Iron Metabolism Genes, Low-Level Lead Exposure, and QT Interval
2009

Iron Genes, Lead Exposure, and Heart Health

Sample size: 613 publication 10 minutes Evidence: moderate

Author Information

Author(s): Park Sung Kyun, Hu Howard, Wright Robert O., Schwartz Joel, Cheng Yawen, Sparrow David, Vokonas Pantel S., Weisskopf Marc G.

Primary Institution: Department of Environmental Health Sciences, University of Michigan School of Public Health

Hypothesis

Do genetic variations in iron metabolism genes increase susceptibility to the effects of low-level lead exposure on QT interval?

Conclusion

Gene variants related to iron metabolism increase the impacts of low-level lead exposure on the prolonged QT interval.

Supporting Evidence

  • A one-interquartile-range increase in tibia lead level was associated with a significant increase in QT interval.
  • Gene variants were found to modify the relationship between lead exposure and QT interval.
  • Subjects with both HFE variants and HMOX-1 L alleles showed a particularly large effect on QT interval.
  • Lead exposure has been linked to cardiovascular disease in previous studies.

Takeaway

This study found that certain genes related to iron can make heart problems worse when people are exposed to low levels of lead.

Methodology

The study used electrocardiograms and lead measurements to assess QT interval and lead exposure in older men.

Potential Biases

Potential for residual confounding factors affecting results.

Limitations

The study's sample was predominantly white men, which may limit generalizability, and the moderate sample size raises concerns about false positives.

Participant Demographics

Community-dwelling older men, predominantly white, aged around 67 years.

Statistical Information

P-Value

0.01

Confidence Interval

95% CI, 4.05–18.65 msec

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1289/ehp.11559

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