Early life exposure to China's 1959-61 famine and midlife cognition

Association of handgrip strength asymmetry and weakness with depression among middle-aged and older population in China: A cohort study

BACKGROUND

Handgrip strength (HGS) weakness and asymmetry were recently reported to be associated with age-related health conditions. However, little is known about their combined effects on depression. We aimed to explore the joint association of HGS asymmetry and weakness with depressive symptoms in Chinese middle and older aged population.

METHODS

8700 participants aged ≥45 years were enrolled from China Health and Retirement Longitudinal Study (2015-2018). HGS weakness was determined as maximal HGS < 28 kg in males and <18 kg in females. HGS asymmetry was measured by HGS ratio and was defined using two different rules. Specifically, HGS ratio < 0.90 or >1.10 (10 % rule) and <0.80 or >1.20 (20 % rule) were considered as asymmetry. Participants were classified into four groups: normal and symmetric HGS, asymmetry only, weakness only, and both weakness and asymmetry. Depressive symptoms were assessed by the 10-item Center for Epidemiologic Studies Depression Scale, with scores ≥12 defined as depression. The logistic regression and multiple linear regression models were conducted to estimate the associations between HGS status and depressive symptoms.

RESULTS

The three-year incidence of depression was 19.2 %. After adjusting for covariates, compared to normal and symmetric HGS, participants with both HGS asymmetry and weakness showed the greatest risk of incident depression (10 % rule: OR 1.55, 95 % CI 1.19-2.02; 20 % rule: OR 1.71, 95 % CI 1.16-2.50). The coexistence of asymmetry and weakness was related to a significant increase in depression score (10 % rule: β 0.96, 95 % CI 0.38-1.54; 20 % rule: β 0.94, 95 % CI 0.08-1.81). The complete case analysis supported the results, and the associations were not modified by age, sex, and hand dominance.

LIMITATIONS

Depressive assessment was based on self-reported screening instrument.

CONCLUSIONS

The presence of both HGS asymmetry and weakness was associated with a higher risk of depression. Examining HGS asymmetry along with weakness may aid in identifying individuals at risk of depression to enable early interventions.

Association between early exposure to famine and risk of renal impairment in adulthood: a systematic review and meta-analysis

Malnutrition early in life increases the later-life risk of noncommunicable diseases, and previous epidemiologic studies have found a link between famine and renal impairment, but no consensus has been reached. This meta-analysis and systematic review were conducted to assess the correlation between early-life famine exposure and the risk of developing renal impairment. Search in Embase, Scopus, Web of Science, PubMed, and Cochrane using keywords that report the correlation between early famine exposure and renal function indicators. RevMan and Stata software were used for data analysis. This meta-analysis contained twelve observational studies. The findings demonstrated a link between prenatal famine exposure and a higher risk of developing chronic kidney disease (CKD) (odds ratio (OR) = 1.73, 95% confidence interval (CI): 1.25, 2.39), a decreased estimated glomerular filtration rate (eGFR) (mean difference (MD) = -10.05, 95% CI: -11.64, -8.46), and increased serum creatinine (Scr) (MD = 0.02, 95% CI: 0.01, 0.03) compared to unexposed individuals. Famine exposure in childhood was associated with decreased eGFR (MD = -9.43, 95% CI: -12.01, -6.84) and increased Scr (MD = 0.03, 95% CI: 0.01, 0.04), but not with CKD (OR = 0.980, 95% CI: 0.53, 1.81). Famine exposure in adolescence and adulthood was associated with decreased eGFR (MD = -20.73, 95% CI: -22.40, -19.06). Evidence certainty was deemed to be of low or extremely low quality. Famine exposure early in life could pose a greater risk of developing renal impairment in adulthood, but this outcome may be driven by uncontrolled age differences between famine-births and post-famine-births (unexposed).

Childhood Adversities and Caregiving for Older Parents: Building Capacity for a Caring Society

OBJECTIVES

This study investigates the relationships between childhood adversities and the provision of informal care for older parents in later life in China.

METHODS

The data came from 4 waves of the China Health and Retirement Longitudinal Study (N = 20,047). Using multilevel logistic regression models, we examined the relationships between adverse experiences in childhood and both the propensity and intensity of caregiving for older parents. Drawing on the regression results, we then estimated the total number of caregivers for older parents in China.

RESULTS

Experiencing 1 additional childhood adversity was associated with a decrease of 8% in the odds of providing informal care (p < .001). The association between childhood adversity and caregiving remained significant after sociodemographic factors and later-life outcomes were controlled for. We estimated that 58.3 million middle-aged adults in China were providing care for parents in 2020. Had people experienced 1 fewer adversity in their childhood, there would have been 2.2 million more caregivers in 2020. Had they experienced 2 fewer adversities, there would have been 3.4 million more caregivers.

DISCUSSION

The factors associated with informal caregiving can be traced back to early-life experiences. To address the shortage of informal care supply, it is crucial to foster a caring culture from the very beginning of human development.

Epigenetic mechanisms linking early-life adversities and mental health

Early-life adversities, whether prenatal or postnatal exposure, have been linked to adverse mental health outcomes later in life increasing the risk of several psychiatric disorders. Research on its neurobiological consequences demonstrated an association between exposure to adversities and persistent alterations in the structure, function, and connectivity of the brain. Consistent evidence supports the idea that regulation of gene expression through epigenetic mechanisms are involved in embedding the impact of early-life experiences in the genome and mediate between social environments and later behavioral phenotypes. In addition, studies from rodent models and humans suggest that these experiences and the acquired risk factors can be transmitted through epigenetic mechanisms to offspring and the following generations potentially contributing to a cycle of disease or disease risk. However, one of the important aspects of epigenetic mechanisms, unlike genetic sequences that are fixed and unchangeable, is that although the epigenetic markings are long-lasting, they are nevertheless potentially reversible. In this review, we summarize our current understanding of the epigenetic mechanisms involved in the mental health consequences derived from early-life exposure to malnutrition, maltreatment and poverty, adversities with huge and pervasive impact on mental health. We also discuss the evidence about transgenerational epigenetic inheritance in mammals and experimental data suggesting that suitable social and pharmacological interventions could reverse adverse epigenetic modifications induced by early-life negative social experiences. In this regard, these studies must be accompanied by efforts to determine the causes that promote these adversities and that result in health inequity in the population.

Cognitive function following early life war-time stress exposure in a cohort of Vietnamese older adults

Although Alzheimer's Disease is a leading cause of death in Vietnam and other post-conflict, low- and middle-income countries, aside from studies of veterans in western populations, research on war-related violence and deprivation as risk factors for cognitive disorders remains sparse. Using data from the Vietnam Health and Aging Study, which relied upon a multistage probability sample of 2447 older adults residing in districts of northern Vietnam differentially exposed to wartime bombing and numerous war-related stressors, this paper investigates associations between early-life war-related stressors and later-life cognitive function in a cohort whose transition to adulthood took place during the American-Vietnam War. Relationships among experiences of severe childhood hunger, war-related violence and environmental hardships, military service, and cognitive function in an analytical sample of 2162 Vietnamese older adults are estimated using quantile regression. Cognitive function is assessed by a modified Mini-Mental State Examination (MMSE) score. Analyses also address posttraumatic stress disorder (PTSD), cardiovascular health, and health behaviors as potential mediators between early life war-related stressors and current cognitive function. Results indicate that experiences of severe hunger in childhood and environmental hardships are associated with poorer cognitive function in older adulthood. PTSD, cardiovascular risk (i.e., hypertension) and disease (i.e., stroke), each of which is heightened by exposure to wartime stressors, are associated with lower cognitive scores. Results suggest that certain war exposures, like involvement in combat duties, are associated with higher cognitive function scores, suggesting that military service either positively selects for cognitive function, or certain forms of service may impart cognitive resilience. Following recent calls to incorporate population-specific stressors to advance explanatory models of cognitive function, these findings suggest that it is critical to assess the enduring scars and resilience of armed conflict in global efforts to understand, prevent, and treat cognitive impairment, Alzheimer's Disease, and related dementias.

Post-traumatic growth in later-life cognitive function? Evidence from the 1976 Great Tangshan Earthquake

OBJECTIVES

This study aimed to explore the long-term impacts of exposure to earthquake in adolescence on later-life cognitive function in China.

METHODS

Data were from the 2015 China Health and Retirement Longitudinal Study (CHARLS). Our analytical sample comprised 4394 participants aged 49 to 78 from two birth cohorts born between 1937 and 1966: exposed cohort during adolescence (born between 1952 and 1966), and non-exposed cohort during adolescence (born between 1937 and 1951). We defined earthquake exposure as the exposure severity of the 1976 Great Tangshan Earthquake (GTE). We selected community environmental characteristics as our key moderators. A difference-in-differences (DID) method was employed to estimate the long-term impact of the GTE on later-life cognitive function.

