Health trends in Sub-Saharan Africa: conflicting evidence from infant mortality rates and adult heights

Trends in chronic childhood undernutrition in Bangladesh for small domains

Chronic childhood undernutrition, known as stunting, is an important population health problem with short- and long-term adverse outcomes. Bangladesh has made strides to reduce chronic childhood undernutrition, yet progress is falling short of the 2030 Sustainable Development Goals targets. This study estimates trends in age-specific chronic childhood undernutrition in Bangladesh's 64 districts during 1997-2018, using underlying direct estimates extracted from seven Demographic and Health Surveys in the development of small area time-series models. These models combine cross-sectional, temporal, and spatial data to predict in all districts in both survey and non-survey years. Nationally, there has been a steep decline in stunting from about three in five to one in three children. However, our results highlight significant inequalities in chronic undernutrition, with several districts experiencing less pronounced declines. These differences are more nuanced at the district-by-age level, with only districts in more socio-economically advantaged areas of Bangladesh consistently reporting declines in stunting across all age groups.

The Impact of Childhood Mortality on Fertility in Rural Tanzania: Evidence From the Ifakara and Rufiji Health and Demographic Surveillance Systems

This manuscript examines the relationship between child mortality and subsequent fertility using longitudinal data on births and childhood deaths occurring among 15,291 Tanzanian mothers between 2000 and 2015. Generalized hazard regression analyses assess the effect of child loss on the hazard of conception, adjusting for child-level, mother-level, and contextual covariates. Results show that time to conception is most reduced if an index child dies during the subsequent birth interval, representing the combined effect of biological and volitional replacement. Deaths occurring during prior birth intervals were associated with accelerated time to conception during future intervals, consistent with hypothesized insurance effects of anticipating future child loss, but this effect is smaller than replacement effects. The analysis reveals that residence in areas of relatively high child mortality is associated with hastened parity progression, again consistent with the insurance hypothesis. Investigation of high-order interactions suggests that insurance effects tend to be greater in low-mortality communities, replacement effects tend to be stronger in high-mortality community contexts, and wealthier families tend to exhibit a weaker insurance response but a stronger replacement response to childhood mortality relative to poorer families.

Scarring and selection effects on children surviving elevated rates of postneonatal mortality in sub-Saharan Africa

Infants in sub-Saharan Africa face adversity: Infections and undernutrition are major causes of infant deaths and can cause physiological damage with long-lasting adverse scarring effects on the human development of the survivors, for example, in terms of health and education. However, selective mortality of more vulnerable children at very high levels of adversity in early life can leave the surviving population to appear on average healthier. This paper estimated the nonlinear effects of postneonatal mortality rate—a proxy for adversity, particularly infections and undernutrition—in a 50 km radius, occurring over the period of infancy, on the subsequent height-for-age and school attendance of the surviving children. The results indicated that an adverse environment in infancy negatively affected height-for-age at age 1–4 years: At relatively low levels of adversity (at the 10th percentile of postneonatal mortality rate), an additional postneonatal death per 100 person-years decreased height-for-age of the survivors by almost 2% of the mean deficit in height (relative to a common growth standard) when comparing siblings born into different levels of adversity. At high levels of adversity, no effect was found for height-for-age while a small positive association was observed for school attendance at age 7–16 years. The results indicated that selective mortality may have canceled out (or even dominated in the case of school attendance) observable scarring effects following high levels of postneonatal mortality rate in sub-Saharan Africa.

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Adversity in early life negatively affects human development in sub-Saharan Africa.

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The postneonatal mortality rate over infancy was used as a proxy for adversity.

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Elevated adversity in infancy negatively affected height-for-age at age 1–4 years.

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At high adversity, selective mortality may cancel out observable scarring effects.

Did parental care in early life affect height? Evidence from rural Spain (19th-20th centuries)

This article examines the relationship between childhood mortality experienced within families and the height of surviving male children. Sibling mortality, controlled by different socioeconomic and environmental variables, is used as an approximation of the hygienic and epidemiological context and practices within the family. The analysis is based on a sample of 2783 individuals born between 1835 and 1977 in 14 villages in north-eastern Spain. The mortality data were obtained from the parish archives of the reference villages, and the height data from military service records of conscriptions at 21 years of age. The data were linked according to nominative criteria using family reconstitution methods. The results suggest the existence of a strong negative relationship between height and the childhood mortality experienced within families. Children born in families in which 50% of the children died before the age of five were up to 2.3 cm shorter than those of families with childhood mortality of less than 25%. General socioeconomic, hygienic and health improvements reduced childhood mortality, causing this link to gradually disappear between the 1940s and 1970s.

