Association between rural-to-urban migration and the cognitive aging trajectories of older Chinese adults: results from a prospective cohort analysis

Healthy aging trajectories and their predictors among Chinese older adults: Evidence from a 7-year nationwide prospective cohort study

OBJECTIVES

This study aimed to identify healthy aging trajectories of Chinese older adults, and explore the factors contributing to these trajectories.

METHODS

We used data from four waves (2011-2018) of China Health and Retirement Longitudinal Study. We developed a healthy aging metric based on the healthy aging framework of World Health Organization (WHO) and Bayesian multilevel item response theory (IRT) method. The healthy aging trajectories were identified using the latent class growth analysis. The predictors of trajectories were explored using multinomial logistic regression analysis. Additionally, we developed two alternative metrics for healthy aging based on the Chinese Healthy Ageing Index (CHAI) and Rowe and Kahn's model of successful aging, respectively. We compared these metrics to the one developed based on the WHO's healthy aging framework.

RESULTS

We identified three distinct healthy aging trajectories with varying scores and decline rates. Individuals who were female, had lower educational levels, resided in rural areas, experienced depression, had more chronic diseases, participated in fewer social activities, had fewer childhood friends, experienced more adverse childhood events, and had worse family financial status in childhood were more likely to experience a worse healthy aging trajectory compared to their counterparts. Supplementary analysis showed that healthy aging metric based on WHO definition and IRT method had the strongest association with health outcomes compared to the metrics based on CHAI, as well as Rowe and Kahn model.

CONCLUSIONS

Our findings provide a foundation for the development of tailored interventions to enhance and sustain healthy aging among Chinese older adults.

Hukou Status and Cognitive Function Among Older Chinese Adults: Does Support from Friends Matter?

OBJECTIVES

This study examined whether older Chinese adults with different types of hukou status (government household registration system) exhibited different cognitive outcomes and whether receiving support from friends, an under-appreciated resource, helped mitigate the negative impacts of agricultural hukou status on cognitive health disparities.

METHODS

Using nationally representative data from the China Longitudinal Aging Social Survey, this study tested these relationships with well-validated measures.

RESULTS

Our results showed that older Chinese adults with agricultural hukou were more likely to have worse cognitive function than those with non-agricultural hukou. Further, friend support characteristics moderated the association between hukou status and cognitive function, whereby having better friend support was related to a weaker negative effect of agricultural hukou status on cognitive function.

DISCUSSION

The findings suggested that agricultural hukou status reflects the effects of accumulated disadvantage across the life course with negative consequences for late-life cognition. The cognitive health disparities between agricultural and non-agricultural residents may be reduced in the context of a higher level of friend support, supporting a stress buffering hypothesis.

The relationship between oral health status, loneliness, and sleep quality among the migrant elderly following children in Weifang, Shandong Province, China: A comparative analysis on different migration types

Background

The migrant elderly following children (MEFC) are a vulnerable group that emerged during fast urbanization in China. The MEFC faced physical and psychological discomfort upon their arrival in the inflow city, particularly those who came from rural areas.

Objective

This study aimed to explore the relationship between oral health status, loneliness, and sleep quality among the MEFC in China and to clarify the disparities in the above mentioned relationship by migration type.

Methods

In 2021, a cross-sectional survey was conducted in Weifang, Shandong Province, using multistage cluster random sampling to collect data from the MEFC aged 60 years and over. In total, 613 respondents [525 rural-to-urban (RTU) and 88 urban-to-urban (UTU)] were included in the final database. The chi-square test, t-test, and structural equation modeling (SEM) were used to investigate the relationship between oral health status, loneliness, and sleep quality among the RTU and UTU MEFC.

Results

Total scores [mean ± standard deviation (SD)] for oral health status, loneliness, and sleep quality were 54.95 ± 6.47, 8.58 ± 3.03, and 4.47 ± 3.60, respectively. SEM revealed that, among the RTU and UTU MEFC, oral health status was positively and significantly related to sleep quality; however, the correlation was slightly stronger in the UTU MEFC. In both groups, there was a significant negative correlation between oral health status and loneliness, which was stronger in the UTU MEFC. In the RTU MEFC, a significant negative correlation between loneliness and sleep quality was observed, and in the UTU MEFC, no significant association between loneliness and sleep quality was observed.

