Anemia rates after one-anastomosis gastric bypass versus sleeve gastrectomy: a retrospective cohort study

To compare postoperative anemia rates after one-anastomosis gastric bypass (OAGB) with those after sleeve gastrectomy (SG) in a large nationwide, population-based cohort study.

We sourced data from the Israeli Bariatric Surgery Registry. The study included a cohort of adults who underwent bariatric surgery (BS) between 2013 and 2017. Hemoglobin (Hb) was measured preoperatively and then 1 and 2 years post-BS. Anemia rates were compared between the patients who underwent OAGB and those who underwent SG, using multivariable analyses.

The study comprised 1,052 patients who underwent OAGB and 5,885 patients who underwent SG. Among them, 24.1% and 23.6% were men, respectively, and the preoperative mean body mass index values were 41.7 ± 5.0 and 42.1 ± 5.1 kg/m2, respectively. The 1-year and 2-year postoperative anemia rates were significantly higher after OAGB than after SG, when adjusted for age, pre-surgery BMI, sex and other covariates (1 year: 37.5% vs. 20.2%; adj-OR = 2.43; 95% CI 2.08–2.86; 2 years: 45.1% vs. 28.5%; adj-OR = 1.92; 95% CI 1.59–2.32).

Patients who underwent OAGB had significantly higher anemia rates 1 year and 2 years postoperatively than those who underwent SG. Consequently, vigilant surveillance and intervention strategies post-OAGB should be considered to mitigate the incidence of anemia and its associated complications.