Midlife Vascular Factors and Prevalence of Mild Cognitive Impairment in Late-Life in Mexico.

OBJECTIVE: To estimate the prevalence of mild cognitive impairment (MCI) and its subtypes and investigate the impact of midlife cardiovascular risk factors on late-life MCI among the aging Mexican population. METHOD: Analyses included a sample of non-demented adults over the age of 55 living in both urban and rural areas of Mexico (N = 1807). MCI diagnosis was assigned based on a comprehensive cognitive assessment assessing the domains of memory, executive functioning, language, and visuospatial ability. The normative sample was selected by means of the robust norms approach. Cognitive impairment was defined by a 1.5-SD cut-off per cognitive domain using normative corrections for age, years of education, and sex. Risk factors included age, education, sex, rurality, depression, insurance status, workforce status, hypertension, diabetes, stroke, and heart disease. RESULTS: The prevalence of amnestic MCI was 5.9%. Other MCI subtypes ranged from 4.2% to 7.7%. MCI with and without memory impairment was associated with older age (OR = 1.01 [1.01, 1.05]; OR = 1.03 [1.01, 1.04], respectively) and residing in rural areas (OR = 1.49 [1.08, 2.06]; OR = 1.35 [1.03, 1.77], respectively). Depression (OR = 1.07 [1.02, 1.12]), diabetes (OR = 1.37 [1.03, 1.82]), and years of education (OR = 0.94 [0.91, 0.97]) were associated with MCI without memory impairment. Midlife CVD increased the odds of MCI in late-life (OR = 1.76 [1.19, 2.59], which was driven by both midlife hypertension and diabetes (OR = 1.70 [1.18, 2.44]; OR = 1.88 [1.19, 2.97], respectively). CONCLUSIONS: Older age, depression, low education, rurality, and midlife hypertension and diabetes were associated with higher risk of late-life MCI among older adults in Mexico. Our findings suggest that the causes of cognitive impairment are multifactorial and vary by MCI subtype.

Imputation of Non-Response in Height and Weight in the Mexican Health and Aging Study.

The way missing data in population surveys are treated can influence research results. Therefore, the aim of this paper is to explain the reasons and procedure for imputing anthropometric data such as height and weight self-reported by individuals in the first four waves of the Mexican Health & Aging Study (MHAS). We highlight the effect of the imputation versus the exclusion of the cases with missing data, by comparing the distribution of these values and their associated effects on the Body Mass Index using a regression model. We conclude that the incorporation of imputed data offers more solid results compared with elimination the cases with missing data. Hence the importance of applying these statistical procedures, with appropriate treatment of the data, making the methodology and the imputed data available to the users by the same source of information, as offered in the MHAS.

El manejo de los datos faltantes en entrevistas por encuestas puede influenciar los resultados de investigación. Por ello, el objetivo de este trabajo es explicar las razones y procedimiento para imputar datos antropométricos como la altura y peso auto reportado por los individuos en las primeras cuatro rondas del Estudio Nacional de Salud y Envejecimiento en México (ENASEM). Destacamos el efecto de la imputación versus la eliminación de los casos con datos faltantes, comparando la distribución de dichos valores y sus efectos asociados en el Índice de Masa Corporal mediante un modelo de regresión. Se concluye que la incorporación de datos imputados ofrece resultados más sólidos comparado con la eliminación de los casos con datos faltantes. De ahí la importancia de aplicar estos procedimientos estadísticos con tratamiento adecuado de los datos, y difundir la metodología aplicada para obtener los datos imputados desde la misma fuente de información, tal como se ofrece en el ENASEM.

Effect of Demographic and Health Dynamics on Cognitive Status in Mexico between 2001 and 2015: Evidence from the Mexican Health and Aging Study.

