Early-Life Conditions and Cognitive Function in Middle-and Old-Aged Chinese Adults: A Longitudinal Study

Association between childhood parental literacy and late-life cognitive function: The Guangzhou Biobank Cohort Study

OBJECTIVES

Evidence on the associations of childhood parental education with late-life cognitive function remains inconsistent. Additionally, studies focusing on dimensions of cognitive function are scarce, with none from China. Therefore, we examined the associations of childhood parental education with late-life cognitive function and it's dimensions and investigated potential interactions.

STUDY DESIGN

A cross-sectional study.

METHODS

Participants were included from the third phase of Guangzhou Biobank Cohort Study. Mini-Mental State Examination (MMSE), Delayed 10-Word Recall Test (DWRT), and childhood parental literacy (could read or write) were collected. Multivariate linear and logistic regression were used.

RESULTS

Among 8891 participants aged ≥50 years, compared with those whose childhood parents could not read/write, those with only the father, only the mother, or both parents able to read/write during childhood had higher scores on the MMSE and its dimensions, and lower odds of mild cognitive impairment (MCI). The coefficients (β) and 95 % confidence intervals (CI) for scores of MMSE were 1.25 (1.10, 1.41), 1.36 (0.86, 1.86), and 2.05 (1.89, 2.21) respectively; the odds ratios and 95 % CIs for MCI were 0.38 (0.33, 0.45), 0.35 (0.18, 0.67), and 0.15 (0.12, 0.19) respectively. More pronounced effects were found in women, those aged ≥60, those with ≤ primary education, and in those whose childhood parents could read/write. Socioeconomic position mediated the association. Cognitive functions of attention and calculation in children of only fathers who could read/write (β = 0.43, 95%CI: 0.35, 0.50) and memory in children of only mothers who could read/write (β = 0.34, 95%CI: 0.16, 0.51) were associated with better outcomes. Consistent results were also found using scores from the DWRT.

CONCLUSIONS

Childhood parental literacy was associated with late-life cognitive function and it's dimensions, which mediated by socioeconomic position. Specifically, having only a father or only a mother who could read/write during childhood was associated with better cognitive function in attention/calculation and memory, respectively. These results add new evidence to support strategies for elderly cognitive health care.

Evidence of the Long-Term Protective Effect of Moderate-Intensity Physical Activity on Cognitive Function in Middle-Aged and Elderly Individuals: A Predictive Analysis of Longitudinal Studies

OBJECTIVE

To investigate the effects of different intensities of physical activity (PA) on cognitive function in middle-aged and elderly individuals, and to predict future trends in cognitive ability using longitudinal data to assess the long-term role of PA in cognitive preservation.

METHODS

Data from the China Health and Retirement Longitudinal Study (CHARLS) were utilized. Mixed-effects models were employed to analyze the impacts of low-intensity PA (LPA), moderate-intensity PA (MPA), and vigorous-intensity PA (VPA) on overall cognition, episodic memory, and mental intactness. Random forest and XGBoost machine learning methods were employed to further validate the effects of PA. ARIMA models predicted future cognitive trends under the influence of PA.

RESULTS

MPA demonstrated significant advantages in preserving cognitive function, particularly in overall cognition and episodic memory. While LPA had some protective effects, they were less significant than those of MPA, and VPA did not show advantages. Machine learning methods confirmed these findings. ARIMA model predictions indicated that the protective effects of MPA on cognitive function are likely to persist in the future.

CONCLUSIONS

Moderate-intensity physical activity is associated with the preservation of cognitive ability in middle-aged and elderly individuals and may continue to provide this benefit in the future; however, further in-depth research is needed for confirmation.

Intergenerational Caregiving Patterns and Cognitive Health among the Sandwich Generation Within Four-Generation Families

This study aims to investigate whether generational differences in intergenerational caregiving patterns (caring for parents only, caring for grandchildren only, and caring for parents and grandchildren simultaneously) are associated with cognitive health disparities among the sandwich generation within four-generation families, drawing upon the theories of intergenerational solidarity and intergenerational stake. Moreover, this study seeks to identify mediators that help explain these disparities. A nationally representative sample of 8,065 respondents was drawn from the 2011 and 2018 waves of the China Health and Retirement Longitudinal Study. The findings reveal that the sandwich generation caring for grandchildren only, as well as those caring for grandchildren and parents simultaneously, exhibit better cognitive health. However, caregiving for parents only is not significantly related to their cognitive health. This study identifies the inability to reduce depressive symptoms as a mediator explaining the insignificant association between caregiving for parents only and the cognitive health of the sandwich generation. The findings underscore the importance of offering support to the sandwich generation within four-generation families to enhance their cognitive health. Moreover, it is imperative to distinguish between different intergenerational caregiving patterns based on generational differences among the sandwich generation, with a specific emphasis on allocating public resources aimed at promoting cognitive health for those engaged in caring for parents.

