The impact of a preoperative evaluation process on weight reduction and glycemic control in patients undergoing bariatric and metabolic surgery

Introduction: Metabolic surgery is a sustainable intervention for obesity and type 2 diabetes. Preoperative education optimizes weight loss and glycemic control outcomes. Objective: This study aimed to determine the effect of a generalized preoperative evaluation process (PEP) in patients who underwent bariatric surgery on weight loss and glycemic control pre- and post-surgery. Methods: Data were retrospectively collected and analyzed for patients with type 2 diabetes who underwent bariatric surgery between 2010 and 2016. Patients were categorized into two groups determined by participation in the PEP. The groups were named the PEP group and non-PEP group. The correlation among engagement in the PEP was determined using the chi-square test and t-test. Statistical analysis with p < 0.05 was deemed significant. Results: 129 patients were included in the study; 86 females (67%) and 43 males (33%). Fifty-nine patients (46%) engaged in the PEP and 70 (54%) patients did not engage in the PEP. A greater reduction in weight loss was observed in the PEP group versus the non-PEP group from initial enrollment to pre-surgery (14.3 +/- 9.2 kg vs. 11.6 +/- 9.2 kg; p = 0.11), and from pre-surgery to 2-years post-surgery (20.6 +/- 14.8 kg vs. 16.9 +/- 15.6 kg; p = 0.17). A greater reduction in HbA1c from initial enrollment to pre-surgery was seen in the PEP group versus the non-PEP group (0.90 +/- 1.28% vs. 0.63 +/- 1.07%); however, this was not maintained from pre-surgery to 2-year post-surgery (0.51 +/- 1.18% vs. 0.70 +/- 1.73%). In both cases, the statistical difference was insignificant. Conclusion: The PEP was not associated with improvements in short-term weight loss or glycemic control pre-surgery and a 2-years post-surgery. Patients may benefit from individually tailored preoperative weight management strategies.