0.08, 0.89], P=0.018) over time when compared to those without DM at baseline, after controlling for covariates. CONCLUSIONS: DM was associated with negative impact on Gait Speed and Repeated Chair Stand Test time in individuals with or at risk of knee OA. Individuals with knee OA and diabetes who exhibit declining physical performance measures are at risk of functional dependence, reduced quality of life, and complex rehabilitation requirements.