Effect of Exposure to Famine during Early Life on Risk of Metabolic Syndrome in Adulthood: A Meta-Analysis

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.

Fetal programming and lactation: modulating gene expression in response to undernutrition during intrauterine life

BACKGROUND

Adverse environmental conditions during intrauterine life, known as fetal programming, significantly contribute to the development of diseases in adulthood. Fetal programming induced by factors like maternal undernutrition leads to low birth weight and increases the risk of cardiometabolic diseases.

METHODS

We studied a rat model of maternal undernutrition during gestation (MUN) to investigate gene expression changes in cardiac tissue using RNA-sequencing of day 0-1 litters. Moreover, we analyzed the impact of lactation at day 21, in MUN model and cross-fostering experiments, on cardiac structure and function assessed by transthoracic echocardiography, and gene expression changes though qPCR.

RESULTS

Our analysis identified specific genes with altered expression in MUN rats at birth. Two of them, Agt and Pparg, stand out for being associated with cardiac hypertrophy and fibrosis. At the end of the lactation period, MUN males showed increased expression of Agt and decreased expression of Pparg, correlating with cardiac hypertrophy. Cross-fostering experiments revealed that lactation with control breastmilk mitigated these expression changes reducing cardiac hypertrophy in MUN males.

CONCLUSIONS

Our findings highlight the interplay between fetal programming, gene expression, and cardiac hypertrophy suggesting that lactation period is a potential intervention window to mitigate the effects of fetal programming.

IMPACT

Heart remodeling involves the alteration of several groups of genes and lactation period plays a key role in establishing gene expression modification caused by fetal programming. We could identify expression changes of relevant genes in cardiac tissue induced by undernutrition during fetal life. We expose the contribution of the lactation period in modulating the expression of Agt and Pparg, relevant genes associated with cardiac hypertrophy. This evidence reveal lactation as a crucial intervention window for preventing or countering fetal programming.

Separate and combined effects of famine exposure and menarche age on metabolic syndrome among the elderly: a cross-sectional study in China

BACKGROUND

Epidemiological studies have revealed multiple risk factors for metabolic syndrome. However, there are no consistent findings on the association between famine exposure, age at menarche, and the prevalence of metabolic syndrome. This cross-sectional study aimed to reveal the individual and combined effects of famine exposure and age at menarche on the prevalence of metabolic syndrome among elderly women.

METHODS

Four thousand seven hundred seventy participants between 60 and 93 years of age were selected from the China Health and Retirement Longitudinal Study. Statistical differences between the baseline characteristics of famine exposure, age at menarche, and metabolic syndrome were evaluated using the t-test, F-test, and Chi-square test. Three multivariable-adjusted logistic regression models were used to test the association between famine exposure, age of menarche, and the odds ratio of metabolic syndrome.

RESULTS

Two thousand one hundred ninety-eight (46.08%) participants had metabolic syndrome, while 2572 (53.92%) participants did not. Furthermore, 3068 (64.32%) women reported onset of menarche under 15 years of age, while 1702 (35.68%) women reported onset of menarche above 16 years of age. Regarding the separate association of famine exposure and age of menarche with metabolic syndrome, in model three, the adolescence/adulthood famine exposure group vs. no famine exposure group odds ratio was 2.45 (95% CI 2.02, 2.97), and the older than 16 years vs. younger than 15 years group odds ratio was 1.23 (95% CI 1.09, 1.39), which was the highest odds ratio among the three models. Regarding the combined association of famine exposure and age of menarche with metabolic syndrome, in model three, among the age of menarche ≤ 15 years group, the adolescence/adulthood famine exposure vs. no famine exposure group odds ratio was 2.45 (95% CI: 1.91, 3.14); among the menarche age ≥ 16 years group, the adolescence/adulthood famine exposure stages vs. exposed group odds ratio was 3.27 (95% CI: 2.44, 4.38), which was the highest odds ratio among the three models.

CONCLUSION

These findings suggested that famine exposure and age at menarche, either separately or in combination, were positively associated with the prevalence of metabolic syndrome among older women.

Diabetes incidence in Austria: The role of famines on diabetes and related NCDs

Undernutrition in early life associates with increased risk for type 2 diabetes in later life. Whether similar associations hold for other diseases remains unclear. We aim to quantify how perinatal exposure to famines relates to the risk of becoming incident with type 2 diabetes in later life. Using population-wide medical claims data for Austrians aged >50y, yearly diabetes incidence was measured in an epidemiological progression model. We find incidence rates that increase from 2013 to 2017 and observe two famine-related birth cohorts of 5,887 patients with incidence rate increases for diabetes of up to 78% for males and 59% for females compared to cohorts born two years earlier. These cohorts show increased risks for multiple other diagnoses as well. Public health efforts to decrease diabetes must not only focus on lifestyle factors but also emphasize the importance of reproductive health and adequate nutrition during pregnancy and early postnatal life.

