Table 4. Toenail trace element concentrations (mg/kg dry nail mass), proportions by quartile, for renal case patients and controls.
| Control | Case | ALL | RR (95% CI) | No AKI | AKI | ALL | RR (95% CI) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N | 36 (66.7%) | 18 (33.3%) | 54 (100%) | p-value | N | 32 (66.7%) | 16 (33.3%) | 48 (100%) | p-value | ||||
| Ni | |||||||||||||
| >25th Percentile | 39 | 12 (57.1%) | 18 (100%) | 30 (76.9%) | 0.002* | 11.9 (5.1, 28.2) ± | 35 | 10 (52.6%) | 16 (100%) | 26 (74.3%) | 0.001* | 12.2 (5.2, 28.9)± | |
| >50th Percentile | 39 | 5 (23.8%) | 14 (77.8%) | 19 (48.7%) | 0.001* | 3.7 (1.5, 9.3) | 35 | 4 (21.1%) | 14 (87.5%) | 18 (51.4%) | <0.001* | 6.6 (1.5, 29.1) | |
| >75th Percentile | 39 | 1 (4.8%) | 8 (44.4%) | 9 (23.1%) | 0.006* | 2.7 (1.5, 4.7) | 35 | 1 (5.3%) | 8 (50%) | 9 (25.7%) | 0.005* | 2.9 (1.5, 5.4) | |
| Al | |||||||||||||
| >25th Percentile | 54 | 24 (66.7%) | 16 (88.9%) | 40 (74.1%) | 0.106 | 2.8 (0.7, 10.8) | 48 | 23 (71.9%) | 14 (87.5%) | 37 (77.1%) | 0.293 | 2.1 (0.6, 7.9) | |
| >50th Percentile | 54 | 14 (38.9%) | 13 (72.2%) | 27 (50%) | 0.042* | 2.6 (1.1, 6.3) | 48 | 12 (37.5%) | 12 (75%) | 24 (50%) | 0.030* | 3.0 (1.1, 8.1) | |
| >75th Percentile | 54 | 5 (13.9%) | 9 (50%) | 14 (25.9%) | 0.008* | 2.9 (1.4, 5.8) | 48 | 5 (15.6%) | 9 (56.3%) | 14 (29.2%) | 0.006* | 3.1 (1.4, 6.8) | |
| V | |||||||||||||
| >25th Percentile | 22 | 13 (72.2%) | 4 (100%) | 17 (77.3%) | 0.535 | 3.0 (1.3, 7.1)± | 17 | 11 (78.6%) | 3 (100%) | 14 (82.4%) | 1.000 | 1.9 (0.8, 4.5)± | |
| >50th Percentile | 22 | 8 (44.4%) | 3 (75%) | 11 (50%) | 0.586 | 3.0 (0.4, 25.8) | 17 | 6 (42.9%) | 3 (100%) | 9 (52.9%) | 0.206 | 6.3 (0.4, 15.4)± | |
| >75th Percentile | 22 | 3 (16.7%) | 3 (75%) | 6 (27.3%) | 0.046* | 3.0 (1.3, 7.2) | 17 | 2 (14.3%) | 3 (100%) | 5 (29.4%) | 0.015* | 15.2 (6.3, 36.8)± |
*Statistically significant at p<0.05.
±Because complete separation was observed, a correction (+ 0.5 to each cell frequency) was utilized to obtain RR estimate.