rss
Occup Environ Med 60:551-562 doi:10.1136/oem.60.8.551
  • Original article

Associations of lead biomarkers with renal function in Korean lead workers

Table 4

Linear regression modelling of renal outcomes with cross product terms for lead dose biomarkers/lead job duration and age in tertiles in all lead workers with outliers removed†

Variable β coefficient SE β p value
†BUN, serum creatinine, measured creatinine clearance, and calculated creatinine clearance models were also adjusted for age, gender, BMI, current/former exposure status, and hypertension. NAG and RBP models were adjusted for age, gender, BMI, systolic blood pressure, current/former exposure status, current alcohol ingestion, and diabetes. The youngest age tertile is the reference. p values for the cross product terms of the middle or oldest age categories with the lead measures reflect the statistical significance of the difference between the slopes of the regression line in that age category and the regression line for the youngest age group. Slopes in the non-reference categories are obtained by adding the beta coefficient of the cross product term to the beta coefficient for the reference category.
BUN (mg/dl) models
    Intercept 14.3380 0.1503 <0.01
    Age, years 0.0882 0.0140 <0.01
    Tibia lead, μg Pb/g bone mineral −0.0103 0.0085 0.23
    Tibia lead*agecat2 −0.0021 0.0107 0.85
    Tibia lead*agecat3 0.0165 0.0096 0.09
    Intercept 14.3530 0.1509 <0.01
    Age, years 0.0783 0.0145 <0.01
    Blood lead, μg/dl −0.0218 0.0157 0.17
    Blood lead*agecat2 0.0091 0.0223 0.68
    Blood lead*agecat3 0.0615 0.0214 <0.01
    Intercept 14.4267 0.1547 <0.01
    Age, years 0.0890 0.0149 <0.01
    DMSA chelatable lead, μg Pb/g creatinine −0.0002 0.0004 0.60
    DMSA chelatable lead*agecat2 −0.0003 0.0005 0.58
    DMSA chelatable lead*agecat3 0.0006 0.0005 0.28
    Intercept 14.1352 0.2082 <0.01
    Age, years 0.1078 0.0194 <0.01
    Lead job duration, years −0.1199 0.0645 0.06
    Lead job duration*agecat2 0.1170 0.0776 0.13
    Lead job duration*agecat3 0.1484 0.0683 0.03
Serum creatinine (mg/dl) models
    Intercept 0.9328 0.0046 <0.01
    Age, years 0.0005 0.0004 0.22
    Tibia lead, μg Pb/g bone mineral −0.0005 0.0003 0.06
    Tibia lead*agecat2 −0.0003 0.0003 0.37
    Tibia lead*agecat3 0.0008 0.0003 <0.01
    Intercept 0.9340 0.0046 <0.01
    Age, years 0.0003 0.0004 0.51
    Blood lead, μg/dl −0.0002 0.0005 0.62
    Blood lead*agecat2 −0.0004 0.0007 0.56
    Blood lead*agecat3 0.0013 0.0007 0.06
    Intercept 0.9351 0.0047 <0.01
    Age, years 0.0008 0.0005 0.09
    DMSA chelatable lead, μg Pb/g creatinine −0.0000 0.0000 0.15
    DMSA chelatable lead*agecat2 −0.0000 0.0000 0.34
    DMSA chelatable lead*agecat3 0.0000 0.0000 0.31
    Intercept 0.9295 0.0063 <0.01
    Age, years 0.0011 0.0006 0.06
    Lead job duration, years −0.0029 0.0020 0.15
    Lead job duration*agecat2 0.0022 0.0024 0.36
    Lead job duration*agecat3 0.0028 0.0021 0.18
Measured creatinine clearance (ml/min) models
    Intercept 122.8823 1.1689 <0.01
    Age, years −0.7016 0.1103 <0.01
    Tibia lead, μg Pb/g bone mineral 0.1057 0.0661 0.11
    Tibia lead*agecat2 0.0649 0.0837 0.44
    Tibia lead*agecat3 −0.1334 0.0753 0.08
    Intercept 122.1588 1.1940 <0.01
    Age, years −0.7388 0.1156 <0.01
    Blood lead, μg/dl 0.0917 0.1242 0.46
    Blood lead*agecat2 0.0539 0.1799 0.77
    Blood lead*agecat3 0.0034 0.1710 0.98
