Insulin Therapy in Medical ICUs Offers Limited Benefit
Complications were reduced, but death rates were not, study finds
WEDNESDAY, Feb. 1, 2006 (HealthDay News) -- Intensive insulin therapy to control the blood sugar levels of patients in an intensive-care unit reduced complications such as kidney failure but did not lower death rates, a new Belgian study found.
The report comes from researchers at Catholic University of Leuven, whose 2001 study showed that such therapy lowered the death rate of patients treated in a surgical intensive-care unit. That study, which found insulin therapy helped prevent such complications as organ failure and severe infection, had started to have an impact on surgical intensive-care treatment.
The new study was done to gauge the effect of insulin therapy on patients in a medical intensive-care unit, not a surgical intensive-care unit. The results appear in the Feb. 2 issue of the New England Journal of Medicine.
The findings were called a disappointment by Dr. Atul Malhotra, an assistant professor of medicine at Brigham and Women's Hospital in Boston, who wrote an accompanying editorial in the journal. He noted that the 2001 study had, to some extent, made aggressive control of blood sugar a feature of intensive-care unit treatment for patients recovering from surgery.
"The results of the [new] study are somewhat disappointing," Malhotra said. "There was no change in the final outcome, mortality."
In the new study, the death rate was higher for patients who stayed in the medical intensive-care unit for less than three days and got the intensive insulin therapy, compared to patients who did not receive the therapy. But for patients who remained in medical intensive care for more than three days, the death rate was lower among those receiving the insulin therapy (43 percent), compared to those who did not get the therapy (52.5 percent).
But, Malhotra noted, that finding is of no value because "unfortunately, there is no easy way to predict the duration of a patient's stay in the ICU; therefore, it remains unclear which patients should receive intensive insulin therapy as they enter the ICU."
However, Dr. Greet Van den Berghe, a professor of medicine and head of the ICU at Catholic University of Leuven, who led both studies, said, "I don't agree with the editorialist."
The number of patients in the new study -- 1,200 -- was too small to determine the benefit of intensive insulin therapy, she said, adding, "We would need 5,000 patients to determine a significant effect on mortality."
In the new study, Van den Berghe said, "the absolute numbers were so similar to our surgical study that we are happy with this. I don't think it is a disappointment, and it is certainly not a negative study."
Larger studies are needed to determine the value of insulin therapy in medical, rather than surgical, intensive-care units, Malhotra said. Two such studies are under way, he said, one in Europe and one with patients in Australia, New Zealand and Canada.
But even those studies might not decide the issue, said Van den Berghe. The Australia-New Zealand-Canada trial will include 5,000 patients, but they will be recruited from both surgical and medical intensive-care units, so the number of medical ICU patients may fall short, she said.
Meanwhile, "our practice in the surgical ICU has been to go for tight blood glucose control," she said. "If you look at our mortality, you can see it has kept mortality down. In the medical ICU, we aim for tight glucose control for all patients. The morbidity benefit is important because it promotes early release from the hospital, which is extremely important for patients and for the medical system."
To learn more about how insulin works, visit the American Diabetes Association.