Why does the Great Chinese Famine affect the male and female survivors differently? Mortality selection versus son preference

Early-life famine exposure and risk of osteoporosis and low bone mineral density: a systematic review and meta-analysis

BACKGROUND

Early-life exposure to famine has been hypothesized to influence long-term bone health, potentially increasing the risk of osteoporosis and fractures in later life. This systematic review and meta-analysis aimed to investigate the association between early-life famine exposure and the risk of osteoporosis, bone mineral density (BMD) loss, and fractures.

METHODS

A comprehensive literature search was conducted across MEDLINE/PubMed, Scopus, Web of Science, and Embase, supplemented by manual searches on Google Scholar. Observational studies examining the impact of early-life famine exposure on osteoporosis, BMD, and fracture risk were included. Data were extracted and quality assessed independently by two reviewers, and meta-analyses were performed using the Mantel-Haenszel method for odds ratios (OR) and Hedges' g for standardized mean differences (SMD). Heterogeneity was assessed using the I2 statistic, and meta-regression analyses were conducted to explore potential sources of heterogeneity.

RESULTS

From 6147 initial studies, 10 met the inclusion criteria, with 8 included in the meta-analysis. The early-life famine-exposed group showed a significantly higher incidence of osteoporosis (OR = 2.12, 95%CI [1.35, 3.34], I2 = 88%) and fractures (OR = 1.58, 95%CI [1.07, 2.33], I2 = 92%) compared to non-exposed individuals. Meta-regression indicated that higher female prevalence in studies made the association with osteoporosis stronger, while higher ages strengthened the association with fractures. Exposure during fetal and childhood stages was particularly associated with increased risks of osteoporosis and fractures. Additionally, famine exposure correlated with lower BMD, particularly in the heels, femoral neck, and total hip regions.

CONCLUSION

Early-life famine exposure is significantly associated with an increased risk of osteoporosis, fractures, and lower BMD in later life. These results emphasize the lasting effects on bones from early lack of nutrition and stress the importance of specific interventions for bone health in groups with past famine experiences. Future studies should investigate the reasons behind these connections and assess preventative approaches to reduce the negative effects on bone health in those impacted.

Individual and combined effects of famine exposure and obesity parameters on type 2 diabetes in middle-aged and older adults: A population-based cross-sectional study

Malnutrition early in life may have adverse effects on health later in life. The relationship between malnutrition and obesity parameters (body mass index [BMI] and waist circumference [WC]) and type 2 diabetes is inconsistent. This study aimed to identify the effects of famine exposure and obesity parameters on type 2 diabetes individually or in combination among middle-aged and older adults in China. Data were extracted from the China Health and Retirement Longitudinal Study Wave1 in 2011. The sample involved 13,065 adults aged 45 to 90. The t- or F test was employed to compare age among groups. The chi-square test was utilized to compare baseline characteristics according to the categorical WC levels/BMI levels/famine exposure and examine between-group differences in type 2 diabetes (diabetes and non-diabetes). Odds ratio (OR) and 95% confidence interval (CI) were estimated by logistic regression models to estimate the individual and combined associations of BMI/WC levels and famine exposure with the prevalence of type 2 diabetes. In this study, 1559 (11.93%) individuals were exposed to Chinese famine during their fetal stage, 5132 (39.28%) and 4428 (33.89%) in childhood and adolescence/adulthood, respectively. Among BMI measurements, 3780 (28.93%) were overweight, and 1487 (11.38%) were obese, whereas WC measurements showed that 5408 (41.39%) were obesity. In addition, 831 (45.48%) males and 996 (54.52%) females reported type 2 diabetes. In multivariable-adjusted regression models, obesity parameters and famine exposure were independently associated with type 2 diabetes prevalence among all participants (P < .001). In the interaction analysis, there existed a trend of higher odds for prevalence of type 2 diabetes across all groups compared to the combination of no-exposed and normal BMI/WC level group (the most increase in odds, adolescence/adulthood-exposed group with central obesity in WC levels: OR 4.51 (95% CI = 3.42-5.95); adolescence/adulthood-exposed group with obesity in BMI levels: OR 5.84 (95% CI = 4.11-8.30; P for interaction <.001). The findings for females exhibited similar to the overall participants, when by gender stratification. Our results suggest famine exposure and obesity parameters have positive combined effects on type 2 diabetes in middle-aged and older adults in China.

The brother's penalty: Boy preference and girls' health in rural China

This paper identifies the health penalty experienced by girls due to having a brother from endogenous sibling gender composition. We propose a girls-to-girls comparison strategy and rule out the confounding effect from the sibship size, birth interval, and birth order. Employing an instrumental variable approach and data from the Chinese Family Panel Studies, we find that girls with a brother are demonstrably shorter and report poorer health. This "brother's penalty" manifests even prenatally. Alternative explanations, such as birth order disadvantages, are carefully addressed and ruled out. The results hold even after excluding gender-neutral ethnic minorities. This observed penalty is likely attributed to unequal resource allocation within families and potential parental neglect. This penalty is amplified in families with lower income and maternal education, implying resource constraints contribute to gender discrimination. Our findings highlight the importance of addressing intrafamily gender bias for ensuring equal opportunities and health outcomes. Clinical trial registration: Not applicable.

Famine exposure in early life increases risk of cataracts in elderly stage

Background

Epidemiological studies have shown that early-life nutritional deficiencies are associated with an increased risk of diseases later in life. This study aimed to explore the correlation between famine exposure during the early stages of life and cataracts.

Methods

We included 5,931 participants from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) 2018 cross-sectional data in our study. Subjects were categorized into three groups by their age during the famine: adulthood group, school age famine exposure group, and teenage famine exposure group. Utilizing binary logistic regression models, we investigated the relationship between early-life famine exposure and cataracts.

Results

Compared to the adulthood group, both the school age exposure group (OR = 2.49, 95%CI = 1.89-3.27) and teenage exposure group (OR = 1.45, 95%CI = 1.20-1.76) had a heightened risk of developing cataracts in elderly stage. And the sex differences in the impact of famine during early years on elderly cataract risk were observed, particularly indicating a higher risk among women who experienced childhood famine compared to men with similar exposure.

Conclusion

Famine exposure during the early stages of life is associated with a heightened risk of developing cataracts in old age. To prevent cataracts in elderly individuals, particularly in females, measures should be taken to address nutritional deficiencies in these specific periods.

Co-benefits from health and health systems to education

This review draws on over 70 studies spanning 2000 to 2023 to analyze the causal effect of health on educational outcomes. Health and health system interventions during the prenatal, infant, and childhood period impact longer-run educational attainment and performance. The magnitude of these effects is both statistically and economically significant, comparable in size to impacts on educational outcomes of interventions found in the literature. These impacts of health and health system interventions differ across gender and socioeconomic status, illustrating how health and health systems can exacerbate or mitigate educational inequalities. By showing the intertwined nature of health and education, this review highlights the importance of a comprehensive approach in policy-making that aligns with the Sustainable Development Goals.

A Systematic Analysis of Early Life Exposure to the Chinese Famine (1959-1961) and the Health of Older Adults - China, 2008-2023

What is already known about this topic?

There is mounting evidence indicating that the aging process initiates during early life stages, with in utero the individual's environment playing a significant role. Consequently, it is crucial to comprehend the enduring effects of early life circumstances on health in old age.

What is added by this report?

In this study, we conducted a meta-analysis to examine the effects of the Chinese Famine (1959-1961) on the health of older adults. We also explored potential mechanisms underlying these effects.

What are the implications for public health practice?

The complex interplay between early life circumstances, multiple health-related sectors, and healthy aging necessitates a comprehensive life-course approach and strategic interventions to enhance public health in an aging society.

Exposure to Chinese famine in early life and height across 2 generations: a longitudinal study based on the China Health and Nutrition Survey

BACKGROUND

Poor nutrition early in life is associated with short stature, which is associated with increased risk of cardiovascular disease and mortality in later life. Less evidence is available about the impact of early-life nutrition on height growth in the subsequent generation.

OBJECTIVES

This study investigated the associations of famine exposure in utero and early childhood with height across 2 generations.

