[1] Univ S Carolina, Sch Med, Div Endocrinol Diabet & Metab, Columbia, SC 29203 USA
[2] Univ Palermo, Dept Clin Med & Emerging Dis, Palermo, Italy
[3] Univ Zurich Hosp, Clin Endocrinol, CH-8091 Zurich, Switzerland
[4] Univ Zurich Hosp, Clin Diabet & Clin Nutr, CH-8091 Zurich, Switzerland