Iron-Deficiency Anemia After Laparoscopic Roux-en-Y Gastric Bypass in Chinese Obese Patients with Type 2 Diabetes: a 2-Year Follow-Up Study

This study was conducted to evaluate the prevalence of iron-deficiency anemia (IDA) after Roux-en-Y gastric bypass (RYGB) in Chinese obese patients with type 2 diabetes (T2DM). Furthermore, we evaluate potential predicting factors for onset of IDA after RYGB. A total of 184 obese T2DM individuals who underwent RYGB were enrolled in the study. Patients were divided into three groups: male, premenopausal female, and postmenopausal female. Hematologic parameters were obtained prior to and after surgery on standardized time intervals up to 24 months postoperatively. At baseline, 6.0 % of patients were anemic, with similar percentages of anemic patients in each group. The relative decrease in the mean hemoglobin (Hb) level was significantly more pronounced for premenopausal female than for postmenopausal female or male. The percentage of anemia in male group had increased to 15.2 and 17.0 % at 6 and 12 months, respectively, and then decreased to 4.5 % at 24-month visit. In postmenopausal female group, the percentages of anemia constantly increase to 34.0 % at 6-month follow-up. Then, it decreased gradually to 25.0 and 26.7 % at 12- and 24-month visits, respectively. In premenopausal female group, the anemia percentages dramatically increased to 62.5 % at 24-month follow-up. Multiple logistic regression indicated that lower serum ferritin level preoperative and female were associated with higher possibility to suffer IDA 2 years after RYGB. Iron-deficiency and IDA are extremely frequent after RYGB in Chinese obese patients with T2DM. Premenopausal female presents unexpectedly high incidence of IDA during the 2-year observation.