METHODS

We used longitudinal data from the China Health and Nutrition Survey. We included 5401 participants (F1) born in 1955-1966 (calendar year around the Chinese famine in 1959-1961) and their 3930 biological offspring (F2). We classified F1 participants into subgroups by famine exposure status (unexposed/exposed) and timing (fetal-/childhood-exposed) according to their birth year and grouped F2 by their parents' exposure. Linear regression models were applied to examine the associations of famine exposure with adult height of F1 and F2. Linear mixed effect models with fractional polynomial functions were performed to estimate the difference in height between exposure groups of F2 during childhood.

RESULTS

Participants (F1) exposed to famine in utero or in childhood were shorter than those unexposed by 0.41 cm (95% CI: 0.03, 0.80) and 1.12 cm (95% CI: 0.75, 1.48), respectively. Offspring (F2) of exposed fathers were also shorter than those of unexposed parents by 1.07 cm (95% CI: 0.28, 1.86) during childhood (<18 y) and by 1.25 cm (95% CI: 0.07, 2.43) in adulthood (≥18 y), and those with exposed parents had a reduced height during childhood by 1.29 cm (95% CI: 0.68, 1.89) (all P values < 0.05). The associations were more pronounced among child offspring of highly-educated F1, particularly for paternal exposure and among female offspring (all P for interaction < 0.05).

CONCLUSIONS

The findings support the intergenerational associations of famine exposure in early life with height in Chinese populations, indicating the public health significance of improving the nutritional status of mothers and children in the long run.

Exposure to Chinese famine and the risk of hyperuricemia in later life: a population-based cross-sectional study

Background

Limited studies have investigated the relationship between famine exposure and the risk of hyperuricemia in later life. Consequently, the primary purpose of the current study was to examine the potential association between exposure to Chinese famine and hyperuricemia, as well as any gender disparities in this relationship.

Method

The data were obtained from the China PEACE (China Patient-Centered Evaluative Assessment of Cardiac Events) Million Persons Project in Rongchang. The study participants were enrolled into different cohorts based on their birthdates: the fetal-exposed cohort (born between 1959 and 1962), the childhood-exposed cohort (born between 1949 and 1958), the adolescence-exposed cohort (born between 1941 and 1948), and the non-exposed cohorts (born between 1963 and 1974). The potential association between famine exposure and hyperuricemia was assessed using binary logistic regression models.

Results

A total of 6,916 individuals were enrolled in the current study with an average age of 60.11 ± 9.22 years, out of which 3,544 were women. After adjusting for confounding factors, fetal (OR = 0.530, 95% CI: 0.411-0.0.683), childhood (OR = 0.642, 95% CI: 0.494-0.833) exposure to the Chinese famine for men was negatively associated with hyperuricemia. Conversely, exposure to the Chinese famine during fetal (OR = 2.144, 95% CI: 1.622-2.834), childhood (OR = 1.485, 95% CI: 1.105-1.997), and adolescence (OR = 1.967, 95% CI: 1.465-2.641) for women was positively associated with hyperuricemia. Furthermore, the impact of famine on hyperuricemia that has been observed in exposed women might be intensified by the presence of dyslipidemia, abdominal obesity, and overweight/obesity.

Conclusion

Women exposed to the Chinese famine during fetal, childhood, and adolescence were positively associated with hyperuricemia, while men exhibited a negative association during fetal and childhood. Additionally, the effect of famine on hyperuricemia in exposed women appears to be intensified by the presence of dyslipidemia, abdominal obesity, and overweight/obesity.

Parental gender preferences over three centuries: Evidence from Argentina

In this paper I examine the evolution of parental gender preferences in Argentina (i.e., parents who prefer a certain gender composition in their children). To do this, I use census microdata that spans the 19th, 20th, and 21st centuries. The estimation strategy exploits the plausibly random assignment in the gender of children. The results show a persistent preference for a mixed gender composition (i.e., having at least one boy and one girl) instead of children of the same gender. This translates into an increase in the probability of having a third child, conditional on already having two children of between 9%-23% for those couples who have children of the same gender -in relation to couples with children of opposite genders-. These preferences are heterogeneous over time and have important implications in terms of fertility (i.e., the reduction of these mixed gender preferences -in favor of greater gender-neutrality- could contribute to reducing the number of children per couple). In addition, the findings of this work support the empirical literature that uses the gender composition of the first two children as an instrumental variable to study the impact of fertility on labor participation.

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.

A Link between Prenatal Stage of Life during the Great Chinese Famine and Subsequent Depressive Symptoms among Middle-Aged and Older Adults

Prenatal malnutrition may increase the risk of depressive symptoms in adulthood. This study investigated the association between prenatal exposure to malnutrition with risk of depressive symptoms in middle-aged and older adults using the Chinese Great Famine of 1959-1961 as a natural experiment. Data were obtained from the China Health and Retirement Longitudinal Study baseline survey (2011). A total of 5391 individuals born from 1956 to 1965 were included in the study. Depressive symptoms were ascertained via the Center for Epidemiological Studies Depression Scale short form. Famine severity was measured using the cohort size shrinkage index. Difference-in-differences models were used to explore the association between prenatal famine exposure and later-life depressive symptoms. Compared with the post-famine cohort (1963-1965), famine cohorts (1959-1962) were 4.74 times (95% CI = 1.28-8.20) as likely to develop depressive symptoms. The stratified analysis found that prenatal exposure to famine was associated with depressive symptoms in rural residents but not those living in urban areas. In rural females, prenatal malnutrition was associated with a higher risk of depressive symptoms. However, there was no significant association between prenatal malnutrition and depressive symptoms in rural males. Our results indicated that prenatal malnutrition may contribute to a higher risk for depressive symptoms in later life among female rural residents.

Exposure to the 1959-1961 Chinese famine and risk of non-communicable diseases in later life: A life course perspective

Child undernutrition and later-life non-communicable diseases (NCDs) are major global health issues. Literature suggests that undernutrition/famine exposure in childhood has immediate and long-term adverse health consequences. However, many studies have theoretical and methodological limitations. To add to the literature and overcome some of these limitations, we adopted a life course perspective and used more robust methods. We investigated the association between exposure to the 1959-1961 Chinese famine and later-life NCDs and if this association depends on: life stage at exposure, famine severity, and sex. We conducted a secondary data analysis of a large-scale, nationally representative, longitudinal study-the China Health and Retirement Longitudinal Study (2011-2018, 11,094 participants). We measured famine exposure/severity using self-reported experience, life stage using age at exposure, and health using the number of NCDs. We performed Poisson growth curve models. We obtained three findings. First, compared with unexposed participants, those exposed before age 18 had a higher risk of later-life NCDs, particularly if exposed in-utero (IRR = 1.90, 95% CI [1.70, 2.12], p < .001) and in the "first 1,000 days" of life (IRR = 1.86, 95% CI [1.73, 2.00], p < .001; for 0-6 months group, IRR = 1.95, 95% CI [1.67, 2.29], p < .001). Second, the famine effects among participants moderately and severely exposed were similar (IRR = 1.18, 95% CI [1.09, 1.28], p < .001 and IRR = 1.24, 95% CI [1.17, 1.32], p < .001). Third, the famine effects did not differ between females and males (IRR = 0.98, 95% CI [0.90, 1.07], p = .703). In an individual's life course, in-utero and the "first 1,000 days" are a particularly sensitive time period with marked long-term implications for NCDs if undernutrition/famine is experienced in this period. However, this window remains open until young adulthood. This highlights the need to invest more in preventing and treating child/adolescent undernutrition to tackle later-life NCDs.

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.

Secular trend of non-communicable chronic disease prevalence throughout the life span who endured Chinese Great Famine (1959-1961)

BACKGROUND

Famine is a risk factor for non-communicable chronic diseases (NCDs), which account for over 80% of deaths in China. The effect of famine on the prevalence of NCDs in terms of various age groups, time periods and cohorts is currently poorly understood.

OBJECTIVE

This study aims to explore long-term trends in the impact of China's Great Famine (1959-1961) on NCDs in China.

METHODS

This study used data from the 2010-2020 China Family Panel Longitudinal Survey across 25 provinces in China. The subjects were aged 18-85 years, and the total number of subjects was 174,894. The prevalence of NCDs was derived from the China Family Panel Studies database (CFPS). An age-period-cohort (APC) model was used to estimate the age, period and cohort effects of NCDs in 2010-2020 and the effect of famine on the risk of NCDs in terms of cohort effects.

