• The effect of plyometric exercise on bone turnover markers and osteokines in younger and older women

      Nelson, Katlynne; Applied Health Sciences Program
      The effect of a single-bout of plyometric exercise on markers of bone turnover and Wnt signalling-related osteokines was studied in 20 younger, pre-menopausal women (23.142.33 years) and 20 older, post-menopausal women (57.904.35 years of age). Blood samples were obtained at rest (i.e., pre-exercise) and 5 min, 1h, and 24h post- exercise and were analyzed for C-terminal crosslinking telopeptides of type I collagen (CTX), osteoprotegerin (OPG), sclerostin and dickkopf-1 (DKK-1), and estradiol. Resting levels of CTX, OPG, and sclerostin were significantly higher while DKK-1 and estradiol were significantly lower in older compared to younger women. CTX was higher at 5 min post-exercise compared to pre-exercise in younger women (326.027.0 vs. 292.029.0 pg/mL; p=0.049); however, no response was seen in older women. Sclerostin significantly decreased from 5 min (319.934.6 pg/mL) to 1h post-exercise (245.329.5 pg/mL) but increased between 1h and 24h post-exercise (368.333.9 pg/mL) only in younger women. DKK-1 decreased in both groups. In younger women, the decrease was continuous from 5 min (2560.20120.65 pg/mL) to 24h post-exercise (2176.60115.29 pg/mL, p=0.006). In post-menopausal women, the decrease was between pre-exercise (1949.69177.95 pg/mL) and 1h post-exercise (1549.82187.11 pg/mL, p=0.001) but returning to near pre-exercise levels 24h post-exercise. In the older women, OPG also decreased from pre-exercise (535.8  36.8 pg/mL) to 5 min post-exercise (475.1 39.0 pg/mL; p=0.048) and remained lower than baseline for up to 24h post-exercise (505.032.4 pg/mL; p=0.046). No changes were seen in the younger women. These results suggest that in women, one session of plyometric exercise is sufficient to induce significant changes in bone turnover and Wnt signalling related osteokines, however, the timing of the response varies significantly between age groups.