Establishing hemoglobin reference values in the Khasi population of Meghalaya, India

INTRODUCTION

A major global health problem, anemia, affects approximately 1.6 billion people worldwide.^[1] The genetic and nutritional factors, along with socio-economic status, particularly in indigenous populations, play an important role in the variation in hemoglobin (Hb) values.^[2,3] Hb is a protein in erythrocytes that plays a major role in oxygen and carbon dioxide transport.^[4] The majority of normal adult Hb is made up of “A” type (HbA) (96% of the total), with very small amounts of A2 (<3%) and F (1%). Hb deficiency occurs when either Hb levels decrease or there is a loss of red blood cell volume, resulting in reduced tissue oxygenation. Risk factors for developing Hb deficiency include being a woman, an infant, or being from a lower socio-economic status.

The underlying cause of anemia is complex and can include: low intake of iron, folate, and Vitamin B12 (nutrient deficiencies); genetic disorders (such as sickle cell disease and thalassemias); chronic disease states, and a socio-economic disadvantage.^[5,6]

Anemia remains a significant public health issue in India, particularly among indigenous populations. Among non-pregnant women, prevalence varies between 38% and 82%, and among men between 18% and 59%.^[7] Populations inhabiting high altitudes, such as Tibetan, Andean, and Ethiopian highlanders, naturally have higher Hb concentrations to allow survival at low oxygen pressure; hence, altitude-corrected cut-offs are needed for diagnosing anemia.^[8-10]

Hbopathies result from genetic disorders related to Hb synthesis. Variants of Hb may be structural variants such as sickle cell disease, HbE, and HbC, or quantitative variants such as alpha- and beta-thalassemia.^[11] In Northeast India, around 10.9% of people carry hemoglobinopathies; it is most prevalent in Tripura, Arunachal Pradesh, and Assam.^[12,13] The Khasi people are more likely to have hemoglobinopathies because of several things, such as genetics, not getting enough nutrients, and not being able to get medical care.^[14]

Meghalaya offers an exceptional setting for examining Hb variation, as it is inhabited by three separate tribes: the Khasi, Garo, and Jaintia peoples. The Khasi community is predominant in the East Khasi Hills, West Khasi Hills, and South West Khasi Hills, adhering to a matrilineal system. Hb concentrations may be influenced by local lifestyle practices and environmental exposures.^[14] According to the National Family Health Survey-5, anemia affected 53.8% of women and 25.5% of men aged 15–49 years in the region.^[14,15]

The main objective of this research is to understand whether the hematological parameters of Hb levels among the Khasi people need to be evaluated in relation to the population. The evaluation will consider the various factors, which include altitude, age, gender, lifestyle, etc. It will also investigate how common Hemoglobinopathies are among the Khasi people and what contributes to the variations in Hb levels among them. Identifying population-specific reference ranges for Hb levels will provide the Khasi community with better tools for diagnosing and treating anemia and hemoglobinopathies.

MATERIAL AND METHODS

The study examines the concentration and variability of Hb in the Khasi Tribe of Meghalaya, located in northeastern India. It also analyzes particular demographic characteristics, lifestyle factors, and environmental effects related to Hb levels. The elevated prevalence of anemia and the possibility that the existing altitude-adjusted Hb reference range for Khasi individuals may not be applicable, as altitude is considered in its determination. A cross-sectional survey was conducted in three districts (East Khasi Hills, West Khasi Hills, and South West Khasi Hills) through a stratified sample method, involving 494 individuals from 39 villages within these districts. The following inclusion criteria applied: Khasi adults aged between 18 and 78 years, who had lived in the survey area for 5 years or longer. Individuals suffering from chronic diseases or blood disorders that influence their Hb levels were excluded from this research study. Structured interviews were carried out to collect the required demographic, dietary, and health-related history data of each participant. It is now possible to test for Hb using the mission Hb meter; therefore, the cyanmethemoglobin method was employed to establish the level of Hb present in the bloodstream. Body mass index (BMI) and other anthropometric characteristics were recorded, and the researchers recorded the health status of respondents as well as the number of children they have, including their births, length of pregnancy, etc. The researcher has collected a rich set of data to support this research project.