Childhood and adult socioeconomic status influence on late-life healthy longevity: evidence from the Chinese longitudinal healthy longevity survey

Background

Older people in low- and middle-income countries are more susceptible to the impact of childhood experiences. This study comprehensively examines how childhood socioeconomic status (SES) and adult SES collectively influence late-life healthy longevity from a life course perspective, providing insights for shaping health-related policies.

Methods

This study analyzed data from the Chinese Longitudinal Healthy Longevity Survey (1998-2018) with 37,264 individuals aged 65 and above. Using R software, we applied continuous-time multi-state models incorporating the Rockwood frailty index with 38 indicators to assess participants' health. Childhood SES or life course SES trajectories were core explanatory variables, while age and gender were controlled. Multinomial regression estimated annual transition probabilities between different states, and the multi-state life table method calculated total and frailty-specific life expectancy (LE).

Results

(1) Social mobility among older people in China showed an upward trend from childhood to adulthood. (2) Transition probabilities for robust-frailty, robust-dead, and frailty-dead increased with age, while frailty-robust decreased. Transition probabilities and LE varied across different childhood SES (low, medium, high) or life-course SES trajectory categories (low-low, low-medium, low-high, medium-low, medium-medium, medium-high, high-low, high-medium, high-high), with probabilities of robust-frailty, robust-dead, and frailty-dead decreasing sequentially across different categories, and frailty-robust increasing sequentially across different categories. Total LE, robust LE, and robust LE proportion increased sequentially across different categories, while frailty LE decreased sequentially across different categories. (3) Women had higher total LE and frailty incidence, but lower recovery rate, mortality risk, robust LE, and robust LE proportion compared to men.

Conclusion

Favorable childhood SES and lifelong accumulation of SES advantages protect against frailty morbidity, improve recovery rate, reduce mortality risk, and increase total LE, robust LE, and robust LE proportion. High childhood SES has a stronger protective effect than high adult SES, indicating the lasting impact of childhood conditions on healthy longevity. Systematic interventions in education, food supply, and medical accessibility for children from impoverished families are crucial.

What is the association between adverse childhood experiences and late-life cognitive decline? Study of Healthy Aging in African Americans (STAR) cohort study

OBJECTIVES

Adverse childhood experiences (ACEs) are associated with higher risk of chronic disease, but little is known about the association with late life cognitive decline. We examined the longitudinal association between ACEs and late-life cognitive decline in the Study of Healthy Aging in African Americans (STAR).

DESIGN

Linear mixed models with random intercepts and slope examined the association of individual and composite ACEs with cognitive change adjusting for years from baseline (timescale), baseline age, sex, parental education, childhood socioeconomic status and childhood social support. Participants reported whether they had experienced nine types of ACEs. Executive function and verbal episodic memory were measured up to three times over a 3-year period using the Spanish and English Neuropsychological Assessment Scales.

SETTINGS

Kaiser Permanente Northern California members living in the Bay Area.

PARTICIPANTS

STAR is a cohort study of cognitive ageing launched in 2018 that has enrolled 764 black Americans ages ≥50 years (mean age=67.5; SD=8.5).

RESULTS

Twenty-one per cent of participants reported no ACEs, 24% one ACE, 20% two ACEs, 17% three ACEs and 17% four or more ACEs. Compared with no ACEs, two ACEs (β=0.117; 95% CI 0.052 to 0.182), three ACEs (β=0.075; 95% CI 0.007 to 0.143) and four or more ACEs (β=0.089; 95% CI 0.002 to 0.158) were associated with less decline in executive function. There were no significant associations between number of ACEs and baseline or longitudinal verbal episodic memory or between individual ACEs and executive function or verbal episodic memory.

CONCLUSION

In this cohort of older black Americans, there was no association between ACEs and baseline cognition or cognitive change in verbal episodic memory; however, experiencing ≥ 2 ACEs was associated with less decline in executive function. These results may indicate that participants who survived to age 50+ and experienced ACEs may have cognitive resilience that warrants further investigation.