The biological index of frailty: A new index for the assessment of frailty in human skeletal remains

OBJECTIVE

Frailty is the physiological stress that individuals suffer during their life. In past populations, frailty is conventionally assessed through the occurrence of different biomarkers of biological stress. Some efforts have been made to propose indexes that combine all biomarkers. However, these indices have some critical limitations: they cannot be used on incomplete skeletons, do not consider the severity and/or healing of lesions, and assign equal importance to different biomarkers. To address these limitations, we propose a new index to assess frailty in skeletal individuals.

MATERIAL AND METHODS

By statistically analyzing a large amount of osteological data available from the Museum of London, and using a Logit model, we were able to define a different weight for each reported biomarker of frailty, based on their importance in increasing the risk of premature death for the individuals.

RESULTS

The biological index of frailty (BIF) is the weighted mean of all biomarkers scored on the individuals, according to a different degree of importance assigned to each one. It also considers the severity and healing of the biomarkers when this is relevant to diagnose frailty. We applied BIF on a sample of Monastics and Non-Monastics from medieval England and compared it with the skeletal index of frailty (SFI).

DISCUSSION

BIF is the first frailty index that gives a different weight to each skeletal biomarker of stress, considers both severity and healing of the lesions, and can be applied on partial skeletal remains. The comparison with SFI showed that BIF is applicable to a larger number of skeletal individuals, revealing new differences between the Monastic and the Non-Monastic groups.

Trends of infant mortality and its determinants in Ethiopia: mixed-effect binary logistic regression and multivariate decomposition analysis

BACKGROUND

Infant mortality remains a serious global public health problem. The global infant mortality rate has decreased significantly over time, but the rate of decline in most African countries, including Ethiopia, is far below the rate expected to meet the SDG targets. Therefore, this study aimed to investigate the trends of infant mortality and its determinants in Ethiopia based on the four consecutive Ethiopian Demographic and Health Surveys (EDHSs).

METHODS

This analysis was based on the data from four EDHSs (EDHS 2000, 2005, 2011, and 2016). A total weighted sample of 46,317 live births was included for the final analysis. The logit-based multivariate decomposition analysis was used to identify significantly contributing factors for the decrease in infant mortality in Ethiopia over the last 16 years. To identify determinants, a mixed-effect logistic regression model was fitted. The Intra-class Correlation Coefficient (ICC) and Likelihood Ratio (LR) test were used to assess the presence of a significant clustering effect. Deviance, Akaike Information Criteria (AIC), and Bayesian Information Criteria (BIC) were used for model comparison. Variables with a p-value of less than 0.2 in the bi-variable analysis were considered for the multivariable analysis. In the multivariable analysis, the Adjusted Odds Ratio (AOR) with 95% Confidence Interval (CI) were reported to identify the statistically significant determinants of infant mortality.

RESULTS

Infant mortality rate has decreased from 96.9 per 1000 births in 2000 to 48 per 1000 births in 2016, with an annual rate of reduction of 4.2%. According to the logit based multivariate decomposition analysis, about 18.1% of the overall decrease in infant mortality was due to the difference in composition of the respondents with respect to residence, maternal age, type of birth, and parity across the surveys, while the remaining 81.9% was due to the difference in the effect of residence, parity, type of birth and parity across the surveys. In the mixed-effect binary logistic regression analysis; preceding interval <  24 months (AOR = 1.79, 95% CI; 1.46, 2.19), small size at birth (AOR = 1.55, 95% CI; 1.25, 1.92), large size at birth (AOR = 1.26, 95% CI; 1.01, 1.57), BMI <  18.5 kg/m² (AOR = 1.22, 95% CI; 1.05, 1.50), and twins (AOR = 4.25, 95% CI; 3.01, 6.01), parity> 6 (1.51, 95% CI; 1.01, 2.26), maternal age and male sex (AOR = 1.50, 95% CI: 1.25, 1.79) were significantly associated with increased odds of infant mortality.

