Modifiable lifestyle factors are associated with lower pain levels in adults with knee osteoarthritis

BACKGROUND: With no cure or effective treatments for osteoarthritis (OA), the need to identify modifiable factors to decrease pain and increase physical function is well recognized. OBJECTIVE: To examine factors that characterize OA patients at different levels of pain, and to investigate the relationships among these factors and pain. METHODS: Details of OA characteristics and lifestyle factors were collected from interviews with healthy adults with knee OA (n=197). The Western Ontario and McMaster Universities Osteoarthritis Index was used to assess pain. Factors were summarized across three pain score categories, and χ(2) and Kruskal-Wallis tests were used to examine differences. Multiple linear regression analysis using a stepwise selection procedure was used to examine associations between lifestyle factors and pain. RESULTS: Multiple linear regression analysis indicated that pain was significantly higher with the use of OA medications and higher body mass index category, and significantly lower with the use of supplements and meeting physical activity guidelines (≥150 min/week). Stiffness and physical function scores, bilateral knee OA, body mass index category and OA medication use were significantly higher with increasing pain, whereas self-reported health, servings of fruit, supplement use and meeting physical activity guidelines significantly lower. No significant differences across pain categories were found for sex, age, number of diseases, duration of OA, ever smoked, alcoholic drinks/week, over-the-counter pain medication use, OA supplement use, physical therapy use, servings of vegetables or minutes walked/week. CONCLUSIONS: Healthy weight maintenance, exercise for at least 150 min/week and appropriate use of medications and supplements represent important modifiable factors related to lower knee OA pain.