Abstract: Objective To explore the factors affecting the numerical accuracy of flash glucose monitoring (FGM) system in patients after pancreatic surgery. Methods A retrospective analysis was conducted on 279 adult patients who underwent elective pancreatic surgery at Peking Union Medical College Hospital from March 2024 to March 2025. Finally, 255 cases were included. All patients wore FGM sensors on the dorsum of the left upper arm one day before surgery, and received point-of-care (POC) capillary blood glucose measurements at least twice postoperatively. The reference blood glucose values were contemporaneous POC blood glucose readings. Paired matching was performed by taking the time points of POC blood glucose detection as benchmarks, and retrieving the closest FGM readings in the Gplus system for pairing. The mean absolute difference of paired blood glucose values was calculated for each subject. LASSO regression was used for variable selection, and Bootstrap resampling was applied to evaluate the occurrence frequency of screened variables. Multiple linear regression analysis was adopted to investigate the correlation between relevant variables and the mean difference of paired blood glucose values. Results The median mean difference between FGM readings and POC blood glucose values was 1.2 mmol/L. Multiple linear regression analysis revealed that maximum postoperative blood glucose (β=0.082, 95% CI: 0.055-0.108, P＜0.001), intraoperative crystalloid infusion (per 1L increment, β=0.124, 95% CI: 0.054-0.194, P＜0.001), jaundice (β=0.215, 95% CI: 0.019-0.412, P＜0.05) and age (per decade increase, β=0.091, 95% CI: 0.031-0.150, P＜0.05) were linearly correlated with the natural logarithm of the mean paired blood glucose difference(R_adj²=0.245). Conclusions Age, jaundice, intraoperative crystalloid infusion volume and maximum postoperative blood glucose are independent influencing factors for postoperative FGM accuracy. Elevations of these indicators are linearly correlated with greater FGM deviation.

Key words: flash glucose monitoring, blood glucose, jaundice, surgery