[1] Katholieke Univ Leuven, Leuven Univ Ctr Metab Bone Dis, B-3000 Louvain, Belgium
[2] Katholieke Univ Leuven, Leuven Univ Dept Geriatr Med, Louvain, Belgium
[3] Katholieke Univ Leuven, Leuven Univ Lab Expt Med, Louvain, Belgium
[4] Ghent Univ Hosp, Unit Osteoporosis & Metab Bone Dis, B-9000 Ghent, Belgium