Effects of early-life environment and adulthood SES on cognitive change in a multiethnic cohort

OBJECTIVES

Early-life socioeconomic status (SES) and adversity are associated with late-life cognition and risk of dementia. We examined the association between early-life SES and adversity and late-life cross-sectional cognitive outcomes as well as global cognitive decline, hypothesizing that adulthood SES would mediate these associations.

METHODS

Our sample (N = 837) was a racially and ethnically diverse cohort of non-Hispanic/Latino White (48%), Black (27%), and Hispanic/Latino (19%) participants from Northern California. Participant addresses were geocoded to the level of the census tract, and US Census Tract 2010 variables (e.g., percent with high school diploma) were extracted and combined to create a neighborhood SES composite. We used multilevel latent variable models to estimate early-life (e.g., parental education, whether participant ever went hungry) and adult (participant's education, main occupation) SES factors and their associations with cross-sectional and longitudinal cognitive outcomes of episodic memory, semantic memory, executive function, and spatial ability.

RESULTS

Child and adult factors were strongly related to domain-specific cognitive intercepts (0.20-0.48 SD per SD of SES factor); in contrast, SES factors were not related to global cognitive change (0.001-0.01 SD per year per SD of SES factor). Adulthood SES mediated a large percentage (68-75%) of the total early-life effect on cognition.

CONCLUSIONS

Early-life sociocontextual factors are more strongly associated with cross-sectional late-life cognitive performance compared to cognitive change; this effect is largely mediated through associations with adulthood SES.

The Association Between Adverse Childhood Experiences and Late-Life Cognition: A Systematic Review of Cross-Sectional and Case-Control Studies

BACKGROUND AND OBJECTIVES

Adverse childhood experiences (ACEs) are a recognized risk factor for unfavorable health outcomes. No prior systematic review has explored the association between ACEs and cognition in late life, a critical period for cognitive fluctuation. The objective of this review is to address the following research question: What is the association between ACEs and late-life cognition?

RESEARCH DESIGN AND METHODS

Articles were obtained from PubMed, PsycINFO, and Scopus. The last search was performed in May 2021. Eligible articles examined the association between exposure to at least 1 ACE and the outcome of late-life cognition, measured either by cognitive testing or the presence/absence of a neurocognitive disorder. Data were synthesized narratively using the synthesis without meta-analysis guidelines, and the risk of bias was assessed using the Newcastle-Ottawa Scale (NOS) and Adapted NOS.

RESULTS

Twenty articles representing 18 unique studies were included in the narrative synthesis. Associations with lower late-life cognition were reported for: childhood maternal death, parental divorce, physical neglect, emotional neglect, physical abuse, and combinations of ACEs. However, most results were statistically nonsignificant, and many were unlikely to be clinically important.

DISCUSSION AND IMPLICATIONS

We found an association between ACEs and late-life cognition. However, the direction and magnitude of association varied between and within types of ACEs and measures of cognitive function. Most included articles had a moderate risk of bias. This review is the first attempt to synthesize the literature on this topic and it outlines the next steps to improve the evidence base in the area.

Childhood experiences and frailty trajectory among middle-aged and older adults in China

This study examined the associations between childhood experiences and frailty trajectory among middle-aged and older Chinese adults. Data were derived from the China Health and Retirement Longitudinal Study. We used data from all four waves (i.e., 2011, 2013, 2015, 2018) and the life history survey in 2014. Data for 10,963 respondents were included. Latent growth curve models were conducted to examine the proposed model. The results show that adverse childhood experiences, self-rated childhood socioeconomic status, and the objective indicators of childhood health and health care were associated with both the baseline level and change rate of frailty. The educational attainment of fathers and perceived childhood health and healthcare conditions were associated with baseline frailty only. Our findings highlight the crucial role of childhood antecedents in the progression of frailty in later life. We further found strong evidence that childhood is an essential life stage for human development. Future social policies and interventions should use childhood experiences as a screening tool and promote child protection, health education, and life course interventions.

Association of Adverse Childhood Experiences and Social Isolation With Later-Life Cognitive Function Among Adults in China

IMPORTANCE

Studies investigating the association of threat-related and deprivation-related adverse childhood experiences (ACEs) with later-life cognitive decline are lacking.