Sources of health disparities such as educational attainment, cardiovascular risk factors, and access to health care affect cognitive impairment among older adults. To examine the extent to which these counteracting changes affect cognitive aging over time among Mexican older adults, we examine how sociodemographic factors, cardiovascular diseases, and their treatment relate to changes in cognitive function of Mexican adults aged 60 and older between 2001 and 2015. Self and proxy respondents were classified as dementia, cognitive impairment no dementia (CIND), and normal cognition. We use logistic regression models to examine the trends in dementia and CIND for men and women aged 60 years or older using pooled national samples of 6822 individuals in 2001 and 10,219 in 2015, and sociodemographic and health variables as covariates. We found higher likelihood of dementia and a lower risk of CIND in 2015 compared to 2001. These results remain after adjusting for sociodemographic factors, cardiovascular diseases, and their treatment. The improvements in educational attainment, treatment of diabetes and hypertension, and better access to health care in 2015 compared to 2001 may not have been enough to counteract the combined effects of aging, rural residence disadvantage, and higher risks of cardiovascular disease among older Mexican adults.

The Mexican Cognitive Aging Ancillary Study (Mex-Cog): Study Design and Methods.

OBJECTIVE: Describe the protocol sample and instruments of the Cognitive Aging Ancillary Study in Mexico (Mex-Cog). The study performs an in-depth cognitive assessment in a subsample of older adults of the ongoing Mexican Health and Aging Study (MHAS). The Mex-Cog is part of the Harmonized Cognitive Assessment Protocol (HCAP) design to facilitate cross-national comparisons of the prevalence and trends of dementia in aging populations around the world, funded by the National Institute on Aging (NIA). METHODS: The study protocol consists of a cognitive assessment instrument for the target subject and an informant questionnaire. All cognitive measures were selected and adapted by a team of experts from different ongoing studies following criteria to warrant reliable and comparable cognitive instruments. The informant questionnaire is from the 10/66 Dementia Study in Mexico. RESULTS: A total of 2,265 subjects aged 55-104 years participated, representing a 70% response rate. Validity analyses showed the adequacy of the content validity, proper quality-control procedures that sustained data integrity, high reliability, and internal structure. CONCLUSIONS: The Mex-Cog study provides in-depth cognitive data that enhances the study of cognitive aging in two ways. First, linking to MHAS longitudinal data on cognition, health, genetics, biomarkers, economic resources, health care, family arrangements, and psychosocial factors expands the scope of information on cognitive impairment and dementia among Mexican adults. Second, harmonization with other similar studies around the globe promotes cross-national studies on cognition with comparable data. Mex-Cog data is publicly available at no cost to researchers.

The effect of educational attainment on cognition of older adults: results from the Mexican Health and Aging Study 2001 and 2012.

Objective: This paper seeks to document changes in the effect of educational attainment on cognitive function of older adults in Mexico, and measure gender differences using data from two time periods. Methods: The data come from the Mexican Health and Aging Study (MHAS), taking the cross-sections of adults aged 60 years or older interviewed in 2001 and 2012. We perform an OLS regression using standardized z-scores for five individual cognitive domains and for total cognition. Results: Total cognitive scores and educational attainment were higher for men than women in both years. When cognitive components were analyzed separately, women had higher verbal memory and verbal recall scores than men. The gender gap in overall cognition score was smaller in 2012 compared to 2001, while the gender gap in educational attainment was larger in 2012 than in 2001. Even though men had higher educational attainment than women, the effect of educational attainment on cognition was higher for women. Similarly, the difference between total scores for each task for men compared to women decreased between 2012 and 2001, except for verbal learning and verbal recall where the gender difference widened. Conclusions: If younger cohorts of women continue to progressively achieve higher levels of education, the gender gap in old-age cognition should close. Additional work should determine the mechanisms through which added formal education seems to translate into higher cognitive gains for women compared to men.

Cross-national health comparisons using the Rasch model: findings from the 2012 US Health and Retirement Study and the 2012 Mexican Health and Aging Study.

