Haemoglobin thresholds to define anaemia in a national sample of healthy children and adolescents aged 1-19 years in India: a population-based study

Relationship between adolescent anemia and school attendance observed during a nationally representative survey in India

BACKGROUND

Anemia has been suggested to be related with schooling outcomes in India. Less is known, however, about whether the observed relationship persists after accounting for all household-level factors which may confound the association between anemia and schooling.

METHODS

Nationally representative data on adolescents aged 15-18 years with data on measured hemoglobin level and school attendance were extracted from India's National Family Health Surveys conducted between 2005 and 2021. We compared school attendance between adolescents living in the same household but with varying levels of hemoglobin concentration, while controlling for age and period effects. We assessed heterogeneity in the relationship between anemia and school attendance across anemia severity groups and socio-demographic characteristics.

RESULTS

The proportion of adolescents with any anemia is 55.2% (95% CI: 55.0-55.5) among young women and 31.0% (95% CI: 30.6-31.5) among young men. In conventional (between-household) regression models, having any anemia is associated with a 2.5 percentage point reduction (95% CI: 2.1-2.8) in school attendance; however, in household fixed-effects models, anemia has qualitatively small and non-significant effects on school attendance. Our results are consistent using alternative model specifications as well as across anemia severity groups, genders, types of relationship to the household head, household wealth quintiles, and states and union territories in India.

CONCLUSIONS

This within-household analysis finds little evidence that anemia is associated with school attendance among adolescents in India. Observational studies likely overstate the connection between anemia and school attendance due to household factors that have not been accounted for.

Selective Extraction and Quantification of Hemoglobin Based on a Novel Molecularly Imprinted Nanopolymeric Structure of Poly(acrylamide-vinyl imidazole)

Imbalances in hemoglobin (Hb) levels can lead to conditions such as anemia or polycythemia, emphasizing the importance of precise Hb extraction from blood. To address this, a novel synthetic imprinted polymer was meticulously developed for capturing and separating Hb. Poly(acrylamide-vinylimidazole) nanopolymer (poly(AAm-VIM)) was synthesized using acrylamide and vinyl imidazole as functional monomers through surfactant-free emulsion polymerization. Characterization using FTIR, particle size, zeta potential, and SEM ensured the polymer's structure. The Hb-imprinted nanopolymer (Hb-poly(AAm-VIM)) demonstrated notable specificity, with a calculated Hb-specific adsorption value (Qmax) of 3.7377 mg/g in a medium containing 2.5 mg/mL Hb. The molecularly imprinted polymer (MIP) exhibited approximately 5 times higher Hb adsorption than the nonimprinted polymer (NIP). Under the same conditions, the imprinted nanopolymer displayed 2.39 and 2.17 times greater selectivity for Hb over competing proteins such as bovine serum albumin (BSA) and lysozyme (Lys), respectively. Also, SDS-PAGE analysis results confirmed the purification of Hb by the molecularly imprinted nanopolymer. These results underscore the heightened specificity and efficacy of the molecularly imprinted nanopolymer in selectively targeting Hb atoms among other proteins. Incorporating such polymers is justified by their notable affinity, cost-effectiveness, and facile production. This research contributes valuable insights into optimizing synthetic imprinted polymers for efficient Hb extraction, with potential in medical diagnostics and treatment applications.

Haemoglobin thresholds to define anaemia from age 6 months to 65 years: estimates from international data sources

BACKGROUND

Detection of anaemia is crucial for clinical medicine and public health. Current WHO anaemia definitions are based on statistical thresholds (fifth centiles) set more than 50 years ago. We sought to establish evidence for the statistical haemoglobin thresholds for anaemia that can be applied globally and inform WHO and clinical guidelines.

METHODS

In this analysis we identified international data sources from populations in the USA, England, Australia, China, the Netherlands, Canada, Ecuador, and Bangladesh with sufficient clinical and laboratory information collected between 1998 and 2020 to obtain a healthy reference sample. Individuals with clinical or biochemical evidence of a condition that could reduce haemoglobin concentrations were excluded. We estimated haemoglobin thresholds (ie, 5th centiles) for children aged 6-23 months, 24-59 months, 5-11 years, and 12-17 years, and adults aged 18-65 years (including during pregnancy) for individual datasets and pooled across data sources. We also collated findings from three large-scale genetic studies to summarise genetic variants affecting haemoglobin concentrations in different ancestral populations.

FINDINGS

We identified eight data sources comprising 18 individual datasets that were eligible for inclusion in the analysis. In pooled analyses, the haemoglobin fifth centile was 104·4 g/L (90% CI 103·5-105·3) in 924 children aged 6-23 months, 110·2 g/L (109·5-110·9) in 1874 children aged 24-59 months, and 114·4 g/L (113·6-115·2) in 1839 children aged 5-11 years. Values diverged by sex in adolescents and adults. In pooled analyses, the fifth centile was 122·2 g/L (90% CI 121·3-123·1) in 1741 female adolescents aged 12-17 years and 128·2 g/L (126·4-130·0) in 1103 male adolescents aged 12-17 years. In pooled analyses of adults aged 18-65 years, the fifth centile was 119·7 g/L (90% CI 119·1-120·3) in 3640 non-pregnant females and 134·9 g/L (134·2-135·6) in 2377 males. Fifth centiles in pregnancy were 110·3 g/L (90% CI 109·5-111·0) in the first trimester (n=772) and 105·9 g/L (104·0-107·7) in the second trimester (n=111), with insufficient data for analysis in the third trimester. There were insufficient data for adults older than 65 years. We did not identify ancestry-specific high prevalence of non-clinically relevant genetic variants that influence haemoglobin concentrations.