RESULTS

The prevalence of NCDs increased with age. Additionally, the prevalence did not clearly decrease over the survey period. Regarding the cohort effect, people born in the years adjacent to the famine period had a higher risk of NCDs; additionally, females, those born in rural areas, and those who lived in provinces with severe famine and post-famine had a higher likelihood of NCDs.

CONCLUSIONS

Experiencing famine at an early age or the experience of famine in a close relative's generation (births after the onset of famine) are associated with an increased risk of NCDs. Additionally, more severe famine is associated with a higher risk of NCDs.

Parental exposure to famine in early life and child overweight in offspring in Chinese populations

BACKGROUND

Little is known about the transgenerational effect of nutrition deficiency in early life. This study aimed to evaluate the associations of fetal and childhood exposure to famine of parents with their offspring's risk of overweight during childhood.

METHODS

This analysis included a total of 3734 participants of the China Health and Nutrition Survey aged 1-17 years whose fathers and/or mothers were born in 1955-1966. These children were classified into subgroups according to parental famine exposure status (unexposed and exposed) and timing (fetal-exposed and childhood-exposed). Random effects models were applied to evaluate the associations of parental famine exposure with body mass index (BMI) and overweight of offspring. Fractional polynomial functions were adopted to describe trajectories of BMI against age.

RESULTS

Compared with children of unexposed parents, there was a lower risk of overweight among offspring of childhood-exposed fathers [OR (95%CI): 0.80 (0.61, 1.04)] or exposed parents [0.84 (0.68, 1.04)], particularly among male offspring, but not among those with exposed mothers only [0.98 (0.65, 1.47)]. For BMI, children with exposed mothers only had a slightly higher BMI [β(95%CI): 0.17 (-0.15, 0.49)], while those with exposed fathers only had no difference [-0.02 (-0.23, 0.19)] or exposed parents had a slightly lower BMI [-0.17 (-0.33, 0.00)] (p < 0.05 for interaction between maternal and paternal exposures). Stratified analysis showed little heterogeneity between male and female offspring, but the association between paternal childhood exposure to famine and lower overweight risk in offspring was more evident in high (vs low) paternal education group (p for interaction< 0.05).

CONCLUSIONS

The transgenerational associations of early-life exposure to famine with lower risks of child overweight may be via the paternal line and differ by the educational levels of parents. Further studies are warranted to confirm the results and reveal the biological mechanisms underlying.

Prenatal exposure to famine and the development of diabetes later in life: an age-period-cohort analysis of the China health and nutrition survey (CHNS) from 1997 to 2015

PURPOSE

Prenatal exposure to famine has been linked to increased diabetes risk in adulthood. However, one fundamental issue to be addressed is that the reported famine-diabetes relation may be confounded by the age differences between the exposed and non-exposed groups. We aimed to determine the association between prenatal exposure to the Chinese famine of 1959-1962 and risk of diabetes by applying age well-controlled strategies.

METHODS

Among 20,535 individuals born in 1955-1966 who participated in the China Health and Nutrition Survey from 1997 to 2015, we constructed age-matched exposed vs. non-exposed groups to investigate the role of prenatal exposure to the Chinese famine of 1959-1962 in relation to diabetes. We also built a hierarchical age-period-cohort (HAPC) model to specifically examine the relation of famine to diabetes risk independent of age.

RESULTS

Compared to the age-balanced men in the non-exposed group, the exposed men born in 1961 had a 154% increased risk of diabetes [odds ratio (OR) 2.54 (95% CI 1.07-6.03), P = 0.04). In the HAPC analysis, the predicted probabilities of diabetes peaked in the 1961-birth cohort of men [3.4% (95% CI 2.4%-5.0%)], as compared to the average probability of diabetes (reference) of 1.8% for men overall. Neither analytical strategy revealed any strong relation between famine exposure and diabetes risk in women.

CONCLUSION

Among the pre-defined Chinese famine period of 1959-1962, early-life exposure to famine was associated with increased diabetes risk in men but not in women, and these relations were independent of age.

Association of early-life famine exposure with low bone mass in adulthood

Famine exposure in early life has been found to have a long-term effect on metabolic diseases, but its effect on bone health was not clear. In this study, we found women, who suffered from famine exposure during their childhood or adolescence period, had significantly decreased BMD at several skeletal sites compared to the age-matched non-exposed groups. The risk of clinical fracture was also elevated in adolescence-exposed women.

PURPOSE

To investigate the correlation between famine exposure at certain stages and bone mass in adulthood.

METHODS

We enrolled participants born in 1943-1962 from the China Osteoporosis Prevalence Study (COPS), which were classified into three famine exposure groups according to their birth year: fetal-famine exposure (1959-1962, n = 1693), childhood-famine exposure (1949-1958, n = 5557), and adolescence-famine exposure (1943-1948, n = 1530). We also selected age-balanced non-exposed participants as the control groups for men and women separately. Bone mineral density (BMD) and vertebral fractures (VFs) were measured by dual X-ray absorptiometry (DXA) and X-ray, respectively. The associations of famine exposure in early life with BMD were assessed via multiple linear regression. Logistic regression was performed to examine the association of famine exposure in early life with fracture risk with adjustments for covariates.

RESULTS

In women, the childhood-exposed and adolescence-exposed groups had significantly decreased BMD at several skeletal sites compared to the age-matched non-exposed groups. No significant decreased BMD was found in the fetal-exposed groups compared to the non-exposed groups in both sexes. Multiple linear regression analysis showed that famine exposure during childhood and adolescence was negatively associated with BMD at the femoral neck after adjusting for covariates in women. The risk of clinical fracture was also elevated in adolescence-exposed women.

CONCLUSION

Famine exposure during early life especially childhood and adolescence is associated with decreased bone mass in adulthood in women but did not affect bone mass in men.

Area-Level Infant Mortality Exposure in Early Life and Alzheimer's Disease Mortality: Examining Variation Based on Age, Sex, and Place of Birth

BACKGROUND

Growing evidence suggests that critical periods in early life may contribute to one's risk of Alzheimer's disease and related dementias (ADRD) in later life. In this paper we explore the role that exposure to infant mortality plays in later life ADRD.

OBJECTIVE

To determine if exposure to early life infant mortality is associated with later mortality from ADRD. Also, we explore how these associations differ by sex and age group, along with the role of state of birth and competing risks of death.

METHODS

We use a sample of over 400,000 individuals aged 50 and above with the NIH-AARP Diet and Health Study with mortality follow-up, allowing us to examine how early life infant mortality rates along with other risk factors play in one's individual mortality risk.

RESULTS

We show that infant mortality rates are associated with death from ADRD among those under 65 years of age, but not those over 65 at baseline interview. Moreover, when factoring in competing risks of death, the associations are relatively unchanged.

CONCLUSION

These results suggest that those exposed to worse adverse conditions during critical periods increase their likelihood of death from ADRD earlier than average, due to that exposure increasing their susceptibility to develop illness later on in life.

Transgenerational associations of parental famine exposure in early life with offspring risk of adult obesity in China

OBJECTIVE

The aim of this study was to investigate the transgenerational associations between exposure to famine in early life and obesity.

METHODS

This study used the longitudinal data from the China Health and Nutrition Survey from 1989 to 2015. A total of 1113 fathers and 1207 mothers (946 mother-father pairs) born in 1955 to 1966 and 1895 adult offspring were included. Offspring were classified into subgroups according to the famine exposure of their parents (unexposed, maternal exposed, paternal exposed, parental exposed) and exposure timing (during fetal development, childhood).

RESULTS

Maternal exposure to famine in early life was associated with elevated levels of BMI, waist circumference, overweight, and central obesity of their children, whereas paternal exposure was inversely associated with these measurements. Compared with children of unexposed parents (P0M0), the maternal exposed group (P0M1) had higher mean BMI, by 1.3 kg/m² (95% CI: 0.3 to 2.4); waist circumference, by 1.5 cm (-1.0 to 3.9); overweight (odds ratio [OR] [95% CI]: 3.1 [1.6 to 6.1]); and central obesity (OR [95% CI]: 1.9 [1.02 to 3.7]). No significant heterogeneity was observed in the associations by sex of offspring.

