Biomass fuel use for household cooking in Swaziland: is there an association with anaemia and stunting in children aged 6-36 months?

Under-5 Malaria and Fever Morbidities as Correlates of Anaemia in Niger: A Heteroscedasticity-Consistent Ordered Probit Approach

Background: The relationship between malaria/other febrile infections and anaemia among under-5 children is a subject of significant policy relevance among African health policy makers. The international significance of addressing anaemia is prominently underscored in the third Sustainable Development Goal (SDG). This paper therefore analysed the effect of malaria/other febrile infections and other maternal and child's demographic variables on the prevalence of anaemia in Niger. Methods: We utilized the under-5 children's module of the Malaria Indicator Survey (MIS) for 2021, which was collected from women of reproductive age (15-49) in selected households. The data were analysed with heteroscedasticity-consistent ordered probit regression model. Results: The results showed that 73.73% of the children was anaemic, while malaria and other febrile infections were present in 14.00% and 33.87%, respectively. Anaemia was highest in the Tillaberi and Dosso regions, where 84.12% and 79.12% of the children were anaemic. The ordered probit regression revealed that anaemia was promoted by malaria, other febrile infections, being a male child, second of multiple birth, and birth order, while wealth index, age, urban residence, and access to newspaper and television reduced it. Conclusions: Anaemia remains a major public health problem among under-5 children in Niger. A comprehensive healthcare intervention to address the problem should consider regional, sectoral, and gender differences in the incidences, with drastic efforts towards prevention of malaria and other fever-inducing illnesses. In addition, interventions to promote households' economic status, reduce maternal fertility, and facilitate preventive practices through nutrition enhancement and health-related media programs hold some promise.

The Intersection of a Child's Demographics and Household Socioeconomic Status in the Multimorbidity of Malaria, Anaemia, and Malnutrition among Children Aged 6-59 Months in Nigeria

Multimorbidity of malaria, anemia, and malnutrition (MAMM) is a condition in which an individual has two or more of these health conditions, and is becoming an emergent public health concern in sub-Saharan African countries. The independent associations of a child's demographic variables and household socioeconomic (HSE) disparities with a child's health outcomes have been established in the literature. However, the effects of the intersection of these factors on MAMM, while accounting for other covariates, have not been studied. Therefore, this study aimed to determine how children's sex, age, and household socioeconomic status interact to explain the variations in MAMM among children aged 6-59 months in Nigeria. Data from the 2018 Nigeria Demographic and Health Survey and the 2018 National Human Development Report (NHDR) were used. This study included weighted samples of 10,184 children aged 6-59 months in Nigeria. A three-level multilevel mixed effect ordinal logistic regression model was used, such that individual characteristics at level 1 were nested in communities at level 2 and nested in states at level 3. Subsequently, predictive probability charts and average adjusted probability tables were used to interpret the intersectional effects. Five models were created in this scenario. Model 1 is the interaction between the child's sex and household wealth status; model 2 is the interaction between the child's sex and age; model 3 is the interaction between the child's age and household wealth status; model 4 has the three two-way interactions of the child's sex, age, and household wealth status; and model 5 includes model 4 and the three-way interactions between a child's sex, age, and household wealth quintiles; while accounting for other covariates in each of the models. The prevalence of children with a 'none of the three diseases' outcome was 17.3% (1767/10,184), while 34.4% (3499/10,184) had 'only one of the diseases', and 48.3% (4918/10,184) had 'two or more' MAMMs. However, in the multivariate analyses, model 3 was the best fit compared with other models, so the two-way interaction effects of a child's age and household wealth status are significant predictors in the model. Children aged 36-47 months living in the poorest households had a probability of 0.11, 0.18, and 0.32 of existing with MAMM above the probability of children of the same age who live in the middle class, more prosperous, and richest households, respectively, while all other covariates were held constant. Thus, the variation in the prevalence of MAMM in children of different ages differs depending on the household wealth quintile. In other words, in older children, the variations in MAMM become more evident between the richer and the poorer household quintiles. Therefore, it is recommended that policies that are geared toward economic redistribution will help bridge the disparities observed in the prevalence of multiple diseases among children aged 6-59 months in Nigeria.

Smoke exposure, hemoglobin levels and the prevalence of anemia: a cross-sectional study in urban informal settlement in Southern Ghana

BACKGROUND

In sub-Saharan African cities, more than half of the population lives in informal settlements. These settlements are close to smoky dumpsites, industrial plants, and polluted roads. Furthermore, polluting fuels remain their primary sources of energy for cooking and heating. Despite evidence linking smoke and its components to anaemia, none of these studies were conducted on populations living in urban informal settlements. This study investigated the risks of anemia/mean Haemoglobin (HB) levels in an informal settlement in Accra, Ghana. Exposure to smoke was examined across various sources, encompassing residences, neighborhoods, and workplaces.

METHODS

The study was a facility-based cross-sectional design among residents at Chorkor, an informal settlement in the Greater Accra region of Ghana. A questionnaire was administered at a community hospital during an interview to gather data on sources of smoke exposure in the household, in the neighbourhood, and in the workplace. A phlebotomist collected blood samples from the participants after the interview to assess their anaemia status.

RESULTS

The population (n = 320) had a high prevalence of anemia, with 49.1% of people fitting the WHO's definition of anemia, while the average HB level was 12.6 ± 2.1 g/dL. Anemia was associated with the number of different types of waste burnt simultaneously [(1 or 2: prevalence ratio (PR): 95% confidence interval (CI), 1.14, 0.99-1.28: 3+: 1.16, 1.01-1.63, p-for-trend = 0.0082)], fuel stacking [(mixed stacking: 1.27, 1.07-1.20: dirty stacking:1.65, 1.19-2.25, p-for-trend = 0.0062)], and involvement in fish smoking (1.22, 0.99-1.06). However, the lower limit of the CIs for number of different forms of garbage burned simultaneously and engagement in fish smoking included unity. Reduced mean HB levels were associated with the number of different types of waste burnt simultaneously [(1 or 2: regression coefficient (β): 95% confidence interval (CI), -0.01, -0.97- -0.99: 3+: -0.14, -0.77- -0.05)], current smoker [(yes, almost daily: -1.40, -2.01- -0.79: yes, at least once a month: -1.14, -1.79- -0.48)], Second-Hand-Smoking (SHS) (yes, almost daily: -0.77, -1.30- -0.21), fuel stacking [(mixed stacking-0.93, -1.33-0.21: dirty stacking-1.04, -1.60- -0.48)], any smoke exposure indicator in the neighbourhood (-0.84, -1.43- -0.25), living close to a major road (-0.62, -1.09- -0.49), and fish smoking (-0.41,-0.93- -0.12).

