Factors associated with knee pain in 5148 women aged 50 years and older: A population-based study

OBJECTIVE This study was performed to investigate the factors associated with the level of knee pain in a nationally representative sample of noninstitutionalized women aged 50 years or older. METHODS Women aged 50 years or older were selected and included in the data analyses from the Korean National Health and Nutrition Examination Surveys (2010-2013). Those having malignant diseases or using osteoarthritis medication were excluded. Significant factors associated with the level of knee pain were analyzed using multivariate regression analysis. RESULTS A total of 5148 women (average age, 62.9 years; standard deviation, 9.3 years) were included. For women without knee osteoarthritis, level of hip pain (p<0.001), presence of back pain (p<0.001), age (p<0.001), and body mass index (BMI) (p<0.001) were found to be significant factors associated with the level of knee pain. For women with knee osteoarthritis, the radiographic grade of knee osteoarthritis (p<0.001), presence of back pain (p<0.001), level of hip pain (p<0.001), presence of depressive symptoms (p<0.001), and BMI (p = 0.026) were the factors significantly associated with the level of knee pain. CONCLUSIONS Women without knee osteoarthritis tended to report increasing knee pain with increasing age. BMI is considered a significant controllable factor in knee pain in women regardless of the presence of radiographic knee osteoarthritis. The presence of depressive symptoms may aggravate knee pain in women with knee osteoarthritis. Attention needs to be focused on concomitant musculoskeletal problems such as lumbar spinal and hip diseases in women with knee pain.