Anemia After Sleeve Gastrectomy and One-Anastomosis Gastric Bypass: An Investigation Based on the Tehran Obesity Treatment Study (TOTS).

BACKGROUND: Bariatric surgery has been associated with iron, folate, and vitamin B12 deficiencies, which can lead to anemia. This study compares the incidence of anemia between sleeve gastrectomy (SG) and one-anastomosis gastric bypass (OAGB). METHODS: Patients from a prospectively collected database of patients with morbid obesity undergoing a primary bariatric procedure from April 2013 to September 2018 were included. Statistical analysis was performed using the general estimation equation. Patients were followed for 6, 12, 24, and 36 months post-surgery. RESULTS: The present study included 2618 patients, of whom 72.3% underwent SG and 27.6% underwent OAGB. The majority of the study population were women (75.7%), and the mean age of the participants was 39.5 ± 11.7 years. At the end of the follow-up, the excess weight loss percentage was 66.15 in the SG group and 75.41 in the OAGB group (P < 0.05). The incidence of anemia at 12-, 24-, and 36-month was 16.2, 19.7, and 24.3% in the SG group and 28.4, 37.6, and 56.5% in the OAGB group, showing significantly higher incidence in the OAGB than the SG group ([Formula: see text] < 0.001). However, there was no significant difference between the SG and OAGB groups regarding the incidence of iron and vitamin B12 deficiency. CONCLUSIONS: The patients undergoing bariatric surgery, especially OAGB, should be closely monitored post-surgery regarding the incidence of anemia, and supplementation in developing countries could be continued even after the first year.

Nutrient Intake and Deficiency of Patients 1 Year After Bariatric Surgery: Tehran Obesity Treatment Study (TOTS).

PURPOSE: This study aimed at assessing nutrient adequacy after 1 year in patients who had undergone gastric bypass (GB) surgery or sleeve gastrectomy (SG) and to investigate the association of nutrient adequacy with anthropometric indices. METHODS: A total of 180 severely obese patients (BMI ≥ 35 kg/m2) were selected among the participants of Tehran Obesity Treatment Study. Nutritional assessments were performed over 3 days of 24-h dietary recall. To evaluate the nutrient adequacy ratio (NAR), the subject's nutrient intake was divided by the dietary reference intakes. The mean adequacy ratio (MAR) was also determined as the sum of NARs divided by the number of involved nutrients (n = 11). RESULTS: The mean age of SG (67%) and GB (32%) patients was 39.2 ± 12 and 41.4 ± 10 years, respectively. SG patients had more postoperative fat-free mass (52.0 ± 12 kg) than GB patients (49.7 ± 8 kg) (P < 0.05). The most common postoperative serum nutrient deficiencies were related to vitamin B12 (30%), ferritin (19%), and 25-hydroxyvitamin D (16.2%). Moreover, high inadequacy of protein (> 80%) and total fat (> 70%) intake was reported. The MAR score showed that almost 45% of the patients had possibly adequate intakes of some nutrients. The adequacy of nutrients was positively associated with fat-free mass (ß = 8.67, P < 0.05). CONCLUSION: These findings revealed that patients had inadequate nutrient intakes 1 year after bariatric surgery, which was accompanied by serum nutritional deficiencies. Compared to GB patients, SG patients had a better body composition. Overall, compliance of patients with dietary guidelines and supplementations needs to be carefully monitored in the postoperative period.