Anemia and the Need for Intravenous Iron Infusion after Roux-en-Y Gastric Bypass

Area of Science:

• Bariatric Surgery
• Gastroenterology
• Hematology

Background:

• Long-term complications of Roux-en-y gastric bypass (RYGB) surgery, including anemia and iron deficiency, require further characterization.
• The incidence and predictors of anemia and the need for intravenous (IV) iron post-RYGB are not well understood.

Purpose of the Study:

• To determine the cumulative incidence of anemia up to 7 years after RYGB.
• To identify risk factors for developing anemia and the need for IV iron therapy post-RYGB.
• To assess the long-term requirement for IV iron in patients undergoing RYGB.

Main Methods:

• Retrospective cohort study of 904 patients who underwent RYGB between 1999 and 2006.
• Inclusion criteria required preoperative and at least one postoperative complete blood count (CBC) >6 months after surgery.
• Univariate and multivariable Cox regression analyses were used to identify predictors of anemia.

Main Results:

• The cumulative incidence of anemia 7 years post-RYGB was 58%.
• Menstruation status and preoperative anemia were significant predictors of postoperative anemia.
• 8.5% of the cohort (22% of anemic subjects) required IV iron a mean of 51 months postoperatively due to oral iron-refractory anemia.

Conclusions:

• Anemia is a frequent long-term complication following RYGB, with a significant proportion of patients, particularly menstruating women, requiring IV iron therapy.
• The risk of developing anemia necessitating IV iron increases over time and can affect even post-menopausal women.
• Further prospective studies are needed to elucidate the exact incidence of iron deficiency anemia and identify high-risk patient populations for IV iron replacement after RYGB.