OBJECTIVES

To evaluate the independent association of threat-related and deprivation-related ACEs with cognitive decline over time among middle-aged and older Chinese adults and to examine the modifying role of social isolation in such associations.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study used cognitive data from the China Health and Retirement Longitudinal Study (CHARLS) baseline survey that was administered between June 1, 2011, and March 31, 2012, and the CHARLS follow-up survey administered between July 1 and September 30, 2015. The life history survey with information of ACEs was additionally administered between June 1 and December 31, 2014. Statistical analysis was performed from March 1 to July 31, 2022. The study population consisted of middle-aged and older adults (age range, 45-97 years) with complete data on ACEs and 2 cognitive assessments and without cognitive impairment at baseline.

EXPOSURES

Five threat-related ACEs (ie, physical abuse, household substance abuse, domestic violence, unsafe neighborhood, and bullying) and 5 deprivation-related ACEs (ie, emotional neglect, household mental illness, incarcerated household member, parental separation or divorce, and parental death) before 17 years of age were queried by questionnaires. The cumulative scores of the 2 ACE dimensions were calculated and grouped into 3 categories as 0, 1, and 2 or more in main analyses.

MAIN OUTCOMES AND MEASURES

Cognitive function was measured by episodic memory and executive function. Global cognition was further calculated as the total score of these 2 dimensions. The raw scores of each cognitive test were standardized to z scores using baseline means and SDs. Linear mixed-effects models were constructed to examine the association between 2 dimensions of ACEs and the rate of annual cognitive decline. The modifying role of baseline social isolation in such associations was assessed with 3-way interaction tests.

RESULTS

Of the 6466 participants included in main analyses, 3301 (51.1%) were men and the mean (SD) age was 57.2 (8.3) years. Compared with no exposures, experience of 1 deprivation-related ACE was associated with faster cognitive decline in global cognition (β = -0.012 [95% CI, -0.022 to -0.002] SD/y) and executive function (β = -0.010 [95% CI, -0.020 to -0.00002] SD/y), whereas individuals with at least 2 childhood deprivations had faster cognitive declines in all cognitive tests (β = -0.035 [95% CI, -0.050 to -0.019] SD/y for global cognition; β = -0.047 [95% CI, -0.068 to -0.025] SD/y for episodic memory; β = -0.019 [95% CI, -0.034 to -0.004] SD/y for executive function). However, such an association was not observed for threat-related ACEs. In addition, baseline social isolation was a significant modifier in the associations between deprivation-related ACEs and cognitive declines in global cognition (β = -0.033 [95% CI, -0.061 to -0.005] SD/y; P = .02 for 3-way interaction) and executive function (β = -0.032 [95% CI, -0.059 to -0.005] SD/y; P = .02 for 3-way interaction).

CONCLUSIONS AND RELEVANCE

Deprivation-related ACEs, but not threat-related ACEs, were associated with faster decline in later-life cognitive function, whereas social isolation could modify such detrimental impact. These findings highlight the potential benefits of promoting social integration in maintaining later-life cognitive function among individuals who have experienced childhood deprivation.

Direct and indirect associations between childhood socioeconomic status and cognitive function in the middle-aged and older adults in China

OBJECTIVES

To investigate whether childhood socioeconomic status (SES) is associated with cognitive function, and what factors might mediate the associations.

METHOD

Using data from the China Health and Retirement Longitudinal Study (CHARLS) and within frameworks of the latency model, the pathway model and the accumulation model, we quantified direct and indirect pathways between childhood SES and cognitive function for Chinese middle-aged and older adults aged 45+ by structural equations modeling.

RESULTS

We found significant direct, indirect and total effects of childhood SES on cognitive function at baseline. The indirect effects were mediated through educational attainment, household consumption, smoking behaviors and social engagement. At follow-ups, cognitive enhancement can be made by indirect pathways through educational attainment, improvement of household consumption and social engagement.

CONCLUSION

Our results supported the latency model, the pathway model and the accumulation model when considering pathways linking childhood SES to cognitive function. The findings underscored the value of taking early interventions to improve SES and cognitive function, especially among those with low childhood SES.

The impact of a history of child abuse on cognitive performance: a cross-sectional study in older patients with a depressive, anxiety, or somatic symptom disorder

BACKGROUND

Child abuse is a major global burden with an enduring negative impact on mental and physical health. A history of child abuse is consistently associated with worse cognitive performance among adults; data in older age groups are inconclusive. Since affective symptoms and cognitive functioning are interrelated among older persons, a synergistic effect can be assumed in patients with affective symptoms who also have suffered from child abuse. This study examines the association between a history of child abuse and cognitive performance in such patients.

