Date Published: July 3, 2019
Publisher: Public Library of Science
Author(s): M. Shafiqur Rahman, Muntaha Mushfiquee, Mohammad Shahed Masud, Tamanna Howlader, Seth Adu-Afarwuah.
Bangladesh is one of the most anemia prone countries in South Asia. Children of age under five years and women of reproductive age are particularly vulnerable in this region. Although several studies have investigated the risk factors of anemia, only few have explored its association with malnutrition, despite its high prevalence in the same group. The objective of this paper is to investigate the association of malnutrition with anemia by conducting separate analyses for under-five children and women of reproductive age using data from the nationally representative 2011 Bangladesh Demographic and Health Survey.
Two binary outcome variables are considered separately: presence of anemia in children under five years of age (Hb<11.0 g/dl) and presence of anemia in women of childbearing age (Hb<12.0 g/dl). The exposures of interest corresponding to these two outcomes are stunting (low height-for-age) and low BMI (<18.5 kg/m2), respectively. Preliminary analysis involves estimating the association between exposure and outcome while controlling for a single confounder by computing adjusted odds ratios (adjOR) using the Cochran-Mantel-Haenszel approach in stratified analysis. Later, associations between the exposures and outcomes are estimated separately for under-five children and women of reproductive age by fitting multivariable regression models that adjust simultaneously for several confounders. The prevalence of anemia is found to be higher among both the stunted children and women with low BMI compared to their healthy counterparts (Children: 56% vs 48%; women: 50% vs 43%). Furthermore, stunted children and women with low BMI have significantly increased odds of developing anemia, as reflected by the adjusted ORs of 1.76 (95% CI:1.10–2.83) and 1.81 (95% CI: 1.11–3.48), respectively. The association of stunting with anemia in children was modified by their age and socio-economic condition, where risk of being anemic decreases with increasing age but with a lower rate for stunted children from richest family. In addition, stunted children of anemic mothers are at greater risk of being anemic compared to non-stunted children of anemic or non-anemic mothers. Again the association between BMI and anemia in women is modified by the level of education, with risk of anemia being lowest among women with low BMI and higher education. Evidence–based policies targeting the vulnerable groups are required to combat anemia and nutritional deficiencies simultaneously under the same program.
Anemia, which is characterized by low level of hemoglobin in the blood, is one of the major public health hazards affecting people in both developed and developing countries [1–3]. Anemia may occur at all stages of life, however, young children and women in the childbearing age are the most vulnerable [4, 5]. When anemia occurs in children, it could affect their cognitive performance and physical growth . In women, anemia could adversely affect their capacity to work and may lead to poor pregnancy outcomes . According to the World Health Organization (WHO), globally about 38% of women of reproductive age and 43% of children under five years of age were affected by anemia in 2011 [2, 3]. Anemia is more prevalent in developing countries [4, 8] contributing to about one million deaths each year world-wide. Three-quarters of these deaths occur in Africa and South-East Asia [2, 3, 9, 10]. Bangladesh has been reported as one of the most anemia prone countries in South Asia [11–13]. According to the National Nutrition Project (NNP), the prevalence of anemia among children of ages 6–59 months was estimated to be 47% in 2004 and 68% in 2013 [14, 15]. The National Micronutrient Survey 2011–12 estimated an anemia prevalence of 33% among the children of the age group 6–59 months and 26% among the non-pregnant and non-lactating women . Another study reported that childhood anemia decreased with increasing age, with a prevalence of 64% among children of ages 6–23 months and 42% among children of ages 24–59 months [15, 16]. Such high prevalence reported by multiple studies indicates that anemia is a major public health threat in Bangladesh. Although Bangladesh has made remarkable progress in health and social development achieving most of the Millenium Development Goals (MDGs) in the last decade , it is still struggling to tackle the burden of some diseases including anemia.
The analysis was based on a sample of 2283 children of ages between 6–59 months (male 41.4% and female 58.6%) and 2467 women of ages between 15–49 years. The average age of the children was 33.03 months with standard deviation (SD) of 15.86 months (results not shown). More than two-fifth of the children (41.4%) were stunted. Fifty one percent of children (n = 2234) with ages between 6 to 59 months were estimated to be anemic. The average age of the women in the sample was 25.91 years with SD of 5.97 years. The percentage of women of reproductive age having BMI<18.5 was 29.25%. Forty five percent of the women (n = 2467) were found to be affected by anemia. Table 1 presents the percentage of anemic children in the different categories of the background risk factors. Results indicate that the prevalence of anemia is higher among stunted children than among normal children (56.5% vs 48.5%). The prevalence of anemia is higher among women with low BMI (<18.5) than among women with normal BMI (>18.5) (49.5% vs 43.2%). Furthermore, prevalence of anemia is found to be higher among stunted children compared to non-stunted children and among women with low BMI compared to those with normal BMI at each level of the confounder in stratified analysis (Tables 3 and 4).
This paper has investigated the association between anemia and stunting among children in age group 6–59 months as well as the association between anemia and BMI among women of reproductive. In general, the prevalence of anemia was markedly high both among stunted children and women of low BMI compared to their normal counterparts. However, the higher prevalence among children suggests that they are more vulnerable to anemia than women. In both cases, there was a positive association between nutritional deficiency (reflected by stunting or low BMI) and anemia that was statistically significant even after controlling for the effects of possible confounders. This study identified important interactions that have interesting interpretations. There was significant interaction between stunting, child’s age and household socio-economic condition (SES). The risk of child anemia decreased with increasing age, however, the rate of decline was lower for stunted children. The implication of this finding is that there is a greater prevalence of anemia among stunted children compared to non-stunted children. In general, improvements in socio-economic status decreased the risk of being anemic in both groups. Thus, very young children belonging to poor households and experiencing stunting form a high risk group and should be the focus of interventions. Again, the presence of maternal anemia significantly increased the risk of child anemia even when there was improvement in socio-economic condition. The interaction effect of stunting and maternal anemia status suggests that stunted children of anemic mothers are at greater risk of being anemic. The strong association observed between maternal anemia and child anemia may be explained by the fact that there are certain factors influencing anemia that are common to both . For example, both the mother and child could have a common dietary pattern and access to the same source of iron-rich micronutrient food. In addition, they share the same environment, have access to the same health facilities and are likely to have similar genetic traits. On the other hand BMI, which reflects nutritional deficiency among the women of reproductive age, is found to be significantly associated with maternal anemia. Although the risk of being anemic decreases with improvements in household economic condition, the difference in risk between women with low BMI and those with normal BMI remained almost the same. On the other hand, education strongly modifies the effect of BMI and has a profound effect on women with low BMI. Higher education lowers the risk of being anemic even if the BMI is low. These findings are similar to those found in other studies conducted for relevant population with similar [27, 28, 44] or different settings [29, 31, 43].