Prevalence of Anemia and Role of β(E)-Globin Gene as an Associating Factor Among College Students of Assam: A Preliminary Report.

Introduction

Anemia is a widespread public health problem associated with an increased risk of morbidity and mortality, especially in pregnant women and young children.(1) Among numerous factors, nutritional (such as vitamin and mineral deficiency) and non-nutritional (such as infections and hemoglobinopathies) factors contribute to the onset of anemia, leading to iron deficiency.(2)

Anemia is still considered a major public health problem in India.(3) The National Family Health Survey-3 (NFHS- 3) revealed a high prevalence of anemia among children (78.9%), ever-married women (56.2%), pregnant women (57.9%) and ever-married men (24.3%) in India.(3) Assam reflects a similar scenario of the national average in prevalence of anemia according to the NFHS-3.(4) In addition to NFHS-2 and 3, sporadic studies conducted in this part of the country also reflect the high prevalence of anemia in the different physiological and age groups of Assam.(56)

Non-nutritional factors associated with anemia, like geohelminthic infestations, malaria, hemoglobinopathies, etc., are widely prevalent owing to the geoclimatic conditions and ethnic affiliation in this part of the country.(7–10) A high prevalence of helminthic infestations has also been reported in Assam, India.(78) The geoclimatic condition of the region also facilitates the transmission of malaria, especially Plasmodium falciparum, in most parts of the state.(9) Variant hemoglobins, i.e., hemoglobin E (Hb E) and sickle cell hemoglobin (Hb S), are also widely prevalent in North East India. Hb E is widely distributed among the autochthonous inhabitants, with variable gene frequency.(11) However, Hb S is mostly confined to the tea garden labor community, a group of people intruded to work in the Tea Gardens of Assam.(12)

The present study on prevalence of anemia and association of hemoglobinopathies among the girl students was planned to obtain preliminary information. Selection of girl students was also based on the fact that women tend to have substantially lower iron stores than men (one-eighth of the total body iron in women compared with one-third in men), making them more vulnerable to iron deficiency when the iron intake is lowered or need increases.

Materials and Methods

The study was conducted in one of the industrial township of Dibrugarh district of Assam. Selection of the educational institute from an industrial township was based on better socioeconomic status of the population residing in the area and, thus, nutritional factors pertaining to anemia were minimized. Two hundred twenty-four students were selected adopting a simple random sampling method. The total girl students of the college (n = 600) were listed serially and using the random number table, students were enrolled for the study. In case of refusal or non-availability, additional students were selected on the basis of a random table. Using finite population correlation for small target population (n = 600) based on assumption and taking the prevalence of anemia as 70% at the 95% confidence level with 5% error, 211 samples would have been sufficient for the study. However, in the present study, 224 college students were included.

Written consent was obtained from each individual before documenting information in a pre-defined proforma and collecting blood sample. Dry blood sample (20 μL of finger-pricked blood) was collected in Whatman No. 1 filter paper from individual students. The air-dried samples were packed in self-sealed Low Density Polyethylene (LDPE) pouches. In a subset of the sample, venous blood (about1 mL) in K3EDTA was collected, preferably from every third individual, to determine the prevalence of hemoglobinopathies in the study cohort. Although prevalence of anemia was the prime objective of the study, however, an attempt was made to determine the association of hemoglobinopathies in the study group. Considering the operational and logistics involved in the study, it was decided to screen every third sample for prevalence of hemoglobinopathies.

The blood samples were transported to the laboratory and the hemoglobin levels of individual samples were estimated by the cyanmethemoglobin method within seven days of sample collection.(13) Hematological indices of individual samples, collected in K3EDTA, were determined within 8 h of blood sample collection. The information generated from individual samples was recorded. Prevalence of variant hemoglobin in the study subjects was determined by a high-performance liquid chromatography (HPLC)-based VARIANT Hemoglobin Testing System(™) using VARIANT β-thalassaemia Short Programme Kit. Standard protocol provided by the manufacturer was adopted for determination of the hemoglobinopathies and thalassaemias.

Results and Discussion

Information generated after analysis of dry blood samples indicates a high prevalence of anemia (76%) among the college students. The mean (± SD) hemoglobin level among the girl students in the age group of 16-21 years was 10.98 ± 1.60 g/dL. Severe anemia (Hb < 7 g/dL) was observed in 1.8% of the study population. However, moderate (Hb 7-9.9 g/dL) and mild (10-11.9 g/dL) anemia was detected in 20.4% and 53.8% patients, respectively. Thus, only 24% of the girl students had hemoglobin level >12 g/dL.

Hemoglobin E (Hb E) was the only variant hemoglobin observed in the study. The gene frequency for βE-globin gene in the study population was 0.263. Prevalence of heterozygous and homozygous state of βE-globin gene is represented in Figure 1.

Figure 1

Distribution of Hb E in the study population

Association of lower level of hemoglobin, with limited sample size, was observed in subjects carrying βE-globin gene. The mean (± SD) hemoglobin levels of the subject with heterozygous and homozygous state of HbE was 10.9 ± 0.95 and 9.7 ± 0.64 g/dL, respectively, against 11.28 ± 1.42 g/dL observed in normal hemoglobin pattern (Hb AA). Thus, a significant difference in the mean level of hemoglobin between normals and subjects carrying βE-globin gene, either heterozygous or homozygous state, was observed (P = 0.007; f = 5.244, ANOVA). Post hoc comparison shows significant difference in hemoglobin level between normals and subjects carrying homozygous state of βE-globin gene (P = 0.005).

The present study indicates a high prevalence of anemia (76.0%) among the college students of Dibrugarh district, Assam. Preliminary data also indicate an association of βE-globin gene in occurrence of anemia. However, contribution of helminthic infestation and other nutritional factors associated with the high prevalence of anemia was beyond the purview of the present study.

It was observed that although various intervention programmes were being initiated by the Government for prevention of anemia, still, no marked reduction on prevalence of anemia was observed in Assam as per the report of NFSH-2 and 3.(4) Prevalence of anemia among the ever-married women (15-49 years) of Assam, according to the report of NFHS-3 (69.6%),was the same as that of the NFHS-2 data (69.7%).(4) The present study has also indicated a substantially high (76%) prevalence of anemia in students of the age group 16-21 years. It is felt that there is a need for evaluation of the associating determinants, both nutritional and non-nutritional factors, and to adopt appropriate control strategy for elimination of anemia from this part of the country.