Osteoarthritis-Related Walking Disability and Arterial Stiffness: Results From a Cross-Sectional Study. 
To compare the 6-minute walking distance (6MWD) in a population-based cohort of patients with osteoarthritis (OA) with that in matched peers from the general population, and to explore the associations between walking ability and risk of cardiovascular disease (CVD) in the OA cohort.  This cross-sectional study included individuals (ages 40-80 years) who had self-reported OA (n = 500) in a previous population-based study and age- and sex-matched peers from the general population (n = 235).  Clinical examinations of the patients with OA included classification according to the American College of Rheumatology criteria, blood sampling, and measuring arterial stiffness (PWV; pulse wave velocity).  Group differences in the 6MWD were calculated with t-tests.  The association between walking ability and CVD risk in the OA cohort was examined using multivariate regression models.  In the age-stratified analyses, the largest mean difference in the 6MWD was observed in the youngest age groups (40-49 years); female patients in the OA group walked 84.6 fewer meters compared with the reference group (579.4 meters and 663.9 meters, respectively; P < 0.001), and male patients walked 88.3 fewer meters compared with the reference group (619.9 meters and 708.3 meters, respectively; P = 0.001).  In the OA group, the 6MWD was significantly associated with PWV in the adjusted analysis (P = 0.001); an increase in the walking distance of 100 meters corresponded to a reduction in PWV of 0.3 meters/second.  Even at age 40 years, patients with OA had a significantly shorter mean walking distance compared with their matched peers, underlining the importance of an early clinical approach to OA.  Furthermore, in the OA group, the 6MWD was significantly associated with arterial stiffness, suggesting that walking ability is important for the CVD risk profile in patients with OA.