[1] Natl Med Ctr XXI Century, Childrens Hosp, Res Unit Anal & Synth Evidence, Mexico City, DF, Mexico
[2] Natl Med Ctr XXI Century, Childrens Hosp, Unit Res Med Nutr, Mexico City, DF, Mexico
[3] Natl Med Ctr XXI Century, Childrens Hosp, Dept Pediat Nephol, Mexico City, DF, Mexico
[4] Inst Mexicano Seguro Social, Ctr Med Nacl, Endocrine Res Unit, Mexico City, DF, Mexico
[5] Univ Nacl Autonoma Mexico, Fac Med, Mexico City, DF, Mexico
[6] Minist Hlth SSA, Adolescent Med Serv, Hosp Infantil Mexico Federico Gomez, Mexico City, DF, Mexico