Presentations at the American College of Rheumatology meeting last month revealed yet more robust evidence of the tight correlation between physical activity (or lack of it) and osteoarthritis. Different studies show that this relationship begins in childhood and extends throughout the lifespan. (Click on Abstract numbers below to read more details about the presentations.)
• Nearly 90% of people with osteoarthritis do not meet recommended weekly levels of physical activity, and they quite literally suffer for lack of it. Researchers from three university medical centers analyzed the intensity of physical activity, as measured using accelerometers, among 1154 adult patients with knee osteoarthritis taking part in the multicenter observational Osteoarthritis Initiative. Almost half were completely inactive; another 40% did not meet recommended activity levels of at least 150 minutes of moderate to vigorous physical activity each week. The completely inactive adults had significantly poorer physical function than even those who got some activity while not meeting the guidelines. (Abstract #243)
• The lack of activity is gender-specific. Women with joint pain and osteoarthritis are particularly unlikely to get enough exercise. Watch for targeted recommendations for women with OA to get moving. This sample of 1680 men and women aged 50 years or older in the National Health and Nutrition Examination Survey assessed physical exercise both by self-report and by accelerometer, and asked subjects whether they had knee pain or had been diagnosed with osteoarthritis. Only 2% of women diagnosed with OA who had knee pain got recommended levels of exercise. Perhaps surpisingly, men with knee pain, OA diagnosis, or both were actually more active than unaffected men, even considering data gathered by accelerometer rather than self-report. (Abstract #2513)
• OA prevention begins with the first step; active children are less likely to develop arthritic knees. This is a logical conclusion based on evidence from the Australian Childhood
Determinants of Adult Health study, which compared various measures of fitness during childhood with knee bone area and cartilage volume in adulthood. Perhaps exercise creates adaptive benefits for growing knees, the authors suggest. (Abstract #2535)
• At the other end of the spectrum, knee osteoarthritis is associated with frailty. Perhaps effectively resolving knee OA could prevent frailty, suggests the multi-university team that found an association between radiographic and clinical signs of knee OA and indicators of frailty such as poor energy, weight loss, and inability to rise from a chair. They used data from the Osteoarthritis Initiative and the Multicenter Osteoarthritis Study. (Abstract #1098)
