TABLE 3.
Plasma marker measures, comparing cognitive impairment categories, among American Indian participants of the Strong Heart Study (2017–2019).
| Comparing dementia, versus cognitive intact | ||||||
|---|---|---|---|---|---|---|
|
Cognitive intact N = 181 45.6% |
MCI N = 140 35.3% |
Dementia N = 41 10.3% |
In‐MCI N = 35 8.8% |
Empirical, optimal cut point | ROC (AUC, sensitivity, specificity) at cut point | |
| pTau181 pg/mL | 7.6 (17.3) | 6.8 (4.7) | 10.2 (18.4) | 6.6 (4.3) | >4.5 | 0.66 (0.78, 0.53) |
| Aβ40 pg/mL | 140.1 (43.6) | 143.9 (45.3) | 155.8 (41.7) | 143.7 (49.0) | <135.5 | 0.63 (0.61, 0.65) |
| Aβ42 pg/mL | 8.2 (2.9) | 8.5 (2.9) | 8.8 (2.3) | 8.3 (2.5) | <7.9 | 0.60 (0.71, 0.49) |
| Aβ42/40 ratio | 0.059 (0.014) | 0.059 (0.014) | 0.057 (0.009) | 0.060 (0.013) | >0.06 | 0.46 (0.51, 0.42) |
| GFAP pg/mL | 162.2 (80.9) | 175.9 (88.0) | 216.2 (88.6) | 186.5 (125.3) | >199 | 0.73 (0.68, 0.78) |
| NfL pg/mL | 34.9 (21.3) | 42.4 (28.7) | 53.7 (31.1) | 43.7 (30.9) | >32.7 | 0.69 (0.73, 0.64) |
Note: Values provided as mean (SD) unless otherwise indicated. Cutpoints and ROC comparisons with major risk factors: age (> 75 years, AUC 0.61), sex (male, AUC 0.54), education (< 13, AUC 0.33), APOE (e4 carrier, AUC 0.59). Statistical tests by Kruskal–Wallis test across cognitive categories, with FDR (false discovery rate) Q‐value estimated by Benjamini–Hochberg method, assessed for significance at Q < 0.1: pTau181 Q < 0.001; Ab40 Q = 0.192; Ab42 Q = 0.420; Ab4240 Q = 0.420; GFAP Q = 0.006, NFL Q < 0.001.