Effects of glycemic variability in type 2 diabetes on surgical site infection after lumbar interbody fusion

English Keywords:Type 2 diabetes mellitus  Glycemic variability  Transforaminal lumbar interbody fusion  Surgical site infection

English Abstract:

  【Abstract】 Objectives: To analyze the correlation between perioperative glycemic variability and surgical site infection(SSI) following transforaminal lumbar interbody fusion(TLIF) in patients with type 2 diabetes mellitus. Methods: This study retrospectively analyzed 305 patients with lumbar degenerative diseases(LDD) and type 2 diabetes who underwent TLIF in the Spinal Surgery Department of Zhongda Hospital Affiliated to Southeast University from January 2018 to April 2021. There were 133 males and 172 females with an average age of 67.6±9.3 years. The medical records of all patients were collected, and postoperative infection cases were determined according to the diagnostic criteria of surgical site infection. General information included gender, age, whether combined with body mass index(BMI)≥25kg/m2, duration of diabetes mellitus, whether combined with hypertension, whether combined with coronary heart disease, fasting blood glucose on admission, preoperative glycosylated hemoglobin A1c(HbA1c), preoperative and postoperative mean fasting blood glucose(MFBG), and preoperative hypoglycemic scheme(①oral hypoglycemic drugs; ②subcutaneous insulin injection; ③combined medication: oral hypoglycemic drugs + subcutaneous insulin injection; ④diet therapy). Surgery-related data included intraoperative blood loss, intraoperative blood transfusion, duration of operation, the number of operative levels≥(2 or not), postoperative drainage time, postoperative drainage volume, and length of the incision. Glycemic variability monitoring indicators included standard deviation of blood glucose(SDBG), coefficient of variation(CV), largest amplitude of glycemic excursions(LAGE), and mean of daily differences (MODD). Patients were divided into the infection group and non-infection. Preoperative and postoperative glycemic variability indexes of the above 2 groups were compared, including SDBG, CV, LAGE, and MODD. The correlation analysis and receiver operating characteristic(ROC) curve were used to investigate the relationship between perioperative glycemic variability and postoperative SSI and its predictive value. Results: A total of 51 patients out of the 305 patients occurred infection. Univariate analysis showed that there were significant differences between the two groups in the duration of diabetes mellitus, preoperative and postoperative MFBG, SDBG, CV, LAGE, MODD, preoperative hypoglycemic regimen, the number of operative levels, postoperative drainage time, and the length of incision(P<0.05). However, there were no significant differences in gender, age, BMI, hypertension, coronary heart disease, fasting blood glucose on admission, preoperative HbA1c, operation time, intraoperative blood loss, intraoperative blood transfusion, and postoperative drainage volume(P>0.05). ROC analysis showed that areas under the curve(AUC) of preoperative SDBG, CV, LAGE, and MODD were 0.840, 0.813, 0.851, and 0.680, and cut-off values were 0.89mmol/L, 13.69%, 2.25mmol/L, and 0.92mmol/L respectively. The AUC of postoperative SDBG, CV, LAGE, and MODD were 0.697, 0.672, 0.693, 0.698, and cut-off values were 1.72mmol/L, 16.09%, 3.95mmol/L, and 1.59mmol/L respectively. The ridge regression results showed that the high preoperative MFBG, SDBG, CV, LAGE, and MODD, and postoperative SDBG, CV, LAGE, MODD, prolonged postoperative drainage duration, and multiple operative segments were found to be the independent risk factors for postoperative SSI following TLIF in patients with type 2 diabetes mellitus (P<0.05), while there was no significant difference in postoperative MFBG between the infection group and non-infection group(P>0.05). Conclusions: Perioperative glycemic variability in patients with type 2 diabetes is closely related to the occurrence of postoperative SSI following TLIF. Reducing blood glucose variability may be beneficial to reduce the incidence of SSI after surgery.