CONCLUSIONS

Fetal and early childhood exposure to famine in parents may be associated with their children's risk of obesity during adulthood. A better understanding of the transgenerational associations is important for developing strategies to reduce obesity risk in future generations.

Prenatal exposure to the Chinese famine of 1959-62 and risk of cardiovascular diseases in adulthood: findings from the China PEACE million persons project

AIMS

Much remains unknown about the role of prenatal exposure to environmental stressors in the development of cardiovascular diseases (CVD). The current study aimed to investigate whether exposure to famine early in life was associated with a higher risk of CVD in adulthood.

METHODS AND RESULTS

Among 71 667 men and women participated in the Patient-centred Evaluative Assessment of Cardiac Events (PEACE) Million Persons Project in southern China, specific years of birth were used to define two cohorts: the exposed group (born during the famine of 1959-62) and the non-exposed group [born before the famine (1949-58) or after the famine (1963-72)]. Multivariable-adjusted generalized linear models were used to examine the associations of famine exposure with the risk of developing CVD, as well as with the 10-year CVD risk defined by well-established risk scores. Compared with the non-famine group, early-life exposure to the Chinese famine was significantly associated with increased risks of total CVD (odds ratio, OR = 1.28, 95% confidence interval: 1.16-1.41), coronary heart disease [OR: 1.23 (1.07-1.41)], acute myocardial infarction [OR: 1.32 (1.01-1.70)], heart failure [OR: 2.01 (1.53-2.60)], and stroke [OR: 1.28 (1.12-1.45)] in adulthood. In those without established CVD, early-life exposure to the famine was associated with higher levels of total cholesterol, systolic blood pressure, waist circumference, risk of diabetes, and therefore 10-year CVD risk.

CONCLUSION

Early-life exposure to the Chinese famine is associated with an elevated CVD risk later in life, independent of known risk factors.

Famine exposure in adolescence is associated with a higher risk of overweight/obesity and abdominal obesity in adulthood: A meta-analysis

Some studies have shown that famine exposure during adolescence can increase cardiovascular disease and diabetes susceptibility in later life. The association between famine exposure in adolescence and overweight/obesity and abdominal obesity in adulthood has been inconsistent. Based on previous studies, we hypothesized that famine exposure in adolescence increases the risk of overweight/obesity and abdominal obesity in adulthood. Eight databases, including PubMed, Embase, Cochrane Library, and Web of Science, were searched from their inception until November 2021. We initially identified 3982 records and finally included 7 articles after screening. The included articles were of moderate to high quality, containing 16 estimates of overweight/obesity and 3 estimates of abdominal obesity. Pooled odds ratios (ORs) with 95% CIs were used to estimate the association between them. The random effects model was adopted as the pooling method. There was a significant association between famine exposure in adolescence and overweight/obesity in adulthood (OR, 1.17; 95% CI, 1.02-1.33). Adolescents exposed to famine had a greater risk of abdominal obesity in adulthood than their unexposed counterparts (OR, 1.35; 95% CI, 1.03-1.76). These results were more pronounced in females than in males. In summary, our meta-analysis indicates that famine exposure during adolescence increases the risk of overweight/obesity and abdominal obesity in adulthood. This suggests that we need to pay timely attention to the nutritional status of adolescents to prevent adverse health consequences of malnutrition. More high-quality studies are needed to confirm these conclusions, given the limitations of this study.

Association between early life famine exposure and risk of metabolic syndrome in later life

BACKGROUND

Previous studies reported that famine exposure had an effect on metabolic syndrome (MetS). However, there is an inadequacy of study regarding the association between famine exposure, adulthood general obesity, and the risk of MetS.

METHODS

A total of 8883 subjects aged ≥40 years from Jiading community in Shanghai were included. We defined famine exposure subgroups as nonexposed (1963-1974), fetal exposed (1959-1962), childhood exposed (1949-1958), and adolescence exposed (1941-1948). MetS was defined based on the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria.

RESULTS

Compared with the nonexposed group, the risks of MetS were increased in the fetal-, childhood-, and adolescence-exposed groups with odds ratios (OR) and 95% confidence intervals (CI) of 1.48 (1.23-1.78), 1.89 (1.63-2.20), and 2.34 (1.99-2.74), respectively. After adjusting for sex, age, smoking status, drinking status, education, body mass index (BMI), and physical activity, the increased risk of MetS related to the fetal-exposed and childhood-exposed groups with OR and 95% CI of 1.42 (1.04-1.94) and 1.50 (1.02-2.21), respectively, were observed only in women. Famine exposure was significantly associated with MetS among individuals with a BMI < 23 kg/m² (p for interaction between BMI categories and famine exposure = 0.0002 in the whole cohort), while there existed a gender difference (p = 0.0023 in females, p = 0.4484 in males). When evaluating the joint effects of the combination of famine exposure in early life and general obesity in adulthood on MetS, we observed the highest estimate in participants with both adulthood general obesity and fetal famine exposure (OR 17.52; 95% CI, 10.07-30.48) compared with those without famine exposure nor adulthood obesity.

CONCLUSIONS

Obesity in adulthood significantly further aggravated the risk of MetS in individuals who experienced early life undernutrition, especially in females.

Cultural Factors in Disaster Response Among Diverse Children and Youth Around the World

PURPOSE OF REVIEW

Disasters and traumatic events are ever present globally but disproportionally impact culturally diverse low resource environments. Culture is an important context through which people experience disasters, develop adaptive strategies, and process external aid and support. This is even more critical for children and youth who are in the process of forming their cultural/ethnic identities. This review identifies literature on these important aspects of culture in disaster response.

RECENT FINDINGS

The literature supports that culture influences the experience of disasters, the development of coping and adaptational approaches, and the acceptability of external aid and support, especially mental health services. Cultural humility, awareness, and sensitivity are crucial in addressing the traumatic impact of disasters in children and youth, especially in the areas of the world that are most at risk for them.

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.

Combined effects of air pollution in adulthood and famine exposure in early life on type 2 diabetes

Famine exposure or air pollution is linked to type 2 diabetes mellitus (T2DM). However, their combined effects on T2DM remain largely unknown. A total of 11,640 individuals were obtained from the Henan Rural Cohort Study. According to their birthdate, participants were divided into three famine exposure subgroups: fetal exposed, childhood exposed, and unexposed groups. The air pollutants (particles with aerodynamics diameters ≤ 1.0 µm (PM₁), ≤ 2.5 µm, and ≤ 10 µm, and nitrogen dioxide) concentrations of each individual were estimated by a spatiotemporal model. Participants were divided into low or high air pollution exposure groups taking the 1st quartile value of air pollutants as the cut-off point. Logistic regression model was used to analyze independent and joint associations between air pollution exposure, famine exposure, and T2DM. Positive associations of air pollution and famine exposure with T2DM were found. Participants who experienced fetal or childhood famine and also were exposed to high concentrations of any kind of the air pollutants had a much higher risk for T2DM than those with no famine and low air pollutants exposure (taking PM_1.0 for example, the odds ratio [OR]: 1.76, 95% confidence interval [CI]: 1.25, 2.47 for fetal famine, and OR: 1.64, 95%CI: 1.13, 2.40 for childhood famine). After stratified analysis, similar results were observed in women. The results indicated that both famine exposure in early life and air pollution exposure in adulthood are related to increased risk for prevalent T2DM, and they have combined effects on T2DM.

Early life famine exposure and anthropometric profile in adulthood: a systematic review and Meta-analysis

Background

Previous famine studies reported the association between early life famine exposure and adulthood anthropometric profile. However, the findings were variable. Thus, a systematic review and meta-analysis was conducted to clarify the association of famine exposure in early life with the anthropometric profiles in adults.

Methods

Potentially relevant studies were searched through Scopus, Medline, Google Scholar and Google for gray literature and reference lists of previous studies. The random effects model (REM) and I² test was used to adapt the pooling method and assess heterogeneity, respectively.

Results

Prenatal famine exposure was associated with increased risk of body mass index [SMD = 0.10 (95% CI: 0.02, 0.18)], waist circumference [SMD = 0.21 (95% CI: 0.11, 0.31)] in adults. Likewise, famine exposure during prenatal life was associated with decreased adult height [SMD) = − 0.26 (95% CI: − 0.44, − 0.09)]. Moreover, famine exposure during early childhood was associated with increased risk of waist circumference [SMD = 0.09 (95% CI: 0.01, 0.16)] and decreased adult height [SMD = − 0.16 (95% CI: − 0.27, − 0.04)].