RESULTS

We found that exposure to the earthquake during adolescence resulted in higher scores of later-life cognitive function (for males: β = 2.18; 95% CI: 0.70-3.66; for females: β = 1.22; 95% CI: 0.11-2.33). For males, this impact was moderated by community environmental characteristics including the old-age allowance program (β = 3.07; 95% CI: 1.94-4.19) and the condition of basic community infrastructures (β = 1.52; 95% CI: 0.84-2.19).

CONCLUSIONS

Our study supports the post-traumatic growth theory. This finding suggest that individuals with early-life traumatic exposure need to be focused on. Additionally, improving the conditions of community infrastructures and establishing a community environment with comfort and security may be pretty important for promoting cognitive function and post-traumatic growth.

Separating Scarring Effect and Selection of Early-Life Exposures With Genetic Data

Causal life course research examining consequences of early-life exposures has largely relied on associations between early-life environments and later-life outcomes using exogenous environmental shocks. Nonetheless, even with (quasi-)randomized early-life exposures, these associations may reflect not only causation ("scarring") but also selection (i.e., which members are included in data assessing later life). Investigating this selection and its impacts on estimated effects of early-life conditions has, however, often been ignored because of a lack of pre-exposure data. This study proposes an approach for assessing and correcting selection, separately from scarring, using genetic measurements. Because genetic measurements are determined at the time of conception, any associations with early-life exposures should be interpreted as selection. Using data from the UK Biobank, we find that in utero exposure to a higher area-level infant mortality rate is associated with genetic predispositions correlated with better educational attainment and health. These findings point to the direction and magnitude of selection from this exposure. Corrections for this selection in examinations of effects of exposure on later educational attainment suggest underestimates of 26-74%; effects on other life course outcomes also vary across selection correction methods.

Association of handgrip strength asymmetry and weakness with functional disability among middle-aged and older adults in China

Background

Little is known about the association of handgrip strength (HGS) asymmetry with functional disability in China. We aimed to examine the individual and combined association of HGS asymmetry and weakness with functional disability among middle-aged and older Chinese adults.

Methods

We included participants aged ≥45 years from two waves of the China Health and Retirement Longitudinal Study (2011 and 2015). HGS weakness was defined as the maximal HGS<28 kg for men and <18 kg for women. HGS asymmetry was measured by dividing the maximal nondominant HGS (kg) by the maximal dominant HGS (kg), with the value <0.90 or >1.10 considered as asymmetry. Functional disability was assessed by activities of daily living (ADL) and instrumental activities of daily living (IADL) and was defined as encountering difficulty in completing one or more ADL/IADL tasks. The logistic regression models were used to explore the association between HGS measures and functional disability.

Results

11 950 (mean age 59.2 ± 9.6 years, 47.9% males) and 7540 (mean age 57.5 ± 8.6 years, 50.1% males) participants were included in the cross-sectional and prospective study, respectively. HGS asymmetry and weakness, individually or simultaneously, were associated with an increased prevalence of functional disability. During the four-year follow-up, 1822 (24.2%) participants had incident functional disability. The separate exposure to HGS asymmetry (odds ratio (OR) = 1.18; 95% confidence interval (CI) = 1.05-1.32) or weakness (OR = 1.59; 95% CI = 1.30-1.95) was independently associated with functional disability. For combined associations, those with both weakness and asymmetry showed the greatest risk of new-onset functional disability (OR = 1.91; 95% CI = 1.45-2.52).

Conclusions

HGS asymmetry and weakness were associated with a higher risk of functional disability. Assessing HGS asymmetry together with weakness may help to better identify those at risk of functional disability to enable early interventions.

Long-term mental health cost of the Great Chinese Famine

The Great Chinese Famine (1959-1961) claimed tens of millions of lives. This study aims to causally examine the long-term mental health cost it imposed on those who survived. To estimate the nationwide total mental health cost, we use a novel dataset to measure the famine intensity of every prefecture-level region, match it to a nationally representative survey, and then identify the long-term effects of the famine on the depression of rural residents then in the early years of their lives. Difference-in-differences estimates reveal that a one-standard-deviation rise in the experienced famine intensity increased a standard measure of depression by about 0.039 and 0.064 if the individual experienced the famine at ages 0-2 and 3-5, respectively. This translates into roughly 7.99 million cases of severe depressive symptoms caused by the famine, which is likely an undercount. Examining the mechanisms behind the large effects, we find that important roles were played by starvation experience and childhood maltreatment, as well as the primary mediators including other health outcomes, economic status, and social relationship. Our findings shed light on how large-scale food security failures impact the mental well-being of the survivors.

The intergenerational legacy of the 1959-1961 Great Chinese Famine on children's cognitive development

We investigate the effect of early exposure to malnutrition on the cognitive abilities of the offspring of survivors in the context of a natural experiment; i.e., the Great Chinese Famine (GCF) of 1959-61. We employ a novel dataset - the China Family Panel Studies (CFPS) - to do so. The paper finds that the cognitive abilities of children whose fathers were born in rural areas during the famine years (1959-1961) were impaired by exposure to the GCF and the negative effect was greater for girls than boys, whereas children whose mothers were born in rural areas during the famine years were not affected. The uncovered gender-specific effect is almost entirely attributable to son preference exhibited in families with male famine survivors.

Intergenerational relationship between parental famine exposure and offspring's obesity risks

BACKGROUND

The intergenerational relationship between parental famine exposure and the obesity risks of offspring has not been well studied.

METHODS

Using a cohort of 3654 respondents whose parents were born between 1950 and 1964 from the national data of the China Family Panel Studies, this study examines the associations between parental exposure to the 1959-1961 Chinese famine and offspring's body mass index (BMI). A cross-sectional difference-in-difference design was used to estimate the effects of parental famine exposures on offspring's BMI by exploiting temporal variations in the duration and period of famine across the parental birth cohorts between 1950 and 1964, and geographical variations in the famine severity at the province level.

RESULTS

After adjusting individual characteristics and province-level fixed effects, we found that parental famine exposures in the preschool and school-age stages were associated with an increased BMI of offspring while there was not a significant association between prenatal famine exposure and offspring's BMI. The stratified analyses further show that the effects of parental famine exposure did not follow the same trajectory in subgroups.

CONCLUSIONS

Famine experiences of parents were associated with increased BMI of offspring, suggesting an intergenerational impact of severe malnutrition on obesity risks.

Daytime napping, biological aging and cognitive function among middle-aged and older Chinese: insights from the China health and retirement longitudinal study

Objective

The complicated association of daytime napping, biological aging and cognitive function remains inconclusive. We aimed to evaluate the cross-sectional and longitudinal associations of daytime napping and two aging measures with cognition and to examine whether napping affects cognition through a more advanced state of aging.

Methods

Data was collected from the China Health and Retirement Longitudinal Study. Napping was self-reported. We calculated two published biological aging measures: Klemera and Doubal biological age (KDM-BA) and physiological dysregulation (PD), which derived information from clinical biomarkers. Cognitive z-scores were calculated at each wave. Linear mixed models were used to explore the longitudinal association between napping, two aging measures, and cognitive decline. Mediation analyses were performed to assess the mediating effects of biological age acceleration on the association between napping and cognition.

Results

Participants aged over 45 years were included in the analyses. Non-nappers had greater KDM-BA and PD [LS means (LSM) = 0.255, p = 0.007; LSM = 0.085, p = 0.011] and faster cognitive decline (LSM = -0.061, p = 0.005)compared to moderate nappers (30-90 min/nap). KDM-BA (β = -0.007, p = 0.018) and PD (β = -0.034, p < 0.001) showed a negative association with overall cognitive z scores. KDM-BA and PD partially mediated the effect of napping on cognition.

Conclusion

In middle-aged and older Chinese, compared to moderate nappers, non-nappers seem to experience a more advanced state of aging and increased rates of cognitive decline. The aging status possibly mediates the association between napping and cognition. Moderate napping shows promise in promoting healthy aging and reducing the burden of cognitive decline in Chinese middle-aged and older adults.

Number of children and cognitive function among Chinese menopausal women: The mediating role of depressive symptoms and social participation

OBJECTIVES

This study examined the association between number of children and cognitive function and its possible hormone and psychosocial pathways in Chinese menopausal women.

METHODS

We analyzed data from the China Health and Retirement Longitudinal Study (CHALRS), including 4803 menopausal women. Ordinary least squares (OLS) regression modeling and structural equation modeling (SEM) were applied to explore the association between number of children and cognitive function and the potential mechanisms.

