Long-Term Effects of Famine on Chronic Diseases: Evidence from China's Great Leap Forward Famine

Exposure to early-life adversity and long-term trajectories of multimorbidity among older adults in China: analysis of longitudinal data from the China Health and Retirement Longitudinal Study

OBJECTIVES

This study aimed to identify long-term distinct trajectories of multimorbidity with ageing from 50 to 85 years among Chinese older adults and examine the relationship between exposure to early-life adversity (ELA; including specific types of adversity and accumulation of different adversities) and these long-term multimorbidity trajectories.

DESIGN

The group-based trajectory models identified long-term multimorbidity trajectories. Multinomial logistic regression models were used to examine the relationship between ELA and the identified multimorbidity trajectories.

SETTING

This study used data from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2018) and the 2014 Life History Survey.

PARTICIPANTS

We used data from 9112 respondents (aged 60 and above) of the 2018 wave of CHARLS.

OUTCOME MEASURES

Each respondent's history of chronic conditions and experiences of ELA were collected from the 2011-2018 waves of CHARLS and the 2014 Life History Survey.

RESULTS

Four heterogeneous long-term trajectories of multimorbidity development were identified: 'maintaining-low' (19.1%), 'low onset-rapidly increasing' (23.3%), 'middle onset-moderately increasing' (41.5%) and 'chronically-high' (16.2%). Our findings indicated that the heterogeneity can be explained by ELA experiences. Across various types of different ELA experiences, exposure to food insufficiency (relative risk ratios from 1.372 (95% CI 1.190 to 1.582) to 1.780 (95% CI 1.472 to 2.152)) and parental quarrel/divorce (relative risk ratios from 1.181 (95% CI 1.000 to 1.394) to 1.262 (95% CI 1.038 to 1.536)) had the most prominent associations with health deterioration. The accumulation of more different ELA experiences was associated with a higher relative risk of developing more severe multimorbidity trajectories (relative risk ratio for five to seven ELAs and chronically high trajectory: 7.555, 95% CI 4.993 to 11.431).

CONCLUSIONS

There are heterogeneous long-term trajectories of multimorbidity in Chinese older adults, and the risk of multimorbidity associated with ELA accumulates over the lifespan. Our findings highlight the role of a supportive early-life family environment in promoting health development across the lifespan, advocating for the integration of life-course approaches to implementing health disparity interventions.

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.

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.

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.

Progression of depressive symptoms after early exposure to famine: The China Health and Retirement Longitudinal Study

BACKGROUND

The effect of early exposure to famine on progression of depressive symptoms has not been studied and the Chinese Famine offers a unique opportunity to explore this association with its long duration and widespread influence.

OBJECTIVE

To investigate the longitudinal association of early famine exposure with subsequent depressive symptoms and whether there existed a critical exposure period.

METHODS

Data from the China Health and Retirement Longitudinal Study (CHARLS) were analysed. Famine exposure was evaluated retrospectively in 2014 and severe famine exposure was defined as starvation to death of family members. Depressive symptoms were assessed prospectively from wave 1 (2011-2012) to wave 4 (2018) using the 10-item Center for Epidemiological Studies Depression Scale (CES-D). Linear mixed model and Cox proportional hazards model were applied to evaluate associations of famine exposure with progression or occurrence of depressive symptoms.

RESULTS

A total of 7053 participants were included. Compared with no famine exposure, severe famine exposure was associated with a faster growth in CES-D score (0.169 point/year, 95 % CI 0.035 to 0.304, P = 0.013) and an elevated risk of occurrence of depressive symptoms (HR 1.360, 95 % CI 1.069 to 1.729, P = 0.012). Further analysis revealed that famine exposure during middle childhood was associated with a faster growth in CES-D score (0.404 point/year, 95 % CI 0.164 to 0.644, P = 0.001).

LIMITATIONS

This is an observational study therefore causal relationship cannot be concluded.