Conclusion

Our finding indicates that exposure to famine during early life was associated with the anthropometric profile of adults. In terms of public health significance, the results of the study further underscore the importance of improving the nutritional status of mothers and children to prevent adulthood diseases in the long run.

Systematic review registration number

PROSPERO CRD42020168424

Supplementary Information

The online version contains supplementary material available at 10.1186/s40795-022-00523-w.

Early-life exposure to hardship increased risk tolerance and entrepreneurship in adulthood with gender differences

We investigate the effect of hardship on entrepreneurship using China’s Great Famine as a quasinatural experiment. This yielded robust evidence that individuals who experienced more hardship were subsequently more likely to become entrepreneurs. Importantly, the increase in entrepreneurship was at least partly due to conditioning rather than selection. Regarding the behavioral mechanism, hardship was associated with greater risk tolerance among men and women but conditioned business ownership only among men. The gender differences were possibly due to a Chinese social norm that men focus on market work and women focus on domestic work combined with interspousal risk pooling in occupational choice.

Many entrepreneurs credit their success to early hardship. Here, we exploit geographical differences in the intensity of China's Great Famine to investigate the effect of hardship during formative years on individual personality and engagement in business entrepreneurship. To exclude factors that might confound the relation between famine intensity and entrepreneurship, we model famine intensity by random weather shocks. We find robust evidence that individuals who experienced more hardship were subsequently more likely to become entrepreneurs (defined broadly as self-employed or business owners). Importantly, the increase in entrepreneurship was at least partly due to conditioning rather than selection. Regarding the behavioral mechanism, hardship was associated with greater risk tolerance among men and women but increased business ownership only among men. The gender differences were possibly due to the intricate relationship between a Chinese social norm—men focus more on market work, while women focus more on domestic work—and interspousal risk pooling associated with occupational choices. Scientifically, these findings contribute to a long-standing debate on whether entrepreneurship is due to nature or nurture, particularly how hardship conditions people to be entrepreneurial. The findings also highlight the importance of gender differences in shaping the effect of early-life experience on life cycle outcomes.

Adolescence exposure to China's great famine period and the association of metabolic syndrome in adulthood: a retrospective study

BACKGROUND

Exposure to famine during early life is related to several adverse health outcomes in adulthood, but the effect of famine exposure during adolescence is unclear. This study aims to examine whether exposure to famine in adolescence is associated with metabolic syndrome (MetS) in adulthood.

METHODS

This study included 4130 Chinese adults (2059 males and 2071 females) aged 59-71 from the 2011 China Health and Retirement Longitudinal Study (CHARLS). All the selected participants were exposed to the three-year time period (1959-1961) of China's Great Famine. Participants were categorized into an adolescent-exposed group (born 01/01/1944-12/31/1948) and a non-adolescent-exposed group (born 01/01/1940-12/31/1941 and 01/01/1951-12/31/1952). Sex-stratified multiple logistic regression models were used to estimate the association between exposure to famine in adolescence and MetS.

RESULTS

Participants exposed to famine during adolescence were more likely to report MetS (aOR = 1.35; 95%CI 1.01-1.78) compared to the non-adolescent-exposed group. Further, males were 45% less likely to report MetS than females (aOR = 0.55; 95%CI 0.36-0.83). After stratification by sex, the effects of famine exposure during adolescence on MetS were detected among males only (aOR = 1.97; 95%CI 1.20-3.24). Additionally, males with a history of drinking were more likely to report MetS compared to those with no history of drinking (aOR = 2.63; 95%CI 1.41-4.90).

CONCLUSIONS

Our findings reveal that exposure to famine during adolescence is associated with higher odds of MetS in adulthood overall, and this association is only pronounced among males. This study emphasizes that undernutrition in early life, including adolescence, may have a long-term effect and be associated with adverse health events in middle-to-late life. Targeting those elderly people who suffered famine during adolescence may help prevent the development of MetS in later life.

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.

Life Course Socioeconomic Status and Healthy Longevity in China

In 2020, China's population aged 60 or older exceeded 264 million, representing 25% of the global population in that age-group. Older adults in China experienced periods of dramatic political and social unrest in early life, as well as economic transformations leading to drastic improvements in living standards during adulthood and older age. However, the implications of life course socioeconomic status (SES) trajectories for healthy longevity in later life have not been systematically studied in China. We utilize data from the China Health and Retirement Longitudinal Study (CHARLS) to comprehensively investigate how early-life conditions and adult SES combine to influence healthy longevity in later life. We find that both childhood and adulthood SES are associated with late-life health. The largest disparities in life expectancy (LE) and disability-free LE are found between those with persistently low SES throughout life and those with consistently high SES. At age 45, the gap in total LE between the most advantaged and least advantaged groups is six years for men and five years for women. Despite China's major policy changes prioritizing equity in income and health care in recent decades, our findings suggest that dramatic health inequalities among older adults remain. Our findings extend the literature on the effect of socioeconomic patterns across the life course on gradients in later-life health and highlight continuing disparities in healthy longevity among older adults in China.

Moderation effect of economic status in the association between early life famine exposure and MAFLD in adulthood

BACKGROUND & AIMS

The double burden of malnutrition (DBM) in China resulted in high prevalence of diet-related non-communicable diseases. The aim of this study was to analyse the moderation of economic status in the association between early famine exposure and metabolic dysfunction associated with fatty liver disease (MAFLD) in adulthood.

METHODS

10 190 participants in the SPECT-China study enrolled from 2014 to 2016 were included in this study. Participants with fetal famine exposure (birth year 1959-1962) or early-childhood famine exposure (birth year 1955-1958) formed the exposure group. The associations with MAFLD were assessed via regression analyses.

RESULTS

In men, economic status could not moderate the association between early life famine and MAFLD after adjusting for age, excess alcohol drinking, current smokers, famine severity, waist circumference, diabetes, hypertension, and dyslipidemia (P for interaction = .52). However, in women and in the total population, economic status could moderate the association between early life famine and MAFLD after adjusting for the above confounders (P for interaction = .01). In the total population and in women, early life famine exposure was associated with MAFLD in both low economic status and high economic status. However, in men, early life famine exposure was not associated with MAFLD in low economic status, while in high economic status, early-childhood famine exposure was associated with MAFLD.

CONCLUSIONS

Economic status could moderate the association between early life famine exposure and MAFLD in total population and in women.

Association of Prenatal Famine Exposure With Inflammatory Markers and Its Impact on Adulthood Liver Function Across Consecutive Generations

Although there has been increasing recognition that famine exposure in the fetal stage damages liver function in adulthood, this deteriorated effect could be extended to the next generation remains vague. This study aimed to explore whether famine exposure was associated with liver function in the two consecutive generations, and its association with the mediation role of inflammatory markers. We analyzed the data of 2,681 participants from Suihua rural area, Heilongjiang Province, China. According to the date of birth, the participants were classified as fetal exposed and nonexposed. The F2 subjects were classified as having no parents exposed to famine, maternal famine exposure, paternal famine exposure, or parental famine exposure. In the mixed-effect models, prenatal exposure to famine was associated with the elevation of Δ aspartate aminotransferase (ΔAST) (β: 0.22, 95% CI: 0.01, 0.43) and Δ alanine aminotransferase (ΔALT) (β: 0.42, 95% CI: 0.19, 0.66) levels in F1 adults. The mediation analysis showed that the inflammatory markers including serum C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α) might mediate the famine-liver function association. This longitudinal data were consistent with the hypothesis that the inflammatory markers explained part of the influence of prenatal famine exposure on liver function injury, and the natal mechanism was needed to be elucidated in the future study.

Grandparental care and childhood obesity in China

Ongoing increases in childhood obesity have become a serious public health concern. Meanwhile, caregiving by grandparents becomes a worldwide social phenomenon. This study estimates the effect of grandparental care on childhood obesity and explores its pathways. Utilizing five waves of panel data from the China Family Panel Studies, we found that grandparental care significantly increases the probability of childhood obesity, adding 3.6 percentage points. The effect is heterogeneous between boys and girls and between grandparents with different education attainments. The channels through which grandparents contribute to childhood obesity include inappropriate dietary patterns and insufficient physical activities. Additionally, we found that grandparents' famine experience generates a long-term fear of hunger, which translates into overfeeding their grandchildren, thus aggravating childhood obesity in China.

