The most recent guidelines for the management of hyperglycemia in critically ill patients recommend against tight glucose control.1-4 The recommendations were based primarily on the results of the large multicenter prospective study, NICE-SUGAR, which reported higher mortality in the group that was randomized to receive tight glucose control (BG 80-110 mg/dL), compared to the conventional group (BG ≤180 mg/dL).5
Several studies suggested that tight glucose control confers greater mortality benefits in non-diabetic patients, compared to patients with a history of diabetes.6-9 Recently, Lanspa and colleagues10 evaluated the effect of tight (80-110 mg/dL) versus moderate (90-140 mg/dL) glucose control on 30-day mortality in diabetic and non-diabetic patients. This was a retrospective cohort analysis of patients of the Intermountain Healthcare System who were treated with eProtocol-insulin from November 2006 to March 2011. Patients with diabetic ketoacidosis and those with less than ten blood glucose readings were excluded. Patients were stratified by the presence or absence of diabetes mellitus and by whether they received the 80-110 mg/dL or 90-140 mg/dL eProtocol-insulin therapy.
Over the study period, 3,529 patients from 12 ICUs of eight hospitals were evaluated. The ICUs included medical, surgical, and mixed ICUs and the hospitals included tertiary care, teaching and private community hospitals. Baseline characteristics for patients in the tight and moderate glucose groups were mostly similar. The logistic regression model demonstrated that moderate glucose control was independently associated with an increased risk of mortality in patients with no history of diabetes (OR 1.36, 95%CI, 1.01-1.84, p=0.05), but was associated with a decreased risk of mortality in patients with diabetes (OR 0.65, 95%CI 0.45-0.93, p=0.01). Tight glucose control was associated with a significantly higher incidence of moderate hypoglycemia (BG<60mg/dL) and severe hypoglycemia (BG<40 mg/dL), compared to moderate glucose control (30.3% and 3.6% vs. 14.3% and 2.0%, respectively, p<0.01 for both). The increased mortality associated with the moderate glucose control in patients without diabetes was also demonstrated in patients who did not develop hypoglycemia (OR 1.61, 95%CI 1.09-2.38, p=0.02). The authors suggested that patients with diabetes develop a relative tolerance to the complications of hyperglycemia and therefore may not benefit from the tight glucose control.
Although this study suggests that moderate glucose control is associated with increased risk of mortality in non-diabetic patients, it is insufficient to support a change in our practice. The results demonstrate that the optimal glucose level in critically ill patients remains unknown and that it does not appear to be the same for all critically ill patients. Future prospective randomized controlled studies are needed to evaluate glucose control in the different types of critically ill populations.
1. Moghissi ES, Korytkowski MT, DiNardo M, et al. American Association of Clinical Endocrinologists and American Diabetes Association consensus statement on inpatient glycemic control. Diabetes Care. 2009;32:1119-31.
2. Dellinger RP, Levy MM, Rhodes A, et al. Surviving Sepsis Campaign: International guidelines for management of severe sepsis and septic shock: 2012. Crit Care Med. 2013;41:580-637.
3. Qaseem A, Humphrey LL, Chou R, et al. Use of intensive insulin therapy for the management of glycemic control in hospitalized patients: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2011;15:260-7.
4. Jacobi J, Bircher N, Krinsely J, et al. Guidelines for the use of an insulin infusion for the ...