CONCLUSION

Although the cross-sectional design precludes causality, smoke exposure was associated with mean HB levels and anaemia among populations living in informal settlements.

Socio-economic, demographic, and contextual predictors of malnutrition among children aged 6-59 months in Nigeria

Malnutrition has remained a global public health issue, particularly in low- and middle-income countries (LMICs). Researchers have committed to studying malnutrition (especially in children under the age of five) to address the nine malnutrition targets, set by the WHO to be achieved by 2025. This study seeks to evaluate the prevalence, the individual and contextual predictors of malnutrition among children aged 6-59 months across Nigeria and its states. Two separates, independently collected, nationally representative cross-sectional surveys, the National Human Development Report (NHDR 2018) and the 2018 Nigeria Demographic and Health Survey (2018 NDHS) were linked for this study. Spatial map was used to describe the prevalence of malnutrition, a 3-level multivariate multilevel logistic regression models were fitted where children/individuals (at level 1) were nested in communities/clusters (at level 2) and nested in states (at level 3). A weighted sample of 7,770 children 6-59 months were considered in this study. The results showed that an estimated 43.6% of children aged 6-59 months are poorly nourished in Nigeria. The proportions of poorly nourished children were generally highest in the Northern Nigeria. Child's gender, age, birth size, preceding birth order, anaemia status, maternal education, work status, body weight, household wealth status, number of bedrooms were among individual/household predictors of malnutrition. On the community level, being from community with high wealth index, distance to nearest health facilities is no big problem. Regional variations and gender inequality index were the state level predictors of malnutrition among children in Nigeria. This study has shown that two-third of children aged 6-59 months in Nigeria were poorly nourished, an indication of a growing concern of double burden of malnutrition in Nigeria.

Exposure to household air pollution from solid cookfuels and childhood stunting: a population-based, cross-sectional study of half a million children in low- and middle-income countries

BACKGROUND

Household air pollution from the incomplete combustion of solid cookfuels in low- and middle-income countries (LMICs) has been largely ignored as a potentially important correlate of stunting. Our objective was to examine the association between solid cookfuel use and stunting in children aged <5 y.

METHODS

We used data from 59 LMICs' population-based cross-sectional demographic and health surveys; 557 098 children aged <5 y were included in our analytical sample. Multilevel logistic regression was used to examine the association between exposure to solid cookfuel use and childhood stunting, adjusting for child sex, age, maternal education and number of children living in the household. We explored the association across key subgroups.

RESULTS

Solid cookfuel use was associated with child stunting (adjusted OR 1.58, 95% CI 1.55 to 1.61). Children living in households using solid cookfuels were more likely to be stunted if they lived in rural areas, the poorest households, had a mother who smoked tobacco or were from the Americas.

CONCLUSIONS

Focused strategies to reduce solid cookfuel exposure might contribute to reductions in childhood stunting in LMICs. Trial evidence to assess the effect of reducing solid cookfuel exposure on childhood stunting is urgently needed.

Household air pollution and childhood stunting in China: A prospective cohort study

Background

Exposure to air pollution, especially indoor air pollution, was associated with an increased risk of childhood stunting. However, few longitudinal studies have explored the long-term impacts of indoor air pollution from household solid fuel use on child growth. We aimed to investigate the association between household air pollution (HAP) from solid fuel use and childhood stunting in Chinese children.

Method

The longitudinal data from the Chinese Family Panel Study over 2010-2018 were included in this study with a total of 6,013 children aged 0-15 years enrolled at baseline. Exposure to HAP was measured as solid fuel use for cooking, while solid fuel was defined as coal and firewood/straw according to the questionnaire survey. Stunting was defined as-2SD below the height-for-age z-score (HAZ) of the reference children. Logistic regression and Cox proportional hazards models with time-varying exposures were employed to estimate the association between childhood stunting and HAP exposure.

Results

At baseline, children with exposure to HAP from combusting solid fuels had a relatively higher risk of stunting [OR (95%CI): 1.42 (1.24-1.63)]. Among children without stunning at baseline, those living in households with solid fuel use had a higher stunting risk over an 8-year follow-up [HR (95%CI): 2.05 (1.64-2.57)]. The risk of childhood stunting was increased for those with HAP exposure from firewood/straw combustion or with longer exposure duration [HR (95%CI): 2.21 (1.74-2.79) and 3.01 (2.23-4.08), respectively]. Meanwhile, this risk was significantly decreased among children from households switching from solid fuels to clean fuels [HR (95%CI): 0.53 (0.39-0.70)]. Solid fuel use was suggested to be a mediator of the relationship between poor socioeconomic factors (i.e., household income and parental education level) and childhood stunning, with a mediation effect ranging from 11.25 to 14.26%.

Conclusions

HAP exposure from solid fuel use was associated with childhood stunting. Poor parental education and low household income might be socioeconomic factors contributing to solid fuel use. Therefore, household energy policies to facilitate access to clean fuels are urgently needed, especially for low-income and low-educated households.

Early-life environmental exposures and anaemia among children under age five in Sub-Saharan Africa: An insight from the Demographic & Health Surveys

BACKGROUND

Reports show that the majority (60%) of children under age five years in Sub-Saharan Africa are anaemic. Studies in the region have mainly focused on the effect of individual, maternal and household socioeconomic status on the prevalence of anaemia. Currently, there is limited understanding of the association between early-life environmental exposures and anaemia among children in Sub-Saharan Africa.

OBJECTIVE

The study examines the association between early-life environmental exposures and anaemia among children under five in Sub-Saharan Africa.

METHODS

The study used health and demographic data from the Demographic and Health Survey (DHS) program and environmental data from NASA's Geospatial Interactive Online Visualization ANd aNalysis Infrastructure (GIOVANNI) and Atmospheric Composition Analysis Group. Three exposure periods were defined for the study, namely: in-utero, post-utero and cumulative life exposures. Multilevel mixed-effect models were used to assess the associations between environmental exposures and anaemia in each exposure period.