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We estimate the longitudinal causal relationship of grandparental care on childhood obesity.

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Our multiple robustness checks support the positive effect of grandparental care on childhood obesity.

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Grandparents' famine experience generates a long-term fear of hunger, which aggravates childhood obesity in China.

Famine and Trajectories of Body Mass Index, Waist Circumference, and Blood Pressure in Two Generations: Results From the CHNS From 1993-2015

Early-life exposures play key roles in the development of metabolic diseases. Whether such effects exist beyond one generation remains unclear. This study aimed to determine the transgenerational association of early-life exposure to the Chinese famine of 1959 to 1962 with the trajectories of body mass index (BMI), waist circumference (WC), and blood pressure (BP) in 2 consecutive generations. We included 21 106 F1 observations born between 1954 and 1967 (median age: 45 years) and 1926 F2 observations (median age: 23 years) from the longitudinal household-based China Health and Nutrition Survey from 1993 to 2015. Trajectories of BMI, WC, systolic BP, and diastolic BP were fitted and compared between groups using linear mixed effect models. Early-life exposure to famine was associated with increased BMI, WC, and BP in 2 consecutive generations with sex and age disparities. In F1, famine was associated with increased BMI, WC, systolic BP, and diastolic BP, especially in men or those aged older than 50 years (P ranged from <0.001 to 0.02). In F2 men but not women, the parental exposure to famine was associated with 0.59 kg/m² ([95% CI, 0.10-1.08], P=0.02) increase in BMI. In F2 aged ≥25 years but not those younger ones, the parental exposure to famine was associated with increased BMI (0.83 kg/m² [0.14-1.51], P=0.03), systolic BP (2.04 mm Hg [0.20-3.88], P=0.03), and diastolic BP (1.73 mm Hg [0.28-3.18], P=0.02). The effects of an adverse developmental environment through famine in early life on BMI and BP later in life may persist beyond one generation.

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.

Ideal Cardiovascular Health Metrics Modify the Association Between Exposure to Chinese Famine in Fetal and Cardiovascular Disease: A Prospective Cohort Study

Background: No study has explored the modification effect of ideal cardiovascular health metrics (ICVHMs) on the association between famine exposure and risk of cardiovascular disease (CVD) so far. We aim to examine the effect of ICVHMs on the association between exposure to famine early in life and the risk of CVD in adulthood.

Methods: A total of 61,527 participants free of CVD were included in this study from the Kailuan Study. All participants were divided into three groups, included nonexposed, fetal-exposed, and childhood-exposed groups. Cox regression was used to estimate the effect of famine exposure and ICVHMs on CVD risk.

Results: After a median of 13.0 (12.7–13.2) years follow-up, 4,814 incident CVD cases were identified. Compared with nonexposed participants, the CVD risk increased in participants with fetal famine exposure (hazard ratio [HR]: 1.21; 95% CI: 1.07–1.37), but not in childhood famine-exposed participants. After stratifying by the number of ICVHMs, the increased CVD risk associated with fetal famine exposure was only observed in participants with less ICVHMs ( ≤ 2) (HR: 1.30; 95% CI: 1.11–1.52, P for interaction=0.008), but disappeared in those with three or more ICVHMs. The modified effect of ICVHMs was sex specific (P for sex interaction = 0.031).

Conclusions: Exposing to famine in the fetal period could increase the risk of CVD in late life; however, ICVHMs might modify the effect of famine exposure on CVD risk, especially in men.

Association of early-life undernutrition and risk of dyslipidemia in adulthood: a population-based cohort study

BACKGROUND

The association of early-life undernutrition and dyslipidemia found in previous studies may be confounded by the uncontrolled age difference between exposed and unexposed participants. The study aimed to investigate the association of early-life undernutrition and the risk of dyslipidemia in adulthood with good control of the age variable.

METHODS

We took the Great Chinese Famine (1959-1961) as a natural experiment of severe undernutrition. This study was based on the baseline investigation of a population-based cohort in rural China. Undernutrition in early life was defined as being exposed to famine at younger than 3 years of age. Three approaches including Adjustment, Restriction, and Matching were applied to control the confounding effect of age. Logistic regression models were applied to evaluate the association between early-life famine and the presence of dyslipidemia. Stratified analysis by gender was also performed, and potential effect modification was tested by adding the interaction term of the famine exposure variable and gender into the model.

RESULTS

Undernutrition in early life was associated with increased risk of borderline high and above (BHA) levels of total cholesterol (TC, OR_Adjustment = 1.61; OR_Restriction = 1.56; OR_Matching = 1.87), triglycerides (TG, OR_Adjustment = 1.33; OR_Restriction = 1.30; OR_Matching = 1.34), low-density lipoprotein cholesterol (LDL-C, OR_Adjustment = 1.75; OR_Restriction = 1.53; OR_Matching = 1.77) and dyslipidemia (OR_Adjustment = 1.52; OR_Restriction = 1.45; OR_Matching = 1.60), as well as high levels of TC, TG, LDL-C and dyslipidemia. An inverse association of undernutrition and risk of low high-density lipoprotein cholesterol (HDL-C) was found. Female participants with undernutrition experience had an increased risk of BHA TG and LDL-C (TG: OR_{Adjustment, female} = 1.45; OR_{Restriction, female} = 1.39; OR_{Matching, female} = 1.51; LDL-C: OR_{Adjustment, female} = 2.11; OR_{Restriction, female} = 1.80; OR_{Matching, female} = 2.15), but this association was not found in males.

CONCLUSION

Early-life undernutrition increased the risk of TC, TG, LDL-C, and dyslipidemia. Gender would significantly modify this effect for TG and LDL-C. These results emphasize the importance of nutritional conditions in the early stages of life to long-term health consequences.

Differential regulation of the DNA methylome in adults born during the Great Chinese Famine in 1959-1961

BACKGROUND

Extensive epidemiological studies have established the association between exposure to early-life adversity and health status and diseases in adults. Epigenetic regulation is considered as a key mediator for this phenomenon but analysis on humans is sparse. The Great Chinese Famine lasting from 1958 to 1961 is a natural string of disasters offering a precious opportunity for elucidating the underlying epigenetic mechanism of the long-term effect of early adversity.

METHODS

Using a high-throughput array platform for DNA methylome profiling, we conducted a case-control epigenome-wide association study on early-life exposure to Chinese famine in 79 adults born during 1959-1961 and compared to 105 unexposed subjects born 1963-1964.

RESULTS

The single CpG site analysis of whole epigenome revealed a predominant pattern of decreased DNA methylation levels associated with fetal exposure to famine. Four CpG sites were detected with p < 1e-06 (linked to EHMT1, CNR1, UBXN7 and ESM1 genes), 16 CpGs detected with 1e-06 < p < 1e-05 and 157 CpGs with 1e-05 < p < 1e-04, with a predominant pattern of hypomethylation. Functional annotation to genes and their enriched biological pathways mainly involved neurodevelopment, neuropsychological disorders and metabolism. Multiple sites analysis detected two top-rank differentially methylated regions harboring RNF39 on chromosome 6 and PTPRN2 on chromosome 7, both showing epigenetic association with stress-related conditions.

CONCLUSION

Early-life exposure to famine could mediate DNA methylation regulations that persist into adulthood with broad impacts in the activities of genes and biological pathways. Results from this study provide new clues to the epigenetic embedding of early-life adversity and its impacts on adult health.

