1. Laboratory of Clinical Biochemistry (M.D.), Attikon General University Hospital, University of Athens, School of Medicine, 12462 Athens, Greece;
2. Division of Endocrinology, Diabetes and Metabolism (K.N.D., C.S.M.), Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215;
3. Section of Endocrinology (C.S.M.), VA Boston Healthcare System, Boston, Massachusetts 02130