Table 1.
Participant characteristics by primary clinical group
| Characteristic | Cognitively unimpaired n = 203 | Cognitively impaired n = 134 | |
|---|---|---|---|
| Cohort, n (%) | |||
| Mayo Clinic Study of Aging | 203 (100) | 37 (28) | |
| Mayo Alzheimer's Disease Research Center | 0 (0) | 73 (54) | |
| Mayo Neurodegenerative Research Group | 0 (0) | 24 (18) | |
| Clinical diagnosis, n (%) | |||
| Cognitively unimpaired | 203 (100) | 0 (0) | |
| MCI | 0 (0) | 71 (53) | |
| Dementia with Alzheimer's clinical syndrome | 0 (0) | 63 (47) | |
| Age, years | |||
| Median (IQR) | 70 (63, 79) | 71 (64, 78) | |
| Min, Max | 52, 94 | 52, 94 | |
| Male sex, n (%) | 110 (54) | 74 (55) | |
| Education, years, median (IQR) | 16 (13, 16) | 16 (13, 17) | |
| APOE ε4, n (%) | 67 (33) | 66 (49) | |
| Clinical Dementia Rating Scale-Sum of Boxes, median (IQR) | 0 (0, 0) | 2 (1, 3) | |
| Montreal Cognitive Assessment, median (IQR) | 26 (24, 27) | 20 (17, 23) | |
| Memory z-score, median (IQR) | 0.6 (−0.2, 1.3) | – | |
| Amyloid PET SUVR | |||
| Median (IQR) | 1.40 (1.34, 1.56) | 2.25 (1.60, 2.59) | |
| Abnormala, n (%) | 70 (34) | 107 (80) | |
| Tau PET SUVR, median (IQR) | 1.19 (1.13, 1.24) | 1.50 (1.21, 2.00) | |
| Cortical thickness, mm, median (IQR) | 2.71 (2.61, 2.80) | 2.54 (2.40, 2.65) | |
| White matter hyperintensity, % of TIV, median (IQR) | 0.58 (0.29, 1.16) | 0.79 (0.49, 1.39) | |
| Total tau PET scans, n (%) | |||
| 2 | 177 (87) | 87 (65) | |
| 3 | 26 (13) | 37 (28) | |
| 4 | 0 (0) | 10 (7) | |
| Tau PET scan interval (first to last), years | |||
| Median (IQR) | 2.4 (1.3, 2.6) | 1.3 (1.1, 2.1) | |
| Min, Max | 1.0, 4.0 | 0.8, 4.1 |
aAbnormal amyloid PET was defined as SUVR ≥ 1.48 (centiloid ≥ 22).