Table 5.
Lead content as related to bone apparent structure measurements. Bone lead at the mid-tibia, bone lead at the calcaneus and the blood:bone lead partition coefficients (PBB) were each related to trabecular separation (Tb.Sp), trabecular thickness (Tb.Th), bone volume fraction (BV/TV), trabecular number (Tb.N), cortical thickness (Ct.Th) and mechanical properties as represented by the polar stress–strain index (SSIp). All base (left) and covariate adjusted models were reported with regression coefficients and 95% confidence intervals. Coefficients were expressed per 1 μg lead/g of bone mineral difference unless otherwise indicated.
| Variable | N | R2 | Unstandardized B (95% CI) |
B (95% CI) Age & BMI-adjusted |
B (95% CI) Age & diabetes-adjusted |
B (95% CI) Age & antiresorptives adjusted |
|---|---|---|---|---|---|---|
| Bone Pb at calcaneus | ||||||
| Tb.Sp/100 μg Pb | 34 | 0.100 | −0.508 (−1.057, 0.041) | −0.716 (−1.226, −0.206) | −0.517 (−1.062, 0.028)b | −0.473 (−1.049, 0.104) |
| Tb.Th/100 μg Pb | 34 | 0.050 | 0.090 (−0.052, 0.231) | 0.122 (−0.022, 0.267)b | 0.080 (−0.061, 0.221) | 0.058 (−0.093, 0.209) |
| Ct.Th/100 μg Pb | 34 | 0.000 | 0.010 (−0.696, 0.715) | 0.214 (−0.371, 0.799) | −0.020 (−0.687, 0.646) | −0.028 (−0.667, 0.611) |
| SSIp | 34 | 0.026 | 591 (−726, 1907) | 498 (−910, 1905) | 666 (−670, 2003) | 951 (−434, 2335) |
| BV/TV/100 μg Pb | 34 | 0.072 | 0.211 (−0.061, 0.482) | 0.296 (0.028, 0.563) | 0.204 (−0.069, 0.478) | 0.167 (−0.122, 0.456) |
| Tb.N/100 μg Pb | 34 | 0.066 | 0.37 (−0.13, 0.88) | 0.54 (0.06, 1.02) | 0.39 (−0.11, 0.89) | 0.36 (−0.17, 0.89) |
| Bone Pb at tibia | ||||||
| Tb.Sp/100 μg Pb | 36 | 0.058 | 0.645 (−0.260, 1.550) | 0.391 (−0.572, 1.355) | 0.526 (−0.441, 1.493) | 0.734 (−0.234, 1.702) |
| Tb.Th/100 μg Pb | 36 | 0.003 | −0.035 (−0.268, 0.198) | −0.040 (−0.293, 0.214) | −0.070 (−0.313, 0.173) | −0.121 (−0.371, 0.129) |
| Ct.Th/100 μg Pb | 36 | 0.186 | −1.192 (−2.060, −0.323) | −0.972 (−1.882, −0.061) | −1.364 (−2.379, −0.348) | −1.316 (−2.262, −0.370) |
| SSIp | 36 | 0.021 | 881 (−1228, 2990) | 987 (−1336, 3311) | 1153 (−1103, 3408) | 1582 (−711, 3875) |
| BV/TV/100 μg Pb | 36 | 0.020 | −0.184 (−0.635, 0.267) | −0.114 (−0.604, 0.376) | −0.176 (−0.658, 0.306) | −0.288 (−0.771, 0.195) |
| Tb.N/100 μg Pb | 36 | 0.040 | −0.49 (−1.32, 0.34) | −0.23 (−1.11, 0.65) | −0.33 (−1.22, 0.56) | −0.49 (−1.38, 0.41) |
| Blood:bone (calcaneus) lead partition coefficient (PBB) | ||||||
| Tb.Sp | 32 | 0.240 | 0.107 (0.036, 0.179) | 0.115 (0.053, 0.178) | 0.104 (0.033, 0.176) | 0.104 (0.028, 0.179) |
| Tb.Th | 32 | 0.126 | −0.019 (−0.039, 0.000) | −0.021 (−0.040, −0.002) | −0.018 (−0.037, 0.002)b | −0.016 (−0.037, 0.005) |
| Ct.Th | 32 | 0.032 | −0.041 (−0.125, 0.042) | −0.050 (−0.125, 0.026) | −0.029 (−0.109, 0.050) | −0.036 (−0.126, 0.054) |
| SSIp | 32 | 0.012 | 5522 (−13,102, 24,147) | 5921 (−13,405, 25,248) | 4255 (−14,966, 23,477) | 1684 (−18,363, 21,731) |
| BV/TV | 32 | 0.166 | −0.042 (−0.079, −0.007) | −0.046 (−0.080, −0.013) | −0.040 (−0.077, −0.004) | −0.038 (−0.076, 0.001)b |
| Tb.N | 32 | 0.139 | −0.07 (−0.14, −0.01) | −0.08 (−0.14, −0.02) | −0.07 (−0.14, 0.00) | −0.07 (−0.14, 0.00y) |
Bold indicates relationships that were significant at the α = 0.05 level.
indicates relationships that were significant at the α = 0.10 level.