INTERPRETATION

Our results enable global harmonisation of clinical and public health haemoglobin thresholds for diagnosis of anaemia. Haemoglobin thresholds are similar between sexes until adolescence, after which males have higher thresholds than females. We did not find any evidence that thresholds should differ between people of differering ancestries.

FUNDING

World Health Organization and the Bill & Melinda Gates Foundation.

A district-level geospatial analysis of anaemia prevalence among rural men in India, 2019-21

BACKGROUND

Despite its considerable impact on health and productivity, anemia among men has received limited attention. In a country as diverse as India, characterized by extensive geographic variations, there is a pressing need to investigate the nuanced spatial patterns of anemia prevalence among men. The identification of specific hotspots holds critical implications for policymaking, especially in rural areas, where a substantial portion of India's population resides.

METHODS

The study conducted an analysis on a sample of 61,481 rural men from 707 districts of India, utilizing data from the National Family Health Survey-5 (2019-21). Various analytical techniques, including Moran's I, univariate LISA (Local Indicators of Spatial Association), bivariate LISA, and spatial regression models such as SLM (Spatial Lag Model), and SEM (Spatial Error Model) were employed to examine the geographic patterns and spatial correlates of anaemia prevalence in the study population.

RESULTS

In rural India, three out of every ten men were found to be anemic. The univariate Moran's I value for anaemia was 0.66, indicating a substantial degree of spatial autocorrelation in anaemia prevalence across the districts in India. Cluster and outlier analysis identified five prominent 'hotspots' of anaemia prevalence across 97 districts, primarily concentrated in the eastern region (encompassing West Bengal, Jharkhand, and Odisha), the Dandakaranya region, the Madhya Pradesh-Maharashtra border, lower Assam, and select districts in Jammu and Kashmir. The results of SLM revealed significant positive association between anaemia prevalence at the district-level and several key factors including a higher proportion of Scheduled Tribes, men in the 49-54 years age group, men with limited or no formal education, individuals of the Muslim faith, economically disadvantaged men, and those who reported alcohol consumption.

CONCLUSIONS

Substantial spatial heterogeneity in anaemia prevalence among men in rural India suggests the need for region-specific targeted interventions to reduce the burden of anaemia among men in rural India and enhance the overall health of this population.

Improving Anemia Assessment in Clinical and Public Health Settings

We aim to provide a practical approach to assess anemia and its primary causes, both in clinical settings and in the context of public health programs. Anemia remains a global challenge; thus, to achieve goals for anemia reduction and assess progress, standardized approaches are required for the assessment of anemia and its causes. We first provide a brief review of how to assess anemia, based on hemoglobin concentrations and cutoffs that correspond to age, sex, and physiologic status. Next, we discuss how to assess the likely causes of anemia in different settings. The causes of anemia are classified as non-nutritional (for example, because of infection, inflammation, blood loss, or genetic disorders) or nutrition-specific (for example, because of deficiencies of iron, vitamin A, riboflavin, vitamin B12, or folate). There is an important overlap between these 2 categories, such as the increased likelihood of iron deficiency in the context of inflammation. Given the multifaceted nature of anemia etiology, we introduce a framework for anemia assessment based on the "ecology of anemia," which recognizes its many overlapping causes. This conceptual framework is meant to inform what data on anemia causes may need to be collected in population surveys. The framework has a supporting table with information on the diagnostic tests, biomarkers and proposed cutoffs, characteristics, and feasibility of collecting the myriad information that can help elucidate the anemia etiology. We also provide examples of how this framework can be applied to interpret the anemia risk factor data from population-based surveys that can inform decisions about context-specific interventions. Finally, we present research gaps and priorities related to anemia assessment.

Anaemia and its causes at the Brazilian Longitudinal Study of Adult Health: a cross-sectional analysis of baseline data

BACKGROUND

Most anaemia studies focus on children and women of childbearing age. We assessed the frequency and main aetiologies of anaemia according to sociodemographic characteristics at the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a cohort of middle-aged adults.

METHODS

The primary analyses included 15,051 participants aged 35-74 years with a valid blood cell count. We built logistic models to analyse the association between socioeconomic characteristics and anaemia diagnosis. We also described the main aetiologies in a subset (n = 209) of participants with anaemia.

RESULTS

Anaemia was present in 3.0% (95% confidence interval [95%CI]: 2.6-3.4%) of men and 7.4% (95%CI: 6.9-8.0%) of women. The frequency of anaemia diagnosis was higher in women in all subgroups except for the oldest age stratum (65-74 years). The frequency of anaemia was particularly high in Blacks (6.0% and 15.5% in men and women, respectively). The most common causes of anaemia were iron deficiency (in women), chronic kidney disease, and chronic inflammation (in men). The frequency of unexplained anaemia was respectively 33.3% and 34.2% for men and women, and this condition was more frequent among participants of Black or Mixed races.

CONCLUSIONS

Anaemia was associated with age, female sex, Black race, and low socioeconomic status. Unexplained anaemia was common and more frequent in individuals of Black and Mixed races. ELSA-Brasil follow-up data may provide further insight into the relevance of unexplained anaemia in this setting.

Assessment of haemoglobin and serum markers of iron deficiency in people with cardiovascular disease

BACKGROUND

The prevalence of anaemia and iron deficiency and their prognostic association with cardiovascular disease have rarely been explored at population level.

METHODS

National Health Service records of the Greater Glasgow region for patients aged ≥50 years with a broad range of cardiovascular diagnoses were obtained. During 2013/14, prevalent disease was identified and results of investigations collated. Anaemia was defined as haemoglobin <13 g/dL for men or <12 g/dL for women. Incident heart failure, cancer and death between 2015 and 2018 were identified.

