Lead exposure biomarkers and mini-mental status exam scores in older men.
BACKGROUND
Lead is neurotoxic; yet, whether cognitive decline in older persons is associated with lead exposure is unknown. We studied whether lead exposure biomarkers are associated with cognitive test scores, as well as the modifying effects of age on the lead-cognition relationship.


METHODS
Lead exposure biomarkers and Mini-Mental Status Exam (MMSE) scores were measured among subjects in the Normative Aging Study. Multiple linear and logistic regression analyses were performed to examine the cross-sectional association of these 2 variables.


RESULTS
We found an odds ratio (OR) of 2.1 for MMSE <24 with an increase from the lowest to the highest quartile of patella lead levels (95% confidence interval [CI] = 1.1 to 4.1). From the lowest to the highest quartile of blood lead the OR for low MMSE was 3.4 (CI = 1.6 to 6.2). There was an interaction between lead biomarkers and age. Among subjects in the lowest quartile of patella lead levels, MMSE score decreased by 0.03 points per year (CI = -0.07 to 0.005), whereas in the highest quartile, MMSE score decreased by 0.13 points per year (CI = -0.19 to -0.07). Similar interactions were found between blood lead levels and age.


CONCLUSIONS
Increased levels of lead in bone and blood are inversely associated with cognitive performance among older men. Lead exposure might accelerate age-associated cognitive decline.
Wright
Robert O
RO
Division of Emergency Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA. robert.wright@channing.harvard.edu
Tsaih
Shirng Wern
SW
Schwartz
Joel
J
Spiro
Avron
A
McDonald
Karen
K
Weiss
Scott T
ST
Hu
Howard
H
D000368:Aged; D015415:Biomarkers; D003071:Cognition; D003430:Cross-Sectional Studies; D006801:Humans; D007855:Lead Poisoning / Q000503:physiopathology / Q000523:psychology*; D008297:Male; D008609:Mental Status Schedule; D009498:Neurotoxins; D014481:United States
D015415:Biomarkers; D009498:Neurotoxins