CONCLUSION

This study found that the infant mortality rate has declined over time in Ethiopia since 2000. Preceding birth interval, child-size at birth, BMI, type of birth, parity, maternal age, and sex of child were significant predictors of infant mortality. Public health programs aimed at rural communities, and multiparous mothers through enhancing health facility delivery would help maintain Ethiopia's declining infant mortality rate. Furthermore, improving the use of ANC services and maternal nutrition is crucial to reducing infant mortality and achieving the SDG targets in Ethiopia.

Secular decline in limb bone strength among South African Africans during the 19th and 20th centuries

OBJECTIVES

South African Africans have been reported to have experienced negative or null secular trends in stature and other measures of skeletal structure across the 19th and 20th centuries, presumably due to poor living conditions during a time of intensifying racial discrimination. Here, we investigate whether any secular trend is apparent in limb bone strength during the same period.

MATERIALS AND METHODS

Cadaver-derived skeletons (n = 221) were analyzed from female and male South African Africans who were born between 1839 and 1970, lived in and around Johannesburg, and died between 1925 and 1991 when they were 17-90 years of age. For each skeleton, a humerus and femur were scanned using computed tomography, and mid-diaphyseal cross-sectional geometric properties were calculated and scaled according to body size.

RESULTS

In general linear mixed models accounting for sex, age at death, and skeletal element, year of birth was a significant (p < .05) negative predictor of size-standardized mid-diaphyseal cortical area (a proxy for resistance to axial loading) and polar moment of area (a proxy for resistance to bending and torsion), indicating a temporal trend toward diminishing limb bone strength. No significant interactions were detected between year of birth and age at death, suggesting that the decline in limb bone strength was mainly due to changes in skeletal maturation rather than severity of age-related bone loss.

DISCUSSION

Limb bone strength is thus potentially another feature of the skeletal biology of South African Africans that was compromised by poor living conditions during the 19th and 20th centuries.

Worldwide estimates of incidence, prevalence and mortality of type 1 diabetes in children and adolescents: Results from the International Diabetes Federation Diabetes Atlas, 9th edition

AIMS

This article describes the methods, results and limitations of the International Diabetes Federation (IDF) Diabetes Atlas 9th edition estimates of worldwide numbers of cases of type 1 diabetes in children and adolescents.

METHODS

Most information in the published literature is in the form of incidence rates derived from registers of newly-diagnosed cases. After systematic review of the published literature and recent conference abstracts, identified studies were quality graded. If no study was available, extrapolation was used to assign a country the rate from an adjacent country with similar characteristics. Estimates of incident cases were obtained by applying incidence rates to United Nations 2019 population estimates. Estimates of prevalent cases were derived from incidence rates after making allowance for higher mortality rates in less-developed countries.

RESULTS

Incidence rates were available for 45% of countries (ranging from 6% in the sub-Saharan Africa region to 77% in the European region). Worldwide annual incidence estimates were 98,200 (128,900) new cases in the under 15 year (under 20 year) age-groups. Corresponding prevalence estimates were 600,900 (1,110,100) existing cases. Compared with estimates in earlier Atlas editions, numbers have increased in most IDF regions, reflecting incidence rate increases, but prevalence estimates have decreased in sub-Saharan Africa because allowance has been made for increased mortality in those with diabetes.

CONCLUSIONS

Worldwide estimates of numbers of children and adolescents with type 1 diabetes continue to increase.

Global country-level estimates of associations between adult height and the distribution of income

OBJECTIVES

This article presents the first estimates of global associations between adult height and the distribution of income, and considers the roles of regional heterogeneity, heterogeneity across low- and high-income countries, and of infant mortality as a potential mediator.

METHODS

Linear parametric and semiparametric regressions predicting mean height and sexual dimorphism in height are estimated using data on one cohort born in 1996 with height measured in 2016. Measurement error in income inequality is addressed using an instrumental variables method.