RESULTS

The findings show that 63% of children in the study were anaemic. It also reveals that mean PM 2.5 exposure for in-utero (34.93 μgm^-3), post-utero (35.23 μgm^-3) and cumulative exposure (35.08 μgm^-3) were seven times higher than the new air quality guideline WHO recommended. A 10 μgm^-3 increase in in-utero, post-utero and cumulative PM 2.5 exposures was associated with 4% to 5% increase in the prevalence of anaemia among children. A 10ppbv increase in in-utero, post-utero and cumulative carbon monoxide exposures was associated with 1% increase in the prevalence of anaemia among children. The spatial risk distribution maps show that socioeconomic factors modify the spatial risk distribution pattern.

CONCLUSION

The findings of the study suggest that early-life exposure to ambient air pollution is significantly associated with anaemia among children in Sub-Saharan Africa. Thus, policies aimed at addressing air quality should be incorporated into targeted interventions for anaemia among children in the region.

Biomass fuel use and birth weight among term births in Nigeria

Despite the high burden of household air pollution from biomass fuel in sub-Saharan Africa, the association of prenatal biomass fuel exposure and birth weight as a continuous variable among term births has not been extensively studied. In this study, our primary aim is to estimate the association between biomass cooking fuel and birth weight among term births in Kaduna, northwestern Nigeria. For replication, we also evaluated this association in a larger and nationally representative sample from the 2018 Nigerian Demographic and Health Survey (DHS). Our primary analysis included 1,514 mother-child pairs recruited from Kaduna, in northwestern Nigeria, using the Child Electronic Growth Monitoring System (CEGROMS). Replication analysis was conducted using data from 6,975 mother-child pairs enrolled in 2018 Nigerian DHS. The outcome variable was birth weight, and the exposure was cooking fuel type, categorized in CEGROMS as liquefied petroleum gas, kerosene, or biomass fuel, and in the DHS as low pollution fuel, kerosene, or biomass fuel. We estimated covariate adjusted associations between birth weight and biomass fuel exposure in CEGROMS using linear regression and using linear mixed model in the DHS. In CEGROMS, adjusting for maternal age, education, parity, BMI at birth, and child sex, mothers exposed to biomass fuel gave birth to infants who were on average 113g lighter (95% CI -196 to -29), than those using liquified petroleum gas. In the 2018 Nigeria DHS data, compared to low pollution fuel users, mothers using biomass had infants weighing 50g (95% CI -103 to 2) lower at birth. Exposure to biomass cooking fuel was associated with lower birth weight in our study of term newborns in Kaduna, Nigeria. Data from the nationally representative DHS provide some support for these findings.

Individual, household and area predictors of anaemia among children aged 6–59 months in Nigeria

Objectives

This study aims to determine the prevalence of anaemia among children aged 6–59 months in all states of Nigeria, including the Federal Capital Territory (FCT), and to quantify the predicted probabilities by individual, household and area factors.

Study design

This study is a secondary analysis of data sets from two national representative cross-sectional surveys in Nigeria: the Nigeria Demographic and Health Survey (2018 NDHS) and the National Human Development Index (2018 NHDR). The state human development index (HDI) and the state multidimensional poverty index (MPI) from the 2018 NHDR were incorporated into the 2018 NDHS.

Methods

The study included a weighted sample of 10,222 children aged 6–59 months. Both univariate and bivariate analyses were computed to determine the prevalence and factors associated with anaemia status, respectively. Multiple binary logistic regression analyses with adjusted predicted probabilities (APPs) were performed to quantify the predictors’ probabilities.

Results

The prevalence of anaemia among children aged 6–59 months in Nigeria was 68.1% (6962/10,222). Zamfara state had the highest prevalence (84.0% [266/317]), while Kaduna state recorded the lowest (50.0% [283/572]). The APPs of being anaemic decreased from 82.9% (95% confidence interval [CI]: 80.0–85.8) for children aged 6–18 months to 60.6% (95% CI: 56.8–64.4) for children aged 43–59 months, when other predictors were held constant. The APP for a child of an anaemic mother is 10.2% points higher than the APP for a child whose mother is not anaemic. In addition, the APPs for children decreased as the age group of their mothers increased. A child from a state that is mildly deprived in the MPI has a lower APP (67.2% [95% CI: 62.2–72.2]) compared with a child from highly deprived MPI state (79.0% [95% CI: 73.4–84.5]).

Conclusions

Health strategies, including supplementation programmes, should be carried out at both ante-natal and post-natal clinics to reduce the prevalence of anaemia, especially in vulnerable population groups.

Household Microenvironment and Under-Fives Health Outcomes in Uganda: Focusing on Multidimensional Energy Poverty and Women Empowerment Indices

Young children in low- and middle-income countries (LMICs) are vulnerable to adverse effects of household microenvironments. The UN Sustainable Development Goals (SDGs)-specifically SDG 3 through 7-urge for a comprehensive multi-sector approach to achieve the 2030 goals. This study addresses gaps in understanding the health effects of household microenvironments in resource-poor settings. It studies associations of household microenvironment variables with episodes of acute respiratory infection (ARI) and diarrhoea as well as with stunting among under-fives using logistic regression. Comprehensive data from a nationally representative, cross-sectional demographic and health survey (DHS) in Uganda were analysed. We constructed and applied the multidimensional energy poverty index (MEPI) and the three-dimensional women empowerment index in multi-variate regressions. The multidimensional energy poverty was associated with higher risk of ARI (OR = 1.32, 95% CI 1.10 to 1.58). Social independence of women was associated with lower risk of ARI (OR= 0.91, 95% CI 0.84 to 0.98), diarrhoea (OR = 0.93, 95% CI 0.88 to 0.99), and stunting (OR = 0.83, 95% CI 0.75 to 0.92). Women's attitude against domestic violence was also significantly associated with episodes of ARI (OR = 0.88, 95% CI 0.82 to 0.93) and diarrhoea (OR = 0.89, 95% CI 0.84 to 0.93) in children. Access to sanitation facilities was associated with lower risk of ARI (OR = 0.55, 95% CI 0.45 to 0.68), diarrhoea (OR = 0.83, 95% CI 0.71 to 0.96), and stunting (OR = 0.64, 95% CI 0.49 to 0.86). Investments targeting synergies in integrated energy and water, sanitation and hygiene, and women empowerment programmes are likely to contribute to the reduction of the burden from early childhood illnesses. Research and development actions in LMICs should address and include multi-sector synergies.

The association between biomass fuel use for cooking and linear growth in young children in Bhaktapur, Nepal

BACKGROUND

There are still many people in the world who prepare their meals on open fires or stoves using solid fuels from biomass, especially in low-and middle-income countries. Although biomass cooking fuels have been associated with adverse health impacts and diseases, the association with child linear growth remains unclear.

