SAN FRANCISCO – Intensive glucose control targeting a blood glucose of 100-140 mg/dL did not significantly reduce perioperative complications or mortality, compared with a less strict glucose target of 141-180 mg/dL in hyperglycemic patients undergoing coronary artery bypass graft surgery, a randomized trial showed.
"Inpatient hyperglycemia is associated with increased hospital complications and mortality," Dr. Guillermo E. Umpierrez said at the annual scientific sessions of the American Diabetes Association. "There have been a lot of controversies regarding what is the best target for glucose targeting in these patients in the perioperative period. There are studies suggesting that improved glycemic control improves outcomes, but others have failed to reproduce this data."
Dr. Guillermo E. Umpierrez
In an effort to address this question, Dr. Umpierrez and his associates at three hospitals in Atlanta conducted the open-label, randomized GLUCO-CABG trial to determine whether intensive glucose control (defined as a blood glucose target of 100-140 mg/dL) reduces perioperative complications, compared with conservative glucose control (defined as a glucose target of 141-180 mg/dL) in hyperglycemic patients undergoing CABG. Their hypothesis was that intensive therapy in the ICU would reduce perioperative complications, compared with a conservative insulin therapy, said Dr. Umpierrez, professor of medicine at Emory University in Atlanta.
The study population included 302 men and women aged 18-80 years with and without a history of diabetes who underwent CABG with or without valve surgery, and who had perioperative hyperglycemia greater than 140 mg/dL during their surgery or ICU stay. Half received intensive insulin therapy, and the other half received conservative insulin therapy. A computerized insulin infusion algorithm (Glytec’s Glucommander) was used to guide continuous IV infusion, which was given in the ICU until the patients were able to eat and/or be transferred to non-ICU services.
The mean age of the patients was 64 years, 72% were male, and their mean body mass index was 30.5 kg/m2. The mean ICU daily blood glucose levels were similar, at 132 mg/dL in the intensive group, compared with 154 mg/dL in the conservative group, and the hospital length of stay was similar between the two groups (11.4 vs. 9.5 days, respectively). In the ICU, a blood glucose level of less than 70 mg/dL occurred in 8% and 2% of the intensive and conservative groups, respectively, a significant difference, while no levels reached less than 40 mg/dL.
After ICU care, there were no differences between the intensive and conservative groups in mean daily blood glucose levels (143 vs. 141 mg/dL, respectively), percentage of patients with hypoglycemia (1% vs. 3%), or hospital readmissions (18% vs. 20%). There were also no differences between groups in rates of mortality, pneumonia, acute kidney injury, respiratory failure, or wound infection.
"The results of this study have significant clinical implications in the management of patients with hyperglycemia and diabetes in critical care units," Dr. Umpierrez said. "This study indicates that a target glucose of 141-180 mg/dL is as safe and effective and results in a lower rate of hypoglycemic events compared to a more intensive target of 100-140 mg/dL."
The study was funded by the National Institutes of Health and by a clinical research award from the American Diabetes Association. Glytec provided the Glucommander and Sanofi provided medications. Dr. Umpierrez has received research funding from and/or has served as an adviser to several pharmaceutical companies.
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