RESULTS

The 2013/14 dataset comprised 197 152 patients, including 14 335 (7%) with heart failure. Most (78%) patients had haemoglobin measured, especially those with heart failure (90%). Of those tested, anaemia was common both in patients without (29%) and with heart failure (prevalent cases in 2013/14: 46%; incident cases during 2013/14: 57%). Ferritin was usually measured only when haemoglobin was markedly depressed; transferrin saturation (TSAT) even less often. Incidence rates for heart failure and cancer during 2015-18 were inversely related to nadir haemoglobin in 2013/14. A haemoglobin of 13-15 g/dL for women and 14-16 g/dL for men was associated with the lowest mortality. Low ferritin was associated with a better prognosis and low TSAT with a worse prognosis.

CONCLUSION

In patients with a broad range of cardiovascular disorders, haemoglobin is often measured but, unless anaemia is severe, markers of iron deficiency are usually not. Low haemoglobin and TSAT, but not low ferritin, are associated with a worse prognosis. The nadir of risk occurs at haemoglobin 1-3 g/dL above the WHO definition of anaemia.

Prevalence of Vitamin B12 and Folate Deficiencies in Indian Children and Adolescents

Deficiencies of vitamin B₁₂ (B₁₂) and folate (FA) are of particular interest due to their pleiotropic role in 1-carbon metabolism. In addition to adverse birth outcomes, deficiencies of B₁₂ and FA, or an imbalance in FA/B₁₂ status, are linked to metabolic disorders. Indian diets that are predominantly plant food-based could be deficient in these vitamins, but there are no national estimates of the prevalence of B₁₂ and FA deficiency in Indian children and adolescents, nor their associations with age, sex and growth indicators. The recent Comprehensive National Nutrition Survey (CNNS-2016-18) provided estimates of the prevalence of B₁₂ and FA deficiency at the national and state levels among preschool (1-4 years: 9976 and 11,004 children, respectively), school-age children (5-9 years: 12,156 and 14,125) and adolescents (10-19 years: 11,748 and 13,621). Serum B₁₂ and erythrocyte FA were measured by the direct chemiluminescence method and their deficiency was defined using WHO cut-offs. The prevalence of B₁₂ and FA deficiency was high among adolescents (31.0%, CI: 28.7-33.5 and 35.6%, CI: 33.1-8.2) compared to school-age (17.3%, CI: 15.4-19.3 and 27.6%, CI: 25.5-29.9) and preschool children (13.8%, CI: 11.7-16.2 and 22.8%, CI: 20.5-25.2, respectively). The prevalence of both B₁₂ and FA deficiency was significantly higher by 8% and 5%, respectively, in adolescent boys compared to girls. There was no association between anthropometric undernutrition and B₁₂ and FA deficiency. There was wide regional variation in the prevalence of B₁₂ and FA deficiency, but no rural-urban differences were observed across all age groups. The national prevalence of B₁₂ deficiency among preschool or school-age children was <20% (the cut-off that indicates a public health problem). However, FA deficiency in these age groups and both FA and B₁₂ deficiencies in adolescents were >20%, warranting further investigation.

Prevalence and Risk Factors of Iron Deficiency Anemia among the Tribal Residential Adolescent School Students of Odisha: A Cross-Sectional Study

Background

Globally, anemia is one of the biggest public health challenges. The highest prevalence of anemia is seen among adolescents. Tribal communities are especially at a disadvantage, with several studies documenting a high prevalence of anemia among tribal adolescents. We investigated the prevalence of anemia and its associated risk factors among the tribal residential adolescent school students in Odisha.

Material and Methods

In a cross-sectional survey, the prevalence of anemia was estimated by spectrophotometry among adolescents of residential schools in three predominantly tribal districts of Odisha. The severity of anemia was defined as per the World Health Organization classification for adolescents.

Results

The mean age of 953 subjects was 13.07 ± 1.48 years. The prevalence of anemia was found to be 37.3%. As per the World Health Organization classification, 19.9% had mild anemia, 16.3% had moderate, and 1% had severe anemia. Consumption of Iron Folic Acid (IFA) was associated with the level of hemoglobin at a statistically significant level.

Conclusion

We found that the prevalence of anemia was lower than in similar studies conducted in other parts of the country. Despite poor coverage of beneficiaries with iron and folic acid at the national level, our study showed better compliance and was associated with a significantly higher level of hemoglobin among those who consumed IFA.

A cross-sectional analysis of ambient fine particulate matter (PM2.5) exposure and haemoglobin levels in children aged under 5 years living in 36 countries

Low haemoglobin (Hb) concentrations and anaemia in children have adverse effects on development and functioning, some of which may have consequences in later life. Exposure to ambient air pollution is reported to be associated with anaemia, but there is little evidence specific to low- and middle-income countries (LMICs), where childhood anaemia prevalence is greatest. We aimed to determine if long-term ambient fine particulate matter (≤2.5 μm in aerodynamic diameter [PM_2.5]) exposure was associated with Hb levels and the prevalence of anaemia in children aged <5 years living in 36 LMICs. We used Demographic and Health Survey data, collected between 2010 and 2019, which included blood Hb measurements. Satellite-derived estimates of annual average PM_2.5 was the main exposure variable, which was linked to children's area of residence. Anaemia was defined according to standard World Health Organization guidelines (Hb < 11 g/dL). The association of PM_2.5 with Hb levels and anaemia prevalence was examined using multivariable linear and logistic regression models, respectively. We examined whether the effects of ambient PM_2.5 were modified by a child's sex and age, household wealth index, and urban/rural place of residence. Models were adjusted for relevant covariates, including other outdoor pollutants and household cooking fuel. The study included 154,443 children, of which 89,904 (58.2%) were anaemic. The country-level prevalence of anaemia ranged from 15.8% to 87.9%. Mean PM_2.5 exposure was 33.0 (±21.6) μg/m³. The adjusted model showed that a 10 μg/m³ increase in annual PM_2.5 concentration was associated with greater odds of anaemia (OR = 1.098 95% CI: 1.087, 1.109). The same increase in PM_2.5 was associated with a decrease in average Hb levels of 0.075 g/dL (95% CI: 0.081, 0.068). There was evidence of effect modification by household wealth index and place of residence, with greater adverse effects in children from lower wealth quintiles and children in rural areas. Exposure to annual PM_2.5 was cross-sectionally associated with decreased blood Hb levels, and greater risk of anaemia, in children aged <5 years living in 36 LMICs.

