Joint association between tryptophan and phenylalanine levels with arsenic-induced skin lesions
| Tryptophan <cut-off value* | Phenylalanine <cut-off value* | N | Cases (%) | Crude | Adjusted† | ||
| Or (95% CI) | P value | Or (95% CI) | P value | ||||
| Yes | Yes | 35 | 26 (74.3) | 1.00 (1.00 to 1.00) | Ref. | 1.00 (1.00 to 1.00) | Ref. |
| No | Yes | 20 | 12 (60.0) | 0.52 (0.16 to 1.68) | 0.273 | 0.49 (0.15 to 1.63) | 0.244 |
| Yes | No | 24 | 12 (50.0) | 0.35 (0.12 to 1.04) | 0.059 | 0.32 (0.10 to 1.02) | 0.053 |
| No | No | 33 | 6 (18.2) | 0.08 (0.02 to 0.25) | <0.001 | 0.08 (0.02 to 0.25) | <0.001 |
| Interaction | 0.320 | 0.49 (0.09 to 2.78) | 0.419 | ||||
*Adjusted for plasma glucose, low-density lipoprotein, triglyceride and urinary dimethyl arsenate.
†Cut-off value was determined using receiver operator characteristic analysis.