Infant diarrhoea and subsequent mortality from heart disease and cancer

Birth in High Infant Mortality States and Dementia Risk in a Cohort of Elderly African American and White Health Care Members

IMPORTANCE

Birth in areas with high infant mortality rates (IMRs) has been linked to worse long-term health outcomes, yet it is completely unknown if it impacts dementia risk.

METHODS

In total 6268 health care members were followed for dementia diagnosis from 1996 to 2015. Birth state IMRs from 1928 were ranked into quartile (worst IMRs quartile range, whites: 69 to 129 deaths/1000 live births, Non-whites: 129 to 277 deaths/1000 live births). Cox proportional hazard models estimated the dementia risk associated with birth state IMR quartile adjusting for demographics and lifecourse health indicators.

RESULTS

Compared with whites born outside of states in the worst IMR quartile, African Americans born in states in the worst IMR quartile had 92% increased dementia risk (HR=1.92; 95% CI: 1.42, 2.59), and African Americans born outside those states had 36% increased risk (HR=1.36; 95% CI: 1.20, 1.53). There was no association between birth state IMR and dementia risk among whites.

CONCLUSIONS

Birth in states with the highest rates of infant mortality was associated with elevated dementia risk among African Americans but not whites. The large absolute difference in IMRs likely reflects harsher early childhood conditions experienced by African Americans. These findings suggest that childhood conditions may play a role in racial disparities in dementia rates.

Environmental enteropathy is associated with cardiometabolic risk factors in Peruvian children

Environmental enteropathy (EE) is a syndrome of altered small intestine structure and function hypothesized to be common among individuals lacking access to improved water and sanitation. There are plausible biological mechanisms, both inflammatory and non-inflammatory, by which EE may alter the cardiometabolic profile. Here, we test the hypothesis that EE is associated with the cardiometabolic profile among young children living in an environment of intense enteropathogen exposure. In total, 156 children participating in the Peruvian cohort of a multicenter study on childhood infectious diseases, growth and development were contacted at 3-5 years of age. The urinary lactulose:mannitol ratio, and plasma antibody to endotoxin core were determined in order to assess intestinal permeability and bacterial translocation. Blood pressure, anthropometry, fasting plasma glucose, insulin, and cholesterol and apolipoprotein profiles were also assessed. Extant cohort data were also used to relate biomarkers of EE during the first 18 months of life to early child cardiometabolic profile. Lower intestinal surface area, as assessed by percent mannitol excretion, was associated with lower apolipoprotein-AI and lower high-density lipoprotein concentrations. Lower intestinal surface area was also associated with greater blood pressure. Inflammation at 7 months of age was associated with higher blood pressure in later childhood. This study supports the potential for a relationship between EE and the cardiometabolic profile.

Auxological perspectives on 'growth' in DOHaD

David Barker established growth as a seminal link between early development and later health attainment and disease risk. This was nothing less than a paradigm shift in health and medicine, turning the focus of disease causality away from contemporary environmental influences to earliest growth as a time when functional anatomy and physiology sets in place critical structures and function for a lifetime. Barker's prodigious work investigated time- and place-specific interactions between maternal condition and exogenous environmental influences, focusing on how growth unfolds across development to function as a mechanistic link to ensuing health. Subsequent applications do not always attend to the specificity and sensitivity issues included in his original work, and commonly overlook the long-standing methods and knowledge base of auxology. Methodological areas in need of refinement include enhanced precision in how growth is represented and assessed. For example, multiple variables have been used as a referent for 'growth,' which is problematic because different body dimensions grow by different biological clocks with unique functional physiologies. In addition, categorical clinical variables obscure the spectrum of variability in growth experienced at the individual level. Finally, size alone is a limited measure as it does not capture how individuals change across age, or actually grow. The ground-breaking notion that prenatal influences are important for future health gave rise to robust interest in studying the fetus. Identifying the many pathways by which size is realized permits targeted interventions addressing meaningful mechanistic links between growth and disease risk to promote health across the lifespan.

Early-Life Environmental Exposures and Height, Hypertension, and Cardiovascular Risk Factors Among Older Adults in India

Environmental exposures like rainfall and temperature influence infectious disease exposure and nutrition, two key early-life conditions linked to later-life health. However, few tests of whether early-life environmental exposures impact adult health have been performed, particularly in developing countries. This study examines the effects of experiencing rainfall and temperature shocks during gestation and up through the first four years after birth on measured height, hypertension, and other cardiovascular risk factors using data on adults aged 50 and above (N = 1,036) from the 2007-2008 World Health Organization Study on Global Ageing and Adult Health (SAGE) and district-level meteorological data from India. Results from multivariate logistic regressions show that negative rainfall shocks during gestation and positive rainfall shocks during the postbirth period increase the risk of having adult hypertension and CVD risk factors. Exposure to negative rainfall shocks and positive temperature shocks in the postbirth period increases the likelihood of falling within the lowest height decile. Prenatal shocks may influence nutrition in utero, while postnatal shocks may increase exposure to infectious diseases and malnutrition. The results suggest that gestation and the first two years after birth are critical periods when rainfall and temperature shocks take on increased importance for adult health.