RESULTS

Across countries higher income per capita is strongly associated with higher mean height, and higher income inequality is associated with lower mean height after holding mean income constant. These relationships vary with mean income: at low incomes, higher mean income strongly predicts greater height but income inequality has no statistically significant effect, whereas for high-income countries, only higher income inequality predicts lower height, and only in Europe. Sexual dimorphism in height is positively associated with mean income at low incomes, but it is not related to income inequality.

CONCLUSIONS

Controlling for income inequality has modest effects on a positive height-income gradient. Greater inequality predicts lower height after holding income per capita constant, suggesting that mean height should be used with caution as a proxy for standard of living in some contexts. The extent to which these associations reflect causality running from economic conditions to height cannot be determined from these results.

Distributional change of women's adult height in low- and middle-income countries over the past half century: An observational study using cross-sectional survey data

BACKGROUND

Adult height reflects childhood circumstances and is associated with health, longevity, and maternal-fetal outcomes. Mean height is an important population metric, and declines in height have occurred in several low- and middle-income countries, especially in Africa, over the last several decades. This study examines changes at the population level in the distribution of height over time across a broad range of low- and middle-income countries during the past half century.

METHODS AND FINDINGS

The study population comprised 1,122,845 women aged 25-49 years from 59 countries with women's height measures available from four 10-year birth cohorts from 1950 to 1989 using data from the Demographic and Health Surveys (DHS) collected between 1993 and 2013. Multilevel regression models were used to examine the association between (1) mean height and standard deviation (SD) of height (a population-level measure of inequality) and (2) median height and the 5th and 95th percentiles of height. Mean-difference plots were used to conduct a graphical analysis of shifts in the distribution within countries over time. Overall, 26 countries experienced a significant increase, 26 experienced no significant change, and 7 experienced a significant decline in mean height between the first and last birth cohorts. Rwanda experienced the greatest loss in height (-1.4 cm, 95% CI: -1.84 cm, -0.96 cm) while Colombia experienced the greatest gain in height (2.6 cm, 95% CI: 2.36 cm, 2.84 cm). Between 1950 and 1989, 24 out of 59 countries experienced a significant change in the SD of women's height, with increased SD in 7 countries-all of which are located in sub-Saharan Africa. The distribution of women's height has not stayed constant across successive birth cohorts, and regression models suggest there is no evidence of a significant relationship between mean height and the SD of height (β = 0.015 cm, 95% CI: -0.032 cm, 0.061 cm), while there is evidence for a positive association between median height and the 5th percentile (β = 0.915 cm, 95% CI: 0.820 cm, 1.002 cm) and 95th percentile (β = 0.995 cm, 95% CI: 0.925 cm, 1.066 cm) of height. Benin experienced the largest relative expansion in the distribution of height. In Benin, the ratio of variance between the latest and earliest cohort is estimated as 1.5 (95% CI: 1.4, 1.6), while Lesotho and Uganda experienced the greatest relative contraction of the distribution, with the ratio of variance between the latest and earliest cohort estimated as 0.8 (95% CI: 0.7, 0.9) in both countries. Limitations of the study include the representativeness of DHS surveys over time, age-related height loss, and consistency in the measurement of height between surveys.

CONCLUSIONS

The findings of this study indicate that the population-level distribution of women's height does not stay constant in relation to mean changes. Because using mean height as a summary population measure does not capture broader distributional changes, overreliance on the mean may lead investigators to underestimate disparities in the distribution of environmental and nutritional determinants of health.

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

We evaluate the long-term effects of famine on chronic diseases using China's Great Leap Forward Famine as a natural experiment. Using a unique health survey, we explore the heterogeneity of famine intensity across regions and find strong evidence supporting both the adverse effect and the selection effect. The two offsetting effects co-exist and their magnitudes vary in different age cohorts at the onset of famine. The selection effect is dominant among the prenatal/infant famine-exposed cohort, while the adverse effect appears dominant among the childhood/puberty famine-exposed cohort. The net famine effects are more salient in rural residents and non-migrants subsamples. Gender differences are also found, and are sensitive to smoking and drinking behaviors. Our conclusion is robust to various specifications. Copyright © 2016 John Wiley & Sons, Ltd.