RESULTS

Overall, the median number of biological children was three among participants. The cognitive function score decreased significantly with increasing numbers of children [β = -0.547, 95 % confidence interval (CI): -0.677, -0.416]. There was a significant interaction between number of children and residence (P = 0.003). Compared with older women with three or less children, women with more than three children had worse cognitive function (β = -0.798, 95 % CI: -1.081, -0.514). Mediation analysis verified that depressive symptoms and social participation partially mediate the associations between the number of children and cognitive function.

LIMITATIONS

First, because of the cross-sectional design, our study was unable to make causal inferences. Second, information about endogenous estrogen exposure was not collected in CHARLS. Third, recall bias may exist due to the use of self-reported data.

CONCLUSION

Our results indicated that a higher number of children is associated with an increased risk for cognitive impairment. We suggest paying special attention to mental and social health among women with multiple children (>3).

Earthquake exposure during adolescence and later-life depressive symptoms: A national cross-sectional survey

Background

This study aimed to examine the association between exposure to the 1976 Great Tangshan Earthquake (GTE) in adolescence and later-life depressive symptoms and to investigate the potential mechanisms underlying this association.

Methods

Data were from the 2015 China Health and Retirement Longitudinal Study (CHARLS). The 10-item short form of the Center for Epidemiologic Studies Depression scale (CESD-10) was chosen to measure depressive symptoms. We used the difference-in-difference (DID) method, binary logistic regression models, and multilevel logistic regression models to explore the association of earthquake exposure during adolescence with later-life depressive symptoms. Additionally, multilevel mediation analysis with structural equation modeling (MMSEM) was conducted to investigate potential mechanisms.

Results

We identified that adolescent exposure to earthquakes was related to a lower risk of depressive symptoms in later life (OR = 0.90, P = 0.019; OR = 0.48, P = 0.031; OR = 0.47, P = 0.034, respectively). However, this significant association was observed only in females (OR = 0.83, P = 0.028; OR = 0.46, P = 0.053; OR = 0.42, P = 0.037, respectively). Moreover, social activity participation played a mediating role in the association between exposure to earthquakes in adolescence and later-life depressive symptoms.

Conclusions

We observed a lower risk of depressive symptoms in later life in survivors of earthquake exposure during adolescence. Further, we found the mediating role of social participation in the association between earthquake exposure in adolescence and later-life depressive symptoms, which gives support for the posttraumatic growth (PTG) theory. Our findings imply that, in order to lower the risk of depression in later life following exposure to a natural disaster in adolescence, it is necessary to take into account the buffering effect of social participation.

Effect of physical activity intervention on cognitive function in China: A cluster randomized trial

INTRODUCTION

Current randomized trial evidence on the effect of physical activity (PA) intervention on cognitive function is scarce and mainly found in well-educated populations, limiting its generalizability. Furthermore, the modification effect of education levels remains understudied. We conducted a cluster randomized trial to evaluate the effects of PA intervention on cognitive function in a general older population, and whether education modifies such effects.

METHODS

Eight villages were randomized to the intervention (four villages, n = 240) or the control (four villages, n = 271). The intervention group received an 8-week multilevel PA intervention based on a socio-ecological model, while the control did not. The intervention has been condensed to three levels with activities occurring at the individual (telephone counseling, printed material, and training sessions), interpersonal (peer group), and community levels (group sharing and coaching). The primary outcome was changes in global cognition (overall cognitive function) measured by the Telephone Interview for Cognitive Status (TICS-10) at 12-month follow-up. Repeated measurements were modeled using the linear mixed model, which assumed that the missing values were missing at random.

RESULTS

The mean age was 70.94 years (standard deviation 5.71) and 55.6% were women. Compared to the control, the orientation improved from baseline at 12-month follow-up (0.24 points [95% confidence interval (CI), 0.03 to 0.46 points; P = 0.03]). Stratified analysis showed that the global cognition and orientation improved at 12-month follow-up among illiterate participants in the intervention (for global cognition, mean difference, 0.57 points [95% CI, 0.03 to 1.10], P = 0.04; for orientation, mean difference, 0.31 points [95% CI, 0.04 to 0.58], P = 0.03).

DISCUSSION

These results confirm the improvements in orientation in older adults, as well as in global cognition and orientation in the illiterate at 12-month follow-up.

Effect modification of socioeconomic status on the association of exposure to famine in early life with osteoporosis in women

BACKGROUND

The present study aimed to explore the effect of modification of socioeconomic status (SES) on the association between famine exposure in early life and osteoporosis in adulthood via the baseline data from the Henan Rural cohort study.

METHODS

A total of 2669 exposed to famine participants were selected from the Henan Rural cohort, and the questionnaires, physical examination and bone mineral density measurement were completed. Specific birth years were used to define five groups: the fetal exposed group, early-childhood exposed group, mid-childhood exposed group, late-childhood exposed group and unexposed group. And the age-matched control group was a combination of the unexposed group and late-childhood exposed group. Multivariable logistic regression models were utilised to analyse the association of famine exposure in early life with osteoporosis in adulthood.

RESULTS

The prevalence rates of osteoporosis of participants exposed to famine during the fetal period, early-childhood, mid-childhood and the age-matched group were 21.67%, 25.76%, 23.90% and 18.14%, respectively. The adjusted odds ratios (95% confidence interval) of participants suffering from famine during the fetal period, early-childhood and mid-childhood versus age-matched group were 1.19 (0.82-1.73), 1.40 (1.04-1.88) and 1.57 (1.16-2.13), respectively. The female participants yielded consistent results. The risk of osteoporosis was higher in more severe famine eara. Moreover, an attenuated effect of early life famine exposure on osteoporosis was observed in female participants with high SES.

CONCLUSIONS

Exposure to famine in early life showed a sex-specific association with an increased risk of osteoporosis in adulthood and the severity of famine may exacerbate this association. In addition, the risk could be modified by SES.

Relationship between digital exclusion and cognitive impairment in Chinese adults

Objective

We aimed to evaluate the relationship between digital exclusion, such as neither mobile payments nor WeChat use, and cognitive impairment in Chinese individuals aged 45 and older.

Methods

A population-based cross-sectional study utilizing data from the fourth national survey of the China Health and Retirement Longitudinal Study (CHARLS). In the fourth wave of CHARLS, 10,325 participants aged 45 and older with complete information were included in this analysis. Self-reported mobile payments and WeChat usage constituted our exposure. Cognitive impairment was the primary outcome. Univariate and multivariate logistic regression were used to assess the relationships between cognitive impairment risk and digital exclusion.

Results

Data were analyzed from 10,325 participants [mean (SD) age, 60.3 (9.1) years; 44.8% women], including 1,232 individuals with cognitive impairment and 9,093 cognitively normal individuals. The overall proportion of users who did not use either mobile payment or WeChat and those who only used WeChat were 81.3 and 6.7%, for cognitively impaired individuals 95.0 and 3.1%, and for cognitively normal individuals 79.5 and 7.2% [neither WeChat nor mobile payments vs. control unadjusted odds ratio (OR), 8.16; P < 0.001; only WeChat use vs. control unadjusted OR, 2.91; P < 0.001]. Participants who did not use either WeChat or mobile payments had an elevated risk for cognitive impairment after adjusting for a number of covariates (neither WeChat nor mobile payments vs. control adjusted OR, 3.48; P < 0.001; only WeChat use vs. control adjusted OR, 1.86; P = 0.021).

Conclusion

Our study reveals a positive correlation between digital exclusion and cognitive impairment in Chinese adults, providing insights for promoting active digital integration among older adults. Further longitudinal research is needed to further validate this hypothesis.

The Association of Age at Diagnosis of Hypertension with Cognitive Decline: the China Health and Retirement Longitudinal Study (CHARLS)

AIM

This study investigated whether an individual's age at diagnosis of hypertension, which is associated with a decline in cognitive performance in the China Health and Retirement Longitudinal Study (CHARLS) participants.

METHODS

Our analysis was based on the CHARLS with baseline data collected between 2011 and 2018. We randomly selected a control participant for each hypertensive participant using propensity score. The cohort comprised 2413 individuals with hypertension and 2411 controls. Participants were divided into three groups as follows: non-hypertension, hypertension diagnose ≥55 years, and hypertension diagnose <55 years. Cognitive performance was measured in both visits and evaluated by the scores of the memory, executive function, and orientation and global cognitive.

