[1] Univ Chile, Sch Publ Hlth, Fac Med, Ave Independencia 939, Santiago, Chile
[2] Univ Chile, Fac Med, Lab Fisiol & Fisiopatol Desarrollo, Programa Fisiopatol, Santiago, Chile
[3] Univ Chile, Ctr Int Estudios Andinos INCAS, Santiago, Chile
[4] Univ Chile, Sch Publ Hlth, Dept Epidemiol, Fac Med, Santiago, Chile