The biological standard of living in Suriname, c. 1870-1975

The physical stature of Surinamese soldiers is estimated to have increased by more than 3cm between 1870 and 1909. In the subsequent four decades, the increase in adult male and female height amounted to 0.3-0.5cm and 0.9-1.0cm per decade, respectively. This increase in height continued and accelerated during the second half of the twentieth century. Height increase among African and Hindustani Surinamese males and females was similar. Height differences between African and Hindustani Surinamese were therefore fairly constant over time, at 4-5cm. Other indicators of nutritional and health status, such as infant mortality, showed continuous improvement, whereas per capita calorie and protein availability improved in the twentieth century.

What has driven the decline of infant mortality in Kenya in the 2000s?

Substantial declines in early childhood mortality have taken place in many countries in Sub-Saharan Africa. Kenya's infant mortality rate fell by 7.6 percent per year between 2003 and 2008, the fastest rate of decline among the 20 countries in the region for which recent Demographic and Health Survey (DHS) data are available. The average rate of decline across all 20 countries was 3.6 percent per year. Among the possible causes of the observed decline in Kenya is a large-scale campaign to distribute insecticide-treated bednets (ITN) which started in 2004. A Oaxaca-Blinder decomposition using DHS data shows that the increased ownership of bednets in endemic malaria zones explains 79 percent of the decline in infant mortality. Although the Oaxaca-Blinder method cannot identify causal effects, given the wide evidence basis showing that ITN usage can reduce malaria prevalence and the huge surge in ITN ownership in Kenya, it is likely that the decomposition results reflect at least in part a causal effect. The widespread ownership of ITNs in areas of Kenya where malaria is rare suggests that better targeting of ITN provision could improve the cost-effectiveness of such programs.

Adult height, nutrition, and population health

In this review, the potential causes and consequences of adult height, a measure of cumulative net nutrition, in modern populations are summarized. The mechanisms linking adult height and health are examined, with a focus on the role of potential confounders. Evidence across studies indicates that short adult height (reflecting growth retardation) in low- and middle-income countries is driven by environmental conditions, especially net nutrition during early years. Some of the associations of height with health and social outcomes potentially reflect the association between these environmental factors and such outcomes. These conditions are manifested in the substantial differences in adult height that exist between and within countries and over time. This review suggests that adult height is a useful marker of variation in cumulative net nutrition, biological deprivation, and standard of living between and within populations and should be routinely measured. Linkages between adult height and health, within and across generations, suggest that adult height may be a potential tool for monitoring health conditions and that programs focused on offspring outcomes may consider maternal height as a potentially important influence.

Inferring the economic standard of living and health from cohort height: Evidence from modern populations in developing countries

Average adult height is a physical measure of the biological standard of living of a population. While the biological and economic standards of living of a population are very different concepts, they are linked and may empirically move together. If this is so, then cohort heights can also be used to make inferences about the economic standard of living and health of a population when other data are not available. We investigate how informative this approach is in terms of inferring income, nutrition, and mortality using data on heights from developing countries over the last 50 years for female cohorts born 1951-1992. We find no evidence that the absolute differences in adult height across countries are associated with different economic living standards. Within countries, however, faster increases in adult cohort height over time are associated with more rapid growth of GDP per capita, life expectancy, and nutritional intake. Using our instrumental variable approach, each centimeter gain in height is associated with a 6% increase in income per capita, a reduction in infant mortality of 7 per thousand (or an 1.25 year increase in life expectancy), and an increase in nutrition of 64 calories and 2 grams of protein per person per day relative to the global trend. We find that increases in cohort height can predict increases in income even for countries not used in the estimation of the relationship. This suggests our approach has predictive power out of sample for countries where we lack income and health data.

Early life mortality and height in Indian states

Height is a marker for health, cognitive ability and economic productivity. Recent research on the determinants of height suggests that postneonatal mortality predicts height because it is a measure of the early life disease environment to which a cohort is exposed. This article advances the literature on the determinants of height by examining the role of early life mortality, including neonatal mortality, in India, a large developing country with a very short population. It uses state level variation in neonatal mortality, postneonatal mortality, and pre-adult mortality to predict the heights of adults born between 1970 and 1983, and neonatal and postneonatal mortality to predict the heights of children born between 1995 and 2005. In contrast to what is found in the literature on developed countries, I find that state level variation in neonatal mortality is a strong predictor of adult and child heights. This may be due to state level variation in, and overall poor levels of, pre-natal nutrition in India.

