HFE H63D polymorphism as a modifier of the effect of cumulative lead exposure on pulse pressure: the Normative Aging Study.
BACKGROUND
Cumulative lead exposure is associated with a widened pulse pressure (PP; the -difference between systolic and diastolic blood pressure), a marker of arterial stiffness and a predictor of cardiovascular disease. Polymorphisms in the hemochromatosis gene (HFE) have been shown to modify the impact of cumulative lead exposure on measures of adult cognition and cardiac function.


OBJECTIVE
We examined whether the HFE mutations modify the impact of lead on PP in -community-dwelling older men.


METHODS
We examined 619 participants with a total of 1,148 observations of PP from a substudy of bone lead levels (a measure of cumulative exposure, measured by in vivo K-shell X-ray fluorescence) and health in the Normative Aging Study between 1991 and 2001. Linear mixed-effects regression models with random intercepts were constructed.


RESULTS
Of the 619 subjects, 138 and 72 carried the HFE H63D and C282Y variants, respectively. After adjusting for age; education; alcohol intake; smoking; daily intakes of calcium, sodium, and potassium; total calories; family history of hypertension; diabetes; height; heart rate; high-density lipoprotein (HDL); total cholesterol:HDL ratio; and waist circumference, baseline bone lead levels were associated with steeper increases in PP in men with at least one H63D allele (p-interaction = 0.03 for tibia and 0.02 for patella) compared with men with only the wild types or C282Y variant.


CONCLUSIONS
The HFE H63D polymorphism, but not the C282Y mutation, appears to enhance susceptibility to the deleterious impact of cumulative lead on PP, possibly via prooxidative or pro-inflammatory mechanisms.
Zhang
Aimin
A
Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA. aiminz@umich.edu
Park
Sung Kyun
SK
Wright
Robert O
RO
Weisskopf
Marc G
MG
Mukherjee
Bhramar
B
Nie
Huiling
H
Sparrow
David
D
Hu
Howard
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005838:Genotype; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D007854:Lead / Q000633:toxicity*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D010329:Patella / Q000737:chemistry; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D013977:Tibia / Q000737:chemistry; D055815:Young Adult
C103673:HFE protein, human; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D007854:Lead