PURPOSE: Cross-national comparisons of patterns of population aging have emerged as comparable national micro-data have become available. This study creates a metric using Rasch analysis and determines the health of American and Mexican older adult populations. METHODS: Secondary data analysis using representative samples aged 50 and older from 2012 U.S. Health and Retirement Study (n = 20,554); 2012 Mexican Health and Aging Study (n = 14,448). We developed a function measurement scale using Rasch analysis of 22 daily tasks and physical function questions. We tested psychometrics of the scale including factor analysis, fit statistics, internal consistency, and item difficulty. We investigated differences in function using multiple linear regression controlling for demographics. Lastly, we conducted subgroup analyses for chronic conditions. RESULTS: The created common metric demonstrated a unidimensional structure with good item fit, an acceptable precision (person reliability = 0.78), and an item difficulty hierarchy. The American adults appeared less functional than adults in Mexico (ß = - 0.26, p < 0.0001) and across two chronic conditions (arthritis, ß = - 0.36; lung problems, ß = - 0.62; all p < 0.05). However, American adults with stroke were more functional than Mexican adults (ß = 0.46, p = 0.047). CONCLUSIONS: The Rasch model indicates that Mexican adults were more functional than Americans at the population level and across two chronic conditions (arthritis and lung problems). Future studies would need to elucidate other factors affecting the function differences between the two countries.

Cohort Profile: The Mexican Health and Aging Study (MHAS).

The Mexican Health and Aging Study (MHAS) was designed to prospectively evaluate the impact of disease on the health, function and mortality of adults over the age of 50 in both urban and rural areas of Mexico. The overall goal of the study is to examine the ageing process and its disease and disability burden in a large representative panel of older Mexicans, using a wide socioeconomic perspective. The study protocols and survey instruments are highly comparable to the U.S. Health and Retirement Study (HRS).The MHAS 2001 baseline is a nationally and urban-rural representative survey of individuals born in 1951 or earlier. Three waves of data have been collected so far: baseline in 2001 and follow-ups in 2003 and 2012. In 2012, the study added a representative sample of the population from the 1952-62 birth cohorts. A fourth wave will be collected in 2015.The data files and documentation are available free of charge at the study website [www.MHASweb.org] in English and [www.ENASEM.org] in Spanish.

Progression of aging in Mexico: the Mexican Health and Aging Study (MHAS) 2012.

OBJECTIVE: To describe the third wave of the Mexican Health and Aging Study (MHAS), completed in 2012, and present preliminary results. MATERIALS AND METHODS: Descriptive analyses by gender and age group of demographic and socioeconomic characteristics, health conditions and health behaviors, as well as social support and life satisfaction measures are presented. In addition, external validations are presented by comparing MHAS 2012 indicators with other national data sources. RESULTS: For the panel of older adults in the sample, the rate of health care insurance coverage increased greatly between 2001 and 2012, a significantly higher change in rural compared to urban areas. The results for 2012 are consistent with the previous two waves for the main indicators of health and physical disability prevalence, risk factors,and behaviors. CONCLUSIONS: The MHAS offers a unique opportunity to study aging in Mexico, as well as to complete cross-national comparisons. The cumulative number of deaths in the cohort should support the study of mortality and its association with health outcomes and behaviors over the life cycle. In addition, the sub-samples of objective markers will enable methodological research on self-reports and associations of biomarkers in old age with similar health outcomes and behaviors.

Normative and standardized data for cognitive measures in the Mexican Health and Aging Study.

OBJECTIVE: To describe the cognitive instrument used in the Mexican Health and Aging Study (MHAS) in Mexican individuals aged 60 and over and to provide normative values for the Cross Cultural Cognitive Examination test and its modified versions (CCCE). MATERIALS AND METHODS: The CCCE was administered to 5,120 subjects as part of a population-based sample free of neurologic and psychiatric disease from the MHAS 2012 survey. Normative data were generated by age and education for each test in the cognitive instrument as well as for the total cognition score. Pearson correlations and analysis of variance were used to examine the relationship of scores to demographic variables. RESULTS: Results present standardized normed scores for eight cognitive domains: orientation, attention, verbal learning memory, verbal recall memory, visuospatial abilities, visual memory, executive function, and numeracy in three education groups within three age groups. CONCLUSION: These findings highlight the need for population-based norms for the CCCE, which has been used in population-based studies. Demographic factors such as age and education must be considered when interpreting the cognitive measures.

