1. Department of Pediatrics, Medical School, University of Ioannina, Ioannina, Greece;
2. Second Department of Cardiology, Medical School, University of Ioannina, Ioannina, Greece;
3. Department of Endocrinology, Medical School, University of Ioannina, Ioannina, Greece;
4. Division of Endocrinology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts