Stress-induced Hyperglycemia, Not Diabetic Hyperglycemia, is Associated with Higher Mortality in Trauma

Hyperglycemia is a normal physiologic response to stress, but may also be due to underlying diabetes mellitus. Regardless of the etiology, hyperglycemia has been shown to adversely affect outcomes in a variety of patient populations. Whereas prior studies have shown higher mortality rates in hyperglycemic trauma patients, no study has differentiated between stress-induced hyperglycemia (SIH) and diabetes mellitus (DM). This prospective observational study included 5117 trauma patients at a single center to determine whether SIH or DM affected overall mortality rates. Patients with a normal hemoglobin A1C and a blood sugar > 200 on admission were identified as SIH, and patients with a hemoglobin A1C > 6.5% and hyperglycemia were identified as diabetics. After adjustment for age, sex, injury mechanism, and injury severity score, patients with SIH had a relative risk (RR) of 2.41 (95% confidence interval [CI] 1.81–3.23) for in-hospital mortality, and patients with DM had a RR of 1.47 (95% CI 1.08–1.93). The risk of developing pneumonia was similarly high in both groups, but other outcomes such as sepsis, urinary tract infection, wound infection, and renal failure did not demonstrate an association with hyperglycemia. The authors conclude that hyperglycemia has a more severe effect on mortality in non-diabetic trauma patients. Comment: Previous studies on tight glycemic control in critically ill patients have shown mixed results. Given the results of the study discussed in this abstract, a focus on tight glycemic control in patients with SIH may be warranted, as they have higher mortality rates. This tight glycemic control may be more beneficial in this subset of patients when compared to hyperglycemic patients with DM.