STUDY: Treatment fails to help children with elevated lead levels
Wednesday, May 9th 2001, 12:00 am
By: News On 6
BOSTON (AP) _ Drug treatment to remove lead from the bloodstream does not improve the intelligence of children with moderately high levels of lead, as doctors had hoped, a study found.
This treatment, called chelation therapy, was first approved by the Food and Drug Administration 10 years ago for children whose lead levels were high _ above 45 micrograms per deciliter.
The Centers for Disease Control and Prevention has warned that moderately high levels above 15 micrograms are also a concern. Studies have shown that increasing the blood level from 10 micrograms to 20 micrograms can decrease youngsters' IQ scores by one to three points.
The CDC made no specific recommendations for chelation therapy in these children with moderately high levels. So the National Institute of Environmental Health Sciences sponsored a study to see if chelation would help them.
The study was conducted on 780 children between ages 1 and 3 from poor city neighborhoods. They were randomly assigned to get dummy pills or a chelation drug called Succimer.
The drug lowered lead levels, but it had no effect on children's intelligence. After three years of follow-up, IQ scores actually averaged one point lower in those getting the treatment. Overall, the children performed below average on a variety of tests that measured their attention span and thinking ability.
The study was directed by Dr. Walter J. Rogan of the environmental institute, based in Research Triangle Park, N.C. It was published in Thursday's New England Journal of Medicine.
An editorial by Drs. John F. Rosen and Paul Mushak of Children's Hospital at Montefiore in New York City said the results suggest the brain effects of too much lead are irreversible.
The primary source of children's lead exposure is flaking lead paint. Preventing this exposure, they wrote, ``is the only satisfactory solution to this devastating problem.''