OBJECTIVES

In a cohort design, we aimed to describe the association between the use of biomass cooking fuels and linear growth in children aged 18-23 months living in the urban and peri-urban community of Bhaktapur, situated in the Kathmandu valley in Nepal.

METHODS

Caretakers of 600 marginally stunted children aged 6-11 months were interviewed about their source of cooking fuel and other socio-demographic characteristics at enrolment into a randomized controlled trial. Children's body length was measured when children were 18-23 months old. In linear regression models, we estimated the association between the use of biomass fuel and length-for-age Z-scores (LAZ), adjusted for relevant confounders. We repeated these analyses in pre-defined sub-groups and different percentiles of LAZ using quantile regression models.

RESULTS

Among study participants, 101 (18%) used biomass as cooking fuel. The association between biomass fuel and LAZ was not statistically significant in the full sample (adjusted regression coefficient: -0.14, 95% CI: -0.28, 0.00). The association was stronger in some of the sub-groups and in the lower tail of the LAZ distribution (those who are stunted), but neither reached statistical significance.

DISCUSSION

Children from households in poor, urban neighborhoods in Nepal which used biomass fuel for cooking were on average slightly shorter than other children, although the association only approached statistical significance. As this was an observational study, residual confounding cannot be excluded. Further studies are needed to confirm these associations, in particular those seen in certain sub-groups.

Household biomass fuel use is associated with chronic childhood malnutrition: Result from a nationwide cross-sectional survey in Bangladesh

Despite significant investment, childhood malnutrition continues to be a significant public health problem especially in least developed countries. The aim of this study was to find association between household biomass fuel (BMF) use and childhood malnutrition in Bangladesh using data from Demographic and Health Survey 2011. We included a total 6891 children under 5 years of age in the analysis. The prevalence of wasting, underweight, and stunting from BMF using household was 16.1% (n = 997; 95%CI, 15.1-17.3), 39.0% (n = 2399; 95%CI, 37.1-40.9), and 43.3% (n = 2620; 95%CI, 41.6-45.1), respectively. Underweight and stunting were significantly higher among children from households using BMF compared with the children from CF using households (underweight, biomass vs clean fuel: 39.0% vs. 23.5%, p < 0.001; stunting, biomass vs clean fuel: 43.3 vs. 31.5%, p < 0.001). The use of BMF in the household was significantly associated with underweight (OR = 1.38; 95%CI: 1.10-1.73) and stunting (OR = 1.58; 95%CI: 1.18-1.98) among children <5 years of age after adjusting possible confounders in mixed effect logistic regression analysis. This study found a significant association between chronic childhood malnutrition and household BMF use which is indicating possible alternative risk factor for malnutrition. Further prospective research is required to explore the mechanism of how BMF use results in chronic malnutrition.

Air Pollution as a Determinant of Undernutrition Prevalence among Under-Five Children in India: An Exploratory Study

AIM

The association of air pollution with prevalence of undernutrition indices (namely, anaemia, stunting, wasting and underweight) among under-five children in India was investigated.

METHODS

Estimates of population weighted annual average gridded PM2.5 concentrations and proportion of households using solid cooking fuel (HSCF usage percent) during 2017 in India, reflecting the magnitude of ambient and household air pollution respectively, were extracted in a state-wise manner from India State Level Disease Burden Initiative (ISLDBI) reports. Their relationships with the corresponding prevalence of anaemia, underweight, wasting and stunting in under-five children were analysed.

RESULTS

The state-level PM2.5 concentrations (mean: 65.5 µg/m3; median: 49.2 µg/m3; range: 17.3-209.0 µg/m3) correlated significantly (P < 0.01) with anaemia (r = 0.65), stunting (r = 0.58) and underweight (r = 0.50) prevalence; while HSCF usage (mean: 49.3%; median: 46.0%; range: 1.9-81.5%) correlated significantly (P < 0.01) with stunting (r = 0.69) and underweight (r = 0.58) prevalence. When examined across median cut-offs and after adjusting for socio-demographic index, the association of anaemia prevalence with PM2.5 concentrations persisted. This association was maintained even after controlling for the coverage of anaemia-specific interventions (namely, iron supplements and deworming medications). The mean difference in PM2.5 concentrations between the high and low PM2.5 states was 58.6 µg/m3, which accounted for 11.8% higher anaemia prevalence in the former as compared to the latter.

CONCLUSION

The burden of childhood undernutrition, particularly anaemia, in India may be linked to PM2.5 levels. To mitigate this burden, it may be necessary to complement the ongoing nutritional interventions with air pollution control measures.

Risk of anaemia among women engaged in biomass-based fish smoking as their primary livelihood in the central region of Ghana: a comparative cross-sectional study

BACKGROUND

Fish smoking using biomass fuel is an important livelihood for women living in the coastal regions of Ghana and may contribute to anaemia risk. We assessed whether women who smoke fish as their primary livelihood are at increased risk of anaemia compared to women in other livelihoods in the Central Region of Ghana.

METHODS

We conducted a comparative cross-sectional study of 330 randomly selected adult women (18-49 years) whose primary livelihood was either fish smoking (FSL) involving the burning of biomass fuel (n = 175) or other livelihoods (OL) not involving burning of firewood (n = 155). Data on participants' recent diet were collected from a single, quantitative 24-h dietary recall and qualitative 7-day food frequency questionnaire of animal-source food (ASF) consumption. We further assessed participants' haemoglobin concentration using the Urit 12 Hemocue system. We compared total iron intakes, the proportion of dietary iron from animal and plant sources, mean haemoglobin concentrations, and anaemia prevalence between FSL and OL women.

RESULTS

Fish was the most frequently consumed ASF by both groups of women. Although OL women consumed more diverse ASFs in the past week compared with the FSL women (3.4 ± 1.2 vs. 2.7 ± 1.3; p < 0.001), the contribution of ASFs to total iron intake in the past day was greater for the FSL women (49.5% vs. 44.0%; p = 0.030). Estimated total dietary iron intake in the past day was generally low (5.2 ± 4.7 mg) and did not differ by group. The unadjusted prevalence of anaemia was 32 and 27.1% among the FSL and OL women, respectively (p = 0.33). After covariates adjustment, the FSL women had statistically higher anaemia prevalence (36.4% vs. 20.5%; p = 0.032) and 80% greater risk of being anemic (RR: 1.8; 95% CI: 1.1, 3.0) than the OL women.

