Among older people, walking and other recreational exercises do not increase the risk of knee osteoarthritis – this is the good news, according to a current survey from the Boston University School of Medicine. The bad news is: in this group, recreational exercises do not protect against knee osteoarthritis either.
"Regular exercise is recommended for middle-aged and older persons," David Felson and his colleagues write in the January issue of Arthritis Care & Research. "The effect of regular exercise on the development of osteoarthritis in older persons, especially those who are overweight, is unclear."
Therefore the scientists evaluated a community-based cohort of 1,279 older adults (mean age at baseline was 53 years), many of whom were overweight or obese, using a questionnaire about physical activities like walking or jogging. Approximately nine years after baseline assessment, subjects were re-examined for knee osteoarthritis. Radiographs were evaluated in both tibio-femoral and patello-femoral compartments and scored for tibio-femoral joint space narrowing. Knees with osteoarthritis at baseline were excluded for all analyses.
Results: Recreational walking, jogging, frequency of working up a sweat or high activity levels relative to peers were not associated with decreased or increased risk for knee osteoarthritis or with joint space loss. Participants with BMI above the median showed no increased risk for knee osteoarthritis. “Although dynamic loading may have a trophic effect on cartilage, there is no measurable protective effect of recommended weight-bearing exercise on osteoarthritis. Physical activity can be done safely without concerns that persons will develop knee osteoarthritis as a consequence”, the authors conclude. JG
Arthritis Care Res (2007); 51: 6-12
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