Cardiometabolic traits mediated the relationship from early life famine exposure to adulthood nonalcoholic fatty liver disease risk

Early life exposure to famine was associated with adulthood metabolic syndrome and nonalcoholic fatty liver disease (NAFLD), and NAFLD was also affected by cardiometabolic traits. However, the role of cardiometabolic traits in the associations from famine exposure to NAFLD was largely unknown. This study aimed to investigate whether the relationship between early life famine exposure and adulthood NAFLD risk was mediated by cardiometabolic traits. Overall, 7578 subjects aged 56·0 (sd 3·7) years in the Dongfeng-Tongji cohort were included and classified into late-exposed (1952-1954), middle-exposed (1954-1956), early-childhood-exposed (1956-1958), fetal-exposed (1959-1961) and non-exposed (1962-1966, reference) group according to the birth year. NAFLD was diagnosed by experienced physicians via abdominal B-type ultrasound inspection. Mediation analysis was used to evaluate the mediating effects of cardiometabolic traits. Compared with those non-exposed, after multivariable adjustment, participants in fetal-exposed group (OR: 1·37; 95 % CI 1·08, 1·73) had 37 % higher risk to develop NAFLD, and the overall childhood-exposed group had marginally significant association with NAFLD (OR: 1·39; 95 % CI 0·99, 1·94). Stratification analysis found the famine-NAFLD associations more evident in women and those born in areas severely affected by famine. Mediation analysis showed that cardiometabolic traits such as total cholesterol, TAG glucose index, γ-glutamyl transpeptidase, alkaline phosphatase and alanine aminotransferase mediated 6·7-22·2 % of the relation from famine exposure to higher NAFLD risk. Early life exposure to famine was related to increased adulthood NAFLD risk, and this relationship was partly mediated by cardiometabolic traits.

Exposure to Chinese Famine in the Early Life, Adulthood Obesity Patterns, and the Incidence of Hypertension: A 22-Year Cohort Study

INTRODUCTION

Little is known regarding the joint associations of famine exposure and obesity patterns with the incidence of hypertension.

METHODS

We defined famine exposure cohorts as follows: nonexposure (born between 1962 and 1965), fetal life exposure (born between 1959 and 1961), early childhood exposure (born between 1956 and 1958), midchildhood exposure (born between 1953 and 1955), and late childhood exposure (born between 1949 and 1952). Obesity patterns were defined as follows: G-/A-: subjects without neither general obesity nor abdominal obesity; G+/A- or G-/A+: subjects with either general obesity or abdominal obesity; G+/A+: subjects with both general obesity and abdominal obesity. Hypertension was defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg or current treatment with antihypertensive medications.

RESULTS

There were 5,235 individuals participating in this study. In the subjects with general or abdominal obesity, famine exposure was associated with a lower risk of hypertension. In males with G-/A-, famine exposures in the midchildhood (p = 0.048; HR: 0.700; HR 95% CI: 0.491-0.998) and late childhood (p = 0.002; HR: 0.560; HR 95% CI: 0.374-0.840) were associated with a lower incidence of hypertension.

CONCLUSION

The coexistence of famine exposure and obesity patterns was associated with the incidence of hypertension.

Metabolites in the association between early-life famine exposure and type 2 diabetes in adulthood over a 5-year follow-up period

INTRODUCTION

Exposure to malnutrition in early life has been found to significantly elevate type 2 diabetes risk in adulthood. However, the changes in metabolites resulting from malnutrition in early life have not been studied. The aim of this study was to identify metabolites with levels associated with type 2 diabetes resulting from exposure to China's Great Famine (1959-1962).

RESEARCH DESIGN AND METHODS

Participants were from SPECT-China 2014 and SPECT-China2 2019, two cross-sectional studies performed at the same site. In total, 2171 subjects participated in SPECT-China and SPECT-China2 simultaneously. The sample size of fetal-exposed (1959-1962) versus non-exposed (1963-1974) individuals was 82 vs 79 in 2014 and 97 vs 94 in 2019. Metabolomic profiling was performed between famine-exposed and non-exposed groups.

RESULTS

Among the different famine exposure groups, the fetal-exposed group (1959-1962) had the greatest incidence rate (12.5%), with an OR of 2.11 (95% CI 1.01 to 4.44), compared with the non-exposed group (1963-1974). Moreover, compared with those in the non-exposed group (1963-1974), four metabolites (indole-3-carbinol (I3C), phosphatidylcholine (PC) (22:6(4Z,7Z,10Z,13Z,16Z,19Z)/16:1(9Z)), pyrimidine, and PC(16:1(9Z)/22:5(4Z,7Z,10Z,13Z,16Z))) showed significantly lower relative intensities in the famine and diabetes groups both in 2014 and 2019. Pyrimidine significantly mediated the association of famine exposure with diabetes, and I3C marginally mediated this association.

CONCLUSIONS

Famine exposure in the fetal period could increase type 2 diabetes risk in adults, even those in their 60s. I3C and pyrimidine are potential mediators of the effects of famine exposure on diabetes development.

Prior undernutrition and insulin production several years later in Tanzanian adults

BACKGROUND

The prevalence, pathology, and existence of malnutrition-associated diabetes remain uncertain, especially with respect to adult-acquired undernutrition.

OBJECTIVE

The aim was to investigate the association of prior undernutrition (low BMI, in kg/m2), acquired in adulthood and insulin during an oral glucose tolerance test (OGTT).

METHODS

We followed up 630 adults recruited 7-14 y previously for other studies. Plasma insulin was measured fasting and at 30 and 120 min during an OGTT. The main exposure was BMI measured 7-14 y prior. The main outcome of interest was plasma insulin, controlling for time during the OGTT using generalized estimating equations, and exploratory outcomes were early insulin response (relative change in insulin and glucose from 0-30 min) and relative insulin and glucose AUCs from 0 to 120 min. Current confounding factors were age, sex, BMI, HIV, socioeconomic status, and physical activity.

RESULTS

In unadjusted analyses, increasing severity of prior malnutrition was associated with lower insulin concentration. In multivariate adjusted analyses, only current BMI was a strong predictor of overall insulin concentration. Associations with prior BMI of insulin responses accounting for glucose were also seen in unadjusted but not adjusted analyses. For insulin concentration but not the outcomes accounting for glucose, there was a sex interaction with prior BMI such that only men had lower insulin if previously malnourished: insulin (pmol/L) at 120 min was 311 (95% CI: 272, 351) for prior BMI ≥18.5, 271 (95% CI: 221, 321) for prior BMI 17.0-18.5, and 237 (95% CI: 194, 297) for prior BMI <17.0; P = 0.03. HIV status showed limited and variable associations with insulin.

CONCLUSIONS

Insulin concentration, fasting and during an OGTT, was normalized in women more than in men several years after adult malnutrition. Chronic malnutrition, as indicated by low prior and current BMI, may contribute to diabetes through low insulin secretion.

Severe malnutrition or famine exposure in childhood and cardiometabolic non-communicable disease later in life: a systematic review

INTRODUCTION

Child malnutrition (undernutrition) and adult non-communicable diseases (NCDs) are major global public health problems. While convincing evidence links prenatal malnutrition with increased risk of NCDs, less is known about the long-term sequelae of malnutrition in childhood. We therefore examined evidence of associations between postnatal malnutrition, encompassing documented severe childhood malnutrition in low/middle-income countries (LMICs) or famine exposure, and later-life cardiometabolic NCDs.

METHODS

Our peer-reviewed search strategy focused on 'severe childhood malnutrition', 'LMICs', 'famine', and 'cardiometabolic NCDs' to identify studies in Medline, Embase, Global Health, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. We synthesised results narratively and assessed study quality with the UK National Institute for Health and Care Excellence checklist.

RESULTS

We identified 57 studies of cardiometabolic NCD outcomes in survivors of documented severe childhood malnutrition in LMICs (n=14) and historical famines (n=43). Exposure to severe malnutrition or famine in childhood was consistently associated with increased risk of cardiovascular disease (7/8 studies), hypertension (8/11), impaired glucose metabolism (15/24) and metabolic syndrome (6/6) in later life. Evidence for effects on lipid metabolism (6/11 null, 5/11 mixed findings), obesity (3/13 null, 5/13 increased risk, 5/13 decreased risk) and other outcomes was less consistent. Sex-specific differences were observed in some cohorts, with women consistently at higher risk of glucose metabolism disorders and metabolic syndrome.

CONCLUSION

Severe malnutrition or famine during childhood is associated with increased risk of cardiometabolic NCDs, suggesting that developmental plasticity extends beyond prenatal life. Severe malnutrition in childhood thus has serious implications not only for acute morbidity and mortality but also for survivors' long-term health. Heterogeneity across studies, confounding by prenatal malnutrition, and age effects in famine studies preclude firm conclusions on causality. Research to improve understanding of mechanisms linking postnatal malnutrition and NCDs is needed to inform policy and programming to improve the lifelong health of severe malnutrition survivors.

