Need for parenteral iron therapy after bariatric surgery

Abstract 

Background

Malabsorptive bariatric procedures such as Roux-en-Y gastric bypass and biliopancreatic diversion/duodenal switch expose the patient to malnutrition and commonly cause iron deficiency. The optimal replacement and monitoring method remain undetermined. To identify high-risk patients who might need intravenous iron supplementation after bariatric surgery, we evaluated bariatric surgery patients who received parenteral iron at a university hospital-affiliated hematology center.

Methods

We performed a retrospective analysis and reviewed the records of 165 patients who had received parenteral iron from May 2004 to June 2007. Of the 165 patients, 42 bariatric surgery patients were identified. The type of bariatric procedure and menstrual status of the patients were compared.

Results

The average patient age was 40 years. Of the 42 patients, 2 were men and 40 were women. Of the 40 women, 32 were premenopausal and 8 were postmenopausal. The patients in the biliopancreatic diversion/duodenal switch group had a significantly lower hemoglobin at presentation (P = .02), relatively lower ferritin levels, and required more additional parenteral iron treatment after the initial resolution of anemia (P = .001). The premenopausal women required earlier parenteral replacement (P = .008) and were at a greater risk of anemia-related hospitalization (P = .00033).

Conclusion

The available published studies lack any data regarding parenteral iron replacement needs after bariatric surgery. Our results have identified the need for long-term parenteral iron replacement therapy after malabsorptive bariatric procedures, especially in premenopausal women. Patients who do not respond to oral iron therapy should be referred early for parenteral iron replacement therapy to prevent anemia-related complications and to maintain patients' quality of life. Iron monitoring should continue indefinitely even after the initial repletion of iron stores and the resolution of anemia.

Keywords: Obesity, Iron deficiency anemia, Bariatric surgery, Parenteral iron therapy