Maternal micronutrient disturbance as risks of offspring metabolic syndrome

Metabolic syndrome (MetS) is defined as a constellation of individual metabolic disturbances, including central obesity, hypertension, dyslipidemia, and insulin resistance. The established pathogenesis of MetS varies extensively with gender, age, ethnic background, and nutritional status. In terms of nutritional status, micronutrients are more likely to be discounted as essential components of required nutrition than macronutrients due to the small amount required. Numerous observational studies have shown that pregnant women frequently experience malnutrition, especially in developing and low-income countries, resulting in chronic MetS in the offspring due to the urgent and increasing demands for micronutrients during gestation and lactation. Over the past few decades, scientific developments have revolutionized our understanding of the association between balanced maternal micronutrients and MetS in the offspring. Examples of successful individual, dual, or multiple maternal micronutrient interventions on the offspring include iron for hypertension, selenium for type 2 diabetes, and a combination of folate and vitamin D for adiposity. In this review, we aim to elucidate the effects of maternal micronutrient intake on offspring metabolic homeostasis and discuss potential perspectives and challenges in the field of maternal micronutrient interventions.

Famine Exposure during Early Life and Risk of Cancer in Adulthood: A Systematic Review and Meta-Analysis

OBJECTIVES

Emerging evidences have explored the association between famine exposure during early life and cancer risk in adulthood, but the results remain controversial and inconsistent. This study aimed to provide a comprehensive evidence on the relation of famine exposure to later cancer risk.

DESIGN

Systematic review and meta-analysis.

METHODS

Relevant reports published up to March, 2022 were identified by searching PubMed, Embase, Web of sciences and Medline databases. Pooled relative ratios (RRs) with 95% confidence intervals (CIs) were used to evaluate the effect famine exposure on cancer risk.

RESULTS

Totally, 18 published articles with 6,061,147 subjects were included in this study. Compared with unexposed group, early life famine exposure dramatically increased the risk of cancer in adulthood (RR=1.13, 95% CI: 1.04-1.22). The pooled RRs were different in terms of sex, exposure severity, exposure period, famine type, study design type and cancer location. A remarkably elevated risk for cancer was discerned in women exposed to famine (RR=1.09, 95% CI: 1.00-1.18), severe exposure (RR=1.12, 95% CI: 1.02-1.22) and adolescence exposure (RR=1.76, 95% CI: 1.02-2.50), Chinese famine exposure (RR=1.55, 95% CI: 1.29-1.82) and cohort studies (RR=1.28, 95% CI: 1.13-1.42). Moreover, a significant association of early-life famine exposure with increased risk of breast (RR=1.16, 95% CI: 1.05-1.27) and stomach cancers (RR=1.89, 95% CI: 1.24-2.54) was observed.

CONCLUSION

This meta-analysis suggests that exposure to famine during early life may increase the risk of cancer in adulthood. The above-mentioned association is pronounced in women exposed to famine, severe exposure, adolescence exposure, Chinese famine, cohort studies, breast and stomach cancers. It is essential for decision-makers to take targeted measures for improving population awareness regarding the long-term effect of early life nutritional status.

Effects of fetal famine exposure on the cardiovascular disease risk in the metabolic syndrome individuals

BACKGROUND

Patients with metabolic syndrome (MS) have a higher incidence of cardiovascular disease (CVD), but the possible mechanisms are not fully understood and further exploration of the possible factors influencing the high incidence of CVD in patients with MS is still needed.

OBJECTIVES

This study aims to examine the association between fetal famine exposure and the risk of CVD in adulthood with MS.

METHODS

Of 13,744 MS patients free of CVD selected from the Kailuan Study in 2006 (referred as the baseline survey) were included in the study. China suffered a severe famine from 1959 to 1962, so the participants born during this period were classified as the uterine famine exposed group. All patients were born between January 1, 1949, and December 31, 1974. Based on the date of birth, all patients were divided into the no-exposed group (born between January 1, 1963, and December 31, 1974), uterine famine exposed group (born between January 1, 1959 and December 31, 1962), and childhood famine exposed group (born between January 1, 1949 and December 31, 1958). After following up to December 31, 2019, the weighted Cox regression analysis model was used to calculate the effect of early life famine exposure in MS individuals on the risk of CVD in adulthood.

RESULTS

During the 12.12 years of follow-up, the incidence of CVD was 5.87%, 10.13%, and 10.90% in the no-exposed group, uterine famine exposed group, and childhood famine exposed group, respectively. Compared with participants in the no-exposed group, the CVD risk and stroke risk increased in participants in the uterine famine exposed group (for CVD, HR: 1.32, 95% CI 1.04-1.67; for stroke, HR:1.37, 95% CI 1.05-1.79), but not in childhood famine exposed group. However, the increased CVD risks were only observed in females or smokers. No increased MI risks were observed for participants in the uterine famine exposed group or childhood famine exposed group.

CONCLUSIONS

Our findings suggested that exposure to famine during uterine life might increase the risk of CVD in adulthood in participants with MS.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

INTERPRETATION

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

Sex Differences at Early Old Stage in Glycolipid Metabolism and Fatty Liver in Offspring Prenatally Exposed to Chinese Great Famine

Background

About 50 years ago, Chinese Great Famine (CGF) affected the entire population in China, and its long-term influence on the offspring has attracted significant attention for research. However, information on possible metabolic differences between sexes is limited. This study explored whether there might be sex differences in the risks of development of glucolipid metabolic dysfunction and fatty liver following prenatal exposure to CGF.