RESULTS

In examining the various aspects that affect the amount of Hb in the blood of the Khasi Tribe in Meghalaya, this research looks at the physical, lifestyle, and socio-demographic variables that contribute to the total Hb amount. The average amount of Hb in males not suffering from anemia is 14.75 ± 0.98 g/dL, while the average amount of Hb in females not suffering from anemia is 13.01 ± 0.60 g/dL [Table 1]. Among the 494 participants, the prevalence of anemia was significantly higher in females (79%) than in males (21%), with 160 persons (32%) diagnosed with the condition [Table 2].

The study found a strong link between anemia and gender, marital status, degree of education, and job [Table 3]. A significant association was found between gender and anemia status. Women were 2.58 times more likely than men to be diagnosed with anemia, which means that women had a much higher burden (χ² = 38.4, p < 0.05).

There was a strong link between marital status and anemia. Married individuals had a 2.55-fold higher prevalence of anemia compared to those who had never married (χ² = 32.9, p < 0.05).

The study found a significant link between how much schooling someone has and how likely they are to have anemia (χ² = 9.23, p < 0.05). People who cannot read or write or just have a high school diploma are more likely to have anemia than people who have more advanced degrees.

Occupation was acknowledged as an additional factor associated with anemia. People who work in “at-risk” jobs are far more likely to have anemia than people who work in other jobs (χ² = 7.85, p < 0.05). Being a farmer or a student can make you more likely to get anemia. Farm workers and students perform a lot of hard labor and have busy schedules, respectively, which makes it harder for them to eat a healthy diet. Because of this, they need more energy and micronutrients than other types of work. Students from economically disadvantaged backgrounds may face increased challenges in accessing a variety of nutrient-dense meals vital for their health, hence raising the risk of anemia.

This study investigated lifestyle characteristics, such as smoking and alcohol consumption, as variables among male participants. Anemia was demonstrated to lack a consistent association with smoking or alcohol consumption. The association of anemia and consumption of tobacco (smoking) and alcohol (drinking) revealed that non-smokers had a slightly greater likelihood of being affected by anemia (χ² = 11.2, p < 0.05) than smokers; likewise, non-drinkers had a slightly greater likelihood of being affected by anemia (χ² = 6.83, p < 0.05) than drinkers. Further investigation will be needed to determine the reason for this unexpected result.

The reproductive health had a significant impact on Hb levels among the female participants. The study found that women who were still menstruating exhibited a larger prevalence of anemia compared to those who were menopausal. Furthermore, a significant discovery was that women who had given birth to more than two children were at a 1.8-fold increased risk of anemia in comparison to those who had fewer children. In addition, the gap between pregnancies was identified as a critical factor, with women who endured a pregnancy interval of <2 years being 1.42 times more susceptible to anemia than those who endured a gap of more than 2 years. The study also found that women with anemia (who have low iron levels) have an increased risk of infant loss when compared to women without anemia, by determining that mothers with anemia are 4.8 times more likely to have an infant die during the pregnancy compared to non-anaemic mothers. Another of the main findings of the study was the increased incidence of postpartum hemorrhage (PPH) in anemic mothers. As a result of having PPH, the mother may continue to have low Hb levels and experience long-term health problems. PPH occurred more frequently among women with more than two children than among women with only two or fewer children (χ² = 12.46; p < 0.001). Women who have had children with inter-pregnancy intervals of no more than 2 years (or have had only 1 child) have a 1.42 times greater risk compared to women with longer inter-pregnancy intervals, and this would suggest possible nutrient deficiencies after delivery.