CONCLUSION

Women who use biomass fuel to smoke fish as their primary livelihood had an increased risk of anaemia. Furthermore, the average 24-h dietary iron intake among both the FSL and OL women was below their daily iron requirement. Interventions to enhance women's dietary iron intake and reduce their livelihood related biomass smoke exposure may be warranted in this population.

Health impacts of indoor air pollution from household solid fuel on children and women

The inefficient and incomplete combustion of solid fuel (SF) is associated with high levels of indoor air pollutants leading to 3.55 million deaths annually. The risk is higher in women and children, due to their higher exposure duration and unique physical properties. The current article aims to provide a critical overview regarding the use of solid fuel, its associated pollutants, their toxicity mechanisms and, most importantly the associated health impacts, especially in women and children. Pollutants associated with SF mostly include polycyclic aromatic hydrocarbons, particulate matter, nitrous oxide, carbon monoxide and sulfur dioxide, and their concentrations are two- to threefold higher in indoor environments. These pollutants can lead to a variety of health risks by inducing different toxicity mechanisms, such as oxidative stress, DNA methylation, and gene activation. Exposed children have an increased prevalence of low birth weight, acute lower respiratory tract infections, anemia and premature mortality. On the other hand, lung cancer, chronic obstructive pulmonary disease and cardiovascular diseases are the major causes of disability and premature death in women. Indoor air pollution resulting from SF combustion is a major public health threat globally. To reduce the risks, it is important to identify future research gaps and implement effective interventions and policies.

Household cooking fuel type and childhood anaemia in sub-Saharan Africa: analysis of cross-sectional surveys of 123, 186 children from 29 countries

OBJECTIVE

This study sought to investigate the joint effect of household cooking fuel type and urbanicity (rural-urban residency) on anaemia among children under the age of five in sub-Saharan Africa.

DESIGN

We analysed cross-sectional data of 123, 186 children under the age of five from 29 sub-Saharan African countries gathered between 2010 and 2019 by the Demographic and Health Survey programme. Bivariate (χ² test of independence) and multilevel logistic regression were used to examine the effect of urbanicity-household cooking fuel type on childhood anaemia. Results were reported as adjusted odds ratios (aORs) with 95% CIs at p<0.05.

OUTCOME MEASURES

Anaemia status of children.

RESULTS

More than half (64%) of children had anaemia. The percentage of children who suffered from anaemia was high in those born to mothers in Western Africa (75%) and low among those born in Southern Africa (54%). Children from rural households that depend on unclean cooking fuels (aOR=1.120; 95% CI 1.033 to 1.214) and rural households that depend on clean cooking fuels (aOR=1.256; 95% CI 1.080 to 1.460) were more likely to be anaemic as compared with children from urban households using clean cooking fuel. Child's age, sex of child, birth order, perceived birth size, age of mother, body mass index of mother, education, marital status, employment status, antenatal care, wealth quintile, household size, access to electricity, type of toilet facility, source of drinking water and geographic region had significant associations with childhood anaemia status.

CONCLUSIONS

Our study has established a joint effect of type of household cooking fuel and urbanicity on anaemia among children under the age of five in sub-Saharan Africa. It is therefore critical to promote the usage of clean cooking fuels among households and women in rural areas. These should be done taking into consideration the significant child, maternal, household, and contextual factors identified in this study.

A Systematic Review and Appraisal of Epidemiological Studies on Household Fuel Use and Its Health Effects Using Demographic and Health Surveys

The domestic combustion of polluting fuels is associated with an estimated 3 million premature deaths each year and contributes to climate change. In many low- and middle-income countries (LMICs), valid and representative estimates of people exposed to household air pollution (HAP) are scarce. The Demographic and Health Survey (DHS) is an important and consistent source of data on household fuel use for cooking and has facilitated studies of health effects. However, the body of research based on DHS data has not been systematically identified, nor its strengths and limitations critically assessed as a whole. We aimed to systematically review epidemiological studies using DHS data that considered cooking fuel type as the main exposure, including the assessment of the extent and key drivers of bias. Following PRISMA guidelines, we searched PubMed, Web of Science, Scopus and the DHS publication portal. We assessed the quality and risk of bias (RoB) of studies using a novel tool. Of 2748 records remaining after removing duplicates, 63 were read in full. A total of 45 out of 63 studies were included in our review, spanning 11 different health outcomes and representing 50 unique analyses. In total, 41 of 45 (91%) studies analysed health outcomes in children <5 years of age, including respiratory infections (n = 17), death (all-cause) (n = 14), low birthweight (n = 5), stunting and anaemia (n = 5). Inconsistencies were observed between studies in how cooking fuels were classified into relatively high- and low-polluting. Overall, 36/50 (80%) studies reported statistically significant adverse associations between polluting fuels and health outcomes. In total, 18/50 (36%) of the analyses were scored as having moderate RoB, while 16/50 (32%) analyses were scored as having serious or critical RoB. Although HAP exposure assessment is not the main focus of the DHS, it is the main, often only, source of information in many LMICs. An appreciable proportion of studies using it to analyse the association between cooking fuel use and health have potential for high RoB, mostly related to confounder control, exposure assessment and misclassification, and outcome ascertainment. Based on our findings, we provide some suggestions for ways in which revising the information collected by the DHS could make it even more amenable to studies of household fuel use and health, and reduce the RoB, without being onerous to collect and analyse.

The Association Between Ambient PM2.5 Exposure and Anemia Outcomes Among Children Under Five Years of Age in India

Anemia is highly prevalent in India, especially in children. Exposure to ambient fine particulate matter (PM2.5) is a potential risk factor for anemia via. systemic inflammation. Using health data from the National Family and Health Survey 2015-2016, we examined the association between ambient PM2.5 exposure and anemia in children under five across India through district-level ecological and individual-level analyses.

METHODS

The ecological analysis assessed average hemoglobin levels and anemia prevalence (hemoglobin < 11 g/dL considered anemic) by district using multiple linear regression models. The individual-level analysis assessed average individual hemoglobin level and anemia status (yes/no) using generalized linear mixed models to account for clustering by district. Ambient PM2.5 exposure data were derived from the Multiangle Imaging SpectroRadiometer (MISR) level 2 aerosol optical depth (AOD) data and averaged from birth date to date of interview.