Cross-National Differences in Disability Among Elders: Transitions in Disability in Mexico and the United States.

OBJECTIVES: Little is known about how exposure to a combination of infectious and chronic conditions throughout the lifecourse could impact disability in old age. This paper compares 2 cohorts of adults who have aged under very different country contexts by contrasting disability transitions among elders in Mexico with elders in the United States. METHODS: Data comes from the Mexican Health and Aging Study (MHAS) and the U.S. Health and Retirement Study (HRS). Estimated probabilities of 2-year transitions among disability states and mortality are presented for adults aged 50 and older. RESULTS: The levels of disability prevalence and 2 year transitions are consistent with a higher rate of disability for the United States compared to Mexico. In 2-year transitions, the U.S. sample was more likely to transition to a disabled state or increase the number of disabilities than the Mexican counterparts, while Mexicans are more likely to move out of disability or reduce the number of disabilities reported. DISCUSSION: The findings suggest that the current rate of disability in old age is lower for a less developed country compared with a developed society. We discuss implications, possible explanations, and likely future scenarios.

Progression of aging in Mexico: the Mexican Health and Aging Study (MHAS) 2012 / Progresión del envejecimiento en México: Estudio Nacional de Salud y Envejecimiento en México (Enasem) 2012

Objective. To describe the third wave of the Mexican Health and Aging Study (MHAS), completed in 2012, and present preliminary results. Materials and methods. Descriptive analyses by gender and age group of demographic and socioeconomic characteristics, health conditions and health behaviors, as well as social support and life satisfaction measures are presented. In addition, external validations are presented by comparing MHAS 2012 indicators with other national data sources. Results. For the panel of older adults in the sample, the rate of health care insurance coverage increased greatly between 2001 and 2012, a significantly higher change in rural compared to urban areas. The results for 2012 are consistent with the previous two waves for the main indicators of health and physical disability prevalence, risk factors,and behaviors. Conclusions. The MHAS offers a unique opportunity to study aging in Mexico, as well as to complete cross-national comparisons. The cumulative number of deaths in the cohort should support the study of mortality and its association with health outcomes and behaviors over the life cycle. In addition, the sub-samples of objective markers will enable methodological research on self-reports and associations of biomarkers in old age with similar health outcomes and behaviors.

Objetivo. Describir la tercera ronda del Estudio Nacional de Salud y Envejecimiento en México (Enasem), completada en 2012, y presentar algunos resultados preliminares. Material y métodos. Se presentan análisis descriptivos por género y grupo de edad, de las características demográficas y socioeconómicas, de las condiciones y comportamientos de salud, así como de las medidas de apoyo social y de satisfacción con la vida. Además, se presentan los resultados de validaciones externas realizadas comparando indicadores del Enasem 2012 con los de otras fuentes de datos nacionales. Resultados. Para el panel de los adultos mayores en la muestra, la tasa de cobertura de aseguramiento en salud aumentó considerablemente entre 2001 y 2012; el cambio fue significativamente mayor en zonas rurales en comparación con las urbanas. Los resultados de los principales indicadores de salud, prevalencia de la discapacidad física, factores de riesgo y comportamientos de salud son consistentes con los de las dos rondas anteriores. Conclusiones. El Enasem ofrece una oportunidad única para estudiar el envejecimiento en México así como para realizar comparaciones entre países. El número acumulado de muertes en la cohorte permitirá un mejor estudio sobre mortalidad y las consecuencias en salud de los comportamientos a lo largo del ciclo de vida. Además, los marcadores objetivos en la submuestra permitirán el análisis metodológico de los autorreportes y de las asociaciones de los biomarcadores con los resultados y los comportamientos de salud en la vejez.

