Higher glycemic variability signals increased mortality risk in gastric surgery patients.

• Each 1% increase in glycemic variability raises 30-day mortality by 15% and 90-day mortality by 14%.
• Critical thresholds identified at glycemic variability levels of 20.24 for 30-day mortality and 33.96 for 90-day mortality.

Monitoring and managing glycemic variability could significantly improve patient outcomes after gastric surgery.

• The predictive model achieving an AUC of 0.83 underscores the clinical relevance of glycemic control in surgical settings.