Diabetes is Associated with Slow Walking Speed in People with Knee Osteoarthritis

Abstract

Walking speed is often considered a sixth vital sign and an important predictor for disability and mortality in older adults. Previous research has shown that a decline in walking speed is associated with diabetes (DM) or osteoarthritis (OA), independently. Slow walking speed may interfere with daily living and basic mobility needs. PURPOSE: The aim of this study was to investigate the impact of diabetes on walking speed in people with knee OA. METHODS: A cross sectional analysis of Osteoarthritis Initiative (OAI) data at 96 months follow up was performed for 2122 individuals aged between 53-87 years with knee pain over 30 days. Participants were grouped into knee OA+diabetes or knee OA only. Walking speed was measured using the average speed of two trials of 20 meter walk test. Diabetes and knee pain over 30 days were assessed via a self-reported questionnaire. Walking speed was categorized as either slow walking speed (<1.0 m/s) or normal walking speed (≥1.0 m/s). Knee pain while walking was assessed immediately after each walk test using a numeric rating scale from 0 to 10. Knee pain while walking was categorized as follows: no pain (0), mild pain (1-3), moderate pain (4-6) and severe pain (7-10). Logistic regression analyses were performed at 0.05 alpha level. RESULTS: A total of 1848 participants had knee OA only and 274 had knee OA+diabetes. A total of 245 individuals had a walking speed < 1.0 m/s with 26.5% of these individuals having diabetes. A total of 1877 participants had a walking speed ≥1.0 m/s with 11.1% of these individuals having diabetes. Logistic regression analyses showed that diabetes was significantly associated with slow walking speed (<1.0 m/s), (odds ratio 1.62; 95% confidence interval [1.11, 2.36], p=0.013) after controlling for age, sex, race, body mass index, depression and pain while walking. CONCLUSION: This study found an association between diabetes and slow walking speed in people with knee OA, independent of knee pain. People with diabetes and knee OA are about 1.6 times more likely to have a slow walking speed (<1.0 m/s) than those with OA alone. Previous research has linked slow walking speed to adverse health outcomes. Further research should explore the complex relationships between walking speed, functional ability, and health outcomes in this population.