Normative and standardized data for cognitive measures in the Mexican Health and Aging Study / Normalización y estandarización de las medidas cognitivas en el Estudio Nacional de Salud y Envejecimiento en México

Objective. To describe the cognitive instrument used in the Mexican Health and Aging Study (MHAS) in Mexican individuals aged 60 and over and to provide normative values for the Cross Cultural Cognitive Examination test and its modified versions (CCCE). Materials and methods. The CCCE was administered to 5 120 subjects as part of a population-based sample free of neurologic and psychiatric disease from the MHAS 2012 survey. Normative data were generated by age and education for each test in the cognitive instrument as well as for the total cognition score. Pearson correlations and analysis of variance were used to examine the relationship of scores to demographic variables. Results. Results present standardized normed scores for eight cognitive domains: orientation, attention, verbal learning memory, verbal recall memory, visuospatial abilities, visual memory, executive function, and numeracy in three education groups within three age groups. Conclusion. These findings highlight the need for population-based norms for the CCCE, which has been used in population-based studies. Demographic factors such as age and education must be considered when interpreting the cognitive measures.

Objetivo. Describir el instrumento cognitivo usado en el Estudio Nacional de Salud y Envejecimiento en México (Ena-sem) en personas mayores de 60 años,y proporcionar valores normativos para el Test Cognitivo Transcultural (CCCE, por sus siglas en inglés) y sus modificaciones. Material y métodos. Se administró el CCCE a 5 120 individuos mayores de 60 años, libres de enfermedad neurológica y psiquiátrica de la Enasem 2012. Los datos normativos se obtuvieron para la puntuación en cada test incluido en el CCCE y para la puntuación total estratificando por edad y escolaridad. Para analizar la relación con las variables demográficas, se aplicaron la correlación de Pearson y el análisis de varianza. Resultados. Los resultados presentan normas estandarizadas para ocho dominios cognitivos: orientación, atención, aprendizaje verbal, memoria de evocación, habilidades espaciales, memoria visual, función ejecutiva y numerología en tres grupos de educación dentro de tres grupos de edad. Conclusión. Estos resultados subrayan la importancia de contar con datos normativos para los tests cognitivos que, como el CCCE, han sido aplicados en estudios poblacionales. Los factores demográficos como la edad y, en particular, la escolaridad deben considerarse al momento de interpretar las medidas aplicadas.

Older adults under a mixed regime of infectious and chronic diseases

OBJECTIVE: Analyze the impact of a mixed regime of infectious and chronic conditions among older adults in Mexico on their health progression. MATERIALS AND METHODS: A total of 12 207 adults from the Mexican Health and Aging Study were included. Logistic regression analyses were conducted to assess the relationship between self-reported health (SRH) and covariates, including infectious and chronic diseases. Changes in SRH between 2001-2003 were analyzed using multinomial analysis. RESULTS: Older age, low SES, poor SRH and type of disease at baseline increase the odds of poor SRH at follow-up. Odds of poor SRH are highest for persons with both types of diseases (OR 2.63, SE 0.24), followed by only chronic (OR 1.86; SE 0.12) and finally only infectious (OR 1.55; SE 0.25). CONCLUSION: Mexico is experiencing a mixed regime of diseases that affects the health and wellbe-ing of older adults. Despite the rising importance of chronic diseases in countries like Mexico, it is premature to disregard the relevance of infectious diseases for public health.

OBJETIVO: Analizar el impacto del régimen epidemiológico mixto presente en México sobre la salud de los adultos mayores. MATERIAL Y MÉTODOS: Participaron adultos mayores de la Encuesta Nacional de Salud y Envejecimiento en México (n=12 207). Se usaron regresiones logísticas para evaluar la relación entre autorreporte de salud (ARS) y variables como enfermedades infecciosas y crónicas. Se analizó el cambio en ARS mediante análisis multinomiales. RESULTADOS: Edad, estatus socioeconómico, pobre ARS y tipo de enfermedad aumentan el riesgo de pobre ARS en el futuro. La razón de probabilidades de pobre ARS fue más alta para individuos con ambos tipos de enfermedad (OR 2.63, SE 0.24), seguida por aquellos con crónicas (OR 1.86; SE 0.12) y aquellos con infecciosas (OR 1.55; SE 0.25). CONCLUSIÓN: El régimen mixto presente en México afecta a los adultos mayores. En países como México, es prematuro dejar de lado el impacto de las enfermedades infecciosas para enfocarse únicamente en prevenir las crónicas.