Aging in the context of cohort evolution and mortality selection

This study examines historical patterns of aging through the perspectives of cohort evolution and mortality selection, where the former emphasizes the correlation across cohorts in the age dependence of mortality rates, and the latter emphasizes cohort change in the acceleration of mortality over the life course. In the analysis of historical cohort mortality data, I find support for both perspectives. The rate of demographic aging, or the rate at which mortality accelerates past age 70, is not fixed across cohorts; rather, it is affected by the extent of mortality selection at young and late ages. This causes later cohorts to have higher rates of demographic aging than earlier cohorts. The rate of biological aging, approximating the rate of the senescence process, significantly declined between the mid- and late-nineteenth century birth cohorts and stabilized afterward. Unlike the rate of demographic aging, the rate of biological aging is not affected by mortality selection earlier in the life course but rather by cross-cohort changes in young-age mortality, which cause lower rates of biological aging in old age among later cohorts. These findings enrich theories of cohort evolution and have implications for the study of limits on the human lifespan and evolution of aging.

Cohort Morbidity Hypothesis: Health Inequalities of Older Māori and non-Māori in New Zealand

This paper describes the mortality trends from 1948 to 2008 between Māori and non-Māori populations. Using the cohort morbidity hypothesis, we propose that health disparities between the populations can be partially explained by different levels of early-life exposure to infectious diseases. We conducted regression analysis and found strong associations between early- and old-age mortality for cohorts. Childhood mortality, rather than mid-life mortality, accounted for greater variance in older age. The mortality trend of the 1948 Māori birth cohort is similar to the 1902 non-Māori birth cohort 46 years earlier. Implications are discussed.

Childhood Morbidity and Health in Early Adulthood: Life course linkages in a high morbidity context

This paper examines whether morbidity in early and later childhood is associated with health later in life. I investigate the relationship between five types of childhood morbidity and risk factors for cardiovascular disease among Guatemalan adults who experienced high levels of morbidity in childhood. The analysis is based on the Human Capital Study (2002-2004), a recent follow-up of the INCAP Longitudinal Study conducted between 1969 and 1977. I find that most types of childhood morbidity are associated with poorer adult health, independent of family background, adult socioeconomic status, and health behaviors. Higher levels of infections in childhood were associated with a low level of high density lipoprotein (HDL), and higher level of triglycerides, plasma glucose, waist circumference, and obesity (but not hypertension). These results are consistent with the literature that finds that childhood morbidity is associated with increased morbidity and mortality at older ages. However, diarrheal disease in later childhood was associated with lower levels of some risk factors, as measured by triglycerides and plasma glucose, suggesting that exposure to bacteria after infancy may be beneficial for some measures of adult health.

Rationale and methodological options for assessing infectious disease and related measures in social science surveys

Infectious disease is an important, but often overlooked, component of population health in high-income nations. Common, everyday infections exact significant costs, including school and work absenteeism, reduced productivity, and substantial health care expenditures. Infectious disease also shapes trajectories of biological risk and health and may be causally linked to chronic disease risk later in life. The size, diversity, and representativeness of samples typically employed in survey-based studies of health present exceptional opportunities for advancing scientific knowledge on the social and economic determinants of infectious disease in childhood and adulthood and to investigate the long-term consequences of infectious disease for well-being and attainment across multiple domains. A wide range of interview-based, anthropometric, and biomarker measurement options are currently available for assessing infectious exposures, inflammation, and immune function in nonclinical settings. These methods afford opportunities for innovative, transdisciplinary research on the causes and consequences of infectious disease across the life course that can address questions of interest to social, life, and biomedical scientists.

Diarrhoea in childhood and cause-specific mortality in older age: analyses of 5642 deaths in 33,261 individuals from the Hertfordshire studies

The objective of these analyses were to examine if episodes of diarrhoea in childhood are related to adult coronary heart disease (CHD) mortality. Data were pooled from two prospective UK cohort studies (participants born 1923--1939). Reported diarrhoea in infancy (3.1%) and between 1 and 5 years (1.1%) was rare. No relationship between diarrhoea in infancy and CHD mortality or mortality from all-causes and cardiovascular disease was observed. Although diarrhoea between 1 and 5 years was also not related to CHD risk, slightly lower rates of total and cardiovascular disease mortality were apparent in this group relative to the diarrhoea-free. In the largest study to date to examine the relation, there was no evidence that diarrhoea in early life had an influence on later CHD mortality.

