Sex, BMI, preoperative FIB-4 index, and iron supplementation were associated with postoperative anemia after laparoscopic sleeve gastrectomy among 619 Chinese patients: a retrospective cohort study.

Abstract

Introduction: Laparoscopic sleeve gastrectomy (LSG) has become a common bariatric procedure in China, and the long-term risk of postoperative anemia remains to be estimated. This study aimed to investigate the incidence and risk factors of anemia at different times after LSG in Chinese population.

Objectives: To investigate the incidence of postoperative anemia and its risk factors in a cohort of Chinese patients with obesity undergoing LSG.

Setting: Huashan Hospital, Fudan University, Shanghai, China.

Methods: A retrospective cohort study was conducted on 619 patients who underwent LSG at a tertiary hospital between 2012 and 2022. The incidence of anemia at different postoperative stages was reported, and risk factors were explored using multivariable logistic regression.

Results: Among the 619 patients, 567, 436, and 189 participated in 0∼3, 3+∼12, and 12+∼60 months follow-up visits, respectively. The cumulative incidence of anemia for each period were 9.3%, 6.6%, and 9.1% for males, lower than those of 13.5%, 20.6%, and 39.2% for females. During the first 3 months of follow-up, preoperative iron deficiency was associated with a higher incidence of postoperative anemia (odds ratio [OR]: 3.67, 95% confidence interval [CI]: 1.11-12.16), and iron supplementation was associated with a lower risk of anemia among all patients (.46, .27-.77) and female patients (.49, .27-.87). In the period of 3+ - 12 months, females with advanced FIB-4 level (≥1.45, an index for liver fibrosis) had a higher incidence of anemia (5.72, 1.24-26.49). Among males, higher preoperative body mass index (BMI) was associated with a lower risk (.79, .64-.98), while weight loss was positively associated with anemia (1.26, 1.06-1.48).

Conclusion: Postoperative anemia was frequent in Chinese patients undergoing LSG and was associated with female gender, lower BMI, advanced preoperative FIB-4 level, and a lack of iron supplementation after surgery.