1. Health Services and Epidemiological Investigation Unit, Mexican Institute of Social Security, Cuernavaca, Mexico
2. Center of Research in Nutrition and Health, Mexican Institute of Social Security, Cuernavaca, Mexico
3. Geriatric Epidemiology Research Center, National Institute of Geriatrics, Mexico City, Mexico
4. Department of Clinical Laboratory and Nutritional Sciences, University of Massachusetts Lowell, Lowell, MA
5. Population Research Center, National Institute of Public Health, Cuernavaca, Mexico