Recurrent Iron Deficiency Anemia in a Patient with Hb D-Punjab Trait Receiving Tirzepatide

Background: Hemoglobin D-Punjab (Hb D-Punjab, also known as Hb D-Los Angeles) is an uncommon structural β-globin variant that is typically clinically silent in the heterozygous state and is not associated with iron deficiency. Recurrent iron deficiency anemia (IDA) despite appropriate oral and intravenous iron replacement warrants a comprehensive evaluation for chronic blood loss, malabsorption, nutritional deficiency, and coexisting hematologic disorders. With the increasing use of incretin-based therapies such as tirzepatide for obesity management, reduced dietary intake has emerged as a potential contributor to micronutrient deficiencies in susceptible individuals. Case Presentation: A 47-year-old woman presented with persistent microcytic hypochromic anemia and recurrent depletion of iron stores despite repeated courses of oral and intravenous iron therapy. Serial laboratory investigations demonstrated hemoglobin values ranging from 11.78 to 13.2 g/dL, with persistent microcytosis (MCV 72.7–77.1 fL), relatively elevated red blood cell counts (4.82–5.42 ×10¹²/L), and recurrently low ferritin levels (as low as 3.1 ng/mL). Hemoglobin electrophoresis demonstrated heterozygous Hb D-Punjab trait (Hb D 40.4%), while persistent microcytosis with a relatively elevated red blood cell count suggested possible coexisting α-thalassemia trait. Evaluation excluded celiac disease, thyroid dysfunction, vitamin B12 deficiency, and gynecological pathology. The patient denied gastrointestinal symptoms but had not undergone endoscopic gastrointestinal evaluation. She had been receiving tirzepatide for weight management, raising the possibility that prolonged appetite suppression and reduced dietary iron intake may have contributed to recurrent iron deficiency, although a causal relationship cannot be established. Conclusion: This case highlights the importance of confirming true biochemical iron deficiency rather than attributing anemia to an incidental hemoglobin variant. Recurrent IDA despite adequate iron replacement requires systematic evaluation for gastrointestinal blood loss, nutritional deficiency, malabsorption, gynecological disorders, and coexisting hematologic conditions. As incretin-based therapies become increasingly used for obesity management, clinicians should remain aware of the potential for nutritional deficiencies in susceptible patients and ensure appropriate clinical and nutritional follow-up. Keywords: Hemoglobin D-Punjab; Iron deficiency anemia; Tirzepatide; Obesity; Hemoglobinopathy; Microcytic anemia; α-thalassemia trait