[1] Univ Ioannina, Med Sch, Dept Hyg & Epidemiol, Ioannina, Greece
[2] Int Hellen Univ, Dept Nutr & Dietet, Thessaloniki, Greece
[3] Univ Athens, Dept Nursing, Athens, Greece
[4] Univ Ioannina, Med Sch, Dept Internal Med, Ioannina, Greece
[5] Tufts Univ, Sch Med, Boston, MA 02111 USA
[6] Univ Athens, Allergy Dept, Pediat Clin 2, Athens, Greece