Mar 29 2009
The April 2009 issue of the peer-reviewed journal Environmental Health Perspectives (EHP) reports on a study examining the association of chronic low-level exposure to lead and accelerated declines in cognition in women age 47–74 years. Study findings suggest that cumulative exposure to lead at levels likely to be experienced in community settings may have adverse consequences for women’s cognition in their later years.
The objective of the study was to examine biomarkers of lead exposure in relation to performance on cognitive tests given to older women. Lead exposure is measured in two ways: blood lead level, which is a reading of recent lead dosage, and bone lead level, which is a cumulative measure of lead exposure over many years. For this study, the researchers assessed bone lead levels in the tibia and the patella.
The analysis of all cognitive tests combined showed levels of all three lead biomarkers were associated with worse cognitive performance, with the association between bone lead and letter fluency scoring dramatically different from the other bone lead/cognitive score associations. Although levels of patella and blood lead also were associated with worse cognitive function, results were statistically significant only for tibia lead, which typically reflects longer-ago exposures than patella lead. The pattern of association suggests that lead exposures in the distant past may be more important than relatively recent exposures in influencing cognitive function in older women.
“The identification of modifiable risk factors for cognitive decline may provide important clues for delaying or even preventing dementia,” wrote first author Jennifer Weuve and colleagues.
“Findings in this study are important because of their long-range consequences on the public health of an aging generation,” said EHP editor-in-chief Hugh A. Tilson, PhD. “Impaired cognition and cognitive decline in older women are associated with heightened risks of dementia, physical disability, hospitalization and reduced quality of life in later years.”
Other authors of the paper included Susan A. Korrick, Marc A. Weisskopf, Louise M. Ryan, Joel Schwartz, Huiling Nie, Francine Grodstein and Howard Hu. Support for this research was provided by the National Institute of Environmental Health Sciences, the National Cancer Institute, the National Institute on Aging and the National Institutes of Health.
The article is available free of charge at: http://www.ehponline.org/members/2008/11846/11846.html.