Working in old age in Mexico: Implications for Cognitive Functioning

Effects of extended working lives on depressive symptoms, physical, and cognitive health in middle and later life: Evidence from China

INTRODUCTION

Many countries are extending working lives to counteract the shrinking labor force caused by population aging. However, the health implications of this approach for middle-aged and older adults remain unclear, particularly in low- and middle-income countries.

METHODS

Data were drawn from the 2011-2020 China Health and Retirement Longitudinal Study to analyze the effect of labor force participation on multidimensional health, with a focus on activities of daily living disability, depressive symptoms, and cognitive impairment. A longitudinal g-formula was applied to address the endogeneity associated with long-term employment and simulate the life course of a synthetic cohort aged 45-80 years. The impact of extending working lives to age 63 for men and age 58 for women on health outcomes was estimated.

RESULTS

Labor force participation was negatively associated with the onset of activities of daily living disability but positively associated with the onset of depressive symptoms and cognitive impairment among middle-aged and older adults. Extending working life slowed the progression of activities of daily living disability but increased the risk of depressive symptoms and cognitive impairment, especially in women. These effects persisted beyond working years and into postretirement. Higher education levels mitigated the negative impact of extended working lives on cognitive function.

CONCLUSIONS

While extending working lives may benefit physical functioning, it poses risks to depressive symptoms and cognitive health, particularly for women. National policies promoting longer working lives should incorporate targeted preventive measures to protect the psychological and cognitive health of middle-aged and older adults.

Association between cognitive decline and depression in middle-aged and older adults: Findings from six large cohorts in different countries

BACKGROUND

The relationship between depression and cognition in middle-aged adults is a topic of interest. Whether poor cognitive function exacerbates depression remains controversial. We clarified the association between cognitive decline and depression based on six nationwide cohorts.

METHODS

89,056 participants were retrieved from six cohorts in Europe, North America, Asia and Africa. Each two consecutive interviews were collected as a sample set with a total of twenty-eight sample sets to assess changes in depression and cognitive function. Multiple linear regression was conducted within each sample set to evaluate the association between cognitive decline and depression. A two-stage meta-analysis was performed to obtain the average effect within each cohort and the overall effect excluding population and regional heterogeneity. Meta-regression and subgroup analysis were used to explore heterogeneity and potential effect modifiers.

RESULTS

Almost all sample sets indicated negative association between changes in cognitive function and depression scores. The average effects varied across regions: Korea (-0.150 [-0.175, -0.126]), Europe (-0.130 [-0.149, -0.112]), South Africa (-0.090 [-0.129, -0.060]), China (-0.083 [-0.137, -0.030]), Mexico (-0.063 [-0.084, -0.042]), and North America (-0.048 [-0.056, -0.040]). The overall effect excluding population and regional heterogeneity was -0.094 [-0.129, -0.060], and was robust across populations of different age, sex, alcohol consumption, daily living activities and marital status.

LIMITATIONS

The cross-sectional design limited our ability to determine causal relationships.

CONCLUSION

Cognitive decline was associated with the exacerbation of depression status in middle-aged and older adults worldwide. Country-level factors, rather than individual-level factors, are more likely to modify this effect.

Cognitive Trajectories and Associated Social and Behavioral Determinants Among Racial/Ethnic Minority Older Adults in the United States

BACKGROUND AND OBJECTIVES

Despite higher risks of developing Alzheimer's disease and Alzheimer's disease-related dementias among racial/ethnic minority populations, some maintain good cognition until old age. The aims of this study were to investigate heterogeneous cognitive trajectories among non-Hispanic Black and Hispanic older adults, examine cognitive impairment prevalence across trajectory classes, and identify associated social and behavioral determinants.

RESEARCH DESIGN AND METHODS

Using 11 waves of data from the Health and Retirement Study (1996-2016), 1,322 non-Hispanic Black and 747 Hispanic adults aged 50+ years in 1996 with normal cognition were included. Latent class growth modeling and multinomial logistic regressions were performed to examine cognitive trajectories and associated determinants.

RESULTS

For both racial/ethnic groups, 3 trajectory classes were identified: high, medium, and low cognition. In the low-cognition class, 87% and 100% of non-Hispanic Black and Hispanic participants, respectively, developed cognitive impairment. For both racial/ethnic groups, older age and living in rural areas during schooltime increased the likelihood of being in the low-cognition class, whereas more education was associated with a lower likelihood. Unique risk and protective determinants for non-Hispanic Black and Hispanic participants were also identified.

