Linear regression modelling of renal outcomes with lead dose biomarkers, lead job duration, and haematopoietic effect biomarkers in all 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. BUN, serum creatinine, four hour creatinine clearance, and calculated creatinine clearance models were adjusted for age, gender, BMI, work status (current v former worker), and hypertension. NAG and RBP models were adjusted for age, gender, BMI, systolic blood pressure, work status (current v former worker), current alcohol ingestion, and diabetes. | ||||
| BUN (mg/dl) models | ||||
| Tibia lead, μg Pb/g bone mineral | −0.0010 | 0.0035 | 0.78 | 0.08 |
| Blood lead, μg/dl | 0.0017 | 0.0099 | 0.86 | 0.08 |
| DMSA chelatable lead, μg Pb/g creatinine | −0.0001 | 0.0002 | 0.50 | 0.09 |
| Lead job duration, years | 0.0014 | 0.0232 | 0.95 | 0.08 |
| ALAP, ng/ml | 0.0167 | 0.0091 | 0.07 | 0.09 |
| ZPP, μg/dl | 0.0039 | 0.0022 | 0.07 | 0.09 |
| Haemoglobin, g/dl | −0.2357 | 0.1119 | 0.04 | 0.09 |
| Serum creatinine (mg/dl) models | ||||
| Tibia lead, μg Pb/g bone mineral | −0.0002 | 0.0001 | 0.17 | 0.36 |
| Blood lead, μg/dl | 0.0001 | 0.0003 | 0.85 | 0.36 |
| DMSA chelatable lead, μg Pb/g creatinine | −0.0000 | 0.0000 | <0.01 | 0.36 |
| Lead job duration, years | −0.0006 | 0.0007 | 0.41 | 0.36 |
| ALAP, ng/ml | 0.0001 | 0.0003 | 0.81 | 0.36 |
| ZPP, μg/dl | 0.0001 | 0.0001 | 0.05 | 0.36 |
| Haemoglobin, g/dl | 0.0095 | 0.0035 | <0.01 | 0.36 |
| Measured creatinine clearance (ml/min) models | ||||
| Tibia lead, μg Pb/g bone mineral | 0.0608 | 0.0276 | 0.03 | 0.26 |
| Blood lead, μg/dl | 0.1079 | 0.0792 | 0.17 | 0.25 |
| DMSA chelatable lead, μg Pb/g creatinine | −0.0004 | 0.0015 | 0.78 | 0.25 |
| Lead job duration, years | 0.2499 | 0.1811 | 0.17 | 0.25 |
| ALAP, ng/ml | −0.1342 | 0.0753 | 0.08 | 0.25 |
| ZPP, μg/dl | −0.0262 | 0.0169 | 0.12 | 0.25 |
| Haemoglobin, g/dl | 0.7858 | 0.8769 | 0.37 | 0.25 |
| Calculated creatinine clearance (ml/min) models | ||||
| Tibia lead, μg Pb/g bone mineral | 0.0140 | 0.0133 | 0.29 | 0.60 |
| Blood lead, μg/dl | −0.0200 | 0.0367 | 0.59 | 0.60 |
| DMSA chelatable lead, μg Pb/g creatinine | 0.0010 | 0.0007 | 0.14 | 0.60 |
| Lead job duration, years | 0.1980 | 0.0858 | 0.02 | 0.60 |
| ALAP, ng/ml | −0.0259 | 0.0345 | 0.45 | 0.60 |
| ZPP, μg/dl | −0.0125 | 0.0081 | 0.12 | 0.60 |
| Haemoglobin, g/dl | −0.9257 | 0.4222 | 0.03 | 0.61 |
| ln NAG (ln [μmol/h/g creatinine]) models | ||||
| Tibia lead, μg Pb/g bone mineral | 0.0016 | 0.0006 | <0.01 | 0.20 |
| Blood lead, μg/dl | 0.0064 | 0.0016 | <0.01 | 0.21 |
| DMSA chelatable lead, μg Pb/g creatinine | 0.0002 | 0.0000 | <0.01 | 0.22 |
| Lead job duration, years | 0.0056 | 0.0038 | 0.14 | 0.19 |
| ALAP, ng/ml | 0.0042 | 0.0015 | <0.01 | 0.20 |
| ZPP, μg/dl | 0.0010 | 0.0004 | <0.01 | 0.20 |
| Haemoglobin, g/dl | 0.0026 | 0.0188 | 0.89 | 0.19 |
| ln RBP (ln [μg/g creatinine]) models | ||||
| Tibia lead, μg Pb/g bone mineral | 0.0005 | 0.0007 | 0.47 | 0.17 |
| Blood lead, μg/dl | 0.0024 | 0.0020 | 0.23 | 0.17 |
| DMSA chelatable lead, μg Pb/g creatinine | 0.0001 | 0.0000 | <0.01 | 0.17 |
| Lead job duration, years | 0.0056 | 0.0046 | 0.23 | 0.17 |
| ALAP, ng/ml | 0.0056 | 0.0019 | <0.01 | 0.18 |
| ZPP, μg/dl | 0.0004 | 0.0004 | 0.36 | 0.17 |
| Haemoglobin, g/dl | −0.0324 | 0.0229 | 0.16 | 0.17 |