TABLE 4.
Conditional Logistic Regression Models on the Association between Blood Metal Concentrations and the Risk of Amyotrophic Lateral Sclerosis
| Metal | Exposure Category, ng/g | Controls, n | Cases, n | Total Group, OR (95% CI) | Excluding Cases Who Died within 3 Years, n = 13, OR (95% CI) |
|---|---|---|---|---|---|
| Arsenic | ≤1.67 | 105 | 39 | 1.00 [Ref] | 1.00 [Ref] |
| >1.67 ≤ 4.37 | 105 | 29 | 0.71 (0.38–1.32) | 0.68 (0.35–1.33) | |
| >4.37 | 109 | 39 | 0.90 (0.47–1.72) | 0.78 (0.39–1.56) | |
| p for trend, linear | 0.517 | 0.296 | |||
| p for trend, spline | 0.198 | 0.110 | |||
| Cadmium | ≤0.51 | 105 | 22 | 1.00 [Ref] | 1.00 [Ref] |
| >0.51 ≤ 0.91 | 105 | 44 | 2.16 (1.18–3.97) | 2.35 (1.21–4.56) | |
| >0.91 | 109 | 41 | 2.04 (1.08–3.87) | 1.94 (0.96–3.92) | |
| p for trend, linear | 0.122 | 0.261 | |||
| p for trend, spline | 0.498 | 0.739 | |||
| Copper | ≤553 | 106 | 38 | 1.00 [Ref] | 1.00 [Ref] |
| >553 ≤ 610 | 104 | 28 | 0.77 (0.44–1.37) | 0.70 (0.38–1.28) | |
| >610 | 109 | 41 | 1.07 (0.59–1.96) | 1.07 (0.57–2.00) | |
| p for trend, linear | 0.360 | 0.310 | |||
| p for trend, spline | 0.738 | 0.693 | |||
| Lead | ≤56.8 | 105 | 25 | 1.00 [Ref] | 1.00 [Ref] |
| >56.8 ≤ 89.0 | 105 | 41 | 1.83 (0.99–3.35) | 1.92 (0.99–3.73) | |
| >89.0 | 109 | 41 | 1.89 (0.97–3.67) | 1.82 (0.88–3.73) | |
| p for trend, linear | 0.153 | 0.176 | |||
| p for trend, spline | 0.297 | 0.380 | |||
| Manganese | ≤12.5 | 106 | 42 | 1.00 [Ref] | 1.00 [Ref] |
| >12.5 ≤ 15.8 | 104 | 35 | 0.87 (0.52–1.46) | 0.93 (0.54–1.63) | |
| >15.8 | 109 | 30 | 0.69 (0.40–1.19) | 0.59 (0.33–1.07) | |
| p for trend, linear | 0.780 | 0.489 | |||
| p for trend, spline | 0.092 | 0.070 | |||
| Mercury | ≤1.84 | 106 | 36 | 1.00 [Ref] | 1.00 [Ref] |
| >1.84 ≤ 4.82 | 104 | 33 | 0.94 (0.54–1.64) | 0.86 (0.47–1.57) | |
| >4.82 | 109 | 38 | 1.06 (0.53–2.11) | 1.10 (0.53–2.28) | |
| p for trend, linear | 0.879 | 0.861 | |||
| p for trend, spline | 0.344 | 0.510 | |||
| Selenium | ≤104 | 109 | 32 | 1.00 [Ref] | 1.00 [Ref] |
| >104 ≤ 123 | 102 | 38 | 1.31 (0.74–2.31) | 1.39 (0.76–2.55) | |
| >123 | 108 | 37 | 1.21 (0.65–2.25) | 1.31 (0.67–2.56) | |
| p for trend, linear | 0.374 | 0.487 | |||
| p for trend, spline | 0.850 | 0.960 | |||
| Zinc | ≤8,425 | 106 | 48 | 1.00 [Ref] | 1.00 [Ref] |
| >8,425 ≤ 9,566 | 105 | 29 | 0.54 (0.30–0.97) | 0.50 (0.27–0.94) | |
| >9,566 | 108 | 30 | 0.50 (0.27–0.94) | 0.50 (0.25–0.98) | |
| p for trend, linear | 0.100 | 0.206 | |||
| p for trend, spline | 0.760 | 0.792 |
CI = confidence interval; OR = odds ratio; Ref = reference.