[1] Univ Hosp Bern, Inselspital, Osteoporosis Policlin, CH-3010 Bern, Switzerland
[2] Univ Bern, CH-3010 Bern, Switzerland
[3] Univ Sheffield, Sch Med, WHO Collaborating Ctr Metab Bone Dis, Sheffield, S Yorkshire, England
[4] Univ Hosp Geneva, Div Bone Dis, WHO Collaborating Ctr Osteoporosis Prevent, Dept Rehabil & Geriatr, Geneva, Switzerland
[5] Med Fac Geneva, Geneva, Switzerland