http://www.mhasweb.org/ (English)

www.enasem.org (Spanish)

Overview
The Mexican Health and Aging Study (MHAS) started as a prospective panel study of health and aging in Mexico. The baseline household survey, with national and urban/rural representation of adults born in 1951 or earlier, was conducted in 2001 with follow-up surveys in 2003, 2012, 2015, and 2018. Another follow-up is planned for 2021. A new cohort of adults born in 1952-1962 was added to the study in 2012, and a cohort of those born in 1963-68 was added in 2018. The MHAS uses study protocols and survey instruments that are highly comparable to the U.S. Health and Retirement Study (HRS). The study is funded by the National Institute on Aging NIA/NIH R01 AG018016 in the United States and by the National Statistical Bureau (Instituto Nacional de Estadística y Geografía, INEGI) in Mexico. The MHAS is coordinated by researchers from the University of Texas Medical Branch (UTMB), and is a collaborative effort among researchers from institutions in the U.S. and Mexico.

Data Collection
MHAS 2001, 2003

  • Interviews conducted in person with paper-pencil by trained full-time interviewers from the INEGI.
  • MHAS 2001 interviews conducted with 15,186 selected individuals and a random sub-sample of 2,573 completed anthropometric measures and performance tests.
  • MHAS 2003 survey protocol included follow-up interviews with MHAS 2001 individuals or their next-of-kin for deceased individuals.

MHAS 2012

  • MHAS 2012 used CAPI and followed up respondents from MHAS 2001 and 2003 and added approximately 6,000 subjects of cohorts born 1952-1962.
  • A section on major events in the last ten years was included to account for the long inter-wave period.
  • A new random sub-sample of 2,089 individuals completed anthropometric measures and performance tests, and provided biomarkers.

MHAS 2015

  • MHAS 2015 followed up respondents, both who had completed one interview or more since the 2001 survey and those who had been added in 2012.
  • A subsample of 2,265 respondents were selected for the MHAS Cognitive Aging Ancillary Study (Mex-Cog), fielded in 2016. The protocol included a comprehensive cognitive assessment and an interview with a knowledgeable informant, as well as anthropometric tests. This was part of the harmonized cognitive protocol (HCAP) coordinated by the HRS, to evaluate the prevalence of dementia among older population in several countries. The Mex-Cog was sponsored by the National Institutes of Health/National Institute on Aging (NIH R01AG051158), and it was completed in collaboration with the National Institute of Public Health (INSP) in Mexico.

MHAS 2018

  • MHAS 2018 followed up study participants and added a new sub sample of 4,500 individuals born in 1963-68.
  • The protocol included collection of hair in a sub sample and collection of saliva among participants aged 60 and older.

The MHAS is a high-quality study, with excellent response and follow-up rates. Response rates for waves in 2001, 2003, 2012, 2015, and 2018 were 91.8%, 93.3% and 88.1%, 88.2% and 80%, respectively.

Biomarkers

  • The Sub-sample received a second household visit by special health personnel from the National Institute of Public Health (INSP).
  • INSP personnel obtained consents and completed the following procedure: 1) take blood pressure, 2) complete anthropometric measures, 3) take blood pressure again, 4) complete performance tests, and 5) take blood samples (fasting was not required).
  • Blood samples were centrifuged, covered, stored in special refrigeration containers, and shipped to a central INSP laboratory.

Venous Blood/Finger Prick

Intravenous Red tube:

  • C-reactive Protein (CRP) (High Sensitivity)
  • Thyroid-Stimulating Hormone (TSH)
  • Total and HDL Cholesterol
  • Vitamin D

Finger prick:

  • Glucose (HbA1c)
  • Hemoglobin (Hb) 

Anthropometric Measures Performance Tests

  • Height
  • Weight
  • Sitting height/knee height
  • Timed balance tests
  • Hip circumference
  • Waist circumference
  • Foot-to-knee distance
  • Timed walk
  • Blood Pressure
  • Hand-grip strength

Genetic Samples

  • Using intravenous blood from 2012, DNA was extracted by the National Institute of Genomic Medicine in Mexico and shipped to the Taub Institute at Columbia University. GWAS for risk of Alzheimer’s Disease and several cardiometabolic conditions will be obtained. Samples will be deposited at the National Centralized Repository for Alzheimer’s Disease at the University of Indiana.
  • Saliva samples from about 7,800 participants were obtained in 2018 from adults aged 60 and older. Samples have been shipped to the National Centralized Repository for Alzheimer’s Disease at the University of Indiana. GWAS for risk of Alzheimer’s Disease will be obtained for this samples and whole genome sequencing will be obtained from a predetermined sub-sample.  Genetic samples were obtained and shipped and will be analyzed under a collaboration with Columbia University Taub Institute for Alzheimer’s Disease (R56 AG059756).

Hair Samples

  • In 2018, hair samples were collected from scalp (or beard) from about 2,500 participants in 6 states, to measure exposure to metals such as lead, magnesium, manganese, and mercury. These samples will be analyzed for levels of these metals under a collaboration with the National Institute of Public Health (INSP) in Mexico.

Publications

https://www.mhasweb.org/Publications/Home.aspx