TABLE 5.
Unconditional Logistic Regression Models on the Association between Blood Metal Concentrations and the Risk of Amyotrophic Lateral Sclerosis, Limited to Noncurrent Smokers and Never‐Smokers a
| Exposure Category, ng/g | Noncurrent Smokers | Never‐Smokers | |||||
|---|---|---|---|---|---|---|---|
| Controls, n | Cases, n | OR b (95% CI) | Controls, n | Cases, n | OR b (95% CI) | ||
| Cadmium | ≤0.51 | 102 | 19 | 1.00 [Ref] | 59 | 14 | 1.00 [Ref] |
| >0.51 ≤ 0.91 | 97 | 38 | 2.16 (1.14–4.09) | 62 | 26 | 1.82 (0.83–4.03) | |
| >0.91 | 69 | 31 | 2.62 (1.32–5.22) | 43 | 13 | 1.38 (0.54–3.54) | |
| p for trend, linear | 0.023 | 0.503 | |||||
| Lead | ≤56.8 | 91 | 22 | 1.00 [Ref] | 56 | 14 | 1.00 [Ref] |
| >56.8 ≤ 89.0 | 92 | 38 | 1.86 (0.99–3.48) | 61 | 24 | 1.83 (0.79–4.24) | |
| >89.0 | 85 | 28 | 1.62 (0.81–3.26) | 47 | 15 | 1.55 (0.60–4.01) | |
| p for trend, linear | 0.178 | 0.637 | |||||
| Zinc | ≤8,425 | 88 | 37 | 1.00 [Ref] | 57 | 21 | 1.00 [Ref] |
| >8,425 ≤ 9,566 | 93 | 25 | 0.60 (0.32–1.12) | 49 | 15 | 0.82 (0.36–1.87) | |
| >9,566 | 95 | 28 | 0.68 (0.36–1.29) | 58 | 17 | 0.84 (0.36–1.94) | |
| p for trend, linear | 0.254 | 0.460 | |||||
a
Smoking status was missing for 2 cases and 8 controls, who were excluded from these analyses.
b
Odds ratio adjusted for matching variables sex, age at recruitment and center.
CI = confidence interval; OR = odds ratio; Ref = reference.