Economic Status Moderates the Association Between Early-Life Famine Exposure and Hyperuricemia in Adulthood

CONTEXT

The double burden of malnutrition (DBM), undernutrition in early life and an obesogenic environment later on, influences later risk of chronic disorders. The Great Famine in China from 1959 to1962 and remarkable economic development from the 1980s provided such a burden for a large number of people in their 60s.

OBJECTIVE

We aimed to analyze the effect of economic status on the association between famine exposure in early life and hyperuricemia in adulthood.

DESIGN AND SETTING

Participants numbering 12 666 were enrolled in China based on the Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China) Study from 2014 to 2016.

PARTICIPANTS

Participants with fetal or childhood famine exposure (birth year 1949-1962) formed the exposure group.

MAIN OUTCOME MEASURE

Hyperuricemia was defined as uric acid (UA) > 420 μmol/L for men and > 360 μmol/L for women. The association of famine with hyperuricemia was assessed via regression analyses.

RESULTS

Early-life famine exposure was negatively associated with UA levels (P = .045) but was not associated with hyperuricemia (P = .226) in the whole study population. Economic status could moderate the association of famine exposure with UA and hyperuricemia (P ≤ .001). In participants with high economic status, early-life famine exposure was positively associated with UA levels (unstandardized coefficients 7.61, 95% CI 3.63-11.59, P < .001), and with hyperuricemia (odds ratio 1.47, 95% CI 1.19-1.81, P < .001).

CONCLUSIONS

Economic status could moderate the association between exposure to famine in early life and hyperuricemia in adulthood, indicating that the DBM might affect hyperuricemia in an opposite direction of the effects of undernutrition in early life alone.

Early-life exposure to famine and late-life depression: Does leukocyte telomere length mediate the association?

BACKGROUND

A positive association between early-life famine exposure and depression has been demonstrated. However, the mechanisms by which famine exposure in early life leads to late-life depression remains unclear. The present study examines the impact of leukocyte telomere length (LTL) and/or religiosity on the relationship between early-life famine exposure and late-life depression in a Chinese minority sample.

METHODS

A cross-sectional study of community-dwelling adults aged 55 or older was conducted in the Ningxia province of western China from 2013 to 2016. Multivariate ordinal logistic regression was used to examine the association between famine exposure and depression status, and a series mediation model was constructed to identify the mediation role of LTL and religiosity.

RESULTS

Compared with famine exposure during adulthood, fetal famine exposure was associated with a higher risk of late-life depression (adjusted odds ratio of 3.17, 95% CI: 1.36-7.38). A cumulative effect of fetal famine exposure on the risk of late-life depression was observed. Participants born in 1961 (the third year of the famine) had the strongest association with late-life depression. LTL played a mediating role in the association between famine exposure and depression which accounted for 21% of the total effect.

LIMITATIONS

The cross-sectional design prevents causal inferences regarding the relationships between famine and depression.

CONCLUSIONS

Fetal famine exposure was associated with an increased risk of late-life depression in a Chinese minority community-dwelling population. Telomere shortening partially mediated this association.

Association between famine exposure in early life with insulin resistance and beta cell dysfunction in adulthood

Objectives

Famine exposure in early life was associated with type 2 diabetes, non-alcoholic fatty liver disease and metabolic syndrome, etc. But evidence in early famine exposure and insulin resistance and beta cell dysfunction were limited. We aimed to investigate whether the association existed between famine exposure in early life and beta cell dysfunction and insulin resistance in adulthood.

Methods

In all, 7912 non-diabetic participants were included in this study, based on SPECT-China study. Participants with fetal or childhood famine exposure (birth year 1949–1962) were exposure group. Insulin resistance was estimated by the homeostasis model assessment index of insulin resistance (HOMA-IR). Beta cell function, represented by insulin secretion, was estimated by the disposition index. The associations of famine exposure with HOMA-IR and disposition index were assessed via linear regression.

Results

In men, we did not observe a significant association between early life famine exposure and ln(HOMA-IR) in all three models (P > 0.05 for all). However, in women, early life famine exposure were found to have significant association with ln(HOMA-IR) after adjustments for urbanization, severity of famine exposure, current smoker, waist circumference, hypertension, and dyslipidemia (unstandardized coefficients 0.055, 95% confidence interval 0.021, 0.088, P = 0.001). Early life famine exposure was observed to be negatively associated with ln(disposition index) after adjustments for the above potential confounders, both in men (model 3: unstandardized coefficients −0.042, 95% confidence interval −0.072,−0.012, P = 0.006) and women (model 3: unstandardized coefficients −0.033, 95% confidence interval −0.058,−0.009, P = 0.008).

Conclusions

In conclusion, exposure to famine in fetal- and childhood- life period is associated with beta cell dysfunction in males and females without diabetes, but early life famine exposure was only associated with insulin resistance in non-diabetic females. These results indicate that malnutrition in early life period may offer a modifiable factor for type 2 diabetes development.

Association Between Fetal Exposure to Famine and Anthropometric Measures in Adulthood: A Regression Discontinuity Approach

OBJECTIVE

The aim of this study was to investigate the differences in six anthropometric measurements of people born during and immediately after the 1959 to 1961 Great Chinese Famine using a regression discontinuity approach.

METHODS

Data were drawn from the baseline of the China Kadoorie Biobank study, and a subset of data from 76,912 participants was analyzed. We performed regression discontinuity among participants who were born during the famine (October 1959 to October 1962) and immediately after the famine period (November 1962 to October 1964) by using local linear and parametric regressions. All analyses were conducted by sex and study area.

RESULTS

Significantly, there were increases of 0.30 kg/m² (P = 0.007) in BMI, 0.81 kg (P = 0.028) in weight, 8.57 mm (P = 0.004) in waist circumference, and 5.07 mm (P = 0.004) in hip circumference for rural women who were exposed to famine during their fetal period compared with those who were not exposed to famine in utero. However, such statistically significant increases in anthropometric values were not observed in local linear regression and most parametric models among rural men or in the urban population.

CONCLUSIONS

Rural Chinese women who were exposed to famine during the fetal period were observed to have higher levels of BMI, weight, waist circumference, and hip circumference in adulthood.

Foetal and childhood exposure to famine and the risks of cardiometabolic conditions in adulthood: A systematic review and meta-analysis of observational studies

A systematic review and meta-analysis of observational studies was performed to provide a deeper understanding of the associations between foetal and childhood exposure to famine and the risks of type 2 diabetes mellitus (T2DM), metabolic syndrome, hypertension, hyperglycaemia, dyslipidaemia, obesity, overweight, coronary heart disease, stroke, and nonalcoholic fatty liver disease (NAFLD) in adulthood. Both foetal and childhood exposure to famine were positively associated with the risks of T2DM (foetal exposure: RR 1.37, 95% CI, 1.23-1.52; childhood exposure: RR 1.33, 95% CI, 1.08-1.64), metabolic syndrome (RR 1.26, 95% CI, 1.07-1.50; RR 1.24, 95% CI, 1.13-1.35), hypertension (RR 1.30, 95% CI, 1.07-1.57; RR 1.33, 95% CI, 1.02-1.74), hyperglycaemia (RR 1.27, 95% CI, 1.11-1.45; RR 1.25, 95% CI, 1.10-1.42), dyslipidaemia (RR 1.48, 95% CI, 1.33-1.66; RR 1.27, 95% CI, 1.12-1.45), obesity (RR 1.19, 95% CI, 1.02-1.39; RR 1.13, 95% CI, 1.00-1.28), overweight (RR 1.17, 95% CI, 1.07-1.29; RR 1.07, 95% CI, 1.00-1.14), coronary heart disease (RR 1.22, 95% CI, 1.00-1.51; RR 1.21, 95% CI, 1.09-1.35), and moderate-to-severe NAFLD (RR 1.66, 95% CI, 1.07-2.57; RR 1.68, 95% CI, 1.41-1.99) in adulthood. No association was observed for the risks of stroke or mild NAFLD. Adjustments for age, alcohol, smoking, body mass index, and physical activity nullified some associations. The associations were generally stronger in women than in men. In summary, foetal and childhood exposure to famine may confer greater risks of developing certain cardiometabolic conditions in adulthood, particularly in women. The extent to which risks for cardiometabolic conditions are associated with early-life famine appears to be determined by certain factors in adulthood.