Both smoking and alcohol intake had a positive association with the risk of anemia. Anemia was significantly associated with tobacco use (χ² = 11.2; p < 0.01) and alcohol consumption (χ² = 6.83; p < 0.05). In this study, it was found that most people who participated had a healthy BMI. In fact, 72% of the males and 66% of the females had a normal BMI. The study showed that only 2% of males and 4% of females were obese, and that 21% of males and 23% of females were overweight. Anemia was seen mainly in adults with normal BMI, but only a small portion of those with anemia were considered underweight, which means that not receiving enough calories or being undernourished may be contributing factors to the development of anemia for these individuals.

Correlation analysis of BMI with Hb levels was limited, meaning that while BMI gives a general idea of an individual’s nutritional status, it may not accurately predict Hb levels independently for this study population.

To predict the association between anemia and the different variables, a binary logistic regression model was used [Table 4]. The study of the Khasi indigenous people showed that gender is a significant predictor of whether an individual is anemic, with females being at a greater risk of developing anemia with an odds ratio (OR) of 0.263 (95% confidence interval [CI]: 0.170–0.407; p < 0.0001) compared to males. This high prevalence of anemia among women may also be attributed to pregnancy, breastfeeding, and other biological processes.

The results indicated that marital status was strongly linked to anemia. Married individuals were at a significantly higher risk than unmarried individuals (OR = 3.64; 95% CI: 2.31–5.74; p < 0.001). This suggests that increased dietary requirements associated with marriage, pregnancy, and lactation might be associated with decreased levels of Hb.

The data indicate that education independently affects the chances of developing anemia. Individuals without secondary education have a greater likelihood of developing anemia than those with secondary education (OR = 2.30; 95% CI: 1.56–3.38; p < 0.001). This means that education can influence health knowledge, food choices, and access to healthcare.

Lifestyle factors also demonstrated unexpected associations. Non-smokers (OR = 0.286; 95% CI: 0.134–0.611; p = 0.001) and individuals who did not consume alcohol (OR = 0.303; 95% CI: 0.119–0.711; p = 0.012) demonstrated higher odds of anemia. Although the statistical importance of these relationships is well established, the actual reason for the relationship is unclear; thus, further research is needed to clarify the relationship.

Reproductive history also had a direct impact on the likelihood of having anemia. Women with 3 or more children had an increased chance of being anemic. This supports the fact that their need for nutrients increased with each pregnancy. In terms of adverse reproductive outcomes, women with anemia were 4.8 times more likely than non-anemic women to experience miscarriage.

A combination of demographic, socioeconomic, reproductive, and lifestyle characteristics influences levels of Hb in this population. As such, there is a need for targeted interventions aimed at improving women’s health, education, and nutrition to reduce the prevalence of anemia among the Khasi.

DISCUSSION

This research provides significant insights regarding Hb concentrations and the incidence of anemia within the indigenous Khasi community of Meghalaya, India. Anemia rates are markedly lower for both sexes; nonetheless, a statistically significant difference reveals that females show higher anemia rates than males. This difference seems to arise from female reproductive traits, such as high blood loss during menstruation and augmented iron demands during pregnancy and lactation.^[4,5]

The high frequency of anemia among married women highlights the need for dietary and healthcare support during their reproductive years, especially during pregnancy and the postpartum period. Married women of reproductive age should receive substantial support for nutrition and healthcare. The prevalence of anemia in postmenopausal women was high; as it was calculated within the subgroup of menopausal women included in the study, and does not represent the prevalence among all female participants. The sample size of menopausal women in our study was relatively small, which may have contributed to the high percentage observed.

Education is vital to combat anemia. Individuals with lower educational achievement are more predisposed to anemia. Recent studies.^[7] validate this hypothesis, indicating that individuals with lower educational achievement have insufficient understanding of their nutritional needs, show inferior dietary habits, and employ medical treatment less often than those with higher educational qualifications. The study indicates that assisting individuals in this demographic necessitates anemia reduction strategies that extend beyond basic vitamin and mineral supplementation. They necessitate particular education to improve their comprehension of nutrition and to promote prompt medical consultation.^[16]

The alterations in the employment sector have resulted in an increase in the prevalence of anemia among agricultural workers and students. Various people from farming communities, such as those in India and SubSaharan Africa, have observed these trends.^[17] Students, particularly those from low-income households, may be forced into taking inferior food choices due to their cost and, therefore, be more vulnerable to being deficient in micronutrients.^[18] These findings demonstrate the necessity of developing individualized nutrition programs based on the profession and the various situations that surround it.