RESULTS

After multivariable adjustment, individuals with hypertension diagnosed <55 years had a significantly faster cognitive decline in memory test (β (95% CI, -1.117 [-1.405, -0.83]), orientation test (β (95% CI, -1.273 [-1.348, -1.198]) and global cognitive (β (95% CI, -1.611 [-1.744, -1.478]) compared with the corresponding controls. A longer hypertension duration was associated with worse memory test (β (95% CI, -0.069 [-0.113 to -0.025]). Among treated individuals, blood pressure control at baseline was inversely associated with the decline in orientation test (β (95% CI, -0.659 [-0.939, -0.380]), orientation test (β (95% CI, -0.259[-0.365, -0.153])and global cognitive (β (95% CI, -0.124 [-0.162, -0.086]).

CONCLUSIONS

Our findings suggest that hypertension diagnosed in mid-life is associated with worse cognition compared to late life. Besides, longer duration of diagnosis is associated with worse memory test. In addition to hypertension, pressure control might be critical for the preservation of cognitive function.

High-Sensitivity C-Reactive Protein, Its Change, and Cognitive Function: A National Population-Based Cohort Study

This study aimed to evaluate the associations of baseline high-sensitivity C-reactive protein (Hs-CRP) and its change with subsequent cognitive decline and cognitive impairment. Data for this study were obtained from the China Health and Retirement Longitudinal Study, a national community-based prospective cohort study. Hs-CRP level and cognitive function were measured repeatedly over a 7-year follow-up. Linear mixed models and cox proportional hazard models were used to evaluate the associations. The study comprised 7385 participants (50.67% women, mean age 59.08 ± 8.86 years) with baseline Hs-CRP ranging from 0.03 to 178.10 mg/L (median: 1.01 mg/L, IQR: 0.55-2.11 mg/L). During a median of 5.79 years follow-up, the highest quartile of the Hs-CRP group showed a faster rate of cognitive decline (-0.0053 SD/year, p = 0.006) and a higher risk of cognitive impairment (HR 1.0814, p = 0.044) than those in the lowest quartile. Individuals in the elevated group of Hs-CRP change had a significantly faster cognitive decline (-0.0070 SD/year, p = 0.016) compared with those in the stable group. In this study, significant longitudinal associations between baseline Hs-CRP, elevated Hs-CRP, and long-term cognitive deterioration were observed. Hs-CRP level could perhaps serve as a predictor for cognitive deterioration in middle-aged and older adults.

Exposure in utero to adverse events and health late-in-life: Evidence from China

This paper estimates the effect of in utero exposure to adverse events on late life diabetes, cardiovascular disease risks and cognition deficiency. We merge data on the regional violence during the Cultural Revolution and the excessive death rates during the Chinese Great Famine with data from the China Health and Retirement Longitudinal Study survey. Results show that female babies who were exposed in utero to the famine have higher diabetes risks, while male babies who were exposed to the Cultural Revolution are shown to have lower cognitive abilities.

The regulatory roles of socio-economic status, social and intellectual activity in the relationship between alcohol consumption and cognitive decline trajectory in middle-aged and elderly Chinese: A prospective cohort study

OBJECTIVES

To determine the relationship between alcohol consumption and cognitive decline, and to further explore the potential regulatory role of education, socio-economic status (SES), and social or intellectual activity in this relationship.

METHODS

6197 participants aged 45-75 years with four repeated measures data from 2011 to 2018 were included. A mixed-effect model was used to explore the relationship between alcohol consumption and the rate of change in cognitive decline, a latent class growth mixed model (LCGMM) was applied to determine the potential trajectory of cognitive decline, and finally, the mediating and moderating analyses were used to determine the regulatory effect of all four variables on the relationship between alcohol consumption and potential trajectory.

RESULTS

Compared to never-drinkers, moderate alcohol consumption was a protective factor for overall cognitive function (β = 0.13, 95% CI: 0.04-0.20, p < 0.001), but there was no statistical correlation with the decline rate of cognitive function. And this protective effect was no longer significant after additional adjustments for education, SES, social and intellectual activity. The LCGMM model divided participants into two trajectories, a high-level-to-decline group including 79.75% of participants (quadratic: β [SE]: -0.90 [0.07], p < 0.001), and a low-level-to-decline group including 20.25% participants (linear: β [SE]: -3.05 [0.49], p < 0.001). With the latter as the reference, SES played a reverse regulation role in the harmful effect of heavy drinking on cognitive trajectories (odd ratio [OR] = 0.46, 95% CI: 0.23-0.93, p < 0.05). Social and intellectual activities played a negative mediating role in the harmful effect of alcohol consumption on cognitive trajectories (light: OR = 0.96, p < 0.001; moderate: OR = 0.96, p < 0.001; heavy: OR = 0.97, p < 0.01).

CONCLUSIONS

Alcohol itself has no protective effect on the decline of longitudinal cognitive trajectory. But the regulatory effect of SES, social and intellectual activities slows down the harm of alcohol consumption on the decline of cognitive function.

CLINICAL TRIAL REGISTRATION

The data used in this study are from publicly available databases. They are retrospective cohort studies without any intervention. Therefore, no clinical trial registration has been conducted.

The Long-Term Effect of Famine Exposure on Cognitive Performance: Evidence from the 1959-1961 Chinese Famine

We examined the long-term impact of the 1959-1961 Chinese Famine on the survivors' cognitive performance in this study. Using data from the 2010 China Family Panel Study, our cohort comparison analysis showed that people who experienced the famine in early childhood (aged 1-3) had a lower score on a vocabulary test and that those who were exposed to the famine in utero did not differ from those born after the famine, probably due to positive selection for the in utero survivors. To deal with the problem of the lack of a comparable control group, we further applied a migrant-stayer comparison approach, with data from the 2016 China Family Panel Study and the 2017 Hong Kong Panel Study of Social Dynamics, to examine the effects of famine exposure at different life stages on adult cognition. We compared the people who stayed in Guangdong with the people who crossed the border to Hong Kong before the famine. The results showed that Guangdong stayers who experienced the famine when they were aged 1-18 had worse performance in immediate word recall. The findings suggested that exposure to malnutrition during childhood has long-term adverse effects on cognitive performance.

Windows of Vulnerability: Consequences of Exposure Timing during the Dutch Hunger Winter

Prior research on early-life exposures to famine has established in utero development as a critical period of vulnerability to malnutrition. Yet, previous research tends to focus narrowly on this stage, at the expense of a more comprehensive examination of childhood. As a result, the literature has yet to compare the severity of the consequences of exposure to malnutrition across developmentally salient periods. Such comparison is crucial not only in the magnitude of effects but also in the nature of outcomes. Using a restricted population registry-linked health survey, this study examines the Dutch Hunger Winter to provide a comprehensive examination of the long-term consequences of in utero, infant, childhood, and adolescent exposure to famine. The results show malnutrition leads to heterogeneous effects depending on when the exposure occurs. In utero exposure to malnutrition leads to deleterious conditions in physical health and lower socioeconomic attainment. For older cohorts, results suggest a resilience to the effects of malnutrition on physical health in late life, but a higher vulnerability to socioeconomic stunting. Furthermore, the results suggest important gender differences in the long-term impact of malnutrition. Males consistently show stronger negative consequences across a wider array of conditions.

Is it just a cure? Re-evaluating the effects of prenatal exposure to the Great Chinese Famine on the risk of infectious diseases in adulthood

BACKGROUND

Very limited studies focused on the early-life adversities on infectious diseases. Taking the Great Chinese famine as a natural experiment, this study re-evaluated the long-term effect of prenatal famine exposure on infectious diseases by using nationally representative data.

METHODS

Using difference-in-difference (DID) models, we analyzed 215,216 adults who participated in the Second National Sample Survey on Disability in 2006 across 734 counties of China to detect the effects of prenatal exposure to the Great Chinese Famine on the risk of infectious diseases in adulthood. Infectious diseases were ascertained by using the combination of self-reports or family members' reports and on-site medical diagnosis by experienced specialists, and the severity of famine was measured by the cohort size shrinkage index (CSSI) at the county level.

RESULTS

All DID estimates of the effects of famine on the probability of infectious diseases were insignificant, with a coefficient of 0.0007 (-0.0024, 0.0026) for all participants and coefficients of 0.0001 (-0.0041, 0.0043) and -0.0002 (-0.0036, 0.0033) for males and females, respectively. That is, the famine cohort dwelling in regions with a greater intensity of famine had similar levels of infectious disease risks than the cohorts with post-famine prenatal exposure experience in less affected famine regions. Furthermore, there were no significant famine and post-famine cohort differences in the DID estimates by examining the variations in subgroups with different types of infectious diseases (trachoma, poliomyelitis, tuberculosis, maternal infections and other infectious diseases).

