Table 4.
Receiver operating characteristic (ROC) analysis of salivary redox biomarkers of patients with Alzheimer’s disease and the control group.
| Biomarker | Saliva | |||||||
|---|---|---|---|---|---|---|---|---|
| AUC | 95%Cl | P-value | Cut off | Sensitivity% | 95%Cl | Specificity% | 95%Cl | |
| Antioxidant barrier | ||||||||
| SOD (mU/mg protein) | 0.7774 | 0.6292 to 0.9256 | 0.001 | < 1.028 | 69.57 | 49.13 to 84.40% | 68.00 | 48.41 to 82.79% |
| CAT (nmol H2O2/min/mg protein) | 0.9183 | 0.8267 to 1.000 | < 0.0001 | < 0.4197 | 82.61 | 62.86 to 93.02% | 84.00 | 65.35 to 93.60% |
| GPx (mU/mg protein) | 0.7409 | 0.5841 to 0.8976 | 0.0043 | < 0.07697 | 73.91 | 53.53 to 87.45% | 72.00 | 52.42 to 85.72% |
| UA (μg/mg protein) | 0.5739 | 0.3950 to 0.7528 | 0.3804 | < 66.40 | 52.17 | 32.96 to 70.76% | 52.00 | 33.50 to 69.97% |
| GSH (ng/mg protein) | 0.6836 | 0.5258 to 0.8415 | 0.0313 | < 2.276 | 72.73 | 51.85 to 86.85% | 72.00 | 52.42 to 85.72% |
| Redox status | ||||||||
| TAC (μmol/mg protein) | 0.5183 | 0.3442 to 0.6923 | 0.8284 | > 5.999 | 52.17 | 32.96 to 70.76% | 52.00 | 33.50 to 69.97% |
| TOS (nmol/mg protein) | 0.92 | 0.8137 to 1.000 | < 0.0001 | > 367.6 | 91.30 | 73.20 to 98.45% | 92.00 | 75.03 to 98.58% |
| OSI (TOS/TAC ratio) | 0.936 | 0.8473 to 1.000 | < 0.0001 | > 59.10 | 90.00 | 69.90 to 98.22% | 92.00 | 75.03 to 98.58% |
| Oxidative and nitrosative stress | ||||||||
| AGE (AFU/mg protein) | 0.9357 | 0.8505 to 1.000 | < 0.0001 | > 0.9610 | 86.96 | 67.87 to 95.46% | 88.00 | 70.04 to 95.83% |
| AOPP (nmol/mg protein) | 0.68 | 0.5307 to 0.8293 | 0.029 | > 20.19 | 56.00 | 37.07 to 73.33% | 56.00 | 37.07 to 73.33% |
| MDA(μg/mg protein) | 0.6876 | 0.5075 to 0.8677 | 0.0298 | > 243.7 | 66.67 | 45.37 to 82.81% | 68.00 | 48.41 to 82.79% |
| NO (ng/mg protein) | 0.672 | 0.5229 to 0.8211 | 0.037 | > 0.1961 | 56.00 | 37.07 to 73.33% | 56.00 | 37.07 to 73.33% |
| Peroxynitrite (nmol/mg protein) | 0.8163 | 0.6927 to 0.9398 | 0.0002 | > 16.74 | 63.64 | 42.95 to 80.27% | 79.17 | 59.53 to 90.76% |
| Nitrotyrosine (pmol/mg protein) | 0.7018 | 0.5405 to 0.8631 | 0.018 | > 2107 | 63.64 | 42.95 to 80.27% | 64.00 | 44.52 to 79.75% |
| Others | ||||||||
| Aβ (AFU/mg protein) | 0.9491 | 0.8941 to 1.000 | < 0.0001 | > 5861 | 86.36 | 66.67 to 95.25% | 84.00 | 65.35 to 93.60% |
| LF (μg/mg protein) | 0.6896 | 0.5368 to 0.8424 | 0.0215 | < 26.36 | 64.00 | 44.52 to 79.75% | 64.00 | 44.52 to 79.75% |
| IL-1β (ng/mg protein) | 0.8528 | 0.7420 to 0.9636 | < 0.0001 | > 76.95 | 84.00 | 65.35 to 93.60% | 84.00 | 65.35 to 93.60% |
AUC—area under curve; SOD—superoxide dismutase; CAT—catalase; GPx—glutathione peroxidase; UA—uric acid; GSH—glutathione; TAC—mean total antioxidant capacity; TOS—mean total oxidant status; OSI—oxidative stress index; AGE—advanced glycation end products; AOPP—advanced oxidation protein products; MDA—malondialdehyde; NO—nitric oxide, Aβ—amyloid beta, LF—lactoferrin; IL-1β—Interleukin 1 Beta.