Low lead levels linked to heart deaths

NEW YORK (Reuters Health) - Research suggests that even low blood levels of lead may raise the risk of adverse heart and circulatory outcomes.

Previous reports have linked lead levels above 10 micrograms per deciliter with increased risks of death. The safety of lower levels, which are present in 99 percent of US adults, was unclear.

To investigate, Dr. Paul Muntner, from Tulane University in New Orleans, and colleagues analyzed data from 13,946 adults who participated in the Third National Health and Nutrition Examination Survey from 1988 to 1994 and were followed for up to 12 years.

The average blood lead level in the study group was 2.58 micrograms/dL, they report in the journal Circulation.

Subjects with levels of 3.62 micrograms/dL or higher were 25 percent more likely to die from any cause and 55 percent more likely to die from cardiovascular causes, compared with subjects with lead levels below 1.94 micrograms/dL.

"Our study found the association of blood lead with cardiovascular death to be evident at levels as low as 2 micrograms/dL," Muntner said in a statement.

"Since 38 percent of US adults had lead levels above 2 micrograms/dL in 1999-2002, the public health implications of these findings are substantial."

Muntner notes that the study was not designed to assess the risks of lead levels below 2 micrograms/dL and adds that further research will be needed to determine if any levels are, in fact, safe.

SOURCE: Circulation, September 26, 2006.