RESULTS

The district-level ecological analysis found that, for every 10 μg m-3 increase in ambient PM2.5 exposure, average anemia prevalence increased by 1.90% (95% CI = 1.43, 2.36) and average hemoglobin decreased by 0.07 g/dL (95% CI = 0.09, 0.05). At the individual level, for every 10 μg m-3 increase in ambient PM2.5 exposure, average hemoglobin decreased by 0.14 g/dL (95% CI = 0.12, 0.16). The odds ratio associated with a 10-μg m-3 increase in ambient PM2.5 exposure was 1.09 (95% CI = 1.06, 1.11). There was evidence of effect modification by wealth index, maternal anemia status, and child BMI.

CONCLUSION

Our results suggest that ambient PM2.5 exposure could be linked to anemia in Indian children, although additional research on the underlying biologic mechanisms is needed. Future studies on this association should specifically consider interactions with dietary iron deficiency, maternal anemia status, and child BMI.Keywords: Anemia; Children; Ambient PM2.5 exposure; India; Association.

A Scoping Review of the Risk Factors Associated with Anaemia among Children Under Five Years in Sub-Saharan African Countries

Background/Purpose: Globally, anaemia is a severe public health condition affecting over 24% of the world's population. Children under five years old and pregnant women are the most vulnerable to this disease. This scoping review aimed to evaluate studies that used classical statistical regression methods on nationally representative health survey data to identify the individual socioeconomic, demographic and contextual risk factors associated with developing anaemia among children under five years of age in sub-Saharan Africa (SSA). Methods/Design: The reporting pattern followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The following databases were searched: MEDLINE, EMBASE (OVID platform), Web of Science, PUBMED, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, Scopus, Cochrane library, African Journal of online (AJOL), Google Scholar and Measure DHS. Results: The review identified 20 relevant studies and the risk factors for anaemia were classified as child-related, parental/household-related and community- or area-related factors. The risk factors for anaemia identified included age, birth order, sex, comorbidities (such as fever, diarrhoea and acute respiratory infection), malnutrition or stunting, maternal education, maternal age, mother's anaemia status, household wealth and place of residence. Conclusion: The outcome of this review is of significant value for health policy and planners to enable them to make informed decision that will correct any imbalances in anaemia across socioeconomic, demographic and contextual characteristics, with the view of making efficient distributions of health interventions.

Risk Factors Associated with Malnutrition among Children Under-Five Years in Sub-Saharan African Countries: A Scoping Review

Background/Purpose: Malnutrition is a significant global public health burden with greater concern among children under five years in Sub-Saharan Africa (SSA). To effectively address the problem of malnutrition, especially in resource-scarce communities, knowing the prevalence, causes and risk factors associated with it are essential steps. This scoping review aimed to identify the existing literature that uses classical regression analysis on nationally representative health survey data sets to find the individual socioeconomic, demographic and contextual risk factors associated with malnutrition among children under five years of age in Sub-Sahara Africa (SSA). Methods: The electronic databases searched include EMBASE (OVID platform), PubMed (MEDLINE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, Web of Science (WoS) and Cochrane Library. Only papers written in the English language, and for which the publication date was between 1 January 1990 and 31 July 2020, were included. Results: A total of 229 papers were identified, of which 26 were studies that have been included in the review. The risk factors for malnutrition identified were classified as child-related, parental/household-related and community or area-related. Conclusions: Study-interest bias toward stunting over other anthropometric indicators of malnutrition could be addressed with a holistic research approach to equally address the various dimension of the anthropometric indicators of malnutrition in a population.

Spatio-temporal trends in anaemia among pregnant women, adolescents and preschool children in sub-Saharan Africa

OBJECTIVE

We investigated the spatiotemporal trends in the burden of maternal, adolescent and child anaemia in sub-Saharan Africa (SSA) and evaluated some individual and household predictors of anaemia.

DESIGN

Average Hb concentrations and anaemia prevalence were estimated, plotted over time and mapped by country and sub-region. Multilevel linear regression models were used to evaluate individual and household predictors of Hb concentration.

PARTICIPANTS

Data from Demographic and Health Surveys (DHS) spanning 2000-2018 were merged into data sets for 37 623 pregnant women, 89 815 older adolescent girls and 401 438 preschool children.

SETTING

The merged DHS represent nationally representative samples from thirty-three countries.

RESULTS

Prevalence of anaemia remains high in SSA, affecting 60, 36 and 44 % of children, adolescents and pregnant women, respectively. Anaemia prevalence among children did not materially improve from 2000 to 2018. Anaemia prevalence among older adolescent girls and pregnant women did not also improve, but this masks a period of improvement followed by depreciation in population anaemia status. Pregnant adolescents had 12·5 g/l (95 % CI: 11·3, 13·6) lower Hb concentration compared with non-pregnant adolescents and 1·7 g/l (95 % CI: 0·7, 2·6) lower Hb concentration compared with pregnant women > 40 years, respectively. Stunting and wasting were associated with 1·3-3·3 g/l lower Hb concentration among children. Other significant predictors of Hb concentration were educational attainment, wealth quintiles, source of drinking water, number of children < 5 years in the household and possession of bed-nets.

CONCLUSION

Anaemia in SSA has not improved remarkably since year 2000 and remains excessive among children.

Two measures of systemic inflammation are positively associated with haemoglobin levels in adolescent girls living in rural India: a cross-sectional study

OBJECTIVE

This study tested the hypothesis that systemic inflammation is inversely associated with haemoglobin levels in adolescent girls in India.

METHODS

The study population consisted of adolescent girls aged between 10 and 19 years living in a remote rural region in Maharashtra State, India. Data were collected on anthropometric measures, and a venous blood sample was taken and tested for complete blood count and C-reactive protein (CRP).

RESULTS

Of 679 individuals who were invited to the research site to participate, data were available from 401 participants giving a response rate of 59%. Median blood CRP was 1.26 mg/l (Range 0.00 to 26.33), and 167 (41.6%) participants had CRP level < 1.0 mg/l. The mean haemoglobin was 12.24 g/dl (standard deviation [SD] 1.51), and the mean total white blood cells (WBC) count was 9.02 × 10³ /μl (SD 2.00). With each g/dl increase in blood haemoglobin, the risk of having an elevated CRP of ≥ 1 mg/l increased with an odds ratio of 1.16 (95% CI 1.01 to 1.33, P = 0.03). Total WBC count was also positively associated with blood haemoglobin, increasing by 0.24 × 10³ /μl (95% CI 0.11 to 0.37, P < 0.001) per g/dl increase in haemoglobin. Both analyses were adjusted for age.