CONCLUSIONS

Early exposure to severe famine was associated with aggravation of depressive symptoms. Middle childhood might be a critical time window for depression prevention.

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.

The relationship between famine exposure during early life and carotid plaque in adulthood

BACKGROUND

Famine exposure is a potential risk factor for adverse cardiometabolic health. However, the relationship between famine exposure during early life and carotid plaque in adulthood remains unclear. Therefore, the aim was to investigate the relationship between famine exposure during early life and the risks for carotid plaque in adulthood.

METHODS

This was a cross-sectional study. Data were collected between 2017 and 2018 in Guangdong, China. Subjects who were born between 1 October 1952 and 30 September 1964, and had the carotid ultrasound measurement were enrolled. All included participants were divided into five groups: no exposure, fetal exposure, early-childhood exposure, mid-childhood exposure, and late-childhood exposure. Carotid plaque was assessed by carotid ultrasound examination. Multivariate logistic regression was used to estimate the odds ratio (OR) and confidence interval (CI) between famine exposure and carotid plaque.

RESULTS

There were 2652 subjects enrolled, 973 (36.7%) of them were males, and the mean age was 59.1 ± 3.6 years. The prevalence of carotid plaque in unexposed, fetal-exposed, early-childhood, mid-childhood, and late-childhood exposed groups were 40.2%, 40.8%, 55.3%, 56.8%, and 62.1%, respectively. When compared with the unexposed group, the fully adjusted ORs for carotid plaque from fetal-exposed, early-childhood, mid-childhood to late-childhood exposed were 1.023 (95% CI: 0.771, 1.357, P = 0.872), 1.755 (95% CI: 1.356, 2.275, P < 0.001), 1.780 (95% CI: 1.391, 2.280, P < 0.001), and 2.119 (95% CI: 1.643, 2.739, P < 0.001), respectively. Subgroup analyses showed that the famine effect on carotid plaque did not interact with body mass index, gender, smoking status, hypertension, and diabetes history (all P for interaction > 0.500).

CONCLUSIONS

Famine exposure during early life was significantly associated with an increased risk of carotid plaque in adulthood.

Impact of Early Life or Intrauterine Factors and Socio-Economic Interaction on Diabetes - An Evidence on Thrifty Hypothesis

Diabetes mellitus is one of the most concerning non-communicable diseases worldwide. The prevalence of diabetes increased rapidly by the influence of socioeconomic interactions. The thrifty hypothesis postulates that certain genes that are involved in positive selection promote efficient fat deposition and storage. This is beneficial for the survival of mankind in adverse conditions. However, in this modern society, these genes have become disadvantageous as people are significantly less likely to experience famines and nutrition shortages. The socioeconomic development that has occurred during the 20th century induced abundance of food supplies in almost all regions of the world. This has led to a rapid rise in the prevalence of obesity, and type 2 diabetes as a consequence. Boom of diabetic pandemic in newly developed countries compare with others those who developed gradually can be explain by thrifty hypothesis, as a result of the difference in the exposure to environmental factors and famine by the ancestors leads. The globalization, urbanization, lack of physical activity, intake of high calorie food and migration is major cause of pandemic emergence of diabetes in high as well as middle and low-income countries.

