[1] Univ Toronto, St Michaels Hosp, Div Endocrinol & Metab, Toronto, ON M5C 2T2, Canada
[2] Univ Alberta, Dept Radiol, Edmonton, AB, Canada
[3] Hop Pierre Boucher, Longueuil, PQ, Canada
[4] Mayo Clin & Mayo Fdn, Mayo Med Sch, Endocrine Res Unit, Dept Med, Rochester, MN 55905 USA
[5] Mayo Clin & Mayo Fdn, Mayo Med Sch, Endocrine Res Unit, Dept Physiol, Rochester, MN 55905 USA
[6] Clin Res Inst Montreal, Montreal, PQ H2W 1R7, Canada
[7] Mayo Clin, Dept Internal Med, Scottsdale, AZ USA