Bone Abstracts

Aim: To investigate the acute effects of oral glucocorticoids in doses used in clinical practice on biochemical indices of function of osteoclasts, osteoblasts and osteocytes.

Methods: In 17 adult patients suffering from various medical pathologies requiring systemic steroid therapy that were never before treated with glucocorticoids, the glucocorticoid treatment was initiated (mean prednisolone equivalent dose of 23.1±12.7 mg/day, range 10–50 mg/day). Fasting morning serum concentrations of osteocalcin (OC), amino terminal propeptide of type 1 procollagen (PINP), type 1 collagen cross-linked C-telopeptide (βCTX), soluble receptor activator of nuclear factor kappaB ligand (sRANKL), osteoprotegerin (OPG), sclerostin, Dickkopf-1 (Dkk-1), and the high-sensitivity C-reactive protein (hsCRP) were measured at baseline and on three consecutive days.

Results: Significant reductions in serum OC, PINP, OPG, sclerostin, and hsCRP were observed during 96 h of glucocorticoid administration while serum βCTX showed a significant percentual increase. A significant positive correlation was found between serum concentrations of Dkk-1 and βCTX after 96 h of treatment with glucocorticoids.

Conclusion: Medium-dose, short-term oral GC regimens cause an immediate decrease of the biochemical markers of osteoblast and osteocyte activity (PINP, OC, OPG and sclerostin, respectively), and a moderate increase of the biochemical marker of bone resorption (βCTX) associated with Dkk-1. A significant drop in serum sclerostin, OPG and OC observed in this study may reflect the rapid glucocorticoid induced apoptosis of osteocytes. The results are in good agreement with negative effects of GCs on bone remodelling, despite suppression of systemic inflammation.