Materials and Methods

There were 11,417 subjects around 55 years of age (6,661 women and 4,756 men). They were divided as the exposed group in which the fetal stage was in CGF, and the unexposed group included those born after CGF. Analysis focused on comparisons between sexes.

Results

Compared to the unexposed group, the BMI and triglyceride (P &lt; 0.05) in men were higher in exposed group, while waist circumference and blood sugar (P &lt; 0.05) in the exposed women were significantly higher. With the ages being properly balanced, the risks of glycolipid metabolic dysfunction were significantly higher in both men and women in the exposed than in the unexposed group (P &lt; 0.001). Prenatal exposure to CGF significantly increased risks of abnormal BMI (P &lt; 0.001, 95% CI: 2.305–2.93), blood sugar (P &lt; 0.05, 95% CI: 1.050–1.401), triglycerides (P &lt; 0.05, 95% CI: 1.006–1.245), and fatty liver (P &lt; 0.001, 95% CI: 1.121–1.390) in men, and increased risks of abnormal blood sugar (P &lt; 0.05, 95% CI: 1.024–1.689) and positive urine sugar (P &lt; 0.05, 95% CI: 1.062–6.211) in women. Height and body weight were either the same or higher in the exposed subjects compared with the unexposed ones, regardless of sexes.

Conclusion

This study is the first to identify sex differences in the long-term effects of CGF on metabolism and fatty liver. Importance of the findings include the benefits of prescribing medicine for the early prevention of certain diseases for each sex before aging based on the differences revealed. This study also shows “catch-up growth” in the offspring prenatally exposed to CGF as possible mechanisms underlying the long-term effects.

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.

Fetal Exposure to Chinese Famine Increases Obesity Risk in Adulthood

Fetal exposure to famine may have long-term consequences in adulthood. The purpose of the present study was to explore the association between famine exposure in fetal life (Chinese famine in 1959–1961) and obesity risk in adulthood. A total of 8054 subjects (3422 male, 4632 female) were recruited from the cross-sectional 2010–2012 China National Nutrition and Health Survey (CNNHS). The subjects born in 1960 and 1961 were selected as the exposed group, while the subjects born in 1963 were selected as the unexposed group. Multiple linear or logistic regression was performed to examine the association between fetal exposure to famine and risk of obesity (body mass index (BMI), waist circumference (WC), obesity, central obesity) adjusting for gender, education level, economic status, physical exercise, sedentary time, smoking, drinking, the intake of livestock and poultry and the intake of cereal and beans. Compared with the unexposed group, WC increased by 0.52 cm after adjusting the covariates (p = 0.021) and females in the exposed group had a significantly higher prevalence of central obesity with an odds ratio (OR) of 1.15 (1.01,1.31) after adjusting the confounders (p = 0.030). WC increased by 0.71 cm, 1.21 cm after adjusting the covariates compared with the unexposed group among the total subjects and the female subjects in urban areas (p = 0.021, p = 0.001). The female subjects had a significantly higher prevalence of obesity and central obesity, with ORs of 1.34 (1.04,1.71) (p = 0.022), 1.28 (1.07,1.53) (p = 0.008) respectively. Our results suggest that fetal exposure to the Chinese famine increased obesity risk in adulthood, and the association was stronger in female and urban subjects.

Prevalence and Correlation of Metabolic Syndrome: A Cross-Sectional Study of Nearly 10 Million Multi-Ethnic Chinese Adults

PURPOSE

This study aimed to examine the prevalence and correlates of metabolic syndrome (MetS) in multi-ethnic populations of Northwest China based on Large-scale provincial health checking data.

PATIENTS AND METHODS

A total of 9,745,640 Chinese aged ≥18 years in Xinjiang, the largest autonomous region of multi-ethnic in China, were enrolled from Feb. to Sep. 2019. MetS was defined by modified Adult Treatment Panel (ATP III) criteria.

RESULTS

The overall prevalence of MetS was 20.85% [Sex: 20.06% female, 21.56% male; Age: 39.22% 60-years and above, 26.32% 40- to 59-years and 9.56% 18- to 39-years; Ethnicity: 28.19% Hui followed by Han (26.39%), Uyghur (18.56%), Other (18.61%), Kazak (17.98%), Mongolian (17.87%), Kyrgyz (14.44%)]. People living in cities and towns (23.03%) or North (24.78%) had higher prevalence of MetS than rural (19.94%) and South (17.66%). Although the prevalence of hypertension, smoking, drinking and lack of physical activity were higher in Kyrgyz, Mongolian and Kazak than those of other ethnic groups, the risk of MetS was lower.

CONCLUSION

The results indicated that a high prevalence of MetS in Hui and Han groups and people living in cities and towns. Living in North Xinjiang and elder population tend to have higher prevalence of MetS. The prevention and management of MetS in these populations should be prioritized.