[1] Univ Nacl Autonoma Mexico, Sch Med, Branch & Res Direct, Inst Nacl Med Genom, Mexico City, DF, Mexico
[2] Univ Iberoamer, Hlth Dept, Mexico City, DF, Mexico
[3] Univ Michigan, Sch Publ Hlth, Dept Epidemiol, Ann Arbor, MI 48109 USA
[4] Natl Inst Publ Hlth, Ctr Invest Nutr & Salud, Cuernavaca, Morelos, Mexico