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

AX6-87
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
Europe (cont’d)
Roels et al. (1994)
Belgium
Study date not
provided
76 Pb smelter workers (including 21 participants from
Cardenas et al. [1993] [Dr. Roels, email communication])
68 controls.
All males.
Matched for age, sex, socioeconomic status, residence, and
workshift characteristics.
Extensive exclusionary criteria included renal disease,
analgesic abuse, chronic medication for gout, diabetes,
occupational exposure to other nephrotoxicants, and prior
EDTA chelation.
Renal outcomes included serum creatinine and urea
nitrogen, measured creatinine clearance, NAG, RBP,
serum and urinary ∃2-microglobulin, as well as other renal
early biological effect markers.
Measured creatinine clearance
121.3 mL/min/1.73 m 2 (workers)
115.5 mL/min/1.73 m 2 (controls)
Multiple linear regression, adjusted for age, urinary
cadmium, hypertension, serum gamma-glutamyl
transpeptidase, smoking, exposure status (exposed vs.
control), and interaction between exposure variables and
hypertension.
Mean blood Pb
43.0 µg/dL (workers)
14.1 µg/dL (controls)
Mean tibia Pb
66 µg/g bone mineral
(workers)
21 µg/g bone mineral
(controls)
Urinary cadmium also
measured.
Creatinine clearance measured before and after an oral
protein load to determine if eicosanoid changes in
Cardenas et al. (1993) had clinical implications (Acute
protein ingestion causes increased renal perfusion and
transient hyperfiltration thought to be mediated by
changes in vasodilator prostanoids. Therefore, it was
hypothesized that, if the changes noted in Cardenas
et al. (1993) were clinically significant, the
hyperfiltration response would be diminished in the Pb
workers.).
All participants had normal baseline creatinine
clearances (>80 mL/min/1.73 m²). Both control and
Pb-exposed workers showed a similar increment in
creatinine clearance after protein load.
However, mean creatinine clearance was statistically
higher in Pb workers compared to controls. Log tibia
Pb was positively correlated with log measured
creatinine clearance in the combined group
(∃ = 0.0319, SE not provided).
This was unexpected as the change in eicosanoids
found in the initial study would not seem to result in
vasodilatation with increased GFR. Unfortunately, it
was not possible to measure eicosanoid levels in the
follow-up study. No other significant associations
between Pb measures and renal outcomes were
observed. Urinary cadmium associated with NAG.