By Serena Gordon
WEDNESDAY, Oct. 29 (HealthDay News) -- Two therapies that looked as if they might help prevent serious complications and deaths in the smallest preterm infants have instead yielded disappointing results, studies show.
The studies -- one that examined insulin therapy and one that looked at the effects of aggressive phototherapy -- found that neither treatment was effective in reducing the risk of death, and there was even a slight increase in the death rate for the insulin treatment group. The aggressive phototherapy (light) study, however, did find a lower risk of neurodevelopmental impairments in preemie babies.
Results of both studies were published in the Oct. 30 issue of the New England Journal of Medicine.
More than 12 percent of babies in the United States are born prematurely (before 37 weeks' gestation), according to the March of Dimes, and that number has risen 30 percent since 1981. Babies born early face a host of serious medical problems, and the less developed they are at birth, generally the more problems they face.
One problem that very low birth weight babies often face is high blood glucose levels (hyperglycemia). This can lead to brain hemorrhage, and it also increases the risk of infection, explained Dr. David Dunger, senior author of the insulin study, and a professor of pediatrics at the University of Cambridge in the United Kingdom.
For adults in intensive care, controlling high glucose levels leads to better outcomes, and so, the scientists theorized that the same might hold true for infants.
The current study included 389 babies from multiple medical centers. Half of the infants were given continuous insulin infusions along with continuous dextrose [sugar] support, and the other half received standard care.
"The insulin treatment was effective in lowering glucose levels and allowing more carbohydrate to be given to the babies, resulting in less weight loss," Dunger said. "However, the treatment had no effect on morbidity or mortality and was associated with an increased risk for low blood sugars."
Additionally, editorial author Dr. Richard Polin, from the College of Physicians at Surgeons at Columbia University in New York City, pointed out that "there was an unexpected finding of increased mortality [among those given insulin]."
The bottom line: "This is a special population -- the smallest, sickest premature babies -- but routine use of insulin is not indicated at this time," according to Polin.
Dunger agreed, but added that severe high blood sugar levels still need to be treated.
The second study looked at a more aggressive form of a commonly used treatment called phototherapy. This light therapy is commonly used to treat babies who are born slightly jaundiced, which means that their level of bilirubin -- a substance secreted by the liver -- is elevated. Babies with jaundice appear yellow-tinged.
In premature babies, bilirubin levels may be elevated, and the current study sought to evaluate whether aggressive phototherapy -- meaning a stronger use of light -- would improve neurodevelopmental or illness outcomes in extremely low birth weight infants.
The study included almost 2,000 babies between 12 hours and 36 hours old. Half were assigned to aggressive phototherapy, while the other half received standard phototherapy.
When the researchers looked at death rates and neurodevelopmental impairments together, they found no significant differences between the groups. The death rate was slightly elevated in the aggressive phototherapy group but didn't reach statistical significance.
"In the smallest babies, we were concerned that there was a trend toward an increase in the rate of death," said the study's lead author, Dr. Brenda Morris, who was an associate professor of pediatrics at the University of Texas Medical Center at Houston at the time of the study.
When the researchers looked at neurodevelopmental outcomes alone, they found a 14 percent decreased risk of neurodevelopmental impairment in the group that received the more aggressive therapy. After the initial analysis, the researchers also looked at the rates of profound impairment and found that those babies who received aggressive therapy were 32 percent less likely to have profound impairments.