CONCLUSIONS

In this population, blood haemoglobin levels were positively associated with two measures of systemic inflammation, contrary to the primary hypothesis being tested. Other unmeasured environmental exposures may modify haemoglobin levels in this population. Understanding this observation may help design better public health interventions to improve the well-being of adolescent girls in India.

Does use of solid fuels for cooking contribute to childhood stunting? A longitudinal data analysis from low- and middle-income countries

Using longitudinal data from the first and second waves of the Young Lives Study (YLS) in Ethiopia, India (Andhra Pradesh), Peru and Vietnam, conducted in 2002 and 2006–07, and a repeated measures mixed model, this study examined the effect of the use of solid fuels for cooking on childhood stunting among children aged 5–76 months. The analysis showed that in all four populations, the average height-for-age z-score (HAZ score) was much lower among children living in households using solid fuels than among children in households using cleaner fuels for cooking. The average HAZ score was lower among children living in households that used solid fuels in both waves of the YLS compared with those whose households used solid fuels in only one of the two waves. A significant reduction was noted in the average HAZ score between the two waves in all countries except Ethiopia. The results of the repeated measures mixed model suggest that household use of solid fuels was significantly associated with lower HAZ scores in all populations, except Ethiopia. The findings also indicate that the reduction in the HAZ scores between waves 1 and 2 was not statistically significant by the type of cooking fuel after controlling for potential confounding factors. The study provides further evidence of a strong association between household use of solid fuels and childhood stunting in low- and middle-income countries using longitudinal data. The findings highlight the need to reduce exposure to smoke from the combustion of solid fuels, by shifting households to cleaner cooking fuels, where feasible, by providing cooking stoves with improved combustion of solid fuels and improved venting, and by designing and implementing public information campaigns to inform people about the health risks of exposure to cooking smoke.

Household air pollution and caste-ethnic differences in undernutrition among children in Nepal

This study investigated whether the association between household air pollution (HAP) and nutritional status (stunting, underweight, or wasting) among children differ by caste/ethnicity. Child anthropometry data for 9,914 children aged 0-59 months were analyzed linearly as Z scores and as dichotomous categories. Exposure to HAP was significantly associated with a decrease in child height-for-age and child weight-for-age, as well as with stunting and underweight. Children in low caste (Dalits) had higher prevalence of stunting (odds ratio [OR] = 1.21; 95% confidence intervals [CI] = 1.01, 1.44), underweight (OR = 1.47; 95% CI = 1.24, 1.75), and wasting (OR = 1.53; 95% CI = 1.21, 1.92) than those children in upper caste group. This association was modestly attenuated with adjustment for HAP. Exposure to HAP partly explained the caste-ethnic difference in undernutrition among children in Nepal.

Environmental Risk Factors Associated with Child Stunting: A Systematic Review of the Literature

BACKGROUND

Stunting, a form of malnutrition characterized by impaired linear growth in the first two years of life, affects one quarter of children globally. While nutritional status remains the key cause of stunting, there is evidence that environmental risk factors are associated with stunting.

OBJECTIVE

The objective of this review is to explore the current literature and compile the environmental risk factors that have been associated with stunting. Further, we seek to discover which risk factors act independently of nutritional intake.

METHODS

A systematic search of the literature was performed using PubMed, EMBASE, Scopus, TOXNET, and CINAHL. A search of the grey literature was conducted. Papers were included in this review if they examined an association between childhood stunting and exposure to environmental risk factors.

FINDINGS

We included 71 reports in the final analysis. The included studies showed that foodborne mycotoxins, a lack of adequate sanitation, dirt floors in the home, poor quality cooking fuels, and inadequate local waste disposal are associated with an increased risk of childhood stunting. Access to safe water sources was studied in a large number of studies, but the results remain inconclusive due to inconsistent study findings. Limited studies were available for arsenic, mercury, and environmental tobacco, and thus their role in stunting remains inconclusive. The identified research did not control for nutritional intake. A causal model identified solid fuel use and foodborne mycotoxins as being environmental risk factors with the potential to have direct effects on childhood growth.

CONCLUSIONS

A diverse range of environmental risk factors are, to varying degrees, associated with stunting, demonstrating the importance of considering how the environment interacts with nutrition. Health promotion activities may be more effective if they consider environmental factors alongside nutritional interventions.

Environmental Risk Factors Associated with Child Stunting: A Systematic Review of the Literature

BACKGROUND

Stunting, a form of malnutrition characterized by impaired linear growth in the first two years of life, affects one quarter of children globally. While nutritional status remains the key cause of stunting, there is evidence that environmental risk factors are associated with stunting.

OBJECTIVE

The objective of this review is to explore the current literature and compile the environmental risk factors that have been associated with stunting. Further, we seek to discover which risk factors act independently of nutritional intake.

METHODS

A systematic search of the literature was performed using PubMed, EMBASE, Scopus, TOXNET, and CINAHL. A search of the grey literature was conducted. Papers were included in this review if they examined an association between childhood stunting and exposure to environmental risk factors.

FINDINGS

We included 71 reports in the final analysis. The included studies showed that foodborne mycotoxins, a lack of adequate sanitation, dirt floors in the home, poor quality cooking fuels, and inadequate local waste disposal are associated with an increased risk of childhood stunting. Access to safe water sources was studied in a large number of studies, but the results remain inconclusive due to inconsistent study findings. Limited studies were available for arsenic, mercury, and environmental tobacco, and thus their role in stunting remains inconclusive. The identified research did not control for nutritional intake. A causal model identified solid fuel use and foodborne mycotoxins as being environmental risk factors with the potential to have direct effects on childhood growth.

CONCLUSIONS

A diverse range of environmental risk factors are, to varying degrees, associated with stunting, demonstrating the importance of considering how the environment interacts with nutrition. Health promotion activities may be more effective if they consider environmental factors alongside nutritional interventions.

Maternal anemia is a potential risk factor for anemia in children aged 6-59 months in Southern Africa: a multilevel analysis

BACKGROUND

The effect of maternal anemia on childhood hemoglobin status has received little attention. Thus, we examined the potential association between maternal anemia and childhood anemia (aged 6-59 months) from selected Southern Africa countries.

METHODS

A cross-sectional study using nationally representative samples of children aged 6-59 months from the 2010 Malawi, 2011 Mozambique, 2013 Namibia, and 2010-11 Zimbabwe demographic and health surveys (DHS) was conducted. Generalized linear mixed models (GLMMs) were constructed to test the associations between maternal anemia and childhood anemia, controlling for individual and community sociodemographic covariates.

