Prevalence of anemia in Northeast India: A review and overview

INTRODUCTION

The Northeast region of India, comprising Assam, Manipur, Mizoram, Nagaland, Meghalaya, Tripura, Arunachal Pradesh, and Sikkim, represents one of the most ethnically heterogeneous populations in India. These states host numerous indigenous tribes, each with distinct cultural and genetic identities. This remarkable diversity is also seen with regard to the distribution of different disease entities, one subject of particular interest in this regard being hematology. This review focuses on the diversity of this region with regard to prevalence of anemia compared to the rest of India, and the distribution of the different conditions responsible for the anemia.

DISTRIBUTION AND HETEROGENEITY OF ANEMIA IN INDIA

CONTRIBUTORS OF ANEMIA IN THE NORTHEAST REGION

Anemia in Northeast India is predominantly nutritional in origin, with iron deficiency as the most common underlying etiology, driven by inadequate dietary iron intake, poor bioavailability of plant-based diets, and micronutrient insufficiencies, particularly among women and children. In addition to iron deficiency, inherited hemoglobinopathies such as hemoglobin E disease, β-thalassemia, and sickle-cell variants contribute to anemia burden in specific tribal groups. Infectious causes also play a significant role: Malaria, endemic in many hilly and forested areas, induces hemolytic anemia, while intestinal parasitic infections (e.g., hookworm) cause chronic blood loss and exacerbate iron-deficiency anemia. Other contributory factors include frequent menstruation and repeated pregnancies depleting iron stores among women, poor sanitation increasing susceptibility to infections, and socioeconomic determinants that limit access to healthy diets and preventive care.^[4,5]

NUTRITIONAL DEFICIENCY ANEMIA PATTERNS

The highest prevalence of anemia is observed in children under 3 years, largely driven by iron deficiency and concurrent micronutrient insufficiencies. Among preschool children aged 3–5 years, the cause of anemia commonly reflects a combination of iron deficiency and infectious exposures. In school-aged children, dietary inadequacy compounded by parasitic infestations contributes substantially. In adults aged 19–59 years, with higher rates among women, anemia is attributable to nutritional depletion alongside emerging contributions from chronic disease. In older adults, nutritional deficiencies coexist with anemia of chronic inflammation, chronic renal and liver disease, and malignancies. Overall, iron deficiency remains the predominant nutritional etiology, particularly in children and women, while non-iron deficiency causes, including Vitamin B12/folate deficiency and chronic disease, contribute significantly across older age groups.^[3,5]

HEMOGLOBINOPATHIES

MISCELLANEOUS CAUSES OF ANEMIA

Beyond nutritional and genetic causes, several systemic conditions contribute to anemia via different mechanisms.

Autoimmune and rheumatologic disorders are important contributors. In a study by Borah and Iqbal, which included a small cohort of patients, 64.5% DMARD-naïve patient of rheumatoid arthritis were anemia. Of these anemia patients, 60% had anemia of chronic disease and 40% had iron deficiency as the major contributors. Interestingly, patients with anemia had a higher disease severity score for rheumatoid arthritis.^[11] Barman et al. investigated the clinicopathological profile of 122 patients of systemic lupus erythematosus (SLE) in the Northeast region. They reported an incidence of hematological manifestation of SLE in 77.46% patients, out of which anemia of chronic disease predominated at 66.2% and hemolytic anemia in 7.74%.^[12] Anemia in these autoimmune diseases results from immune-mediated suppression of erythropoiesis, shortened red cell survival, and impaired iron utilization driven by chronic inflammation. Pro-inflammatory cytokines increase hepcidin, limiting iron absorption and release from macrophages, while autoantibodies and complement may cause hemolysis, collectively reducing effective red blood cell production.^[13]

Anemia is one of the most common complications of chronic kidney disease (CKD). Anemia prevalence increases with CKD progression, and the prevalence in India is as high as 84.5%.^[14] In a study in Northeast India, it was found that anemia was present in all the patients of CKD. The authors noted that pallor was a very common clinical finding, present in 86.7% of patients, and laboratory documentation of anemia was reported in 100% of cases.^[15] Anemia is highly prevalent in chronic liver disease patients, affecting approximately 85.3% of cases, with moderate and severe anemia commonly observed. The high incidence correlates with advanced disease and hematological abnormalities, underscoring its clinical significance in liver disease management in India.^[16] A study in Tripura on patients of chronic liver disease showed the incidence of anemia in 98% cases.^[17] Anemia in chronic liver and kidney disease arises from multifactorial mechanisms. In CKD, reduced renal erythropoietin production, iron dysregulation with elevated hepcidin, and chronic inflammation impair erythropoiesis and iron availability, contributing to anemia. Furthermore, there is blood loss during hemodialysis, which is an important factor in hemodialysis-dependent CKD patients. In chronic liver disease, gastrointestinal blood loss, hypersplenism, nutritional deficiencies, and bone marrow suppression contribute to anemia. Interestingly, in the Northeast region of India, HbE disease co-exists with these chronic conditions, compounding the severity of anemia and increasing transfusion dependency in this chronic disease setting.

Infections contribute significantly to anemia. A large cross-sectional study across high and low malaria endemic districts reported an overall anemia prevalence of 55.3%, mostly moderate anemia, alongside 8.9% malaria positivity, highlighting co-endemic malaria as a contributor to reduced hemoglobin levels in children and adults. While precise regional data on anemia from HIV, tuberculosis, and helminthiasis are limited, given the global and national trends, these conditions would be significant contributors to anemia in the region. Cancers are another contributor to the prevalence, and 40–50% of patients with cancer are anemic.^[18,19]

CONCLUSION

Anemia in India is widespread yet profoundly heterogeneous. Northeast India exhibits distinct epidemiological patterns, shaped by age-specific vulnerability, high prevalence of hemoglobinopathies, infection burden, and chronic systemic diseases. While nutritional deficiencies remain central, genetic disorders, autoimmune diseases, CKD, malignancy, and infections represent critical non-nutritional contributors. Population based dataset discusses mostly nutritional and hemoglobinopathy-associated anemia. However, multiple variables interact and contribute to anemia, evident in hospital-based data, complicating the diagnostic and treatment planning. A context-specific, multifactorial diagnostic and management approach is therefore essential for effective anemia control in Northeast India.