1. Department of Internal Medicine and Medical Disciplines (C.C., E.R., J.P., S.R., L.C., S.P., S.M.), “Sapienza” Rome University, 00161 Rome, Italy;
2. Faculty of Economics (L.N.), LUSPIO University, 00145 Rome, Italy;
3. Division of Endocrinology (D.J.M.), Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032;
4. Department of Laboratory Medicine and Pathology (R.S.), Mayo Clinic, Rochester, Minnesota 55905