Prevalence and morphological subtype distributions of anaemia in a Chinese rural population: the Henan Rural Cohort study

OBJECTIVE

This study aimed to evaluate the recent prevalence and the distributions of morphological subtypes of anaemia in the rural population.

DESIGN

Anaemia was defined according to the WHO and the Chinese criteria, and the morphological subtypes of anaemia were classified based on the erythrocyte parameters. The age-standardised prevalence was calculated according to the data of the Population Census 2010 in China.

SETTING

A cross-sectional study in Henan Province.

PARTICIPANTS

33 585 subjects aged 18-79 years old.

RESULTS

The standardised prevalence of anaemia across the WHO and the Chinese definitions was 13·63 % and 5·45 %, respectively. Regardless of which criteria was used, the standardised prevalence of anaemia was higher among women than among men and that increased with age in men, while markedly decreased after menopause in women. There were shifts in morphological patterns of anaemia using the WHO and the Chinese criteria that the standardised prevalence of microcytic anaemia was 3·74 % and 2·97 %, normocytic anaemia was 9·20 % and 2·34 %, and macrocytic anaemia was 0·75 % and 0·14 %, respectively. Besides, there were differences in the influencing factors of anaemia according to different criteria or gender. However, age, education level and renal damage were consistently significantly associated with anaemia in all participants.

CONCLUSIONS

Anaemia may still be a serious health problem in rural China. It is necessary to reformulate prevention and management strategies to reduce the disease burden of anaemia.

Statistical haemoglobin thresholds to define anaemia across the lifecycle

Detection of anaemia is critical for clinical medicine and public health. Current WHO values that define anaemia are statistical thresholds (5 ^th centile) set over 50 years ago, and are presently <110g/L in children 6-59 months, <115g/L in children 5-11 years, <110g/L in pregnant women, <120g/L in children 12-14 years of age, <120g/L in non-pregnant women, and <130g/L in men. Haemoglobin is sensitive to iron and other nutrient deficiencies, medical illness and inflammation, and is impacted by genetic conditions; thus, careful exclusion of these conditions is crucial to obtain a healthy reference population. We identified data sources from which sufficient clinical and laboratory information was available to determine an apparently healthy reference sample. Individuals were excluded if they had any clinical or biochemical evidence of a condition that may diminish haemoglobin concentration. Discrete 5 ^th centiles were estimated along with two-sided 90% confidence intervals and estimates combined using a fixed-effect approach. Estimates for the 5 ^th centile of the healthy reference population in children were similar between sexes. Thresholds in children 6-23 months were 104.4g/L [90% CI 103.5, 105.3]; in children 24-59 months were 110.2g/L [109.5, 110.9]; and in children 5-11 years were 114.1g/L [113.2, 115.0]. Thresholds diverged by sex in adolescents and adults. In females and males 12-17 years, thresholds were 122.2g/L [121.3, 123.1] and 128.2 [126.4, 130.0], respectively. In adults 18-65 years, thresholds were 119.7g/L [119.1, 120.3] in non-pregnant females and 134.9g/L [134.2, 135.6] in males. Limited analyses indicated 5 ^th centiles in first-trimester pregnancy of 110.3g/L [109.5, 111.0] and 105.9g/L [104.0, 107.7] in the second trimester. All thresholds were robust to variations in definitions and analysis models. Using multiple datasets comprising Asian, African, and European ancestries, we did not identify novel high prevalence genetic variants that influence haemoglobin concentration, other than variants in genes known to cause important clinical disease, suggesting non-clinical genetic factors do not influence the 5 ^th centile between ancestries. Our results directly inform WHO guideline development and provide a platform for global harmonisation of laboratory, clinical and public health haemoglobin thresholds.

To what extent classic socio-economic determinants explain trends of anaemia in tribal and non-tribal women of reproductive age in India? Findings from four National Family Heath Surveys (1998-2021)

BACKGROUND

Despite unprecedented socio-economic growth experienced by Indians in the past few decades, and a long history of anti-anaemia public health measures, prevalence of anaemia in Indian non-pregnant women of reproductive age group (NPWRA) has not declined. This warrants a firm understanding of what explains the anaemia situation over time, preferably by sub-populations. Therefore, we aimed to examine the trends of anaemia in tribal NPWRA (least privileged) and compare with the trends in the NPWRA of general caste (most privileged) between 1998 to 2021. Additionally, the study also explored explanation of any decline and tribal/general narrowing of these trends.

METHODS

We studied four rounds of National Family Health Survey (1998-99, 2005-06, 2015-16, 2019-21). We examined the trend of anaemia (haemoglobin < 12 g/dl) and its possible determinants in tribal and general NPWRA and estimated the portion of "decline" and "narrowing" that could be explained by the underlying and intermediate determinants (wealth, education, residence, parity and food security) using multiple logistic regression.

