Insulin-Dependent Diabetic Patients are at Increased Risk of Postoperative Hyperglycemia When Undergoing Total Joint Arthroplasty.

BACKGROUND: Diabetic patients are at an increased risk of prosthetic joint infection (PJI) after total joint arthroplasty (TJA). The relationship between insulin-dependence and PJI has not been investigated. We aimed at evaluating whether insulin-dependent diabetes mellitus (IDDM) patients were more susceptible to postoperative hyperglycemia and PJI than their non-insulin-dependent diabetes mellitus (NIDDM) counterparts. METHODS: A retrospective review was conducted of diabetic patients undergoing TJA (hip or knee) from January 2011 to December 2016. Preoperative hemoglobin A1c (A1c) and postoperative glucose measurements were observed. Patients were stratified as IDDM or NIDDM. The A1c values that predicted hyperglycemia >200 mg/dL for each group were calculated. Primary end point was postoperative hyperglycemia >200 mg/dL and secondary end point was PJI. RESULTS: There were 773 patients meeting inclusion criteria. The IDDM cohort had a higher preoperative A1c (6.97% vs 6.28%, P < .0001) and postoperative glucose (235.2 vs 163.5, P < .0001). IDDM patients were more likely to have postoperative hyperglycemia (63.84% vs 20.83%, P < .0001; odds ratio, 5.2; 95% confidence interval, 3.66-7.4). Overall, an A1c of >7.45% predicted postoperative hyperglycemia >200 mg/mL (odds ratio, 6.94; 95% confidence interval, 4.32-11.45). When separating our 2 cohorts, an A1c of >6.59% in IDDM, and >6.60% in NIDDM, was associated with an increased risk of postoperative hyperglycemia (P < .0001). PJI was similar between the 2 cohorts (2.52% vs 2.38%, P = .9034). CONCLUSION: IDDM patients undergoing TJA are 5.2 times more likely to have postoperative hyperglycemia >200 mg/dL than their NIDDM counterparts, although increased risk of PJI was not found in this study. Despite the higher A1c and postoperative hyperglycemia in IDDM patients, there was found to be no clinical difference between A1c cutoff values for postoperative hyperglycemia between IDDM and NIDDM patients.