Breast-Feeding in London, 1905–19

Medical Officer of Health reports for London boroughs, 1900–19, are analysed to determine the incidence of neonatal breast-feeding, duration of lactation, reasons for early supplementation and premature weaning, and their relationship with infant mortality. In a sample of 222,989 infants, breast-feeding rates were very high. Over 90% were breast-fed in the first month, almost 80% at 3 months, and over 70% at 6 months. The poorest boroughs had the highest rates of neonatal breast-feeding, but also a higher incidence of early supplementation and premature weaning. There was a significant positive correlation between breast-feeding and infant mortality due to poor maternal diet and health, poor nutritional quality of supplementary and substitute foods, and the use of an unhygienic feeding bottle. Energetic campaigns to counteract these problems probably contributed to the fall of infant mortality in this period.

The association of childhood socioeconomic conditions with healthy longevity at the oldest-old ages in China

Based on unique data from the largest-ever sample of the Chinese oldest-old aged 80 and older, our multivariate logistic regression analyses show that either receiving adequate medical service during sickness in childhood or never/rarely suffering from serious illness during childhood significantly reduces the risk of being ADL (activities of daily living) impaired, being cognitively impaired, and self-reporting poor health by 18%-33% at the oldest-old ages. Estimates of effects for five other indicators of childhood conditions are similarly positive but mostly not statistically significant. Multivariate survival analysis shows that better childhood socioeconomic conditions in general tend to reduce the four-year period mortality risk among the oldest-old. But after additional controls for 14 covariates are put into the model, the effects are not statistically significant, thus suggesting that most of the effects of childhood conditions on oldest-old mortality are indirect-at least to the point of affecting current health status at the oldest-old ages, which itself is strongly associated with mortality. While acknowledging limitations of the present analyses due to a lack of information on childhood illness, the oldest-olds'recollection errors, and other data problems, we conclude, based on this and other studies, that policies that enhance childhood health care and children's socioeconomic well-being can have large and long-lasting benefits up to the oldest-old ages.

Association of diarrhoea in childhood with blood pressure and coronary heart disease in older age: analyses of two UK cohort studies

BACKGROUND

There is a suggestion that acute dehydration in childhood may lead to elevated blood pressure. We examined if episodes of diarrhoea in childhood, a recognized proxy for acute dehydration, were related to measured blood pressure and coronary heart disease in older adults.

METHODS

Data were pooled from two prospective UK cohort studies (participants born 1920-39) in which episodes of diarrhoea were ascertained from health visitor records from birth until 5 years of age. Blood pressure and coronary heart disease were assessed during medical examination in men and women over 64 years of age. In total, 5203 men and women had data on diarrhoea in early life, adult blood pressure and a range of covariates; 4181 of these also had data on coronary heart disease status.

RESULTS

The prevalence of diarrhoea in infancy (3.3%) and between 1 and 5 years (1.1%) was low. There was no relation of diarrhoea from either period (age- and sex-adjusted results for diarrhoea in infancy presented here) with measured blood pressure [coefficient for systolic; 95% CI (confidence interval): 0.44; -2.88-3.76] or coronary heart disease (Odds ratio, OR; 95% CI: 0.91; 0.54-1.54) in adulthood. There was a similar lack of association when hypertension was the outcome of interest. These observations were unchanged after adjustment for a range of covariates.

CONCLUSIONS

In the largest study to date to examine the relation, there was no evidence that diarrhoea in early life had an influence on measured blood pressure, hypertension or coronary heart disease in older adults.

The origins of the developmental origins theory

Current orthodoxy states that coronary heart disease results from the unhealthy lifestyles of westernized adults together with a contribution from genetic inheritance. This does not provide a secure basis for prevention of the disease. Geographical studies gave the first clue that the disease originates during intra-uterine development. Variations in mortality from the disease across England and Wales were shown to correlate closely with past differences in death rates among newborn babies. In the past most deaths among newborns were attributed to low birthweight. This led to the hypothesis that undernutrition in utero permanently changes the body's structure, function and metabolism in ways that lead to coronary heart disease in later life. The association between low birthweight and coronary heart disease has been confirmed in longitudinal studies of men and women around the world. The developmental model of the origins of the disease offers a new way forward.