RESULTS

The distribution of determinants improved over 23 years in both the groups but more in tribals. But anaemia either remained unchanged or increased in both except 7.1 points decline in tribals between 2006-2016, leading also to 7 points narrowing of tribal/general gap. The modest attenuation of beta coefficients representing the change of anaemia prevalence (log of odds) in tribals from -0.314(-0.377, -0.251) to -0.242(-0.308, -0.176) after adjustment with determinants could explain only 23% of the decline. Similarly, only 7% of the narrowing of the tribal/general anaemia gap could be explained.

CONCLUSIONS

The structural determinants wealth, education, food security, parity and urban amenities improved immensely in India but anaemia did not decline in this 23-year period. This implies that the "usual suspects" - the structural determinants are not the main drivers of anaemia in the country. The main driver may be absolute and/or functional deficiency status of micronutrients including iron attributable to inadequate uptake and absorption of these elements from Indian diets; and therefore, their effects are noticeable in every socio-economic stratum of India. Future research for aetiologies and new interventions for anaemia alleviation in India may focus on these factors.

Shooting shadows: India's struggle to reduce the burden of anaemia

Despite several efforts by the Government of India, the national burden of anaemia remains high and its growing prevalence (between 2015-2016 and 2019-2021) is concerning to India's public health system. This article reviews existing food-based and clinical strategies to mitigate the anaemia burden and why they are premature and insufficient. In a context where multiple anaemia control programmes are in play, this article proposes a threefold strategy for consideration. First, except the Comprehensive National Nutrition Survey, 2016-2018, which measured Hb concentration among children and adolescents aged 1-19 years using venous blood samples, all national surveys use capillary blood samples to determine Hb levels, which could be erroneous. The Indian government should prioritise conducting a nationwide survey for estimating the burden of anaemia and its clinical determinants for all age groups using venous blood samples. Second, without deciding the appropriate dose of Fe needed for an individual, food fortification programmes that are often compounded with layering of other micronutrients could be harmful and further research on this issue is needed. Same is true for the pharmacological intervention of Fe tablet or syrup supplementation programmes, which is given to individuals without assessing its need. In addition, there is a dire need for robust research to understand both the long-term benefit and side effects of Fe supplementation programmes. Third and final, the WHO is in process of reviewing the Hb threshold for defining anaemia, therefore the introduction of new anaemia control programmes should be restrained.

Age and sex trend differences in hemoglobin levels in China: a cross-sectional study

BACKGROUND

Both age and gender are the influence factors of hemoglobin concentration. However, the changing trend of hemoglobin levels between males and females with age remains unclear. This study aimed to explore their changing characteristics in different genders.

METHODS

A cross-sectional study was conducted in Physical Examination Center of the First Affiliated Hospital of Wannan Medical College in Wuhu, China from 2014 to 2016. The generalized linear model was applied to explore the relationship between age, gender and hemoglobin levels.

RESULTS

Among the 303,084 participants, the mean age for females and males was 46.9 ± 13.4(15-98) and 48.1 ± 13.7(14-98) years old, respectively. Generalized smoothing splines showed that hemoglobin levels increased up to age 25 and then decreased in men; in women the levels increased up until age 20, and then decreased, with slight increase again (β = 0.244, P < 0.01). After dividing all participants into hyperglycemia and normal groups, only the normal female group showed a significant upward trend (β = 0.257, P < 0.01) between ages 50-59.

CONCLUSIONS

Hemoglobin concentration changes with age and the curve is different in males and females. The slightly upward trend of female hemoglobin in the age range of 50-59 years old should be considered in developing the reference range of hemoglobin making.

Comparison between School-Age Children with and without Obesity in Nutritional and Inflammation Biomarkers

Childhood obesity is a major health problem. We examined differences between children with obesity and normal weight in nutritional and inflammation biomarkers. A cross-sectional study was conducted among healthy children aged 10-12 years from Arab villages in Israel. Parents were interviewed regarding sociodemographic and children's health status. Body weight and height measurements were performed and weight categories were defined using the 2007 WHO growth curves. Blood samples were tested for complete blood count, levels of iron, ferritin, lipids, uric acid, and C-reactive protein (CRP). Overall, 146 children (59.0% males, mean age = 11.3 [SD = 0.5]) were enrolled. In total 43.8%, 14.1% and 42.3% of the participants had normal weight, overweight and obesity, respectively. A multivariable logistic regression model showed that children with overweight and obesity had lower iron, and HDL-C levels than children with normal weight. Levels of CRP, uric acid, LDL-C and lymphocytes were higher among children with overweight and obesity. In conclusion, our findings highlight the worse metabolic and nutritional status in overweight and obese children. Such markers play a role in metabolic syndrome, thus suggesting that metabolic syndrome might start in childhood.

Contribution of malaria and sickle cell disease to anaemia among children aged 6-59 months in Nigeria: a cross-sectional study using data from the 2018 Demographic and Health Survey

OBJECTIVES

To estimate the fraction of anaemia attributable to malaria and sickle cell disease (SCD) among children aged 6-59 months in Nigeria.

DESIGN

Cross-sectional analysis of data from Nigeria's 2018 Demographic and Health Survey (DHS).

SETTING

Nigeria.

PARTICIPANTS

11 536 children aged 6-59 months from randomly selected households were eligible for participation, of whom 11 142 had complete and valid biomarker data required for this analysis. Maternal education data were available from 10 305 of these children.

PRIMARY OUTCOME MEASURE

Haemoglobin concentration.

