Table 3

Linear regression modelling of renal outcomes with lead dose biomarkers, lead job duration, and haematopoietic effect biomarkers in all current lead workers with outliers removed*

Lead variable	β coefficient	SE β	p value	Model r²
*The renal outcomes were each modelled separately with one of the seven lead measures included at a time (resulting in a total of 42 models). Regression results from each model are presented only for the association of the lead measure with the renal outcome. Only models in which the lead variable was at least borderline significant (p<0.1) are displayed. BUN, serum creatinine, four hour creatinine clearance, and calculated creatinine clearance models were adjusted for age, gender, BMI, and hypertension. NAG and RBP models were adjusted for age, gender, BMI, systolic blood pressure, current alcohol ingestion, and diabetes.
BUN (mg/dl) models
Haemoglobin, g/dl	−0.2314	0.1244	0.06	0.08
Serum creatinine (mg/dl) models
Tibia lead, μg Pb/g bone mineral	−0.0002	0.0001	0.05	0.28
DMSA chelatable lead, μg Pb/g creatinine	−0.0000	0.0000	<0.01	0.28
ZPP, μg/dl	0.0002	0.0001	0.02	0.28
Haemoglobin, g/dl	0.0089	0.0038	0.02	0.28
Measured creatinine clearance (ml/min) models
Tibia lead, μg Pb/g bone mineral	0.0530	0.0303	0.08	0.21
Lead job duration, years	0.3989	0.1967	0.04	0.21
ZPP, μg/dl	−0.0310	0.0182	0.09	0.20
Calculated creatinine clearance (ml/min) models
Tibia lead, μg Pb/g bone mineral	0.0243	0.0139	0.08	0.60
Lead job duration, years	0.2238	0.0903	0.01	0.60
ZPP, μg/dl	−0.0168	0.0084	0.05	0.60
ln NAG (ln [μmol/h/g creatinine]) models
Tibia lead, μg Pb/g bone mineral	0.0013	0.0006	0.04	0.18
Blood lead, μg/dl	0.0050	0.0017	<0.01	0.19
DMSA chelatable lead, μg Pb/g creatinine	0.0002	0.0000	<0.01	0.20
ALAP, ng/ml	0.0033	0.0016	0.03	0.18
ZPP, μg/dl	0.0009	0.0004	0.02	0.18
ln RBP (ln [μg/g creatinine]) models
DMSA chelatable lead, μg Pb/g creatinine	0.0001	0.0000	<0.01	0.16
ALAP, ng/ml	0.0049	0.0019	0.01	0.17