The present study demonstrated that the majority of participants had a normal BMI, with relatively low proportions of obesity and overweight individuals. Despite this, anaemia was predominantly observed among individuals with normal BMI, while only a small proportion of anaemic participants were underweight. These findings suggest that anaemia in this population may not be solely attributable to generalized undernutrition or inadequate caloric intake. Instead, micronutrient deficiencies, poor dietary diversity, reproductive health factors, chronic infections, and socioeconomic conditions may contribute significantly to Hb variation. Furthermore, the weak correlation observed between BMI and Hb levels indicates that BMI alone may not be a reliable indicator of micronutrient status or anaemia risk in this population.

The findings indicate that anemia in this population may not be solely attributable to undernutrition measured by BMI. Several studies have demonstrated that individuals with normal BMI can still suffer from “hidden hunger,” including iron, folate, or Vitamin B12 deficiencies, particularly in populations consuming diets with poor micronutrient diversity. Furthermore, chronic infections, reproductive health factors, and socioeconomic determinants may contribute to anemia independent of BMI status.^[19]

A surprising negative relationship was found between anemia and both drinking alcohol and smoking tobacco. The inverse association observed between anaemia and smoking or alcohol consumption in the present study should be interpreted cautiously and does not imply a protective effect. Previous studies have shown inconclusive findings, with some studies having demonstrated that smokers develop compensatory mechanisms that lead them to have higher Hb levels, due to the stimulation of increased red blood cell production associated with carbon monoxide exposure.^[20]

Moderate alcohol consumption may also help to increase the absorption of iron; however, consuming alcohol in excess could negatively affect the function of the bone marrow, causing anemia to develop.^[21] The relationship of these two associations also demonstrates the complexity of lifestyle factors in relation to developing anemia, indicating the need to conduct more research to clarify how they may affect anemia risk.

However, both smoking and alcohol consumption are well-established risk factors for multiple adverse health outcomes and cannot be considered beneficial. The observed associations in this study may also reflect underlying socio-demographic, nutritional, and lifestyle-related confounding factors. Therefore, these findings should be interpreted within the broader epidemiological and clinical context.

Anemia was strongly associated with reproductive characteristics among the women in this study. The increased prevalence of anemia was most directly related to increased parity and closely spaced pregnancies, suggesting that frequent pregnancies with inadequate recovery periods may result in a loss of iron stores in the long term.^[22,23] The amplified risk of negative maternal and postpartum results for anemic women shows that there is a need for greater expansion of maternal health programs, including iron supplementation, nutrition counselling, and spacing of births, to decrease the incidence of anemia in these women.^[24]

CONCLUSION

As per this study on the Khasi tribe, the major contributors to anemia for them are mainly sociodemographic, lifestyle, nutrition and maternal health, rather than the altitude factor. In order to efficiently treat or prevent anemia in this population, cultural reflections and targeted interventions must be developed to eradicate the underlying cause of anemia among this population. Raising awareness of anemia, providing women with access to quality prenatal and postnatal care, advocating for adequate birth spacing, and providing adequate nutrition postpartum will assist in treating anemia in the Khasi population.

An increase in screening and supplement programs for communities, access to adequate nutrition for families, and access to affordable iron-rich diets will help fight against anemia. To properly address this problem requires a holistic approach that incorporates healthcare, education, and social support in the context of community-based resources. Future research should also examine how genetic makeup affects the prevalence of anemia in the Khasi population and evaluate the current strategies to prevent and treat anemia. In order to achieve a meaningful and sustained impact on managing anemia, local communities must be involved in plans of action that recognize the different cultural perspectives and align with local values and expectations.