Physical stature decline and the health status of the elderly population in England

Few research papers in economics have examined the extent, causes or consequences of physical stature decline in aging populations. Using repeated observations on objectively measured data from the English Longitudinal Study of Aging (ELSA), we document that reduction in height is an important phenomenon among respondents aged 50 and over. On average, physical stature decline occurs at an annual rate of between 0.08% and 0.10% for males, and 0.12% and 0.14% for females-which approximately translates into a 2-4 cm reduction in height over the life course. Since height is commonly used as a measure of long-run health, our results demonstrate that failing to take age-related height loss into account substantially overstates the health advantage of older birth cohorts relative to their younger counterparts. We also show that there is an absence of consistent predictors of physical stature decline at the individual level. However, we demonstrate how deteriorating health and reductions in height occur simultaneously. We document that declines in muscle mass and bone density are likely to be the mechanism through which these effects are operating. If this physical stature decline is determined by deteriorating health in adulthood, the coefficient on measured height when used as an input in a typical empirical health production function will be affected by reverse causality. While our analysis details the inherent difficulties associated with measuring height in older populations, we do not find that significant bias arises in typical empirical health production functions from the use of height which has not been adjusted for physical stature decline. Therefore, our results validate the use of height among the population aged over 50.

Comparing the Relationship Between Stature and Later Life Health in Six Low and Middle Income Countries

This paper examines the relationship between stature and later life health in 6 emerging economies, each of which are expected to experience significant increases in the mean age of their populations over the coming decades. Using data from the WHO Study on Global Ageing and Adult Health (SAGE) and pilot data from the Longitudinal Ageing Study in India (LASI), I show that various measures of health are associated with height, a commonly used proxy for childhood environment. In the pooled sample, an additional 10cm increase in height is associated with between a 2 and 3 percentage point increase in the probability of being in very good or good self-reported health, a 3 percentage point increase in the probability of reporting no difficulties with activities of daily living or instrumental activities of daily living, and between a fifth and a quarter of a standard deviation increase in grip strength and lung function. Adopting a methodology previously used in the research on inequality, I also summarise the height-grip strength gradient for each country using the concentration index, and provide a decomposition analysis.

Sexual relationship power and malnutrition among HIV-positive women in rural Uganda

Inequality within partner relationships is associated with HIV acquisition and gender violence, but little is known about more pervasive effects on women's health. We performed a cross-sectional analysis of associations between sexual relationship power and nutritional status among women in Uganda. Participants completed questionnaires and anthropometric measurements. We assessed sexual relationship power using the Sexual Relationship Power Scale (SRPS). We performed logistic regression to test for associations between sexual relationship power and poor nutritional status including body mass index, body fat percentage, and mid-upper arm circumference. Women with higher sexual relationship power scores had decreased odds of low body mass index (OR 0.29, p = 0.01), low body fat percentage (OR 0.54, p = 0.04), and low mid-upper arm circumference (OR 0.22, p = 0.01). These relationships persisted in multivariable models adjusted for potential confounders. Targeted interventions to improve intimate partner relationship equality should be explored to improve health status among women living with HIV in rural Africa.

The economic consequences of reproductive health and family planning

We consider the evidence for the effect of access to reproductive health services on the achievement of Millennium Development Goals 1, 2, and 3, which aim to eradicate extreme poverty and hunger, achieve universal primary education, and promote gender equality and empower women. At the household level, controlled trials in Matlab, Bangladesh, and Navrongo, Ghana, have shown that increasing access to family planning services reduces fertility and improves birth spacing. In the Matlab study, findings from long-term follow-up showed that women's earnings, assets, and body-mass indexes, and children's schooling and body-mass indexes, substantially improved in areas with improved access to family planning services compared with outcomes in control areas. At the macroeconomic level, reductions in fertility enhance economic growth as a result of reduced youth dependency and an increased number of women participating in paid labour.

