Incidence and risk factors for the development of anemia following gastric bypass surgery.

In order to evaluate the incidence and risk factors for the development of anemia after Roux-en-Y gastric bypass (RYGB), the authors performed a retrospective analysis of 206 patients who received daily supplements of ferrous sulfate tablets for 2 weeks following their operation and were followed for a minimum of 86 weeks. They found that 21 patients (10.2%) developed postoperative iron deficiency anemia, and that menstruation and peptic ulcer disease were risk factors for the development of anemia.
The prevalence of anemia following bariatric surgery ranges between 10% and 60% depending on the study population, the type of intervention, macro- and micronutrient supplementation, the duration and quality of the follow-up, and the definition of anemia (see Muoz M et al., Nutr Hosp 2009;24(6):640-654). In the present study, anemia was defined as Hb < 11 g/dL in men, and < 10 g/dL in women, and therefore the actual prevalence of anemia (WHO criteria) was most probably underestimated, thus compromising risk factor analysis. In addition, the authors did not suggest a clear option for treating these cases of iron deficiency anemia. – Manuel Muoz