People hospitalized in intensive care units, or ICUs, often experience spikes in blood sugar, and current practice is to try to lower these levels.
But a new study found that this strategy might actually boost the person's risk of death by 10%.
"Intensively lowering blood glucose in critically ill patients is not beneficial and may be harmful," said Simon Finfer, MB, a senior staff specialist in intensive care at Royal North Shore Hospital in Sydney, Australia, and lead author of the study. "Based on our findings, we do not recommend pursuing a normal blood glucose level in critically ill patients."
Expert groups remain cautious about the study's findings, however. In a joint statement the American Diabetic Association (ADA) and the American Association of Clinical Endocrinologists (AACE) warned against "letting this study swing the pendulum of glucose control too far in the other direction, where providers in hospitals are complacent about uncontrolled hyperglycemia."
The study was published in the New England Journal of Medicine.
Intensive glucose lowering has been recommended to control high blood sugar, which is common in people who are acutely ill and has been associated with organ failure and death.
For the study, Dr. Finfer's team randomly assigned more than 6,100 ICU patients to either intensive or conventional blood sugar control. The researchers used infusions of insulin to achieve specific blood sugar levels. The participants were then followed for 90 days.
"We found that intensively lowering blood glucose levels increased a patient's risk of dying by 10%," Dr. Finfer said. Overall, 24.9% of those whose blood sugar was controlled by conventional means died within 90 days compared with 275% of those who were given intensive infusions about a one-tenth rise. The percentage of people who experienced hypoglycemia, or low blood sugar, was also higher in the intensely treated group compared with the conventional care group.
The findings reveal that the current practice of intensively lowering blood glucose increases the risk of death among patients in the ICU, Dr. Finfer said.
New Guidelines Needed
"International guidelines should be revised to reflect this new evidence," he said. "Many professional organizations recommend very tight glucose control for ICU patients. They will now need to take this new evidence into consideration and adjust their recommendations accordingly."
Silvio E. Inzucchi, MD, a professor of medicine at Yale University School of Medicine and author of an accompanying journal editorial, believes the findings might change clinical practice in the ICU.
The study "raises a big question mark about intensive blood sugar control in intensive care patients," Dr. Inzucchi said. "We used to think that keeping the sugar levels in the normal range was a good thing. This study says the opposite. The truth is probably somewhere in the middle.
"Get the sugars down, but keeping them in the slightly elevated range, is probably not a bad thing, at least during the short course of most hospitalizations," he said. "Medicine is always changing as new evidence emerges. We need to incorporate new findings into our practice patterns."
Expert Group Reaction
For their part, the ADA and AACE stress that doctors must still closely monitor and manage the blood sugar levels of very ill patients.
The findings should not lead to an abandonment of the concept of good glucose management in the hospital setting," the groups said in their joint statement. They also pointed out that the study compared patients receiving either very strict glucose control or, in the conventional treatment arm, less strict but still well-controlled blood sugar management.
ADA and AACE have also convened a special inpatient task force to examine the issue. "Until more information is available, it seems reasonable for clinicians to treat critical care patients with the less intensive-yet good-glucose-control strategies used in the conventional arm (of the study)."