Among individuals with the degenerative arthritis commonly referred to as osteoarthritis (OA), pain is what patients describe as having the largest impact on the performing of daily activities---and the main cause of visits to the doctor. While it is therefore not surprising that the main focus of treatment would obviously be on the relief of that pain, such an approach may be too narrow for the optimal management of OA—or any other disease for that matter. It seems both patient and physician are neglecting the negative role fatigue plays in the daily lives of the lives of patients suffering from OA. Fatigue can be a predictor of bad things to come, particularly in an older population, as it is one of the five clinical indicators in most models of frailty, the others being:
• Impaired strength
• Impaired endurance
• Impaired balance
• Increased vulnerability to trauma or other stressors.
Relevant to OA, when fatigue in older adults has been measured as tiredness in the performance of daily activities, it predicted the development of mobility problems, dependence in the performance of daily activities, and the risk of an (early) death.
Health care providers—and perhaps patients themselves—buy into the assumption that pain causes fatigue, and therefore the relief of that pain will result in a corresponding reduction in fatigue. However, it may be that this assumption is flawed, because pain and fatigue may have different etiologies and a complex interplay. Interestingly, fatigue has been cited as the primary reason that an older adult might limit his or her activity, and thus the relationship between fatigue and activity must be better characterized. In fact, previous studies have found that when assessing symptoms within and across days (“momentary fatigue” and pain) and related physical activity, it was found that fatigue was more related to reduced physical activity than pain in women afflicted with OA. In addition, researchers found that women with OA were 4 times more likely to experience an increased level of fatigue after an intense session of physical activity compared with matched healthy patients.