Conclusion

The sleep quality among the MEFC in this study was higher compared to previous studies. Oral health status was negatively correlated with loneliness and positively associated with sleep quality, whereas loneliness was negatively correlated with sleep quality. These three associations differed significantly between the UTU and RTU MEFC. The government, society, and families should take measures to improve oral health and reduce loneliness among the MEFC to improve their sleep quality.

Urbanicity-Perspectives from Neuroscience and Public Health: A Scoping Review

Urban residency is associated with exposure to environmental factors, which can influence health in many ways. Neuroscientific research, as well as Public Health research, aim towards broadening evidence in the field of Urban Health. However, it is unclear whether the association between urban living and mental illnesses is causal rather than explainable by other selective effects. This review seeks to gather information on the current evidence regarding urban living and neurological outcomes to demonstrate how Public Health and Neuroscience could complement each other in the field of Urban Health. A scoping review was conducted in four electronic databases according to the PRISMA-statement guidelines. 25 empirical studies were included. Outcomes such as schizophrenia and psychotic disorders, social and cognitive functioning were scrutinised. Evidence was found for alteration of brain functioning and brain structure. Most studies researching cognitive functioning or cognitive decline displayed possible protective effects of urban living compared to rural living. The different study designs in Public Health and Neuroscience could profit from each other. Although the comparability of studies is limited by the inconsistent assessments of urbanity. Synergies and potentials to combine aspects of Public Health and Neuroscience in the field of Urban Health to improve population health became apparent.

Association between childhood friendship and cognitive ageing trajectory in later life: evidence from the China Health and Retirement Longitudinal Study (CHARLS)

Background

Childhood experience has been suggested to affect cognitive function in later life. However, the association between childhood friendship status and cognitive ageing trajectory in middle-aged and older adults has not been fully assessed. This study examined the association between childhood friendship status and cognitive ageing trajectory and identified factors modifying this association.

Methods

We used four waves of data from the China Health and Retirement Longitudinal Study (CHARLS), a national representative longitudinal study of adults aged 45 years or older, 2011–2018. The CHARLS included surveys on childhood friendship and cognitive assessments. Childhood friendship status was categorised as poor, fair, and good. To examine the association between childhood friendship and cognitive ageing trajectory in later life, we applied multilevel linear regression models, and explored potential influences of sociodemographic factors, health status and behaviours, and childhood conditions on this association.

Results

Of the 4,350 participants, 1,919 (44.1%) were women. The mean age was 56.29 ± 7.80 years. We found childhood friendship was significantly associated with cognitive ageing trajectory in later life, with a dose–response relationship. After adjusting for covariates, comparing to participants with poor childhood friendships, those with better childhood friendships had lower rates of cognitive decline (β = 0.12, 95% confidence interval [CI]: 0.03 to 0.22 [interaction term of fair friendship and time]; β = 0.19, 95% CI: 0.10 to 0.28 [interaction term of good friendship and time]) and higher level of cognitive functions (β = 0.40, 95% CI: 0.22 to 0.58 [fair friendships]; β = 0.61, 95% CI: 0.43 to 0.79 [good friendships]). These associations were stronger for those who were female, less educated, and had experienced more adverse childhood experiences.

Conclusions

Childhood friendship is associated with cognitive ageing in later life. Enhancing childhood friendships can play an important role to promote healthy ageing in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03181-6.

Earlier migration, better cognition? The role of urbanization in bridging the urban-rural cognition gaps in middle and older age

OBJECTIVES

With the process of population aging and urbanization, a vast amount of studies have confirmed the increasing urban-rural cognition gaps, while less is known about the extent to which cognition gaps can be explained by urban-rural difference and urbanization status. This study aimed to examine the role of urbanization in bridging the cognition gaps for Chinese middle-aged and older adults.

METHOD

Based on the national representative China Health and Retirement Longitudinal Study (CHARLS) 2015, the Blinder-Oaxaca decomposition method was employed. The method uses stratified linear regression to disaggregate cognition gaps into explained and unexplained differences, as well as the absolute and relative attribution of explanatory factors.

RESULTS

There were significant cognitive differences between urban and rural samples. Migrating to the urban predicts better cognition among the rural-born. A larger environment-related explained gap existed for those fully urbanized and those migrating earlier, indicating that migration can operate through a beneficial and cumulative change in the environment and bridge the urban-rural cognition gap.

CONCLUSION

Public health actions targeting cognitive disparities can benefit from focusing on the unequal distribution in urban-rural social and economic recourses. Areas of priority include promoting their socioeconomic status, physical functioning, social support, and lifestyles.