Modifying Effects of the HFE Polymorphisms on the Association between Lead Burden and Cognitive Decline
2007

HFE Polymorphisms and Lead Exposure's Impact on Cognitive Decline

Sample size: 358 publication 10 minutes Evidence: moderate

Author Information

Author(s): Florence T. Wang, Howard Hu, Joel Schwartz, Jennifer Weuve, Avron S. Spiro III, David Sparrow, Huiling Nie, Edwin K. Silverman, Scott T. Weiss, Robert O. Wright

Primary Institution: Harvard School of Public Health

Hypothesis

HFE variant alleles may modify the relationship between lead burden and cognitive decline in older adults.

Conclusion

HFE polymorphisms significantly enhance susceptibility to lead-related cognitive impairment.

Supporting Evidence

  • Higher tibia lead was associated with steeper cognitive decline among participants with at least one HFE variant allele.
  • A 15 μg/g increase in tibia lead was associated with a 0.2 point annual decrement in MMSE score among HFE variant allele carriers.
  • The association between tibia lead and cognitive decline appeared progressively worse in participants with more copies of HFE variant alleles.

Takeaway

Older men with certain gene variations are more affected by lead exposure, which can hurt their thinking skills.

Methodology

The study measured lead levels in bones and assessed cognitive function using the Mini-Mental State Examination among older men.

Potential Biases

Potential misclassification of bone lead data and confounding factors not fully accounted for.

Limitations

The study's sample size for certain genotypes was small, and there may be selection bias due to attrition.

Participant Demographics

Participants were community-dwelling men aged 21-81, predominantly of northern European descent.

Statistical Information

P-Value

0.03

Confidence Interval

95% CI, –0.39 to –0.05

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1289/ehp.9855

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