Semp?rtegui F, Estrella B, Tucker KL, Hamer DH, Narvaez X, Semp?rtegui M, Griffiths JK, Noel SE, Dallal GE, Selhub J, Meydani SN. Metabolic syndrome in the elderly living in marginal peri-urban communities in Quito, Ecuador. Public Health Nutr. 2011 May; 14(5):758-67.