Analysis of leukopenia and anemia after gastric bypass surgery

Abstract Background Although anemia is a well-described complication after Roux-en-Y gastric bypass (RYGB) in association with iron deficiency, no studies have been published regarding changes in the white blood cell count. Methods Mixed longitudinal models were used to follow the changes in white blood cell count, platelet count, and hematocrit over time after RYGB. Results A total of 590 patients, who had undergone RYGB from 2006 to 2010, inclusively, had laboratory studies available. The mean follow-up was 398 days (range 30–1484). The incidence of leukopenia (white blood cell count ≤4000 cm 3 ) increased significantly from 2.0% (12 of 590) before surgery to 14.6% (86 of 590) afterward ( P P P Conclusion RYGB is associated with a generalized decrease in the white blood cell and platelet counts. These decreases do not seem clinically important, unlike the substantial decrease in red blood cell mass in premenopausal women. A generalized suppression of hematopoiesis might occur after RYGB.