Early-life origins of the race gap in men's mortality

Using a life course framework, we examine the early life origins of the race gap in men's all-cause mortality. Using the National Longitudinal Survey of Older Men (1966-1990), we evaluate major social pathways by which early life conditions differentiate the mortality experiences of blacks and whites. Our findings indicate that early life socioeconomic conditions, particularly parental occupation and family structure, explain part of the race gap in mortality. Black men's higher rates of death are associated with lower socioeconomic standing in early life and living in homes lacking both biological parents. However these effects operate indirectly through adult socioeconomic achievement processes, as education, family income, wealth, and occupational complexity statistically account for the race gap in men's mortality. Our findings suggest that policy interventions to eliminate race disparities in mortality and health should address both childhood and adult socioeconomic conditions.

Infection, inflammation, height, and longevity

Using historical data from cohorts born before the 20th century in four northern European countries, we show that increasing longevity and declining mortality in the elderly occurred among the same birth cohorts that experienced a reduction in mortality at younger ages. Concurrently, these cohorts also experienced increasing adult height. We hypothesize that both the decline in old-age mortality and the increase in height were promoted by the reduced burden of infections and inflammation. Thus, early growth and cardiovascular diseases of old age may share infectious and inflammatory causes rooted in the external environment.

Inflammatory exposure and historical changes in human life-spans

Most explanations of the increase in life expectancy at older ages over history emphasize the importance of medical and public health factors of a particular historical period. We propose that the reduction in lifetime exposure to infectious diseases and other sources of inflammation--a cohort mechanism--has also made an important contribution to the historical decline in old-age mortality. Analysis of birth cohorts across the life-span since 1751 in Sweden reveals strong associations between early-age mortality and subsequent mortality in the same cohorts. We propose that a "cohort morbidity phenotype" represents inflammatory processes that persist from early age into adult life.

The long arm of childhood: The influence of early-life social conditions on men’s mortality

Increasingly, social scientists are turning to childhood to gain a better understanding of the fundamental social causes of adult mortality. However, evidence of the link between childhood and the mortality of adults is fragmentary, and the intervening mechanisms remain unclear. Drawing on the National Longitudinal Survey of Older Men, our analysis shows that men’s mortality is associated with an array of childhood conditions, including socioeconomic status, family living arrangements, mother’s work status, rural residence, and parents’ nativity. With the exception of parental nativity, socioeconomic-achievement processes in adulthood and lifestyle factors mediated these associations. Education, family income, household wealth, and occupation mediated the influence of socioeconomic status in childhood. Adult lifestyle factors, particularly body mass, mediated the effects of family living arrangements in childhood, mother’s work status, and rural residence. Our findings bring into sharp focus the idea that economic and educational policies that are targeted at children’s well-being are implicitly health policies with effects that reach far into the adult life course.

Does childhood health affect chronic morbidity in later life?

Our analysis examines whether childhood health has long-term and enduring consequences for chronic morbidity. As a part of this analysis, we address two methodological issues of concern in the literature. Is adult height a surrogate for childhood health experiences in modeling chronic disease in later life? And, are the effects of adult socioeconomic status on chronic disease overestimated when childhood health is not accounted for? The analysis is based on a topical module to the third wave of the Health and Retirement Study, a representative survey of Americans aged 55-65 in 1996. Our results support the hypothesis that poor childhood health increases morbidity in later life. This association was found for cancer, lung disease, cardiovascular conditions, and arthritis/rheumatism. The associations were highly persistent in the face of statistical controls for both adult and childhood socioeconomic status. No support was found for using adult height as a proxy for the effects of childhood health experiences. Further, the effects of adult socioeconomic status were not overestimated when childhood health was excluded from the explanatory models. Our results point to the importance of an integrated health care policy based on the premise of maximizing health over the entire life cycle.

Understanding the twentieth-century decline in chronic conditions among older men

I argue that the shift from manual to white-collar jobs and reduced exposure to infectious disease were important determinants of declines in chronic disease rates among older men from the early 1900s to the 1970s and 1980s. The average decline in chronic respiratory problems, valvular heart disease, arteriosclerosis, and joint and back problems was about 66%. Occupational shifts accounted for 29% of the decline; the decreased prevalence of infectious disease accounted for 18%; the remainder are unexplained. The duration of chronic conditions has remained unchanged since the early 1900s, but when disability is measured by difficulty in walking, men with chronic conditions are less disabled now than they were in the past.

