Acute Effects Of Swimming And Running On Serum Cartilage Oligomeric Matrix Concentration

Abstract

Symptomatic knee osteoarthritis affects an estimated 10 and 13% of American males and females, respectively, over the age of 60; and this prevalence will likely increase in the future due to increased obesity incidence and an aging population. Physical exercise is known to mitigate knee osteoarthritis symptoms, but it is unclear how exercise modes involving different joint load (e.g., running and swimming) affect knee joint health. Serum cartilage oligomeric matrix protein (COMP) concentration is often used to represent articular cartilage metabolism due to physical activity. PURPOSE: Compare the effects of running and swimming on serum COMP concentration in healthy and active older adults. METHODS: Blood samples were collected before and after physical exercise for two groups of older adults. The first group consisted of runners (n = 20; Age = 56 ± 4 yrs; BMI = 24.5 ± 3.2) who completed a 5000-m run. The second group consisted of swimmers (n = 19; Age = 60 ± 6 yrs; BMI = 24.0 ± 2.7) who completed a 1500-m swim. Serum COMP concentrations were quantified via an enzyme-linked immunoassay. Repeated measures analysis of variance was used to compare effects of group (runners or swimmers) and time (pre-exercise, immediately post-exercise, and 15-, 30-, and 60-min post-exercise) on serum COMP concentration. RESULTS: A significant group × time interaction existed for serum COMP concentration (p < 0.01). For the runners, serum COMP increased 29% from pre-exercise (171.4 ± 41.1 ng/μL) to immediately post-exercise (220.7 ± 63.2 ng/μL; p < 0.01). For the swimmers, however, serum COMP did not increase from pre-exercise (179.5 ± 60.7 ng/μL) to immediately post-exercise (187.9 ± 59.0 ng/μL; p = 0.99). CONCLUSION: Assuming that serum COMP concentration increase immediately following physical exercise represents knee articular cartilage metabolism due to physical exercise, the present findings demonstrate that running results in more articular cartilage metabolism than swimming. This supports the idea that running, involving ground reaction force and greater joint load (relative to swimming), might contribute to knee joint health in active able-bodied older adults.