CONCLUSION

No significant impact of prenatal exposure to the Chinese famine was observed on the risk of infectious diseases in adulthood. Famine survivors may be "cured" by the famine and were resilient to adverse environments in their life course because selective mortality may weaken the association between adverse prenatal exposure and later health.

Maternal diet during pregnancy and child neurodevelopment up to age 3.5 years: the nationwide Étude Longitudinale Française depuis l'Enfance (ELFE) birth cohort

BACKGROUND

Dietary guidelines available to pregnant women are made to improve maternal health and fetal development. But their adequacy to sustain offspring neurodevelopment has remained understudied.

OBJECTIVES

We assessed the association between compliance with nutritional guidelines during pregnancy and neurodevelopment in preschool children.

METHODS

The analyses were based on data for 6780 to 11,278 children from the Étude Longitudinale Française depuis l'Enfance (ELFE) study, a nationwide birth cohort. Maternal diet during the last 3 mo of pregnancy was evaluated at delivery by using a validated 125-item FFQ. From this FFQ, food group consumption, a diet quality score (adapted National Health and Nutrition Program Guideline Score), and a nutrient intake score (Probability of Adequate Nutrient intake based Diet quality index) were calculated and dietary patterns were derived by principal component analysis. Child neurodevelopment was reported by parents at 1 and 3.5 y with the Child Development Inventory (CDI-1, CDI-3.5) and at 2 y with the MacArthur-Bates Communicative Development Inventories (MB-2), and assessed by a trained investigator at 3.5 y with the Picture Similarities test (British Ability Scales, PS-3.5). Associations between maternal diet and child neurodevelopment were assessed by multivariable linear regression models on standardized variables.

RESULTS

Higher nutrient intake score was associated with higher neurodevelopmental scores from 1 to 3.5 y (β = 0.04; 95% CI: 0.02, 0.06 for CDI-1; β = 0.03; 95% CI: 0.01, 0.05 for MB-2; and β = 0.03; 95% CI: 0.01, 0.05 for CDI-3.5). Higher fruit and vegetables or fish intake and lower pork-meat products intake were related to higher CDI-3.5 scores (β = 0.03; 95% CI: 0.01, 0.05 for fruit and vegetables; β = 0.03; 95% CI: 0.01, 0.05 for fish; and β = -0.02; 95% CI: -0.04, 0.00 for pork-meat products). A higher score on the processed food pattern was associated with poorer neurodevelopmental score at 1 y (β = -0.05; 95% CI: -0.06, -0.03).

CONCLUSIONS

Higher diet quality during pregnancy was associated with higher parent-reported neurodevelopmental scores in early childhood. The negative association of pork-meat products consumption with early neurodevelopmental scores needs to be further confirmed.

The Influence of Alcohol Consumption, Depressive Symptoms and Sleep Duration on Cognition: Results from the China Health and Retirement Longitudinal Study

AIM

Healthy cognition-related factors include alcohol consumption, depressive symptoms, and sleep duration. However, less is known about the role of these factors in the dyad or tripartite relationships. In this study, we examined whether there were potential mediation effects, moderation effects, and interactions between these factors in the longitudinal study.

METHODS

Both cross-sectional data analysis and a longitudinal study were performed using baseline and 2018 data from the China Health and Retirement Longitudinal Study (CHARLS) cohort. CHARLS is a nationwide survey program covering 450 villages and 150 counties in 28 provinces that aims to investigate comprehensive demographic information. After selecting participants from the CHARLS cohort, 15,414 were included in the study. Non-drinkers, those who drink more than once a month, and those who drink less than once a month were defined by their alcohol consumption. Depressive symptoms were defined as nondepressed (less than or equal to 12) and depressed (more than 12). Sleep duration was defined as 7-8 h per night, ≤6 h per night, and ≥9 h per night. The total cognitive scores were calculated from memory, orientation, and executive tests. The PROCESS macro in SPSS was used to analyze all mediations and moderating mediations.

RESULTS

Alcohol consumption has a positive correlation with cognition. The global cognition z scores of participants with depressive symptoms were significantly lower than those of the control (all p's < 0.001), in different models. The memory score (β: -0.148; 95% CI: -0.240 to -0.056; p = 0.002), the executive score (β: -0.082; 95% CI: -0.157 to -0.006; p = 0.033), and the global cognition score (β: -0.105; 95% CI: -0.187 to -0.023; p = 0.012) of participants defined as ≤6 h per night were, obviously, less than the control (7-8 h per night). An association between depression and alcohol consumption has been found, and the protective effects have been reversed by depression, which caused the cognition decline. Sleep duration was identified as a moderator, influencing the relationship between depressive symptoms and cognitive function. Besides, there was an interaction causing cognition decline among alcohol consumption, depressive symptoms, and sleep duration. Cognitive function showed a marked downward trend with increasing age.

CONCLUSIONS

In this model, depression primarily mediates the relationship between alcohol consumption and cognition, and sleep duration changes the mediation effect. Furthermore, there is a significant interaction between alcohol consumption, depressive symptoms, and sleep duration, which are significantly associated with cognitive function.

Early life environments and cognition in adulthood: New evidence using a semiparametric approach and quantile regression

Theories and empirical evidence document the importance of early life environmental factors on later life cognition. A next question is how and in what dimension associations between early life environments and later life cognition vary. Using data from the UK Biobank in conjunction with time-place-specific infant mortality rates, we assessed heterogeneous and non-linear associations between early life conditions and later life cognition. We found that the association between the infant mortality rate and later life cognition increased once the UK achieved very low infant mortality rates, suggesting that additional decreases in infant mortality rates in an industrialized society continue to improve later life cognition. We also found that infant mortality rates have stronger effects at upper quantiles of the cognition distribution. This implies that adverse early life environments may have an important role for an early manifestation of cognitive aging.

Early-Life Exposure to the Chinese Famine of 1959-1961 and Type 2 Diabetes in Adulthood: A Systematic Review and Meta-Analysis

BACKGROUND

The fast-growing literature suggests that the Chinese famine of 1959-1961 drives current and future type 2 diabetes (T2D) epidemics in China. This conclusion may be premature, as many Chinese famine studies have major methodological problems. We examine these problems, demonstrate how they bias the study results, and formulate recommendations to improve the quality of future studies.

METHODS

We searched English and Chinese databases for studies that examined the relationship between prenatal exposure to the Chinese famine and adult T2D from inception to 8 February 2022. We extracted information on T2D cases and study populations of individuals born during the famine (famine births), before the famine (prefamine births), and after the famine (postfamine births). We used random-effects models to compare the odds of T2D in famine births to several control groups, including postfamine births, combined pre- and postfamine births, and prefamine births. We used meta-regressions to examine the impacts of age differences between comparison groups on famine effect estimates and the role of other characteristics, including participant sex, age, and T2D assessments; famine intensity; residence; and publication language. Potential sources of heterogeneity and study quality were also evaluated.

RESULTS

Twenty-three studies met our inclusion criteria. The sample sizes ranged from less than 300 to more than 360,000 participants. All studies defined the famine exposure based on the participants' dates of birth, and 18 studies compared famine births and postfamine births to estimate famine effects on T2D. The famine and postfamine births had an age difference of three years or more in all studies. The estimates of the famine effect varied by the selection of controls. Using postfamine births as controls, the OR for T2D among famine births was 1.50 (95% CI 1.34-1.68); using combined pre- and postfamine births as controls, the OR was 1.12 (95% CI 1.02-1.24); using prefamine births as controls, the OR was 0.89 (95% CI 0.79-1.00). The meta-regressions further showed that the famine effect estimates increased by over 1.05 times with each one-year increase in ignored age differences between famine births and controls. Other newly identified methodological problems included the poorly assessed famine intensity, unsuitable study settings for famine research, and poor confounding adjustment.

INTERPRETATION

The current estimates of a positive relationship between prenatal exposure to the Chinese famine and adult T2D are mainly driven by uncontrolled age differences between famine births and postfamine births. Studies with more rigorous methods, including age-balanced controls and robust famine intensity measures, are needed to quantify to what extent the famine exposure is related to current T2D patterns in China.

Afternoon Napping Durations in Chinese Population Over 60 Years Old: Longitudinal Associations With Cognitive Performance

Introduction

Previous studies indicated inconsistent associations between daytime napping and cognitive decline. This study aimed to examine the associations between self-reported changes in napping and longitudinal cognitive performance.

Methods

A national representative sample of 4,024 participants over 60 was obtained from the China Health and Retirement Longitudinal Study from 2011 to 2018. Afternoon napping and potential factors were collected by a questionnaire. Cognitive performance was assessed on three aspects. The generalized additive models and generalized estimating equations were used to examine relationships between daytime napping and longitudinal global cognition, and generalized linear models were used to examine the longitudinal associations between change in napping at four waves and cognition in wave 4.