RESULTS

The GLMMs showed that anemic mothers had increased odds of having an anemic child in all four countries; adjusted odds ratio (aOR = 1.69 and 95% confidence interval [CI]:1.37-2.13) in Malawi, (aOR = 1.71; 95% CI: 1.37-2.13) in Mozambique, (aOR = 1.55; 95% CI: 1.08-2.22) in Namibia, and (aOR = 1.52; 95% CI: 1.25-1.84) in Zimbabwe. Furthermore, the odds of having an anemic child was higher in communities with a low percentage of anemic mothers (aOR = 1.52; 95% CI: 1.19-1.94) in Mozambique.

CONCLUSIONS

Despite the long-standing efforts to combat childhood anemia, the burden of this condition is still rampant and remains a significant problem in Southern Africa. Thus, public health strategies aimed at reducing childhood anemia should focus more on addressing infections, and micronutrient deficiencies both at individual and community levels in Southern Africa.

Solid fuel use is associated with anemia in children

Over 3 billion people use solid fuels as a means of energy and heating source, and ~ 50% of households burn them in inefficient, poorly ventilated stoves. In 2010, ~ 43% of the 640 million preschool children in 220 countries suffered from a certain degree of anemia, with iron deficiency as the main cause in developed countries whereas its causes remained multifactorial in the undeveloped group. In this study, we explore the relations of country-wide variables that might affect the people's health status (from socioeconomic status to more specific variables such as water access). We found independent relationship between solid fuel use and anemia in children under five years old (p < 0.0001), taking into account the prevalence of anemia in pregnant woman and the access to improved water sources. Countries in which the population uses solid fuel the most have over three times higher anemia rates in children than countries with the lowest prevalence of solid fuels use. There is still a complex relationship between solid fuels use and anemia, as reflected in its worldwide significance (p < 0.05) controlled for measles immunization, tobacco consumption, anemia in pregnant mothers, girl's primary education, life expectancy and improved water access but not (p > 0.05) when weighing for sanitation access or income per capita.

Prenatal anemia control and anemia in children aged 6-23 months in sub-Saharan Africa

It is unclear whether routine prenatal anemia control interventions can reduce anemia risk in young children. This study examines the associations between prenatal iron supplementation and/or deworming and anemia in children aged 6-23 months in sub-Saharan Africa (SSA). We analyzed data from Demographic and Health Surveys conducted between 2003 and 2014 in 25 SSA countries. The surveys collected data on prenatal iron supplementation and deworming and determined children's hemoglobin levels through blood testing. We assessed the associations between prenatal iron supplementation and/or deworming and anemia using multinomial logistic regression. The study included 31,815 mother-child pairs: 25.0%, 41.4%, and 4.8% of children had mild, moderate, and severe anemia, respectively. Compared with children whose mothers did not take iron and deworming drugs prenatally, the risk of moderate/severe anemia was reduced among children whose mothers took only iron supplements for ≥6 months (odds ratio [OR]: 0.58; 95% confidence interval [CI]: 0.45-0.76); only deworming drugs (OR: 0.73; 95% CI: 0.56-0.93); deworming drugs plus iron for <6 months (OR: 0.79; 95% CI: 0.67-0.93); and deworming drugs plus iron for ≥6 months (OR: 0.77; 95% CI: 0.59-0.99). Prenatal use of only iron for <6 months was not associated with moderate/severe anemia. Prenatal iron and/or deworming drugs had no effect on mild anemia. Prenatal anemia control interventions are associated with reduced risk of moderate/severe anemia but not with mild anemia in young children in SSA. Iron supplements should be taken for ≥6 months or with deworming drugs prenatally to reduce moderate/severe anemia risk in children.

Does smoke from biomass fuel contribute to anemia in pregnant women in Nagpur, India? A cross-sectional study

BACKGROUND

Anemia affects upwards of 50% of pregnant women in developing countries and is associated with adverse outcomes for mother and child. We hypothesized that exposure to smoke from biomass fuel--which is widely used for household energy needs in resource-limited settings--could exacerbate anemia in pregnancy, possibly as a result of systemic inflammation.

OBJECTIVE

To evaluate whether exposure to smoke from biomass fuel (wood, straw, crop residues, or dung) as opposed to clean fuel (electricity, liquefied petroleum gas, natural gas, or biogas) is an independent risk factor for anemia in pregnancy, classified by severity.

METHODS

A secondary analysis was performed using data collected from a rural pregnancy cohort (N = 12,782) in Nagpur, India in 2011-2013 as part of the NIH-funded Maternal and Newborn Health Registry Study. Multinomial logistic regression was used to estimate the effect of biomass fuel vs. clean fuel use on anemia in pregnancy, controlling for maternal age, body mass index, education level, exposure to household tobacco smoke, parity, trimester when hemoglobin was measured, and receipt of prenatal iron and folate supplements.

RESULTS

The prevalence of any anemia (hemoglobin < 11 g/dl) was 93% in biomass fuel users and 88% in clean fuel users. Moderate-to-severe anemia (hemoglobin < 10 g/dl) occurred in 53% and 40% of the women, respectively. Multinomial logistic regression showed higher relative risks of mild anemia in pregnancy (hemoglobin 10-11 g/dl; RRR = 1.38, 95% CI = 1.19-1.61) and of moderate-to-severe anemia in pregnancy (RRR = 1.79, 95% CI = 1.53-2.09) in biomass fuel vs. clean fuel users, after adjusting for covariates.

CONCLUSION

In our study population, exposure to biomass smoke was associated with higher risks of mild and moderate-to-severe anemia in pregnancy, independent of covariates.

TRIAL REGISTRATION

ClinicalTrials.gov NCT 01073475.

The stunting syndrome in developing countries

Linear growth failure is the most common form of undernutrition globally. With an estimated 165 million children below 5 years of age affected, stunting has been identified as a major public health priority, and there are ambitious targets to reduce the prevalence of stunting by 40% between 2010 and 2025. We view this condition as a 'stunting syndrome' in which multiple pathological changes marked by linear growth retardation in early life are associated with increased morbidity and mortality, reduced physical, neurodevelopmental and economic capacity and an elevated risk of metabolic disease into adulthood. Stunting is a cyclical process because women who were themselves stunted in childhood tend to have stunted offspring, creating an intergenerational cycle of poverty and reduced human capital that is difficult to break. In this review, the mechanisms underlying linear growth failure at different ages are described, the short-, medium- and long-term consequences of stunting are discussed, and the evidence for windows of opportunity during the life cycle to target interventions at the stunting syndrome are evaluated.