Air Quality Criteria for Lead Volume II of II - (NEPIS)(EPA) - US ...

AX6-100
Table AX6-4.2 (cont’d). Renal Effects of Lead in the Occupational Population
Reference, Study
Location, and
Period Study Description Pb Measurement Findings, Interpretation
Asia (cont’d)
Weaver et al. (2005b)
South Korea
1999-2001
652 Pb workers including 149 females and 200 former
workers.
Patella Pb measured in the third evaluation of the same
study reported in Weaver et al. (2003a). Data collection
performed a mean of 2.2 yrs after collection of the data
presented in Weaver et al. (2003a).
Same renal outcomes as Weaver et al. (2003a).
Serum creatinine
0.87 mg/dL
Calculated creatinine clearance
97.0 mL/min
Multiple linear regression, adjusting for age, gender, BMI,
work status (current vs. former worker), HTN or blood
pressure (depending on model), diabetes, smoking status,
and, for the clinical measures, use of analgesics
Interaction models assessed effect modification by age,
dichotomized at the 67th percentile.
Mean blood Pb
30.9 µg/dL
Mean tibia Pb
33.6 µg/g bone mineral
Mean patella Pb
75.1 µg/g bone mineral
Mean DMSA-chelatable Pb
0.63 μg Pb/mg creatinine
All 4 Pb measures were correlated (Spearman’s r = 0.51 –
0.76).
Patella, blood and DMSA-chelatable Pb levels positively
associated with NAG.
Higher DMSA-chelatable Pb associated with lower serum
creatinine and higher calculated creatinine clearance.
Interaction models
All four Pb measures associated with higher NAG among
participants in oldest age tertile.
Higher blood, tibia, and patella Pb associated with higher
serum creatinine among older participants.
-Beta coefficients less in the Pb workers whose ages were in
the younger two-thirds of the age range; difference between
slopes in the two age groups was statistically significant only
for association of blood Pb and serum creatinine.
Inverse DMSA associations (higher DMSA-chelatable Pb
associated with lower serum creatinine and higher calculated
creatinine clearance) significant in younger workers.
Patella Pb associations were consistent with those of blood and
tibia Pb; DMSA-chelatable Pb associations unique.
Authors hypothesized that similarities between patella, blood,
and tibia Pb associations could be due, in part, to high
correlations among the Pb biomarkers in this population.
Despite similar high correlations, DMSA-chelatable Pb
associations with serum creatinine and calculated creatinine
clearance were unique. This biomarker is dependent on renal
function and the collection time was only 4 h. Therefore, the
amount of Pb that is excreted in this relatively short time period
after chelation may be influenced not only by bioavailable Pb
burden, but also by high-normal as well as actual supranormal
glomerular filtration which are more common in the younger
workers.