    Intercept 122.7379 1.2142 <0.01
    Age, years −0.6909 0.1170 <0.01
    DMSA chelatable lead, μg Pb/g creatinine 0.0022 0.0035 0.54
    DMSA chelatable lead*agecat2 −0.0038 0.0043 0.39
    DMSA chelatable lead*agecat3 −0.0021 0.0041 0.62
    Intercept 122.6602 1.6132 <0.01
    Age, years −0.7604 0.1531 <0.01
    Lead job duration, years 0.3278 0.5060 0.52
    Lead job duration*agecat2 0.5192 0.6061 0.39
    Lead job duration*agecat3 −0.4382 0.5352 0.41
Calculated creatinine clearance (ml/min) models
    Intercept 101.5733 0.5636 <0.01
    Age, years −1.2002 0.0525 <0.01
    Tibia lead, μg Pb/g bone mineral 0.0214 0.0320 0.50
    Tibia lead*agecat2 0.0519 0.0410 0.21
    Tibia lead*agecat3 −0.0481 0.0362 0.18
    Intercept 101.4901 0.5616 <0.01
    Age, years −1.1891 0.0539 <0.01
    Blood lead, μg/dl −0.0265 0.0584 0.65
    Blood lead*agecat2 0.0526 0.0830 0.53
    Blood lead*agecat3 −0.0271 0.0800 0.74
    Intercept 101.5341 0.5756 <0.01
    Age, years −1.2315 0.0556 <0.01
    DMSA chelatable lead, μg Pb/g creatinine 0.0017 0.0017 0.30
    DMSA chelatable lead*agecat2 0.0006 0.0020 0.76
    DMSA chelatable lead*agecat3 −0.0014 0.0019 0.46
    Intercept 101.8421 0.7663 <0.01
    Age, years −1.2920 0.0714 <0.01
    Lead job duration, years 0.2908 0.2392 0.22
    Lead job duration*agecat2 −0.0047 0.2881 0.99
    Lead job duration*agecat3 −0.1621 0.2532 0.52
ln NAG (ln [μmol/h/g creatinine]) models
    Intercept 5.0814 0.0438 <0.01
    Age, years 0.0166 0.0025 <0.01
    Tibia lead, μg Pb/g bone mineral 0.0004 0.0014 0.75
    Tibia lead*agecat2 0.0024 0.0017 0.16
    Tibia lead*agecat3 0.0017 0.0016 0.28
    Intercept 5.0769 0.0436 <0.01
    Age, years 0.0154 0.0026 <0.01
    Blood lead, μg/dl 0.0016 0.0025 0.52
    Blood lead*agecat2 0.0063 0.0036 0.08
    Blood lead*agecat3 0.0089 0.0035 0.01
    Intercept 5.0857 0.0443 <0.01
    Age, years 0.0155 0.0026 <0.01
    DMSA chelatable lead, μg Pb/g creatinine 0.0000 0.0001 0.58
    DMSA chelatable lead*agecat2 0.0002 0.0001 0.03
    DMSA chelatable lead*agecat3 0.0002 0.0001 0.08
    Intercept 5.0778 0.0505 <0.01
    Age, years 0.0183 0.0033 <0.01
    Lead job duration, years −0.0040 0.0106 0.71
    Lead job duration*agecat2 −0.0002 0.0126 0.99
    Lead job duration*agecat3 0.0169 0.0112 0.13
ln RBP (ln [μg/g creatinine]) models
    Intercept 3.4745 0.0546 <0.01
    Age, years 0.0185 0.0031 <0.01
    Tibia lead, μg Pb/g bone mineral 0.0027 0.0017 0.12
    Tibia lead*agecat2 −0.0015 0.0022 0.49
    Tibia lead*agecat3 −0.0028 0.0020 0.15
    Intercept 3.4527 0.0545 <0.01
    Age, years 0.0189 0.0032 <0.01
    Blood lead, μg/dl 0.0044 0.0032 0.17
    Blood lead*agecat2 −0.0035 0.0045 0.44
    Blood lead*agecat3 −0.0030 0.0043 0.49
    Intercept 3.4622 0.0548 <0.01
    Age, years 0.0176 0.0033 <0.01
    DMSA chelatable lead, μg Pb/g creatinine 0.0002 0.0001 0.03
    DMSA chelatable lead*agecat2 −0.0000 0.0001 0.80
    DMSA chelatable lead*agecat3 −0.0002 0.0001 0.14
    Intercept 3.4920 0.0626 <0.01
    Age, years 0.0164 0.0041 <0.01
    Lead job duration, years 0.0134 0.0131 0.31
    Lead job duration*agecat2 −0.0095 0.0157 0.55
    Lead job duration*agecat3 −0.0084 0.0138 0.55

This Article

  1. Abstract
  2. Full text
  3. PDF
Free sample

This recent issue is free to all users to allow everyone the opportunity to see the full scope and typical content of OEM.
View free sample issue >>

Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.