RESULTS

We found that 70.6% (95% CI: 62.7% to 78.5%) of severe anaemia was attributable to malaria compared with 12.4% (95% CI: 11.1% to 13.7%) of mild-to-severe and 29.6% (95% CI: 29.6% to 31.8%) of moderate-to-severe anaemia and that SCD contributed 0.6% (95% CI: 0.4% to 0.9%), 1.3% (95% CI: 1.0% to 1.7%) and 10.6% (95% CI: 6.7% to 14.9%) mild-to-severe, moderate-to-severe and severe anaemia, respectively. Sickle trait was protective against anaemia and was associated with higher haemoglobin concentration compared with children with normal haemoglobin (HbAA) among malaria-positive but not malaria-negative children.

CONCLUSIONS

This approach used offers a new tool to estimate the contribution of malaria to anaemia in many settings using widely available DHS data. The fraction of anaemia among young children in Nigeria attributable to malaria and SCD is higher at more severe levels of anaemia. Prevention of malaria and SCD and timely treatment of affected individuals would reduce cases of severe anaemia.

Childhood and Adolescent Anemia Burden in India: The Way Forward

The burden of anemia in Indian children, based on capillary blood sampling, is believed to be profound and worsening (67.1%) according to the successive National Family Health Surveys (NFHS). This might be an overestimate. The recent Comprehensive National Nutrition Survey of Indian children, that used venous blood sampling, found only less than half (30.7%) the NFHS prevalence, of which only one third was due to iron deficiency (ID). Unfortunately, the apparently worsening NFHS anemia burden estimate has been interpreted as an inadequacy of the present iron supplementation policy. This has led to additional iron supply through mandatory rice fortification. However, the lack of efficacy of iron supplementation appears inevitable, if the true prevalence of iron deficiency anemia is only about 10%. Thus, etiology is a critical consideration when devising appropriate and effective prevention policies. Future policies must focus on precision, thoughtfulness, restraint, and community engagement.

Iron metabolism: pathways and proteins in homeostasis

Iron is essential to human survival. The biological role and trafficking of this trace essential inorganic element which is also a potential toxin is constantly being researched and unfolded. Vital for oxygen transport, DNA synthesis, electron transport, neurotransmitter biosynthesis and present in numerous other heme and non-heme enzymes the physiological roles are immense. Understanding the molecules and pathways that regulate this essential element at systemic and cellular levels are of importance in improving therapeutic strategies for iron related disorders. This review highlights the progress in understanding the metabolism and trafficking of iron along with the pathophysiology of iron related disorders.

A risk-based approach to measuring population micronutrient status from blood biomarker concentrations

Background

Nutrient biomarkers and their definitive cut-offs are used to classify individuals as nutrient-deficient or sufficient. This determinism does not consider any uncertainty, and a probability approach, using biomarker distributions, is then preferable to define the risk of nutrition deficiency when in populations.

Method

Healthy 1–19-year-old children and adolescents were selected from the Comprehensive National Nutrition Survey (CNNS), to obtain probability distributions of their retinol, zinc and vitamin B₁₂, along with erythrocyte folate. Model-based estimates of location, scale and shape parameters of these distributions were obtained across ages. Subsequently, in the entire sample of 1–19 year old children of CNNS, the population risk of deficiency (PRD) which is average risk of deficiency in individuals in the population was computed, which is “of concern” when >50%. When individual risk of deficiency is >97.5% it is called “severe risk of deficiency” (SRD).

Results

In the entire CNNS sample, the PRD of concern was low for serum retinol (3.6–8.2%), zinc (0–5.5%), and SRD of vitamin B₁₂ and erythrocyte folate were 2.3–7.2% and 4.2–9.7%, respectively, across age and sex groups.

Conclusion

This proposed method assesses the adequacy of nutrient exposures without relying on pre-defined deterministic biomarker cut-offs to define micronutrient deficiency and avoids errors in exposure assessment.

A proposed method for defining the required fortification level of micronutrients in foods: An example using iron

In 2006, the WHO published a framework for calculating the desired level of fortification of any micronutrient in any staple food vehicle, to reduce micronutrient malnutrition. This framework set the target median nutrient intake, of the population consuming the fortified food, at the 97.5th percentile of their nutrient requirement distribution; the Probability of Inadequacy (PIA) of the nutrient would then be 2.5%. We argue here that the targeted median nutrient intake should be at Estimated Average Requirement (50^th percentile), since the intake distribution will then overlap the requirement distribution in a population that is in homeostasis, resulting in a PIA of 50%. It is also important to recognize that setting the target PIA at 2.5% may put a sizable proportion at risk of adverse consequences associated with exceeding the tolerable upper limit (TUL) of intake. This is a critical departure from the WHO framework. For a population with different age- and sex-groups, the pragmatic way to fix the fortification level for a staple food vehicle is by achieving a target PIA of 50% in the most deprived age- or sex-group of that population, subject to the condition that only a very small proportion of intakes exceed the TUL. The methods described here will aid precision in public health nutrition, to pragmatically determine the precise fortification level of a nutrient in a food vehicle, while balancing risks of inadequacy and excess intake.

Reference cut-offs to define low serum zinc concentrations in healthy 1-19 year old Indian children and adolescents

BACKGROUND/OBJECTIVES

Population zinc (Zn) status assessment is based on serum zinc concentration (SZC) cut-offs defined by the International Zinc Nutrition Consultative Group (IZiNCG). The objective of this study is to derive reference SZC cut-offs in apparently healthy 1-19 year Indian children and adolescents using comprehensive national nutrition survey (CNNS) data, and to measure the prevalence of Zn deficiency.