Results

After controlling the potential confounders, participants with afternoon napping were significantly related to better global cognition than no nappers at baseline. A change from short napping to no/long napping was associated with worse cognitive performance (β = −2.593, P < 0.001). A move from no napping to short/long napping was also associated with lower cognition scores (β = −0.694, P < 0.001). For participants with moderate napping, a >30 min increase (β = −1.558, P < 0.001) in afternoon napping was associated with worse cognitive function in wave 4.

Conclusion

We observed that adults over 60 years old with napping <30 min per day may be at lower risk of cognitive decline. Change in napping, especially a move to extreme napping would be a risk marker underlying health conditions that impact cognition or go along with cognitive decline.

Dyadic effects on depressive symptoms of spouse caregivers and their care recipients: evidence from China

OBJECTIVES

The likelihood of providing care to a spouse in middle and older ages has increased as life expectancy increases, but knowledge about how the caregiver and care recipient influence each other's mental health is limited. This study examined whether a partner's physical, cognitive, and mental health in a spousal caregiving dyad are associated with the other partner's depressive symptoms in China and whether the dyadic effects vary by gender.

METHODS

This study used data from Wave 3 (2015) and Wave 4 (2018) follow-up surveys of the China Health and Retirement Longitudinal Study (CHARLS). The analytic sample featured 1,245 dyads of care recipients aged 45 or older and their spouse caregivers. The Actor-Partner Interdependence Model was used to test the dyadic effects among all couples in the analytic sample, couples with wife caregivers and couples with husband caregivers, respectively.

RESULTS

We found that caregiver's depressive symptoms at Wave 3 were significantly associated with care recipient's depressive symptoms at Wave 4 in the full sample. Regardless of caregiver or care recipient roles, wives' mental health was impacted by their husbands' depressive symptoms, but not vice versa. Wife recipient's cognitive impairment was associated with husband caregiver's lower depressive symptoms.

CONCLUSION

This study sheds light on the mental health of couples in the context of caregiving in China. The findings indicate that interventions to support couples in a caregiving dyad need to consider the influence they have on each other, and the gender and health conditions of each in the dyad.

The association between undiagnosed diabetes and cognitive function: findings from the China health and retirement longitudinal study

BACKGROUND

The cognitive function of people with diabetes has gained an increasing interest in recent years, and this study focuses on exploring the relationship between undiagnosed diabetes and cognitive function among the middle-aged and elderly people in China.

METHODS

The data came from the China Health and Retirement Longitudinal Study (CHARLS) which was conducted between July and October 2015. 9855 subjects were enrolled in the study. Executive function and episodic memory were used to assess cognitive function. The subjects were divided into three groups: no diabetes, diagnosed diabetes, and undiagnosed diabetes, and weighted multiple linear regression models were established to evaluate the association of undiagnosed diabetes with cognitive function.

RESULTS

After controlling for covariates, undiagnosed diabetes was statistically associated with executive function (β = -0.215, P < 0.01). In the age group of ≥65 years, undiagnosed diabetes was statistically associated with executive function (β = -0.358, P < 0.01) and episodic memory (β = -0.356, P < 0.01). When adjusting for confounders, no statistically significant associations were found between diagnosed diabetes and cognitive function except in 45-54 age group (β = 0.374, P < 0.05).

CONCLUSIONS

The cross-sectional study suggested that undiagnosed diabetes was linked to poor cognitive function, especially in the elderly population. Timely diagnosis and active treatment of diabetes are important to reduce the occurrence of cognitive impairment. Further prospective cohort studies are required to articulate the association between undiagnosed diabetes and cognitive function.

A Multilevel Physical Activity Intervention Among Chinese Rural Older Adults (Stay Active While Aging): A Study Protocol for a Clustered Randomized Controlled Trial

Background

Although a large number of studies have confirmed the benefits of physical activity (PA) in preventing age-related diseases and disabilities, a growing number of older people spent more time in sedentary behavior as opposed to PA. To reverse the alarming trend, numerous studies have corroborated the effectiveness of PA interventions in improving PA among older adults. However, such research is scarce in rural China, where a majority of older adults do not meet the PA recommendation. The Stay Active While Aging (SAWA) aimed to conduct an intervention to improve the PA level among older adults in rural China.

Methods

The SAWA is designed as a single-blind, clustered randomized controlled trial carried out in rural Sichuan, China with an 8-week intervention and a 24-month follow-up. The intervention group will receive a multilevel intervention (individual, interpersonal, and community levels), while the control group will not. The primary outcome is the PA level. Secondary outcome measures include sedentary behavior level, self-efficacy, self-regulation, cognitive function, night-time sleep quality, and anthropometry. The difference-in-differences (DID) will be performed to investigate the between-group differences, adjusted for baseline data and covariates.

Discussion

The SAWA trial will provide a multilevel intervention based on the socio-ecologic model among older adults in rural China. We target the PA level and health status changes while also focus on the maintenance of such intervention during 24 months. If the SAWA produces positive results, it will be possible to recommend similar strategies to be implemented in other Chinese older adults and beyond.

Trial registration

ChiCTR2100045653 (https://www.chictr.org.cn/index.aspx).

Early-life exposure to Chinese famine and stroke risk in mid- to late life: the mediating roles of cognitive function and depression

BACKGROUND

Limited research has examined the role that famine exposure plays in adulthood stroke risk. We aim to explore the causal implications of early exposure to the Great Chinese Famine on stroke risk and determine whether these associations were mediated by cognitive function, and depression.

METHODS

We sampled 12,681 individuals aged 45 years and older from the China Health and Retirement Longitudinal Study (CHARLS) and divided them into fetally exposed, childhood-exposed, adolescence/adulthood-exposed and unexposed groups. Stroke was defined by self- or proxy-reported physician diagnosis. Based on a counterfactual framework, marginal structural models were used to estimate the natural direct effect and the natural indirect effects through cognitive function and depression for causal inference.

RESULTS

We found that early-life exposure to Chinese famine was directly related to increased stroke risk in mid- to late life. Cognitive function and depression accounted for a greater part of the effect for childhood famine exposure, mediating 36.35% (95%CI: 14.19, 96.19%) of the overall association between famine exposure and incident stroke, than for the fetal, adolescence/adulthood famine exposure groups. However, the natural indirect effect through depression was not significant in the fetally exposed group. The results were robust in the sensitivity analysis of model specification and unobserved confounding.

CONCLUSIONS

Our findings are consistent with the latency, pathway, and accumulation models, supporting the life-course theory. Early stages of life exposed to the Chinese Famine were associated with higher risk of stroke in mid- to late life. Enhanced cognitive and depression interventions may reduce stroke risk in middle-aged and older Chinese adults who exposure to famine in early life.

The Effect of Prenatal Exposure to Climate Anomaly on Adulthood Cognitive Function and Job Reputation

Background: The long-term effect of abnormal climate on cognitive function and socioeconomic status remains elusive. We explored the association between prenatal exposure to climate anomaly and adulthood cognitive function and job reputation. Methods: We obtained repeated cognitive and job reputation measurements from 17,105 subjects for the years 2010, 2014, and 2018, and ascertained their birth date and other covariates. We used sea surface temperature (SST) anomalies in the Southern Pacific Ocean as the indicator for global climate anomaly in the main analyses. We calculated its averaged values for different gestational periods and analyzed its possible nonlinear associations with adulthood cognitive function and job reputation. We also calculated associated economic loss due to prenatal exposure to abnormal climate. Results: We found an inverted U-shaped curve between climate anomaly and adulthood cognition. During the entire pregnancy, for SST anomalies increasing/decreasing 1 °C from 0 °C, newborn individuals will have adulthood cognition (measured by math test) changed by −2.09% (95% confidence interval (CI): −2.31%, −1.88%) and −3.98% (95% CI: −4.32%, −3.65%), respectively. We observed a similar inverted U-shaped pattern for cognitive function measured by word test and job reputation. Such an association is likely to be mediated by regional meteorological conditions, not local ones. Subgroup analyses identified females and people from less-developed regions as even more vulnerable to prenatal abnormal climate, finding an interactive effect with other social factors. The economic loss was assessed as the salary reduction due to declined cognition among all newborn individuals in China. For SST anomalies increasing/decreasing by 1 °C from 0 °C, individuals born each year in China would earn 0.33 (95% CI: 0.40, 0.25) and 1.09 (95% CI: 1.23, 0.94) billion U.S. dollars equivalent less in their annual salary at adulthood because of lowered cognitive function, respectively. Conclusion: Prenatal exposure to abnormal global climate patterns can result in declined adulthood cognitive function, lowered job reputation, and subsequent economic loss.

