Management of Iron Deficiency Anemia in CKD with Diabetes
Initiate intravenous iron therapy immediately in this patient with hemoglobin 97 g/L (9.7 g/dL), low serum iron, and normal ferritin, as this represents functional iron deficiency requiring IV iron supplementation before considering ESA therapy. 1, 2
Diagnostic Classification
This patient has functional iron deficiency rather than absolute iron deficiency, characterized by:
- Normal ferritin levels (adequate iron stores) but low serum iron (insufficient circulating iron for erythropoiesis) 3
- Hemoglobin 97 g/L is below the anemia threshold of <120 g/L for females and <130 g/L for males in CKD 3
You must obtain transferrin saturation (TSAT) immediately to confirm functional iron deficiency, defined as TSAT ≤20-30% with ferritin >100 ng/mL in non-dialysis CKD patients 3, 4
Immediate Iron Replacement Protocol
Administer IV iron as first-line therapy:
- Give 100-125 mg IV iron weekly for 8-10 doses (total 1,000 mg over 8-10 weeks) 2
- IV iron is superior to oral iron in CKD patients due to hepcidin-mediated impaired intestinal absorption 4, 5
- For non-dialysis CKD patients, either IV iron or a 1-3 month trial of oral iron is acceptable, but IV iron produces faster results 3, 1
Target parameters after initial iron repletion:
Monitoring Schedule
Check hemoglobin and iron parameters 2 weeks after completing the 8-10 week iron course:
- Expect hemoglobin increase of approximately 20 g/L (2 g/dL) within 3-4 weeks 2
- Monitor iron status (TSAT and ferritin) at least every 3 months during ongoing treatment 3, 1
- Check more frequently when initiating therapy or if blood loss suspected 3
Safety Thresholds
Withhold IV iron if:
- Ferritin exceeds 500 ng/mL 3, 1, 2
- TSAT exceeds 30-50% 3, 2
- Active infection is present (inflammation alone is not a contraindication) 5
Monitor for 60 minutes after each IV iron infusion with resuscitative equipment and trained personnel immediately available 3, 1
ESA Therapy Considerations
Do NOT initiate ESA therapy yet because:
- All correctable causes of anemia, particularly iron deficiency, must be addressed first 3, 1
- ESAs should only be considered if hemoglobin remains <100 g/L after optimizing iron status 1
- In diabetes with CKD, targeting hemoglobin 100-120 g/L (10-12 g/dL) balances quality of life benefits against cardiovascular risks 6
- Higher hemoglobin targets (>120 g/L) are associated with increased stroke, vascular access thrombosis, and mortality 3
Maintenance Strategy After Initial Correction
Once hemoglobin reaches 110-120 g/L and ferritin >100 ng/mL:
- Transition to maintenance IV iron 25-125 mg monthly, adjusted based on iron parameters 2
- Withhold if ferritin exceeds 800 ng/mL or TSAT exceeds 50% to prevent iron overload 2
- Continue monitoring every 3 months 3, 1
Critical Pitfall to Avoid
Do not start ESA therapy before correcting iron deficiency - this is the most common error in CKD anemia management. ESAs will fail or require dangerously high doses if iron stores are inadequate, increasing cardiovascular risk and costs 4, 5, 7. The functional iron deficiency in this patient (normal ferritin but low serum iron) specifically indicates that iron must be repleted before erythropoiesis can be effectively stimulated 3.