Tall claims: Mortality selection and the height of children in India

Data from three rounds of nationally representative health surveys in India (1992/93, 1998/99 and 2005/06) are used to assess the impact of selective mortality on children's anthropometrics. The nutritional status of the child population was simulated under the counterfactual scenario that all children who died in the first three years of life were alive at the time of measurement. The simulations demonstrate that the difference in anthropometrics due to selective mortality would be large only if there were very large differences in anthropometrics between the children who died and those who survived. Differences of this size are not substantiated by the research on the degree of association between mortality and malnutrition. The study shows that although mortality risk is higher among malnourished children, selective mortality has only a minor impact on the measured nutritional status of children stratified by gender.

Early-life environment, height and BMI of young men in Italy

This paper explores the relationship between the two main dimensions of early-life environment, namely disease burden (measured by infant mortality) and economic conditions (measured by income or consumption per capita), and height and body-mass index (BMI) for six annual cohorts of young Italian men born between 1973 and 1978. By combining micro-level data on height and weight with regional- and province-level information, we are able to link individual height and BMI at age 18 to regional and provincial averages of environmental variables in the year of birth. Our results are consistent with the hypothesis that, in rich low-mortality settings, the negative effects of childhood disease dominate the positive selection effects of mortality. We find that both income and disease matter, although income matters more than disease for height, while the opposite is true for BMI.

Height of nations: a socioeconomic analysis of cohort differences and patterns among women in 54 low- to middle-income countries

Background

Adult height is a useful biological measure of long term population health and well being. We examined the cohort differences and socioeconomic patterning in adult height in low- to middle-income countries.

Methods/Findings

We analyzed cross-sectional, representative samples of 364538 women aged 25-49 years drawn from 54 Demographic and Health Surveys (DHS) conducted between 1994 and 2008. Linear multilevel regression models included year of birth, household wealth, education, and area of residence, and accounted for clustering by primary sampling units and countries. Attained height was measured using an adjustable measuring board. A yearly change in birth cohorts starting with those born in 1945 was associated with a 0.0138 cm (95% CI 0.0107, 0.0169) increase in height. Increases in heights in more recent birth year cohorts were largely concentrated in women from the richer wealth quintiles. 35 of the 54 countries experienced a decline (14) or stagnation (21) in height. The decline in heights was largely concentrated among the poorest wealth quintiles. There was a strong positive association between height and household wealth; those in two richest quintiles of household wealth were 1.988 cm (95% CI 1.886, 2.090) and 1.018 cm (95% CI 0.916, 1.120) taller, compared to those in the poorest wealth quintile. The strength of the association between wealth and height was positive (0.05 to 1.16) in 96% (52/54) countries.

Conclusions

Socioeconomic inequalities in height remain persistent. Height has stagnated or declined over the last decades in low- to middle-income countries, particularly in Africa, suggesting worsening nutritional and environmental circumstances during childhood.

Health and wealth in Uzbekistan and sub-Saharan Africa in comparative perspective

The study investigates the magnitude of differences in child and adult mortality by wealth in Uzbekistan, a former soviet country of Central Asia, and compares it with similar indicators from sub-Saharan Africa. Data were derived from Demographic and Health Surveys. An "Absolute Wealth Index" was built from data on goods owned by households and quality of housing, and scaled from 0 to 12. Wealth was distributed evenly in Uzbekistan, with a symmetric distribution around a mean of 5.5 modern goods. In sub-Saharan Africa, on the contrary, the wealth distribution had a lower mean (2.5) and was highly skewed towards the left, revealing a high proportion of very poor people. Adult and child mortality levels were lower in Uzbekistan. Despite these major differences, the relationships between mortality indicators and the wealth index were similar in the two cases. The magnitude of mortality differentials by wealth was of the same order in both cases, with gradients ranging from 2.5 to 1 for child mortality and 1.5 to 1 for adult mortality (poorest versus richest). However, mortality levels remained lower in Uzbekistan than in sub-Saharan Africa at the same level of wealth for both children and adults. A similar relationship was found between nutritional status and wealth index in both cases. On the contrary, there were no differences by wealth in use of health services and level of education in Uzbekistan, whereas wealth gradients were steep for the same variables in sub-Saharan Africa. The study suggests that mortality differentials were primarily due to nutritional status, and not to access and use of health services or to education. The discussion focuses on health and social policies during the colonial and post-colonial period that have produced these patterns.