The association of fatigue severity with pain level, obesity indices and functional performances in women with knee osteoarthritis

INTRODUCTION: Knee osteoarthritis is most common among women with obesity. It may lead to physical inactivity that, in turn, causes fatigue or lack of physical enthusiasm to perform meaningful daily activities. Hence, this study aimed to examine whether pain level, obesity indices and functional performances are associated with fatigue severity in women with knee osteoarthritis (KOA).

MATERIALS AND METHODS: This cross-sectional study recruited women referred to physiotherapy to manage OA. The measurements included fatigue severity (fatigue severity scale); pain level (numerical rating scale); obesity indices (body mass index, fat %, waist circumference); functional performances (upper limb strength, lower limb strength, mobility, exercise capacity and quality of life). A simple linear regression analysis was used to determine which independent variable may be associated with fatigue severity.

RESULTS: Ninety-six women with unilateral KOA participated in this study (Mean age, 55.70, Standard Deviation, SD 6.90) years; Mean fatigue severity, 34.51, SD 14.03). The simple linear regression analysis showed that pain level (β=4.089, p<0.001), fat % (β=0.825, p<0.001) and QoL (β=0.304, p<0.001) were significantly associated with fatigue. After controlling for pain level, only fat % was significantly associated with fatigue (β=0.581, p=0.005).

CONCLUSION: Pain level, fat %, and QoL appear to be associated with fatigue severity in women with KOA. In addition, pain symptoms may interact with factors associated with fatigue severity.