METHODS

Cross-sectional data were collected from the 'Routine Outcome Monitoring for Geriatric Psychiatry & Science' project, including 179 older adults (age 60-88 years) with either a unipolar depressive, any anxiety, or somatic symptom disorder referred to specialized geriatric mental health care. A history of physical, sexual, and psychological abuse, and emotional neglect was assessed with a structured interview. Cognitive functioning was measured with three paper and pencils tests (10-words verbal memory test, Stroop Colour-Word test, Digit Span) and four tests from the computerized Cogstate Test Battery (Detection Test, Identification Test, One Card Learning Test, One Back Test). The association between a history of child abuse and cognitive performance was examined by multiple linear regression analyses adjusted for covariates.

RESULTS

Principal component analyses of nine cognitive parameters revealed four cognitive domains, i.e., visual-verbal memory, psychomotor speed, working memory and interference control. A history of child abuse was not associated with any of these cognitive domains. However, when looking at the specific types of child abuse separately, a history of physical abuse and emotional neglect were associated with poorer interference control. A history of physical abuse was additionally associated with better visual-verbal memory.

CONCLUSIONS

The association between a history of child abuse and cognitive performance differs between the different types of abuse. A history of physical abuse might particularly be a key determinant of cognitive performance in older adults with a depressive, anxiety, or somatic symptom disorder. Future studies on the impact of these disorders on the onset of dementia should take child abuse into account.

TRIAL REGISTRATION

ROM-GPS is registered at the Dutch Trial Register ( NL6704 at www.trialregister.nl ).

Childhood Stressors, Relationship Quality, and Cognitive Health in Later Life

OBJECTIVES

The rising prevalence of cognitive impairment, Alzheimer's disease, and related disorders signals the need for a better understanding of how social factors may affect cognitive health for millions of Americans. Drawing from cumulative inequality theory, we aim to understand the implications of a stressful childhood on social relationships and cognitive health in later life.

METHODS

This study utilizes longitudinal data (2006-2016) from the Health and Retirement Study to examine pathways, both direct and indirect through social relationships in adulthood, from childhood stressors to cognitive health trajectories over time.

RESULTS

Respondents reporting a greater number of stressors in childhood had worse cognitive health over time, but those negative effects were not as steep as time progressed. Early-life stressors are also associated with less social support and more social strain in adulthood which, in turn, are associated with initial cognitive health. Finally, pathway analyses confirm that childhood stressors are indirectly associated with initial cognitive health through social strain and social support.

DISCUSSION

Findings reveal that a stressful childhood creates chains of risks that have lifelong implications for cognitive health, both directly and indirectly by creating obstacles for developing healthy and supportive social relationships.

Income-Related Mortality Inequalities and Its Social Factors among Middle-Aged and Older Adults at the District Level in Aging Seoul: An Ecological Study Using Administrative Big Data

This study investigated income-related health inequality at sub-national level, focusing on mortality inequality among middle-aged and older adults (MOAs). Specifically, we examined income-related mortality inequality and its social factors among MOAs across 25 districts in Seoul using administrative big data from the National Health Insurance Service (NHIS). We obtained access to the NHIS's full-population micro-data on both incomes and demographic variables for the entire residents of Seoul. Slope Index of Inequality (SII) and Relative Index of Inequality (RII) were calculated. The effects of social attributes of districts on SIIs and RIIs were examined through ordinary least squares and spatial regressions. There were clear income-related mortality gradients. Cross-district variance of mortality rates was greater among the lowest income group. SIIs were smaller in wealthier districts. Weak spatial correlation was found in SIIs among men. Lower RIIs were linked to lower Gini coefficients of income for both genders. SIIs (men) were associated with higher proportions of special occupational pensioners and working population. Lower SIIs and RIIs (women) were associated with higher proportions of female household heads. The results suggest that increasing economic activities, targeting households with female heads, reforming public pensions, and reducing income inequality among MOAs can be good policy directions.

Adverse Childhood Experiences and Mild Cognitive Impairment in Later Life: Exploring Rural/Urban and Gender Differences Using CHARLS

This paper aims to examine whether and how adverse childhood experiences are associated with mild cognitive impairment among middle-aged and older adults in China, and if the associations vary by gender and rural/urban residence. Using four waves of data from the China Health and Retirement Longitudinal Study, cox proportional hazard models were applied. Results showed that the rural and female subsamples were significantly disadvantaged and were more likely to be cognitively impaired. Moreover, childhood family socioeconomic status and childhood social relationships were significantly associated with the risk of mild cognitive impairment for the study sample. Our findings suggest that, for middle-aged and older Chinese adults, adverse childhood experiences could have long-lasting impacts on cognitive functioning throughout the life course.