Understanding the twentieth-century decline in chronic conditions among older men

I argue that the shift from manual to white-collar jobs and reduced exposure to infectious disease were important determinants of declines in chronic disease rates among older men from the early 1900s to the 1970s and 1980s. The average decline in chronic respiratory problems, valvular heart disease, arteriosclerosis, and joint and back problems was about 66%. Occupational shifts accounted for 29% of the decline; the decreased prevalence of infectious disease accounted for 18%; the remainder are unexplained. The duration of chronic conditions has remained unchanged since the early 1900s, but when disability is measured by difficulty in walking, men with chronic conditions are less disabled now than they were in the past.

Hypothesized foetal and early life influences on adult heart disease mortality: an ecological analysis of data for the Republic of Ireland

Spatial disparities in the prevalence of heart disease are frequently explained in terms of adult lifestyle factors (e.g. diet, smoking, alcohol consumption, stress, exercise, etc.). However, research in recent years suggests an alternative explanation: namely, that the risk of heart disease in adult life may be influenced either by living conditions shortly after birth or by foetal development before birth. This paper outlines the evolution of this line of thought, and tests whether these hypotheses are consistent with ecological data for deaths from ischaemic heart disease between 1981 and 1990 and infant deaths between 1916 and 1935 in the Republic of Ireland. Support for the hypotheses is found to be ambiguous. Possible interpretations of these findings are discussed, paying particular attention to the anomalous nature of infant mortality in Ireland between 1916 and 1935.

Lifecourse exposure and later disease: a follow-up study based on a survey of family diet and health in pre-war Britain (1937-1939)

There is an increasing interest in the origins of adult disease in early life. The elucidation of such explanations of current morbidity and mortality must depend upon the follow-up of previously established cohorts. This paper describes the design of and background to such a follow-up of one of the richest data sources for this type of research: Sir John Boyd Orr's survey of diet and health in pre-war Britain. 1,352 families from 16 centres in England and Scotland were surveyed; 3,762 children aged up to 19 years from these families were examined. Socio-economic information and detailed one week dietary diary records are available for all families. Detailed medical examinations (including anthropometry) were undertaken on children in 14 of the centres. Most of the information is cross-sectional although 1,322 children were examined on two or more occasions one year apart to assess the effects of dietary supplementation. Dietary records were retrieved for 1,343 (99.3%) of the families. Medical examination records were found for 3,560 (94.6%) of the children who were examined in the survey and attempts have been made to trace 4,973 children who were either examined or whose family participated in the dietary survey. The data demonstrate relationships between family food expenditure and height in childhood and housing conditions. Eighty-five per cent (4211/4973) of the children have been traced and flagged on the National Health Service Central Register, Southport. The characteristics of those traced do not differ significantly from those we have been unable to trace although untraced females were slightly heavier. To date 696 (16.5%) of the cohort have died. The cohort will be used to investigate the relationship between diet, nutritional status (height, weight, cristal height), health and social circumstances in childhood, and mortality and morbidity in adulthood.

Deprivation in infancy or in adult life: which is more important for mortality risk?

Previous ecological studies have suggested that early life factors are important causes of adult cardiovascular and respiratory disease, by showing geographic correlations between past infant mortality rates and present adult mortality rates. However, these studies inadequately take account of the fact that areas which were severely deprived earlier this century remain the most deprived today. Thus the ecological relation between infant and adult mortality rates could simply reflect persistence in the geographic distribution of poor socioeconomic circumstances. To explore this hypothesis further infant mortality rates for 1895-1908 for 43 counties in England and Wales were correlated with cause-specific adult mortality for 1969-73 in people aged 65-74 years, with and without adjustment for present-day social deprivation and social class. The strong simple correlations found between infant mortality in 1895-1908 and adult mortality from various causes in 1969-73 were generally much attenuated or abolished by controlling for indices of present-day socioeconomic circumstances. Our results suggest that previous studies give no strong support for any direct influence of factors acting in early life on adult coronary heart disease mortality risk. Studies which gather data about infancy, childhood, and the full course of adult life are required to clarify this issue.

The intrauterine and early postnatal origins of cardiovascular disease and chronic bronchitis

Geographical differences in mortality from cardiovascular disease and chronic bronchitis within England and Wales are closely related to past differences in infant mortality. This paper examines the separate relations of mortality during 1968-78 with neonatal and post-neonatal mortality during 1911-25. These divisions of infant mortality are indicators of the intrauterine and early postnatal environments respectively. Stroke is related to neonatal mortality and therefore to the intrauterine environment. Prenatal determinants of blood pressure levels may be one mechanism underlying this. Bronchitis is related to postnatal mortality and therefore to the postnatal environment. This may reflect the long term effects of lower respiratory tract infection in early childhood. Ischaemic heart disease is related to both neonatal and post-neonatal mortality and therefore to the intrauterine and postnatal environments. The links may include blood pressure and as yet unknown processes established in early postnatal life.