Intensive insulin therapy targeting a glucose level between 100 mg/dL to 140 mg/dL in the intensive care unit (ICU) did not reduce perioperative complications in patients undergoing coronary artery bypass surgery (CABG), new data published in Diabetes Care indicate.
“Several cohort studies as well as prospective clinical trials in cardiac surgery patients have reported that improvement in glycemic control can reduce short- and long-term complications and hospital mortality,” the researchers wrote.
However, several recent randomized trials in mixed ICU populations do not support these conclusions, they noted.
For their open-label clinical trial, the researchers randomly assigned 152 patients with diabetes and 150 patients without diabetes who had hyperglycemia to an intensive glucose target of 100 mg/dL to 140 mg/dL (n=151) or a conservative target of 141 mg/dL to 180 mg/dL (n=151) after undergoing CABG.
Both groups received continuous insulin infusion (CII) in the ICU that were adjusted for their respective targets. After discontinuation of CII, patients transitioned to a single treatment protocol targeting a glucose level of <140 mg/dL before meals during hospital stay and 90 days post-discharge.
A composite of complications, including mortality, wound infection, pneumonia, bacteremia, respiratory failure, acute kidney injury and major cardiovascular (CV) events served as the primary outcome.
In the ICU, mean glucose levels were 132 mg/dL in the intensive control group and 154 mg/dL in the conservative group (P<.001), the researchers reported. Results revealed no significant differences between groups in the composite of complications (42% vs. 52%, respectively; P=.08).
Data showed heterogeneity in treatment effect according to diabetes status, although there were no differences in complications among diabetes patients in the intensive vs. conservative groups (49% vs. 48%, respectively; P=.87).
Among patients without diabetes, however, the rate of complications was lower in the intensive vs. conservative groups (34% vs. 55%; P=.008).
“Our study indicates that intensive therapy with a target glucose between 100 and 140 mg/dL in the ICU resulted in a lower, but not significant, reduction in the composite of perioperative complications including mortality, sternal wound infection, bacteremia, respiratory failure, acute kidney injury, and [major adverse CV events] compared with a conservative glucose target between 141 and 180 mg/dL,” the researchers wrote.
“Although the study was not powered to determine differences in the rate of complications in patients with and without diabetes, we found significant differences in the frequency of complications in patients treated with intensive and conservative insulin therapy in patients without diabetes.”
They noted that large, prospective, randomized studies are necessary to confirm these findings.