Effect of Adding Insulin Glargine on Glycemic Control in Critically III Patients Admitted to Intensive Care Units: A Prospective Randomized Controlled Study

Objective: We aimed to examine the effects of adding a longer-acting insulin glargine to existing glucose control on reducing blood-glucose fluctuations in an intensive care unit (ICU). Methods: A total of 110 patients randomly received adjuvant insulin glargine 15 lU/day (glargine) or placebo (control), in addition to daily infusion of insulin to maintain glucose levels at a target of 140-180 mg/dL. End points were mean and variance of blood glucose and frequency of hypoglycemia, hyperglycemia, ICU stay, and mortality. Data were analyzed with repeated-measures ANOVA and Mann-Whitney U test. Results: Average daily glucose level was significantly less in the glargine group than controls (P<0.0001), while there was no difference in daily variance in blood glucose between the two groups. The duration of glucose concentrations being within the target range was identical between the glargine and control groups (16.6 +/- 4.9 vs 16.4 +/- 4.6 hours/day, P=0.844) during the 7 days of admission. The frequency of hypoglycemia was greater in the glargine group and total duration of hyperglycemia (>180 mg/dL) much longer among controls (P<0.001). Similar mortality rates were observed in both groups, while ICU length of stay was 2 days shorter in the glargine group. Conclusion: Addition of insulin glargine to routine protocols more effectively reduces glucose levels and decreases incidence of hyperglycemic episodes and regular insulin usage. This adjustment may be associated with decreases in duration of ICU stay or increases in hypoglycemic events.