Early-Life Exposure to the Chinese Famine and Risk of Cognitive Decline

Previous studies on the Chinese famine suggested long-term effects of early-life famine exposure on health conditions. This study aims to investigate the association between exposure to the Chinese famine of 1959-1961 at different early-life stages and the risk of cognitive decline in adulthood. A total of 6417 adults born between 1952 and 1964 in the 2015 survey data of China Health and Retirement Longitudinal Study were included in this study. Cognitive performance was estimated through a series of comprehensive neuropsychological tests, including the Telephone Interview of Cognitive Status (TICS-10), word recall, and pentagon drawing. Multiple generalized linear model (GLM) was employed to detect the association between multi-stage early-life famine exposure and late-life cognitive performance. Compared with the unexposed group, respondents exposed to famine in the fetal period performed worse in the TICS (difference -0.52, 95% confidence interval (CI): -0.93 to -0.10), word recall (difference -0.46, 95% CI: -0.74 to -0.19), and general cognition (difference -1.05, 95% CI: -1.64 to -0.47). Furthermore, we also found negative effects of famine exposure on performance of word recall and pentagon drawing in the early (word recall difference -0.56, 95% CI: -1.00 to -0.11; pentagon drawing difference -0.76, 95% CI: -1.40 to -0.12), mid (word recall difference -0.46, 95% CI: -0.81 to -0.11; pentagon drawing difference -0.66, 95% CI: -1.16 to -0.16), and late (word recall difference -0.30, 95% CI: -0.55 to -0.04; pentagon drawing difference -0.75, 95% CI: -1.13 to -0.37) childhood-exposed groups. Early-life famine exposure in different stages is positively associated with late-life cognitive decline. Fetal famine exposure might affect the overall cognitive status in adulthood, and childhood famine exposure has potential adverse effects on visuospatial episodic memory.

Prenatal malnutrition and adult cognitive impairment: a natural experiment from the 1959-1961 Chinese famine

The current measures of cognitive functioning in adulthood do not indicate a long-term association with prenatal exposure to the Dutch famine. However, whether such association emerges in China is poorly understood. We aimed to investigate the potential effect of prenatal exposure to the 1959-1961 Chinese famine on adult cognitive impairment. We obtained data from the Second National Sample Survey on Disability implemented in thirty-one provinces in 2006, and restricted our analysis to 387 093 individuals born in 1956-1965. Cognitive impairment was defined as intelligence quotient (IQ) score under 70 and IQ of adults was evaluated by the Wechsler Adult Intelligence Scale - China Revision. Famine severity was defined as excess death rate. The famine impact on adult cognitive impairment was estimated by difference-in-difference models, established by examining the variations of famine exposure across birth cohorts. Results show that compared with adults born in 1956-1958, those who were exposed to Chinese famine during gestation (born in 1959-1961) were at greater risk of cognitive impairment in the total sample. Stratified analyses showed that this effect was evident in males and females, but only in rural, not in urban areas. In conclusion, prenatal exposure to famine had an enduring deleterious effect on risk of cognitive impairment in rural adults.

Long-term effect of prenatal exposure to malnutrition on risk of schizophrenia in adulthood: Evidence from the Chinese famine of 1959-1961

BACKGROUND

Schizophrenia is a common major mental disorder and prenatal nutritional deficiency may increase its risk. We aimed to investigate long-term impact of prenatal exposure to malnutrition on risk of schizophrenia in adulthood using the Chinese famine of 1959-1961 as a natural experiment.

METHODS

We obtained data from the Second National Sample Survey on Disability implemented in 31 provinces in 2006, and restricted our analysis to 387,093 individuals born from 1956 to 1965. Schizophrenia was ascertained by psychiatrists based on the International Statistical Classification of Diseases, Tenth Revision. Famine severity was defined as cohort size shrinkage index. The famine effect on adult schizophrenia was estimated by difference-in-difference models, established by examining the variations of famine exposure across birth cohorts.

RESULTS

Compared with the reference cohort of 1965, famine cohorts (1959-1962) had significantly higher odds (OR: 1.84; 95% CI: 1.13, 3.00; P = 0.014) of schizophrenia in the rural population. After adjusting for multiple covariates, this association remained significant (OR: 1.82; 95% CI: 1.11, 2.98; P = 0.018). We did not observe statistically significant differences in odds of schizophrenia among famine cohorts compared with the reference cohort in the urban population.

CONCLUSIONS

Prenatal malnutrition exposure has a detrimental impact on risk of schizophrenia in adulthood in the rural population. Further studies were needed to investigate corresponding mechanisms on this topic.