Older adults under a mixed regime of infectious and chronic diseases.

OBJECTIVE: Analyze the impact of a mixed regime of infectious and chronic conditions among older adults in Mexico on their health progression. MATERIALS AND METHODS: A total of 12 207 adults from the Mexican Health and Aging Study were included. Logistic regression analyses were conducted to assess the relationship between self-reported health (SRH) and covariates, including infectious and chronic diseases. Changes in SRH between 2001-2003 were analyzed using multinomial analysis. RESULTS: Older age, low SES, poor SRH and type of disease at baseline increase the odds of poor SRH at follow-up. Odds of poor SRH are highest for persons with both types of diseases (OR 2.63, SE 0.24), followed by only chronic (OR 1.86; SE 0.12) and finally only infectious (OR 1.55; SE 0.25). CONCLUSION: Mexico is experiencing a mixed regime of diseases that affects the health and well-being of older adults. Despite the rising importance of chronic diseases in countries like Mexico, it is premature to disregard the relevance of infectious diseases for public health.

The Impact of Physical Activity on Disability Incidence among Older Adults in Mexico and the United States.

Evidence suggests that transitions among older adults towards healthy habits, such as physical activity, appear underway in developed countries such as the USA but not in developing countries such as Mexico. However, little is known about the potential benefit of physical activity in preventing disability among elders in countries at different stages of epidemiological transition. We explore the impact of physical activity on the disablement process among elders in Mexico compared to the USA. Data are from two waves of the Mexican Health and Aging Study and the Health and Retirement Study. We examine the impact of exercise on the transition from no disability to ADL limitations two years later. Findings indicate that exercise is more common in the U.S. than in Mexico. There is a positive effect of exercise on negative outcomes in both countries. However, the protective effect of exercise is stronger in the U.S. than in Mexico.

Coexistence of Obesity and Anemia in Older Mexican Adults.

INTRODUCTION: Developing countries in Latin America (LA) are experiencing rapid aging as a result of advances in medical interventions. This rapid aging has not occurred with comparable improvements in standards of living. Chronic conditions are becoming highly prevalent while exposure to infectious communicable diseases is very common. This unique situation where communicable and non-communicable diseases coexist in the presence of low socioeconomic status place countries in LA in a unique epidemiological situation. Mexico presents a very good example where the impact of this situation on health warrants further analysis. METHODS: We use data from the Mexican National Health and Nutrition Survey (ENSANut 2006), a cross-sectional study representative of all urban and rural areas of Mexico. A total of 5,605 adults older than 60 years of age with valid values for Body Mass Index and Hemoglobin were analyzed. We first included a descriptive analysis of the coexistence of anemia and obesity by age, gender and characteristics of the living environment. We reported the weighted percentages for each covariate by each of four nutritional condition categories (obese and anemic, only-obese, only-anemic, not obese and not anemic). We used multinomial logit regressions to determine the association of socioeconomic characteristics, health status and the living environment with the presence of the three nutritional condition categories. RESULTS: In the ENSANut cohort 10.3% of older adults are anemic, 25.0% are obese and 2.6% are both anemic and obese. Approximately 62% has neither anemia nor obesity. Within the 38% that fall in the three nutritional condition categories, the co-existence of obesity & anemia appears to be associated with metropolitan area residence, living alone, being male, having relatively high wealth, and reporting two or more chronic health conditions. Analyzing the effect of the covariates to distinguish between outcome categories, living environment, age, gender, wealth, and smoking show a significant effect when comparing across the three nutritional categories. CONCLUSIONS: Older Mexican adults with both obesity & anemia have a different profile compared to that of adults with only one of the conditions. Future studies need to do a careful clinical evaluation of this group and design clinical interventions to avoid complications. Additionally, social support initiatives that target specific groups of older adults according to their health and social needs must be established.