1. Endocrinology Service and Research Unit in Endocrine Diseases, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, IMSS, México City, Mexico
2. Endocrinology Service, Centro Médico Nacional 20 de noviembre, ISSSTE, México City, Mexico
3. Neuroendocrinology Clinic, Department of Endocrinology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México City, Mexico
4. Neuroendocrinology Service, Instituto Nacional de Neurología y Neurocirugía, México City, Mexico
5. División of Education and Research, American British Cowdray Medical Center, México City, Mexico