Association of Metabolic Score for Insulin Resistance with Intraoperative QTc Interval Changes During Laparoscopic Sleeve Gastrectomy: A Prospective Observational Study.

BACKGROUND: Preoperative metabolic status may influence cardiac repolarization under anesthesia. This study investigated the relationship between the Metabolic Score for Insulin Resistance (METS-IR) and intraoperative QTc dynamics during laparoscopic sleeve gastrectomy (LSG). METHODS: This prospective observational study included 75 patients with severe obesity (body mass index ≥ 40 kg/m²) undergoing LSG. Preoperative METS-IR was calculated from laboratory data. The QT interval, Fridericia-corrected QT interval (QTcF), Tp-e interval, and Tp-e/QT ratio were recorded at baseline (T0), post-intubation (T1), pneumoperitoneum-supine (T2), pneumoperitoneum-reverse Trendelenburg (T3), and post-extubation (T4). Associations between METS-IR and ΔQTcF were evaluated using Spearman correlation and mixed-effects modeling. Exploratory ROC analysis evaluated a ≥ 15 ms ΔQTcF response. RESULTS: The METS-IR-ΔQTcF association was most evident at T3 (ρ = 0.390, p < 0.001). In the mixed-effects model, the METS-IR × T3 interaction was significant after adjustment for perioperative covariates (β = 8.13, 95% CI 5.20 to 11.06, p < 0.001); however, the T3-specific estimate was borderline (β = 0.51, 95% CI - 0.07 to 1.09, p = 0.086), indicating that the association was sensitive to model specification. Exploratory analysis for a ≥ 15 ms ΔQTcF response at T3 showed modest discrimination (AUC = 0.654, 95% CI 0.527 to 0.780, p = 0.017), with high sensitivity but limited specificity. CONCLUSION: In this exploratory cohort of hemodynamically stable patients undergoing uncomplicated LSG, METS-IR was associated with QTcF dynamics, particularly at T3. However, evidence for the T3 association varied by model specification, and the findings do not support clinical use of METS-IR.