Reality of post-gastrectomy stress hyperglycemia revealed by continuous glucose monitoring: a prospective study

Postoperative stress hyperglycemia is reported to be associated with increased postoperative complications (PCs) following various surgical procedures. However, most reports of postoperative hyperglycemia are based on conventional, point blood glucose measurements. We sought to clarify trends in post-gastrectomy glucose levels using continuous glucose monitoring (CGM) and investigate the relationship between postoperative hyperglycemia and stress-related factors such as PCs and the degree of surgical invasiveness.

The subjects of this prospective study were 40 patients who underwent gastrectomy between November, 2022 and September, 2023. We recorded their glucose levels by CGM immediately after surgery until discharge (up to 2 weeks postoperatively).

There was no increase in glucose levels caused by open gastrectomy, a strong inflammatory response, or PCs. Hyperglycemia, defined as the percentage of time that the glucose level was > 140 mg/dL, was associated only with the preoperative HbA1c value (P = 0.039). Patients with an HbA1c ≥ 6% had a significantly longer duration of hyper- and hypo-glycemia and greater glycemic variability than those with an HbA1c < 6% (glucose level < 70 mg/dL, P = 0.027; > 140 mg/dL, P = 0.001, coefficient of variation P = 0.024).

No association was observed between stress hyperglycemia during the acute phase following gastrectomy and PCs. Only patients with an elevated HbA1c had high rates of hypo- and hyper-glycemia and large glycemic variability, despite perioperative glucose management.