Effects of physical activity on sclerostin concentrations.

Osteoporosis is a serious medical and socioeconomic problem of the 21st century. Mechanical load is a key regulator which controls bone formation and remodelling, with participation of osteocytes. Sclerostin is produced and released by mature osteocytes into bone surface, where it inhibits the conveyance of osteoblast proliferation and differentiation activating signals from mesenchymal cells, thus suppressing new bone formation. The goal of the study was an evaluation of the effects of a 12-week physical training programme on the levels of bone turnover markers [Sclerostin, Osteocalcin (OC), C-terminal telopeptide of type I collagen (β-CTX)] in blood serum of women with osteopenia.

MATERIALS & METHODS: The study included 50 women of the Regional Menopause and Osteoporosis Centre of the WAM Teaching Hospital, at the age of 50-75 years with the diagnosis of osteopenia, obtained on the basis of hip and/or lumbar spine densitometry (T-score from -1.0 to -2.5 SD). During the initial 12 weeks (between point 1 and 2), the patients maintained their previous, normal level of physical activity. During subsequent 12 weeks (between point 2 and 3), a programme of exercise was implemented. The programme included the interval training on a bicycle ergometer, three times a week for 36 minutes. During the entire study duration, all the patients received a supplementation of calcium (500 mg) and vit. D3 (1800 IU) once daily. Serum levels of OC, alkaline phosphatase (ALP), β-CTX and sclerostin were assayed at 3 time points.

RESULTS: After the course of the exercise cycle, the OC concentration was increased, sclerostin levels decreased, while no statistical differences were observed in β-CTX levels vs. the period of physical inactivity. No correlations were found between sclerostin level changes and osteocalcin level changes during the training time, because of too small groups. Neither statistically significant were the differences in alkaline phosphatase, calcium and phosphorus levels.

CONCLUSIONS: The obtained results emphasise the role of physical training as an effective stimulation method of bone formation processes in women with osteopenia. Sclerostin can be a marker of physical activity. < /p > < p >.