Iron absorption and iron status are impaired after Roux-en-Y gastric bypass

Background/aim: Currently, the most widely performed surgical weight loss procedure in the treatment of morbid obesity is the Roux-en-Y gastric bypass (RYGBP) operation which combines restriction of food intake with malabsorption of calories and various nutrients, resulting in weight loss and nutritional deficiencies, respectively. Various types of anemia may complicate RYGBP of which iron deficiency anemia (IDA) is particularly common and may result from many mechanisms including poor intake, malabsorption, and mucosal bleeding from marginal ulceration. The objective of our study was to evaluate the effects RYGBP on iron status and iron absorption at different stages after surgery. We hypothesized that iron absorption would be markedly impaired immediately after surgery and would not improve after such a procedure.

Methods: Anthropometric, body-composition, dietary, hematologic, and iron-absorption measures were determined in 22 severe and morbidly obese patients [mean age: 25.9–65.8 y; weight: 114.2–170.1kg, body mass index (BMI: in kg/m²): 42.9–56.8] who underwent RYGBP. The Roux-en-Y loop length was 125–150cm. Determinations were carried out before and after 3 month.

Results: After RYGBP serum ferritin (µg/L) decreased from 120.2±67.2 to 91.6±40.3 (p<0.05), transferrin saturation (%) from 20.3±9.4 to 18.4 (p<0.05), while serum transferrin receptor (mg/l) increased from 2.8±1.2 to 4.4±0.8 (p<0.05) indicating reduced iron after 3 month. Figure 1 demonstrates the impaired iron absorption in morbid obese patients (n=22) compared to controls (n=19).

Conclusion: Iron absorption is significantly impaired after RYGBP leading to splenished iron stores already 3 month after surgery.

Fig.1

Fig.2