Weight loss before bariatric surgery and its impact on poor versus excellent outcomes at 2 years.

Purpose: To identify preoperative factors that influence the outcomes of gastric bypass surgery, in terms of excess weight loss at 24 months.

Methods: This retrospective study included two groups of patients who underwent laparoscopic gastric bypass surgery. Group A (poor outcomes) had ≤ 50%EWL or BMI ≥ 30 kg/m; group B (excellent outcomes) had ≥ 80%EWL at 24 months. A comparative analysis of demography, anthropometry, comorbidities, and metabolic status was performed. A linear regression model was used to evaluate %EWL association; the number of preoperative and postoperative consultations were also compared.

Results: A total of 202 patients completed follow-up; 71 (35.1%) and 78 (38%) had poor and excellent outcomes (%EWL 44.1 ± 9.4% vs. 92 ± 10.9%), respectively. Mean age was 40.4 ± 8.9 years. Patients with poor outcomes had higher weight and BMI, lesser preoperative %EWL, higher dyslipidemia and diabetes rates with longer periods of evolution, and increased HbA1c% levels. In the linear regression analysis, preoperative %EWL and initial and preoperative BMI were statistically significant determinants of %EWL at 24 months Diabetes remission was 46.2% (group A) vs. 66.6% (group B). Group A had higher non-attendance rates after surgery.

Conclusion: The factors independently associated with greater %EWL at 24 months between groups were higher preoperative %EWL, and lower initial and preoperative BMI.