SUBJECTS/METHODS

Apparently healthy children (n = 12,473) were selected from the CNNS, by including the highest 2 wealth quintiles, and excluding stunted, thin and obese children, and those with CRP > 5 mg/L, anaemia, hypo-albuminemia, diabetes, recent diarrhoea and history of smoking. The 2.5th centile of age-based distributions defined the SZC cut-offs, used to measure the prevalence of Zn deficiency in India, as against the IZiNCG cut-offs.

RESULTS

The present study SZC cut-offs were significantly lower, by 10-18 µg/dL, than the IZiNCG cut-offs; more in adolescents. Prevalence of Zn deficiency in the entire CNNS, with these cut-offs, was 2.7 (<10 years) to 5.5 (10-19 years) times lower than with the IZiNCG cut-offs. No geographical state, nor any age group, had Zn deficiency as a serious public health problem (≥20%). In contrast, with IZiNCG cut-offs, 9-27 states (depending on age group) had a public health problem.

CONCLUSIONS

The present study reference SZC cut-offs for Zn deficiency are lower than the IZiNCG cut-offs, and their rigorous selection from a national sample makes them more appropriate for use in India. A re-examination of the global applicability of IZiNCG recommended cut-offs in other LMICs appears appropriate.

Dietary diversity as a sustainable approach towards micronutrient deficiencies in India

The silent epidemic of micronutrient deficiencies (MNDs) continues to be a major public health challenge in the developing world, including India. The prevalence of iron, iodine, zinc, vitamin A and folate deficiencies is alarmingly high worldwide. India is additionally facing a high prevalence of vitamin D and B12 deficiencies. To combat the hidden epidemic of MNDs, various governments around the world have mostly relied on supplementation or fortification-based interventions. India launched salt iodization programme in 1962 and vitamin A and iron-folate supplementation programmes in 1970. Yet, even after decades of these programmes, MNDs are still widespread in the country. Due to slow progress in alleviating the burden of most MNDs, the Government of India aims to scale up fortification-based intervention programmes. However, there are safety and effectiveness concerns with such approaches. Hence, overdependence on supplementation and fortification alone may be counterproductive. Instead, food based dietary diversification approach can be the way forward. In this article, we list the common MNDs in India, evaluate major policy interventions, discuss concerns pertaining to fortification and suggest the need for a concurrent food-based approach, in particular dietary diversification, as a long-term and sustainable strategy to address population-based MNDs.

Childhood and Adolescent Anemia Burden in India: The Way Forward

The burden of anemia in Indian children, based on capillary blood sampling, is believed to be profound and worsening (67.1%) according to the successive National Family Health Surveys (NFHS). This might be an overestimate. The recent Comprehensive National Nutrition Survey of Indian children, that used venous blood sampling, found only less than half (30.7%) the NFHS prevalence, of which only one third was due to iron deficiency (ID). Unfortunately, the apparently worsening NFHS anemia burden estimate has been interpreted as an inadequacy of the present iron supplementation policy. This has led to additional iron supply through mandatory rice fortification. However, the lack of efficacy of iron supplementation appears inevitable, if the true prevalence of iron deficiency anemia is only about 10%. Thus, etiology is a critical consideration when devising appropriate and effective prevention policies. Future policies must focus on precision, thoughtfulness, restraint, and community engagement.

Overview of Anemia; risk factors and solution offering

OBJECTIVE

The study aims to determine the picture risk factor-related anemia and the solution offered by searching the literature and reviewing it.

METHOD

using literature studies. Article searches using online data-based Science Direct, PubMed, and Google Scholar from 2019 to 2021. They have obtained as many as 20 articles based on inclusion criteria and relevance.

RESULT

Anaemia in young women is still a severe problem among the community. There need to be early detection measures to quickly determine the incidence of anemia and describe anemia as one of the information for all circles young women. Women have a higher risk of anemia, especially young women. This is due to strict dietary habits to prevent weight gain, resulting in malnutrition due to the unmet intake of essential nutrients for the body. Whereas in adolescence, there is an increase in iron demand due to growth and menstruation. Therefore it is very important to provide smart solutions to the incidence of anemia. One that is offered is early detection so that prevention can be done. The use of information technology can be used to conduct early detection of anemia in adolescents because it has been widely utilized among the community, especially adolescents.

CONCLUSION

From the entire literature review, it seems that nutritional status greatly influences the incidence of anemia suffered, and young women are a target for the best intervention. Early detection and use of technology are innovative solutions offered.

Defining hypoxaemia from pulse oximeter measurements of oxygen saturation in well children at low altitude in Bangladesh: an observational study

Background

WHO defines hypoxaemia, a low peripheral arterial oxyhaemoglobin saturation (SpO₂), as <90%. Although hypoxaemia is an important risk factor for mortality of children with respiratory infections, the optimal SpO₂ threshold for defining hypoxaemia is uncertain in low-income and middle-income countries (LMICs). We derived a SpO₂ threshold for hypoxaemia from well children in Bangladesh residing at low altitude.

Methods

We prospectively enrolled well, children aged 3–35 months participating in a pneumococcal vaccine evaluation in Sylhet district, Bangladesh between June and August 2017. Trained health workers conducting community surveillance measured the SpO₂ of children using a Masimo Rad-5 pulse oximeter with a wrap sensor. We used standard summary statistics to evaluate the SpO₂ distribution, including whether the distribution differed by age or sex. We considered the 2.5th, 5th and 10th percentiles of SpO₂ as possible lower thresholds for hypoxaemia.

