BackgroundConcerns have been raised regarding the impact of preoperative intravenous dexamethasone on postoperative glycemic control in diabetic patients undergoing total joint arthroplasty (TJA). This study aimed to determine relationships between preoperative different dexamethasone regimens and postoperative fasting blood glucose (FBG), as well as to identify risk factors for postoperative FBG ≥ 200 mg/dl in diabetic patients undergoing TJA.MethodsThis retrospective study included 1216 diabetic patients undergoing TJA and categorized into group A (dexamethasone = 0 mg), group B (dexamethasone = 5 mg), and group C (dexamethasone = 10 mg). All dexamethasone was administered before skin incision. FBG levels were monitored until postoperative day (POD) 3. Analyses were conducted for periprosthetic joint infection (PJI) and wound complications during 90 days postoperatively. And the risk factors for postoperative FBG ≥ 200 mg/dl were identified.ResultsPreoperative dexamethasone administration resulted in a transiently higher FBG on POD 0 and POD 1 (all P < 0.001). However, no differences were observed on POD 2 (P = 0.583) and POD 3 (P = 0.131) among three groups. While preoperative dexamethasone led to an increase in postoperative mean FBG and postoperative maximum FBG (all P < 0.001), no differences were found in wound complications (P = 0.548) and PJI (P = 1.000). Increased HbA1c and preoperative high FBG, but not preoperative dexamethasone, were identified as risk factors for postoperative FBG ≥ 200 mg/dl. Preoperative HbA1c level of ≥ 7.15% was associated with an elevated risk of postoperative FBG ≥ 200 mg/dl.ConclusionsAlthough preoperative intravenous administration of 5 mg or 10 mg dexamethasone in diabetic patients showed transient effects on postoperative FBG after TJA, no differences were found in the rates of PJI and wound complications during 90 days postoperatively. Notably, patients with a preoperative HbA1c level of ≥ 7.15% and elevated preoperative FBG may encountered postoperative FBG ≥ 200 mg/dl.