DISCUSSION AND IMPLICATIONS

This study reveals the heterogeneity of cognitive trajectories among racial/ethnic minority older adults and various associated social and behavioral determinants. More prevention interventions and accessible, affordable diagnosis and treatment should be provided to older racial/ethnic minorities with these characteristics to reduce disparities. More research is needed to further explore associations between unique determinants and cognition in racial/ethnic minority populations to better inform interventions.

Economic insecurity exposure and cognitive function in late life

OBJECTIVES

This study took the State-owned Enterprises (SOE) reform from 1996 to 2002 in China as a natural experiment to explore the consequences of economic insecurity exposure during early-adulthood and mid-adulthood on cognitive function in later life.

METHODS

Data were obtained from the China Health and Retirement Longitudinal Survey (CHARLS), 2014 and 2015. CHARLS is a nationally representative survey covering 28 provinces in China. A total of 4536 urban dwellers born earlier than 1971 (aged 25 years old and above at the start of the SOE reform in 1996) were included in our analyses. Using province-year-level economic loss from the layoffs, we examined the impact of economic insecurity exposure on the cognitive function score by using a difference-in-differences model with 1996-2002 as the cut-off.

RESULTS

Individuals exposed to economic insecurity have significantly decreased cognitive function, in which a 1% point increase in expected economic loss would decrease the cognitive function score by 0.09 (95% CI: -0.17 to -0.01). Given that the average intensity of expected economic loss was 11.59% and the mean score of cognitive function was 21.26, exposure to the SOE reforms led to an average decrease in the cognitive function score by at least 4.91%.

CONCLUSIONS

Providing cognitive health surveillance and psychological counselling may be important for preventing cognitive decline among those experiencing economic insecurity.

Rural and urban differences in lifetime occupation and its influence on mortality among Mexican adults

OBJECTIVE

To determine how primary lifetime occupation type is associated with mortality, and how the relationship varies by rural and urban dwelling.

MATERIALS AND METHODS

Data come from 2001-2018 Mexican Health and Aging Study (adults aged 50+, n=11 094). We created five occupation categories. Cox proportional hazard models predicted mortality using baseline covariates.

RESULTS

In both rural and urban settings, participants with manual jobs, such as agriculture and production/industrial jobs, had an increased risk of mortality compared to those with administrative/professional jobs. In urban settings, participants in the domestic/service and no main job categories had higher risk of mortality than those in the administrative/professional category. For men these differences remained, but not for women.

CONCLUSION

In a context of rural and urban demographic shifts, it is crucial to consider the implications that occupation as a socioeconomic factor can have on health and to identify the most vulnerable groups.

Rural/urban dwelling across the life-course and late-life cognitive ability in Mexico

BACKGROUND

Urban advantages in older adults' cognitive function have been observed. Less is known about early-life urban dwelling and late-life cognition. We evaluate how rural/urban dwelling throughout life and rural to urban shifts in life relate with cognition in Mexico, a country experiencing aging and urbanization.

METHODS

Data came from the 2003 and 2012 Mexican Health and Aging Study (n = 12,238 adults age 50+). Early-life urban dwelling was self-reported. Late-life urban dwelling was based on population size of respondents' community of residence (community 2500+ people) at the time of survey. Cognitive function was measured across several cognitive tasks. We assess differences in baseline cognitive function and nine-year decline across groups using a latent change score model.

RESULTS

Cross-sectionally, compared to always rural dwellers, rural-urban transitions were associated with cognitive benefits, though individuals residing in urban areas continuously through life exhibited the highest levels of cognitive function (β = 0.89, 95% CI: 0.83, 0.96) even after adjusting for SES, health, and health behaviors (β = 0.28, 95% CI: 0.22, 0.35). Longitudinally, always urban dwellers exhibited slower decline than always rural dwellers when adjusting for baseline cognition (β = 0.11, 95% CI: 0.03, 0.18), though faster decline when baseline cognition was not adjusted (β = -0.11, 95% CI: -0.18, -0.04). No differences were observed for cognitive change across comparison groups after adjusting for potential mechanisms.

CONCLUSIONS

Early- and late-life urban dwelling may result in cognitive advantages for older Mexican adults. Clinicians should consider where individuals resided throughout life to better understand a patient's likelihood of experiencing poor cognitive outcomes.