1 Department of Medicine, University of Chicago, Chicago, IL, USA.
2 Department of Endocrine and Metabolic Diseases, IRCCS Istituto Auxologico Italiano, Milan, Italy; BIOMETRA, University of Milan, Milan, Italy.
3 Thyroid Centre, Department of Internal Medicine, Erasmus Medical Centre, Rotterdam 3015 GE, Netherlands. Electronic address: w.e.visser@erasmusmc.nl.