Níveis séricos de nutrientes associados a eritropoiese no período pós-operatório tardio de cirurgia de bypass gástrico em Y-de-Roux

Abstract

Background: Roux-en-Y gastric bypass (RYGB) is a restrictive malabsorptive surgical technique used for surgical treatment of obese patients. The RYGB is associated with the development and/or exacerbation of nutrient deficiencies involved in erythropoiesis, such as proteins, iron, folic acid and vitamin B12. Aims: The aims of the study were to assess dietary intake and serum levels of specific nutrients associated with erythropoiesis in the late postoperative period (PO) of RYGB. Methods: A retrospective longitudinal study for medical records analysis and a cross-sectional observational study for outpatient care, developed at a university hospital of high complexity. The initial sample based on the medical records of patients submitted to RYGB, over the period of 1999-2004 (n=108). Patients in this sample who were evaluated in the outpatient setting after 12 years or more of RYGB were included in the final sample (n=56). A semi-structured form was used for registering postoperative laboratory-clinical evolution. During the outpatient care were registered dietary history and anthropometric data, and requested laboratory tests and three-day food intake record. Results: Highest excess weight loss was registered at 2-3 years PO for preoperative body mass index (BMI) of <50kg/m2 (87.2%), and at 1-2 years PO for preoperative BMI of ≥50kg/m2 (66.6%). After a highest loss of excess weight, a variable but progressive recovery of excess body weight was identified. In the PO RYGB after 12 years, patients in the preoperative BMI <50 kg/m² and ≥ 50 kg/m² presented mean values of excess weight loss of 60.1% and 41.7%, respectively (p = 0.003). At some post-RYGB point, were registered deficiencies in hemoglobin (n=41, 57.7%), albumin (n=12, 24.0%), iron (n=18, 28.6%), folic acid (n=16, 25.4%), vitamin B12 (n=15, 25.4%). In the late RYGB PO, mean dietary intake was below Estimated Average Requirement for folic acid between women and men, and vitamin C between men. Low serum levels for iron (n=11, 35.5%) and vitamin B12 (n=3, 10.0%), but not for folic acid, were identified 12 years or more after RYGB. Conclusion: Systematic dietary guidance and monitoring, with regular clinical-laboratory follow-ups, including in the late PO, are essential to the nutritional health of post-RYGB patients.