Results

Our primary analytical sample included 1470 children (mean age 18.6±9.5 months). Median SpO₂ was 98% (IQR 96%–99%), and the 2.5th, 5th and 10th percentile SpO₂ was 91%, 92% and 94%. No child had a SpO₂ <90%. Children 3–11 months had a lower median SpO₂ (97%) than 12–23 months (98%) and 24–35 months (98%) (p=0.039). The SpO₂ distribution did not differ by sex (p=0.959).

Conclusion

A SpO₂ threshold for hypoxaemia derived from the 2.5th, 5th or 10th percentile of well children is higher than <90%. If a higher threshold than <90% is adopted into LMIC care algorithms then decision-making using SpO₂ must also consider the child’s clinical status to minimise misclassification of well children as hypoxaemic. Younger children in lower altitude LMICs may require a different threshold for hypoxaemia than older children. Evaluating the mortality risk of sick children using higher SpO₂ thresholds for hypoxaemia is a key next step.

Perspective: When the cure might become the malady: the layering of multiple interventions with mandatory micronutrient fortification of foods in India

When public health programs with single nutrients are perceived to have a poor impact on the target health outcome, the policy response can be to supply more, by layering additional mandatory programs upon the extant programs. However, we argue for extreme caution, because nutrients (like medicines) are beneficial in the right dose, but potentially harmful when ingested in excess. Unnecessary motivations for the reactionary layering of multiple intervention programs emerge from incorrect measurements of the risk of nutrient inadequacy in the population, or incorrect biomarker cutoffs to evaluate the extent of nutrient deficiencies. The financial and social costs of additional layered programs are not trivial when traded off with other vital programs in a resource-poor economy, and when public health ethical dilemmas of autonomy, equity, and stigma are not addressed. An example of this conundrum in India is the perception of stagnancy in the response of the prevalence of anemia to the ongoing pharmacological iron supplementation program. The reaction has been a policy proposal to further increase iron intake through mandatory iron fortification of the rice provided in supplementary feeding programs like the Integrated Child Development Services and the School Mid-Day Meal. This is in addition to the ongoing pharmacological iron supplementation as well as other voluntary iron fortifications, such as those of salt and manufactured food products. However, before supplying more, it is vital to consider why the existing program is apparently not working, along with consideration of the potential for excess intake and related harms. This is relevant globally, particularly for countries contemplating multiple interventions to address micronutrient deficiencies. Supplying more by layering multiple nutrient interventions, instead of doing it right, without thoughtful considerations of social, biological, and ethics frameworks could be counterproductive. The cure, then, might well become the malady.

Evaluation of Hemoglobin Cutoff Levels to Define Anemia Among Healthy Individuals

Importance

Anemia, defined as low hemoglobin (Hb) concentration insufficient to meet an individual's physiological needs, is the most common blood condition worldwide.

Objective

To evaluate the current World Health Organization (WHO) Hb cutoffs for defining anemia among persons who are apparently healthy and to assess threshold validity with a biomarker of tissue iron deficiency and physiological indicator of erythropoiesis (soluble transferrin receptor [sTfR]) using multinational data.

Design, Setting, and Participants

In this cross-sectional study, data were collected and evaluated from 30 household, population-based nutrition surveys of preschool children aged 6 to 59 months and nonpregnant women aged 15 to 49 years during 2005 to 2016 across 25 countries. Data analysis was performed from March 2020 to April 2021.

Exposure

Anemia defined according to WHO Hb cutoffs.

Main Outcomes and Measures

To define the healthy population, persons with iron deficiency (ferritin <12 ng/mL for children or <15 ng/mL for women), vitamin A deficiency (retinol-binding protein or retinol <20.1 μg/dL), inflammation (C-reactive protein >0.5 mg/dL or α-1-acid glycoprotein >1 g/L), or known malaria were excluded. Survey-specific, pooled Hb fifth percentile cutoffs were estimated. Among individuals with Hb and sTfR data, Hb-for-sTfR curve analysis was conducted to identify Hb inflection points that reflect tissue iron deficiency and increased erythropoiesis induced by anemia.

Results

A total of 79 950 individuals were included in the original surveys. The final healthy sample was 13 445 children (39.9% of the original sample of 33 699 children; 6750 boys [50.2%]; mean [SD] age 32.9 [16.0] months) and 25 880 women (56.0% of the original sample of 46 251 women; mean [SD] age, 31.0 [9.5] years). Survey-specific Hb fifth percentile among children ranged from 7.90 g/dL (95% CI, 7.54-8.26 g/dL in Pakistan) to 11.23 g/dL (95% CI, 11.14-11.33 g/dL in the US), and among women from 8.83 g/dL (95% CI, 7.77-9.88 g/dL in Gujarat, India) to 12.09 g/dL (95% CI, 12.00-12.17 g/dL in the US). Intersurvey variance around the Hb fifth percentile was low (3.5% for women and 3.6% for children). Pooled fifth percentile estimates were 9.65 g/dL (95% CI, 9.26-10.04 g/dL) for children and 10.81 g/dL (95% CI, 10.35-11.27 g/dL) for women. The Hb-for-sTfR curve demonstrated curvilinear associations with sTfR inflection points occurring at Hb of 9.61 g/dL (95% CI, 9.55-9.67 g/dL) among children and 11.01 g/dL (95% CI, 10.95-11.09 g/dL) among women.

Conclusions and Relevance

Current WHO cutoffs to define anemia are higher than the pooled fifth percentile of Hb among persons who are outwardly healthy and from nearly all survey-specific estimates. The lower proposed Hb cutoffs are statistically significant but also reflect compensatory increased erythropoiesis. More studies based on clinical outcomes could further confirm the validity of these Hb cutoffs for anemia.