Intergenerational effects of early-life health shocks during the Chinese 1959–1961 famine

A large literature has examined early-life insult and later-life health outcomes. However, whether early-life exposure might persist into the outcomes of future generations remains unclear. Using data from the China Family Panel Studies, this study examines the intergenerational effects of early-life health shocks during the great famine in China, distinguishes the intergenerational effects of in utero and early-life famine exposure, and estimates whether there is a sex-specific transgenerational response. Difference-in-difference results show that first-generation male in utero famine exposure (1959–1961) is associated with a series of health and economic disadvantages in the second generation, compared with the unexposed post-famine-born cohort (1964–1965) in China. The effect persists in the third generation but attenuates, and there is no same-sex transgenerational response. These findings may suggest a novel source of multigenerational persistence in health and economic poverty and may point to a need to consider evidence of transgenerational mechanisms.

Catch-up growth in juvenile rats, fat expansion, and dysregulation of visceral adipose tissue

BACKGROUND

Accelerated catch-up growth following intrauterine restriction increases the risk of developing visceral adiposity and metabolic abnormalities. However, the underlying molecular mechanisms of such metabolic programming are still poorly understood.

METHODS

A Wistar rat model of catch-up growth following intrauterine restriction was used. A gene expression array was performed in the retroperitoneal adipose tissue sampled at postnatal day (PD) 42.

RESULTS

Five hundred and forty-six differentially expressed genes (DEGs) were identified (adjusted p value < 0.05). Gene ontology enrichment analysis identified pathways related to immune and lipid metabolic processes, brown fat cell differentiation, and regulation of PI3K. Ccl21, Npr3, Serpina3n, Pnpla3, Slc2a4, and Serpina12 were validated to be upregulated in catch-up pups (all p < 0.01) and related to several fat expansion and metabolic parameters, including body weight at PD42, postnatal body weight gain, white and brown adipose tissue mass, plasma triglycerides, and insulin resistance index (all p < 0.05).

CONCLUSIONS

Genes related to immune and metabolic processes were upregulated in retroperitoneal adipose tissue following catch-up growth in juvenile rats and were found to be associated with fat expansion and metabolic parameters. Our results provide evidence for several dysregulated genes in white adipose tissue that could help develop novel strategies to prevent the metabolic abnormalities associated with catch-up growth.

IMPACT

Catch-up growth presents several dysregulated genes in white adipose tissue related to metabolic abnormalities. Ccl21, Npr3, Serpina3n, Pnpla3, Slc2a4, and Serpina12 were validated to be upregulated in catch-up pups and related to visceral fat expansion and metabolic parameters. Profiling and validation of these dysregulated genes in visceral adipose tissue could help develop novel strategies to prevent the metabolic abnormalities associated with catch-up growth.

Association of famine exposure and the serum calcium level in healthy Chinese adults

OBJECTIVE

Famine exposure and higher serum calcium levels are related with increased risk of many disorders, including Alzheimer's disease, atherosclerosis, diabetes, and osteoporosis. Whether famine exposure has any effect on serum calcium level is unclear. Besides, the normal reference range of serum calcium is variable among different populations. Our aims are 1) determining the reference interval of calcium in Chinese adults; 2) exploring its relationship with famine exposure.

METHODS

Data in this study was from a cross-sectional study of the epidemiologic investigation carried out during March-August 2010 in Jiading district, Shanghai, China. Nine thousand and two hundred eleven participants with estimated glomerular filtration rate (eGFR) ≥60ml/min/1.73m² were involved to calculate reference interval of total calcium from 10569 participants aged 40 years or older. The analysis of famine exposure was conducted in 9315 participants with complete serum biochemical data and birth year information.

RESULTS

After rejecting outliers, the 95% reference interval of total serum calcium was 2.122~2.518 mmol/L. The equation of albumin-adjusted calcium was: Total calcium + 0.019* (49-Albumin), with a 95% reference interval of 2.151~2.500 mmol/L. Compared to the age-balanced control group, there was an increased risk of being at the upper quartile of total serum calcium (OR=1.350, 95%CI=1.199-1.521) and albumin-adjusted calcium (OR=1.381, 95%CI=1.234-1.544) in subjects experienced famine exposure in childhood. Females were more vulnerable to this impact (OR= 1.621, 95%CI= 1.396-1.883 for total serum calcium; OR=1.722, 95%CI= 1.497-1.980 for albumin-adjusted calcium).

CONCLUSIONS

Famine exposure is an important environmental factor associated with the changes in circulating calcium concentrations, the newly established serum calcium normal range and albumin-adjusted calcium equation, together with the history of childhood famine exposure, might be useful in identifying subjects with abnormal calcium homeostasis and related diseases, especially in females.

Chinese famine exposure in early life and metabolic obesity phenotype in middle age: Results from the China health and retirement longitudinal study

OBJECTIVE

To assess the association between early life exposure to famine and the risk of metabolic obesity phenotypes among adults in middle age.

METHODS

The study selected two comparison groups. Comparison A consisted of a non-exposed group born between 1963-1965 from the China Health and Retirement Longitudinal Study (CHARLS) 2015 wave (N=862) and a fetal-exposed group born between 1959-1961 from the 2011 wave (N=507). Comparison B consisted of an early childhood-exposed group born between 1955-1957 from the 2011 wave (N=830) and a fetal-exposed group born between 1959-1961 from the 2015 wave (N=552). Multivariable logistic regressions were conducted to explore the associations between different periods of famine exposure and obesity, metabolic health status, and metabolic obesity phenotypes, with stratification by sex.

RESULTS

Compared with the non-exposed group, participants exposed to famine in the fetal period had a significantly lower risk of overweight/obesity (OR: 0.78, 95%CI: 0.63-0.97) and a higher risk of metabolically unhealthy status (OR: 1.73, 95%CI: 1.34-2.23) and metabolically unhealthy non-obesity (MUNO) (OR: 2.12, 95%CI: 1.46-3.08) at the age of 50-52 years. In the sex-stratified analysis, males exposed to famine in the fetal period had a significantly lower risk of overweight/obesity (OR: 0.59, 95%CI: 0.43-0.80) and metabolically healthy obesity (MHO) (OR: 0.56, 95%CI: 0.37-0.85), while such associations were not found in females. Compared with the early childhood exposure group, participants in the fetal exposure group had a significantly lower risk of metabolic unhealthy status (OR: 0.65, 95%CI: 0.51-0.85) and MUNO (OR: 0.50, 95%CI: 0.35-0.72). Those associations were observed in both males and females.

CONCLUSION

Exposure to famine in early life increased the risk of metabolically unhealthy status in adulthood. Different metabolic subtypes should be identified at an early stage and followed by classification, intervention, and treatment.

The association between water source and depressive symptoms in China: A cross-sectional and longitudinal study

BACKGROUND

This study investigates the associations between residential water sources and symptoms of depression and the relationships between switching residential water sources and symptoms of depression in middle-aged and elderly people in China.

METHODS

The cross-sectional study included 12,713 participants and the longitudinal study included 8,286 participants. Symptoms of depression were evaluated using the Center for Epidemiologic Studies Depression Scale. Multiple logistic and Cox regression analyses were used to identify associations between water sources and symptoms of depression.

RESULTS

Participants without tap water were more likely to have depressive symptoms than participants with tap water (odds ratio (OR): 1.30; 95% confidence interval (CI): 1.19-1.42) (hazard ratio (HR): 1.18; 95% CI: 1.09-1.28). The lack of access to tap water in residence was positively related to the prevalence and incidence of symptoms of depression in almost all subgroups. Changing the water source from non-tap to tap water decreased the risk of depressive symptoms (HR: 0.69; 95% CI: 0.60 - 0.79).

LIMITATIONS

The results may not be generalizable to the whole population.

CONCLUSIONS

These results suggest that no tap water in residence is a risk factor for depressive symptoms. Therefore, providing tap water in residence may help prevent depression.

What doesn't kill you makes you "smarter": The long-term association between exposure to epidemic and cognition

Emerging epidemics have devastating impacts on people's lives and livelihoods. However, acting as a severe health shock, exposure to an epidemic may induce positive changes in health behaviors among survivors, thereby leading to long-lasting improvement in population health. This study examined the long-term association between exposure to the 2002-2004 severe acute respiratory syndrome outbreak and middle-aged and older Chinese adults' cognition assessed in 2011-2015. Drawing on data from the 2011-2015 China Health and Retirement Longitudinal Study, we found that community exposure to the outbreak was associated with significantly higher scores on episodic memory, after adjusting for demographic characteristics, adulthood socioeconomic status and health, and community socioeconomic conditions. No such a significant association was found for mental intactness. Mediation analysis showed that community exposure to the epidemic was associated with increased participation in social activities, maintaining close family relationships with adult children and grandchildren, and increased participation in regular physical exercise, all of which were positively associated with cognitive functioning in middle-aged and older Chinese adults. These findings suggest that positive post-epidemic behavioral changes are possible and may have long-term health benefits for survivors.

