Blood glucose level changes and risk factors for hyperglycemia after total knee arthroplasty in non-diabetic patients: A prospective, observational study.

Abstract

Postoperative hyperglycemia secondary to surgical stress predisposes patients to infection regardless of diabetes status, including after total knee arthroplasty (TKA). However, glycemic changes following TKA in patients without diabetes mellitus (DM) remain incompletely understood, as do the risk factors for postoperative hyperglycemia. We investigated detailed blood glucose level (BGL) changes, including those before each meal, and examined risk factors for postoperative hyperglycemia in non-diabetic TKA patients. In this prospective study, 147 knees of 129 patients without DM who underwent TKA between July 2021 and November 2025 were included. Their BGL were measured preoperatively, at 9 PM on the day of surgery, and before every meal until the morning of postoperative day (POD) 3. The BGLs at each measurement time point were compared using one-way analysis of variance. Risk factors for hyperglycemia at the time of the highest postoperative BGL were assessed using multivariate regression analysis. And the cut-off values of risk factors obtained through the multiple regression analysis for predicting hyperglycemia above 140 mg/dl were evaluated using the receiver operating characteristics curve. Compared to preoperative levels, mean BGL was significantly higher from the day of surgery to the evening of POD 2, peaking at mid-day on POD 1. Multiple regression analysis revealed that an increased BGL at the mid-day on POD 1 was significantly associated with advanced age, with a cut-off value of 76 years for predicting hyperglycemia, area under the curve of 0.601 (P = 0.035), and sensitivity and specificity of 58.0% and 61.5%, respectively. BGL after TKA in non-diabetic patients remain significantly higher than preoperatively until the evening of POD 2, with the highest mean BGL at mid-day on POD 1. Hence, careful monitoring of BGLs is necessary until the evening of POD 2, particularly in patients aged 76 years or older.