Table 3.
Serum levels of lipophilic POPs (μg/kg lipid) in cases and controls in the two recruitment periods
| Parameters | 2000–2003 | 2011–2014 | p-value a | p-value b | p-value c | ||||
|---|---|---|---|---|---|---|---|---|---|
| Median serum levels | Median serum levels | all | cases | controls | |||||
| All | Cases | Controls | All | Cases | Controls | ||||
| ∑PCB | 1995.18 | 2048.80 | 1985.94 | 798.50 | 1014.90 | 577.40 | <0.001 | 0.266 | <0.001 |
| ∑PCB Grp1 | 173.75 | 172.07 | 173.75 | 76.00 | 93.35 | 53.50 | <0.001 | 0.280 | <0.001 |
| ∑PCB Grp2 | 755.42 | 696.47 | 767.50 | 220.80 | 290.65 | 173.10 | <0.001 | 0.097 | <0.001 |
| ∑PCB Grp3 | 1062.77 | 1106.39 | 1062.68 | 515.00 | 628.50 | 354.00 | 0.002 | 0.400 | 0.001 |
| ∑DL-PCB | 173.86 | 149.32 | 182.90 | 60.00 | 70.05 | 49.90 | <0.001 | 0.044 | <0.001 |
| PCB99 | 78.65 | 70.28 | 81.36 | 31.00 | 38.50 | 23.00 | <0.001 | 0.019 | <0.001 |
| PCB101 | 7.27 | 5.44 | 9.16 | 3.00 | 3.00 | 3.00 | <0.001 | <0.001 | 0.012 |
| PCB105 | 19.17 | 16.59 | 22.29 | 5.60 | 7.95 | 5.00 | <0.001 | 0.013 | <0.001 |
| PCB118 | 99.76 | 99.61 | 99.76 | 34.00 | 48.50 | 32.00 | <0.001 | 0.019 | <0.001 |
| PCB138 | 378.43 | 357.47 | 385.24 | 110.00 | 165.00 | 79.00 | <0.001 | 0.041 | <0.001 |
| PCB153 | 585.14 | 636.81 | 583.66 | 270.00 | 355.00 | 200.00 | 0.002 | 0.399 | 0.001 |
| PCB156 | 50.00 | 46.13 | 56.63 | 15.00 | 22.50 | 14.00 | <0.001 | 0.256 | <0.001 |
| PCB170 | 120.00 | 113.62 | 128.75 | 51.00 | 65.50 | 36.00 | 0.005 | 0.676 | 0.001 |
| PCB180 | 353.61 | 349.44 | 353.61 | 170.00 | 195.00 | 120.00 | 0.007 | 0.591 | 0.002 |
| PCB183 | 36.94 | 39.83 | 36.72 | 13.00 | 18.50 | 12.00 | <0.001 | 0.061 | <0.001 |
| PCB187 | 162.05 | 166.19 | 161.95 | 73.00 | 88.00 | 51.00 | <0.001 | 0.061 | <0.001 |
| ∑OCP | 2303.45 | 2531.58 | 2127.71 | 1013.00 | 1539.50 | 847.00 | <0.001 | 0.062 | <0.001 |
| Cis-Nonachlor | 79.29 | 94.30 | 77.84 | 40.00 | 46.50 | 29.00 | <0.001 | 0.165 | 0.001 |
| Trans-Nonachlor | 405.42 | 509.67 | 343.07 | 200.00 | 270.00 | 150.00 | 0.011 | 0.606 | 0.004 |
| HCB | 257.01 | 265.04 | 257.01 | 110.00 | 130.00 | 85.00 | <0.001 | 0.008 | <0.001 |
| Mirex | 37.50 | 33.52 | 40.82 | 19.00 | 21.00 | 13.00 | 0.009 | 0.926 | 0.010 |
| Oxychlordane | 235.94 | 301.72 | 213.64 | 110.00 | 115.00 | 82.00 | 0.005 | 0.429 | 0.003 |
| p,p’DDE | 1129.46 | 1288.21 | 1039.19 | 550.00 | 680.00 | 420.00 | <0.001 | 0.018 | <0.001 |
| p,p’DDT | 29.51 | 31.54 | 25.00 | 9.50 | 10.00 | 8.00 | <0.001 | <0.001 | <0.001 |
| βHCH | 40.63 | 42.26 | 38.96 | 15.00 | 17.50 | 12.00 | <0.001 | 0.004 | <0.001 |
The differences between the two recruitment periods were tested with independent samples t-test. aThe p-value form independent samples t-test on ln-transformed variables between all the participants; bThe p-value from independent samples t-test on ln-transformed variables between the cases; cThe p-value from independent samples t-test on ln-transformed variables between the controls; Bold text: significant finding; ∑PCB: PCB 99, 101, 105, 118, 128, 138, 153, 156, 170, 180, 183, 187; ∑PCB group 1 (estrogenic PCBs): PCB 101, 187; ∑PCB group 2 (anti-estrogenic and dioxin-like PCBs): PCB 105, 118, 128, 138, 156, 170; ∑PCB group 3 (CYP1A1 and CYP2B inducing PCBs): PCB 99, 153, 180, 183; ∑DL-PCBs (dioxin-like PCBs): PCB 105, 118, 156; ∑OCP: p,p′-DDT, p,p′-DDE, mirex, β-HCH, HCB, cis- and trans-nonachlor, and oxychlordane. The serum concentration of the lipophilic POPs was measured in μg/kg lipid