Perioperative hyperglycemia and risk of adverse events among patients with and without diabetes.

Objective: To study the association between diabetes status, perioperative hyperglycemia, and adverse events in a statewide surgical cohort.

Background: Perioperative hyperglycemia may increase the risk of adverse events more significantly in patients without diabetes (NDM) than in those with diabetes (DM).

Methods: Using data from the Surgical Care and Outcomes Assessment Program, a cohort study (2010-2012) evaluated diabetes status, perioperative hyperglycemia, and composite adverse events in abdominal, vascular, and spine surgery at 53 hospitals in Washington State.

Results: Among 40,836 patients (mean age, 54 years; 53.6% women), 19% had diabetes; 47% underwent a perioperative blood glucose (BG) test, and of those, 18% had BG ≥180 mg/dL. DM patients had a higher rate of adverse events (12% vs 9%, P < 0.001) than NDM patients. After adjustment, among NDM patients, those with hyperglycemia had an increased risk of adverse events compared with those with normal BG. Among NDM patients, there was a dose-response relationship between the level of BG and composite adverse events [odds ratio (OR), 1.3 for BG 125-180 (95% confidence interval (CI), 1.1-1.5); OR, 1.6 for BG ≥180 (95% CI, 1.3-2.1)]. Conversely, hyperglycemic DM patients did not have an increased risk of adverse events, including those with a BG 180 or more (OR, 0.8; 95% CI, 0.6-1.0). NDM patients were less likely to receive insulin at each BG level.

Conclusions: For NDM patients, but not DM patients, the risk of adverse events was linked to hyperglycemia. Underlying this paradoxical effect may be the underuse of insulin, but also that hyperglycemia indicates higher levels of stress in NDM patients than in DM patients.