Early life socioeconomic status predicts cognition regardless of education level

BACKGROUND AND PURPOSE

Early life socioeconomic status (SES) may impact cognitive performance later in life. We investigated the effect on cognitive performance of early life SES, education, and late life SES in the Brazilian Longitudinal Study of Adult Health.

METHODS

Path analysis was used to decompose associations between SES measures across the lifespan and cognition. The model included direct paths to cognition from early life SES, education, and late life SES, and indirect paths from early life passing through education and late life SES. We investigated whether the effects of early life SES are similar across middle-aged and older adults.

RESULTS

In 13,395 adults, the mean age was 51.5 (8.9) years, 54% were female, 53% were white, and 56% had at least college education. The direct path from early life SES remained significant in the presence of mediation paths through education, late life SES, or both, contributing to cognitive performance in both middle-aged and older adults. The indirect and total effect of early life SES was smaller for middle-aged compared to older adults. Early life SES continues to impact cognitive performance later in life independently of educational attainment and late life SES. The higher percent of mediation through education suggests that education may improve later life cognition even in the presence of low early life SES.

CONCLUSIONS

Our results highlight the importance of public health initiatives to improve early life SES and education to foster cognitive aging in low- and middle-income countries.

Life-course pathways from childhood socioeconomic status to type 2 diabetes in mid-late Chinese adulthood

The relationship between childhood socioeconomic status (SES) and type 2 diabetes (T2D) remains inconclusive, and the pathways and mechanisms driving this relationship have yet to be clarified. This study aimed to examine the pathways linking childhood SES to T2D prevalence in mid-late adulthood in a low- and middle-income country. The incidence of T2D diagnosed in mid-late Chinese adulthood was assessed using self-reports from the Health and Retirement Longitudinal Study (CHARLS). Childhood SES was assessed by the education, occupation, survivorship of the parents and the financial situation of the family, whereas adulthood SES was assessed by education and wage. This study performed structural equation modeling to clarify the direct and indirect pathways from childhood SES to T2D via childhood health, childhood food shortage, adulthood SES and physical activity. A total of 15,132 participants were included, and the prevalence of T2D was 5.24%. This study found that childhood SES was directly associated with T2D in mid-late adulthood, the probability of developing T2D increased by 9.20% of the standard deviation for each decrease in standard deviation in childhood SES. Childhood SES was indirectly associated with T2D via adulthood SES, physical activity, childhood health and food shortage. Adulthood SES and physical activity mainly mediated the indirect pathway from childhood SES and T2D. This study showed direct and indirect pathways from disadvantaged childhood SES to increased risk of T2D in mid-late Chinese adulthood. Childhood SES, adulthood SES, physical activity, childhood health and food shortage were identified as life-course interventional targets that should be considered in the development of effective strategies to reduce the burden of T2D and SES-related health inequities in childhood.

Association of life course socioeconomic status and adult height with cognitive functioning of older adults in India and China

BACKGROUND

Cognitive functioning is an important measure of intrinsic capacity. In this study, we examine the association of life course socioeconomic status (SES) and height with cognitive functioning among older adults (50+) in India and China. The age pattern of cognitive functioning with measures of life course socioeconomic status has also been examined.

METHODS

Cross-sectional comparative analysis was conducted using the WHO's Study on global AGEing and adult health (SAGE) data for India and China. Multilevel mixed-effect linear regression analysis was used to examine the association of life course socioeconomic status and adult height with cognitive functioning.

RESULTS

In both India and China, parental education as a measure of childhood socioeconomic status was positively associated with cognitive functioning. The association between adult socioeconomic status and cognitive functioning was positive and significant. Height was significantly and positively associated with improved cognitive functioning of older adults in India and China. Furthermore, the age-related decline in cognitive functioning score was higher among older adults whose parents had no schooling, particularly in China. The cognitive functioning score with age was much lower among less-educated older adults than those with higher levels of education in China. Wealthier older adults in India had higher cognitive functioning in middle ages, however, wealth differences narrowed with age.

CONCLUSIONS

The results of this study suggest a significant association of lifetime socioeconomic status and cumulative net nutrition on later-life cognitive functioning in middle-income settings.