From the Guidelines
The patient's lab results indicate iron deficiency, with a low iron saturation of 15% (normal range 20-55%), and I recommend starting oral iron supplementation with ferrous sulfate 325 mg once or twice daily, taken on an empty stomach with vitamin C (such as orange juice) to enhance absorption. This recommendation is based on the most recent and highest quality study available, which suggests that iron deficiency should be confirmed by iron studies prior to investigation, and that a good response to iron therapy is highly suggestive of absolute iron deficiency 1. The patient's low iron saturation and high TIBC levels are indicative of iron deficiency, and oral iron supplementation is a effective treatment option. Alternatively, ferrous gluconate 300 mg or ferrous fumarate 200 mg daily can be used if ferrous sulfate causes significant gastrointestinal side effects.
Some key points to consider when treating this patient include:
- The importance of monitoring for potential interactions between iron supplements and diabetes medications, given the patient's type 2 diabetes
- The need to determine the cause of iron deficiency, which could include gastrointestinal blood loss, poor dietary intake, or malabsorption
- The importance of follow-up labs to assess response to therapy, monitoring hemoglobin, ferritin, and iron saturation
- The potential for common side effects of oral iron, such as constipation, nausea, and black stools, and the possibility of improving tolerance by starting with a lower dose and gradually increasing.
It's also important to note that the distinction between absolute and functional iron deficiency is crucial, and that a TSAT of < 20% may not always be an accurate discriminator between patients who are or are not iron deficient 2. However, in this case, the patient's low iron saturation and high TIBC levels suggest absolute iron deficiency, and oral iron supplementation is a appropriate treatment option.
From the Research
Patient's Iron Levels
- The patient's iron level is 58 mcg/dL, which is below the reference range of 37-145 mcg/dL.
- The patient's TIBC (Total Iron Binding Capacity) is 395 mcg/dL, which is above the reference range of 228-428 mcg/dL.
- The patient's iron saturation is 15%, which is below the reference range of 20-55%.
Diagnosis of Iron Deficiency
- According to the study by 3, transferrin or TIBC measurement outperforms iron measurement and saturation index in predicting iron deficiency.
- The study found that transferrin or TIBC measurement had a mean area under the ROC curve of 0.94, compared to 0.77 for iron measurement and 0.87 for saturation index.
- This suggests that the patient's high TIBC level and low iron saturation may indicate iron deficiency, despite the iron level being within the reference range.