Study objective: Sleeve gastrectomy is effective in morbid obesity, and it improves glucose homeostasis. In gastric cancer patients with type 2 diabetes mellitus, gastrectomy, including total gastrectomy (TG), is beneficial for glycaemic control. However, the effects of gastrectomy and different reconstructive techniques on the incidence of postoperative diabetes in gastric cancer patients are unclear. This study investigated the development of new-onset diabetes in these patients, focusing on different reconstruction methods. Design: A comparative study Setting: Electrical medical records Patients: This study included 715 patients without diabetes who underwent TG at Tokyo Metropolitan Bokutoh Hospital between August 2005 and March 2019. Interventions: Patients underwent reconstruction by Roux-en-Y (RY) or other surgical techniques (OT), with diabetes onset determined by HbA1c levels or medical records. Measurements: Analyses included two-sample t-tests, chi-squared tests, and the Kaplan-Meier method with log-rank tests to compare the onset curves between the two groups. Main Results: Stratified data analysis compared the RY and OT reconstruction methods. Log-rank test results (P=0.0217) indicated a statistically significant difference in the incidence of new-onset diabetes between RY and OT groups in gastric cancer patients. Conclusion: This first-of-its-kind study provides insight into how different methods of gastric reconstruction affect postoperative diabetes. The results suggest significant differences in new-onset diabetes mellitus after surgery based on the reconstruction method. This research highlights the need for careful surgical planning to consider potential postoperative diabetes, particularly in patients with a family history of diabetes mellitus. Future studies should investigate the role of gut microbiota and other reconstructive techniques, such as laparoscopic jejunal interposition, in developing postoperative diabetes.

The authors have declared no competing interest.

This study did not receive any funding

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Ethics committee/IRB of Tokyo Metropolitan Bokutoh Hospital gave ethical approval for this work.

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All data produced in the present study are available upon reasonable request to the authors.