Effects of Intravenous or Inhalation Anesthesia on Blood Glucose in Patients with Type 2 Diabetes Mellitus: A PRISMA-Compliant Systematic Review and Meta-Analysis

<i>Background and Objectives</i>: Perioperative hyperglycemia is associated with increased risks of infection and mortality. Patients with type 2 diabetes mellitus (T2DM) exhibit variable glycemic responses to surgical stress, highlighting the importance of optimal perioperative glucose control. The aim of this study is to conduct a systematic review and meta-analysis comparing the effects of intravenous versus inhalation anesthesia on perioperative blood glucose levels in patients with T2DM undergoing surgery. <i>Materials and Methods:</i> We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) and non-randomized studies identified from Medline, EMBASE, CENTRAL, and Google databases up to 24 October 2024. Eligible studies included adult surgical patients with type 2 diabetes mellitus. Two investigators independently screened studies, extracted data, and assessed methodological quality using the GRADE approach. <i>Results:</i> Five studies (3 RCTs and 2 non-RCTs) involving a total of 512 participants were included. Intraoperatively, inhalation anesthesia was associated with significantly higher blood glucose levels compared to intravenous anesthesia (mean difference [MD]: 12.52 mg/dL; 95% confidence interval [CI]: 0.70-24.35) in the overall analysis. However, subgroup analysis by study design showed no significant differences. Postoperatively, inhalation anesthesia resulted in significantly higher glucose levels than intravenous anesthesia, both in the overall analysis (MD: 23.56 mg/dL; 95% CI: 3.65-43.48) and in RCTs alone (MD: 28.20 mg/dL; 95% CI: 3.67-52.73). <i>Conclusions:</i> Intravenous anesthesia is associated with lower perioperative blood glucose levels compared to inhalation anesthesia, both during and after surgery. Although the effect was not consistently significant across all subgroups, these findings suggest a potential advantage of intravenous anesthesia in patients with T2DM and warrant validation in larger randomized trials.