Serum Levels of Sclerostin and Dickkopf-1: Effects of Age, Gender and Fracture Status

<b><i>Background:</i></b> Fragility fractures, especially hip fractures, are a very common complication of osteoporosis in elderly subjects. Sclerostin (SOST) and dickkopf-1 (DKK-1) are inhibitors of the canonical wnt signalling pathway and thus could be involved in the pathogenesis of age-related bone fragility. <b><i>Objective:</i></b> To investigate SOST and DKK-1 in a large group of geriatric patients with hip fractures and to relate the wnt inhibitors to age and gender. <b><i>Methods:</i></b> This was a cross-sectional study carried out in a department of acute geriatric care in a district hospital in Upper Austria and a hospital in Vienna, Austria. A total of 256 geriatric patients (172 women and 84 men) and 67 young control subjects were selected after exclusion. Medical history was obtained, a comprehensive geriatric assessment was performed and serum levels of SOST, DKK-1 and bone formation markers were analysed. <b><i>Results:</i></b> DKK-1 levels increased with age and in the presence of hip fractures. In contrast, SOST levels were lower in patients with hip fractures. When compared to women, men had higher SOST levels but lower DKK-1 levels. <b><i>Conclusion:</i></b> Serum levels of the inhibitors of the canonical wnt signalling pathway reflect different biological events and are useful for the study of bone fragility in geriatric patients.