What doesn't kill her, will make her depressed

In this paper we study the long run effects of the 1959-61 Chinese Famine on mental health outcomes. We focus on cohorts that were born during the famine and examine their mental health as adults, when they are roughly 55 years of age. We find that early-life exposure to this famine leads to a large statistically significant negative impact on women's mental health, while there is limited effect on men. This gender differential effect is observed because male fetuses experience a stronger natural selection as compared to female fetuses, which implies that in the longer run, surviving females may exhibit larger detrimental effects of early-life famine exposure. Thus, the observed effects are a composite of two well-established factors, the survival of the fittest and the Fetal Origins hypothesis.

Different hypertension thresholds and cognitive decline: a pooled analysis of three ageing cohorts

BACKGROUND

The 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for high blood pressure (BP) in adults came up with a new definition of hypertension with a threshold BP level of 130/80 mmHg. But the 2018 European Society of Cardiology (ESC)/European Society of Hypertension (ESH) guidelines adhered to a conventional hypertension definition as BP ≥ 140/90 mmHg. We aimed to compare the trajectories of cognitive decline between participants with BP < 130/80 mmHg in all BP measurement waves and others with all BP < 140/90 mmHg.

METHODS

This pooled analysis involved middle-aged and older participants from three nationally representative ageing cohorts, including the Health and Retirement Study (HRS), the English Longitudinal Study of Ageing (ELSA), and the China Health Retirement Longitudinal Study (CHARLS). Participants were divided into the Normal (BP < 130/80 mmHg on all occasions throughout the study), the Borderline (BP < 140/90 mmHg on all occasions throughout the study but not in the Normal group), and the High (the rest of participants) BP groups. Global cognitive Z score was calculated from tests on memory, executive function, and orientation.

RESULTS

A total of 17,590 participants (HRS 6964, median follow-ups 12 years; ELSA 5334, median follow-ups 16 years; CHARLS 5292, median follow-ups 7 years) were included. No significant difference in global cognitive decline rate was detected between the Normal and the borderline groups (men, pooled β = - 0.006 standard deviation [SD]/year; 95% confidence interval [CI], - 0.020 to 0.008; P = 0.377; women, pooled β = 0.006 SD/year; 95% CI - 0.005 to 0.018; P = 0.269). Participants in the High group had a significantly faster cognitive decline (men, pooled β = - 0.011 SD/year; 95% CI - 0.020 to - 0.002; P = 0.013; women, pooled β = - 0.017 SD/year; 95% CI - 0.026 to - 0.008; P < 0.001) than that in the Borderline group.

CONCLUSIONS

Individuals in the Borderline group did not experience significantly faster cognitive decline compared with those in the Normal group. It might not be necessary for individuals with borderline BP (between 130/80 and 140/90 mmHg) to initiate antihypertension therapy in consideration of cognitive decline.

Low-to-Moderate Alcohol Intake Associated with Lower Risk of Incidental Depressive Symptoms: A Pooled Analysis of Three Intercontinental Cohort Studies

BACKGROUND

The existing findings of the longitudinal impact of low-to-moderate drinking on symptomatic depression were controversial, as results ranged from finding no association to finding both a protective and adverse association.

METHODS

The present study examined the association between low-to-moderate alcohol consumption and incident depressive symptoms by pooled analysis of three European, American and Chinese representative samples of middle-aged and older adults.

RESULTS

A total of 29,506 participants (55.5% female) were included. During 278,782 person-years of follow-up, we found that subjects with low-to-moderate drinking had a significantly lower incidence of depressive symptoms compared to never-drinking subjects, with pooled hazard ratios of 0.87 (95% confidence interval [CI]: 0.79-0.96) for men and 0.87 (95% CI: 0.80-0.95) for women, whereas heavy drinkers failed to show significantly higher risk of depressive symptoms. Furthermore, a J-shaped relation between alcohol consumption and incident depressive symptoms was identified in Chinese men, US men, and UK men and women.

LIMITATIONS

The classification of depressive symptoms based on the Center for Epidemiologic Studies Depression Scale may not be completely comparable to diagnosis from a clinical setting.

CONCLUSIONS

Low-to-moderate alcohol consumption was significantly associated with a lower risk of depressive symptoms on a long-term basis compared to never drinking. Our results support the threshold of moderate drinking in current US guidelines. However, caution should be exercised in engaging in guideline-concordant drinking habits, for even moderate drinkers are at risk of developing heavy drinking habits and experiencing future alcohol-related problems.

Risk of cognitive impairment in children after maternal exposure to the 1998 Yangtze River flood during pregnancy: analysis of data from China's second National Sample Survey on Disability

BACKGROUND

More research is needed to understand the long-term effects of prenatal exposure to adverse events, such as floods and other natural disasters, on cognitive outcomes in childhood. We aimed to explore the risk of cognitive impairment in children following maternal exposure to the 1998 Yangtze River flood in China during pregnancy.

METHODS

For this study we obtained and analysed individual-level data from the second China National Sample Survey on Disability (CNSSD), which was done in 2006. We defined the flood period as June-August, 1998. The analytical sample comprised children from four birth cohorts, defined according to their month of birth: the post-partum exposed cohort (children born between June, 1997, and May, 1998), the prenatal exposed cohort (children born between June, 1998, and May, 1999), the preconception exposed cohort (children born between June 1999, and May, 2000), and the unexposed cohort (children born between June, 2000, and May, 2001). In the CNSSD, cognitive impairment was assessed and diagnosed by validated screening tools and procedures. Difference-in-difference models were used to examine variations in the effects of maternal flood exposure on cognitive impairment in childhood across the different birth cohorts and regions.

FINDINGS

108 175 children born between June, 1997, and May, 2001, and aged 4-8 years at the time of the survey, were included in our analysis. 1131 children had a cognitive impairment; the prevalence of cognitive impairment was 1·05% (95% CI 0·99-1·11). Maternal exposure to flood during pregnancy increased the risk of cognitive impairment among children (adjusted odds ratio [OR] 2·18 [95% CI 1·54-3·08]; p<0·0001). No significant sex-specific differences were observed, and the risk of cognitive impairment was especially high when maternal flood exposure occurred during the first trimester of pregnancy (adjusted OR 5·05 [95% CI 3·88-6·58]; p<0·0001). The risk of cognitive impairment also increased with longer durations of maternal flood exposure and with increasing severity of flooding; the risk was highest in the prenatal exposed cohort with 3 months of flood exposure in the most severely affected area (adjusted OR 5·56 [95% CI 1·58-19·54]; p=0·007).

INTERPRETATION

Prenatal flood exposure had a long-term negative effect on cognitive development of children. Greater maternal support and public health interventions during pregnancy and early life after a natural disaster are warranted to facilitate healthy cognitive development in later life.

FUNDING

National Social Science Foundation of China.

Prenatal and early-life exposure to the Great Chinese Famine increased the risk of tuberculosis in adulthood across two generations

Global food security is a major driver of population health, and food system collapse may have complex and long-lasting effects on health outcomes. We examined the effect of prenatal exposure to the Great Chinese Famine (1958-1962)-the largest famine in human history-on pulmonary tuberculosis (PTB) across consecutive generations in a major center of ongoing transmission in China. We analyzed >1 million PTB cases diagnosed between 2005 and 2018 in Sichuan Province using age-period-cohort analysis and mixed-effects metaregression to estimate the effect of the famine on PTB risk in the directly affected birth cohort (F1) and their likely offspring (F2). The analysis was repeated on certain sexually transmitted and blood-borne infections (STBBI) to explore potential mechanisms of the intergenerational effects. A substantial burden of active PTB in the exposed F1 cohort and their offspring was attributable to the Great Chinese Famine, with more than 12,000 famine-attributable active PTB cases (>1.23% of all cases reported between 2005 and 2018). An interquartile range increase in famine intensity resulted in a 6.53% (95% confidence interval [CI]: 1.19-12.14%) increase in the ratio of observed to expected incidence rate (incidence rate ratio, IRR) in the absence of famine in F1, and an 8.32% (95% CI: 0.59-16.6%) increase in F2 IRR. Increased risk of STBBI was also observed in F2. Prenatal and early-life exposure to malnutrition may increase the risk of active PTB in the exposed generation and their offspring, with the intergenerational effect potentially due to both within-household transmission and increases in host susceptibility.