What is the appropriate management for an adult patient with anemia of chronic disease (ACD) and impaired glucose regulation, as indicated by a hemoglobin A1C (HbA1c) of 6.7%, and normal iron, Total Iron-Binding Capacity (TIBC), and ferritin levels?

Management of Anemia with Normal Iron Studies and Prediabetes

This patient does NOT have anemia of chronic disease (ACD) based on the laboratory findings provided. The iron studies (iron 69 mcg/dL, TIBC 263 mcg/dL, transferrin saturation 26%, ferritin 177 ng/mL) are all within normal ranges, which excludes both iron deficiency anemia and classic ACD 1.

Laboratory Analysis

The patient has mild normocytic anemia with an elevated RDW:

• Hemoglobin 10.5 g/dL (low for adult male, reference 13.2-17.1 g/dL) 1
• MCV 96.2 fL (normal, 81.4-101.7 fL) - this is normocytic, not microcytic 1
• RDW 17.6% (elevated, normal 11.0-15.0%) - suggests mixed red cell populations 1
• Normal iron parameters exclude iron deficiency 1

Key distinguishing features that rule out ACD:

• Transferrin saturation of 26% is normal (ACD requires <20%) 1
• Ferritin 177 ng/mL is normal (ACD with inflammation typically shows ferritin >100 ng/mL with low transferrin saturation) 1
• No evidence of inflammation on labs (normal WBC, normal CRP not shown but would be needed) 1

Required Additional Workup

The elevated RDW with normocytic anemia and normal iron studies mandates further investigation:

• Reticulocyte count - essential to determine if bone marrow is responding appropriately; low/normal reticulocytes suggest deficiency or marrow suppression, elevated suggests hemolysis 1
• Vitamin B12 and folate levels - normocytic anemia with elevated RDW can indicate early B12/folate deficiency before macrocytosis develops 1
• Comprehensive metabolic panel review - the eGFR of 86 mL/min/1.73m² is mildly reduced; chronic kidney disease becomes a significant cause of anemia when GFR <60, especially <30 1
• Hemolysis workup if reticulocytes elevated - haptoglobin, LDH, indirect bilirubin 1
• Hemoglobin electrophoresis if microcytosis were present with normal iron studies (not applicable here but important to exclude thalassemia trait) 1

Management of Concurrent Prediabetes

The HbA1c of 6.7% indicates prediabetes (diagnostic threshold ≥6.5% suggests diabetes, requires confirmation):

• This elevated glucose state does NOT cause the anemia directly 1
• However, uncontrolled diabetes can lead to chronic kidney disease over time, which would contribute to anemia 1
• The current eGFR of 86 mL/min/1.73m² shows early renal impairment that warrants monitoring 1

Diabetes management is critical to prevent progression of kidney disease:

• Confirm diabetes diagnosis with repeat HbA1c or fasting glucose
• Initiate lifestyle modifications and consider metformin
• Monitor renal function every 3-6 months given mild eGFR reduction 1

Differential Diagnosis Priority

Given normal iron studies, the anemia workup should focus on:

1. Vitamin deficiencies (B12, folate) - common, easily treatable, suggested by elevated RDW 1
2. Early chronic kidney disease - eGFR 86 suggests stage 2 CKD; anemia typically develops with GFR <60 but monitoring is warranted 1
3. Hemolysis - if reticulocyte count is elevated 1
4. Bone marrow disorders - if reticulocyte count is inappropriately low and other causes excluded 1
5. Occult chronic disease - though inflammatory markers would typically be elevated 2, 3

Common Pitfalls to Avoid

Do not diagnose ACD based solely on the presence of chronic disease without meeting laboratory criteria:

• ACD requires transferrin saturation <20% AND either low serum iron with normal/elevated ferritin 1
• Normal transferrin saturation (26%) definitively excludes ACD 1

Do not supplement iron empirically:

• Iron studies are normal; supplementation is not indicated and could be harmful 1, 3
• Iron supplementation without deficiency can promote oxidative stress and is contraindicated 3

Do not attribute anemia solely to prediabetes:

• Hyperglycemia itself does not cause anemia 1
• Focus on identifying the true cause through systematic workup 1

Immediate Next Steps

Order the following tests urgently:

• Reticulocyte count (absolute and percentage) 1
• Vitamin B12 and folate levels 1
• Peripheral blood smear review 1
• If reticulocytes elevated: haptoglobin, LDH, indirect bilirubin 1

Refer to hematology if:

• Cause remains unclear after extended workup 1
• Reticulocyte count is inappropriately low suggesting bone marrow pathology 1
• Anemia worsens or becomes symptomatic 1