Moustapha Kassem1, Franz Jakob2. 1. Endocrinology and Metabolism, University Hospital of Odense, Winslow Vej 25, DK-5000 Odense C, Denmark. 2. Orthopedic Center for Musculoskeletal Research, Experimental and Clinical Osteology, Orthopedic Department, University of Würzburg, Brettreichstraße 11, D-97074 Wuerzburg, Germany.