TABLE 1.
Study participants.
| HC | DS | p‐value | |
|---|---|---|---|
| N = 131 | N = 261 | ||
| Age, y, median [IQR] | 53.65 [48.70;57.81] | 46.96 [37.77;51.81] | <0.001 |
| Sex, no. (%) | <0.001 | ||
| Female | 93 (70.99%) | 108 (41.38%) | |
| APOE ε4 status, no. (%) | 0.15 | ||
| ε4+ | 36 (27.69%) | 51 (20.56%) | |
| Intellectual disability, no. (%) | |||
| Mild | 76 (29.46%) | ||
| Moderate | 148 (57.36%) | ||
| Severe/profound | 34 (13.18%) | ||
| AD diagnostic group, no. (%) | |||
| aDS | 158 (60.54%) | ||
| pDS | 41 (15.71%) | ||
| dDS | 62 (23.75%) | ||
| Vascular risk factors, no (%) | |||
| Hypertension (N = 323) | 14 (21.88%) | 4 (1.54%) | <0.001 |
| Dyslipidemia (N = 323) | 17 (26.56%) | 47 (18.15%) | 0.18 |
| Diabetes mellitus (N = 322) | 2 (3.12%) | 12 (4.65%) | 0.74 |
| CAMCOG‐DS, median [IQR] | 69.00 [51.00;82.00] | ||
| CSF biomarkers, pg/mL, median [IQR] | |||
| Aβ42/Aβ40 (N = 251) | 0.11 [0.10;0.11] | 0.06 [0.04;0.08] | <0.001 |
| pTau181 (N = 251) | 32.30 [24.90;41.40] | 55.05 [24.52;133.55] | <0.001 |
| NfL (N = 267) | 349.80 [298.92;418.61] | 542.30 [304.32;871.20] | <0.001 |
| GFAP (N = 183) | 3.35 [3.14;3.50] | 3.61 [3.40;3.78] | <0.001 |
| YKL‐40 (N = 236) | 2.20 [2.11;2.29] | 2.26 [2.03;2.37] | 0.50 |
Notes: Data are n (%) or median (IQR).
Abbreviations: Aβ42/Aβ40, concentration ratio between amyloid beta peptide 1‐42 and amyloid beta peptide 1‐40 (pg/mL); AD, Alzheimer's disease; aDS, asymptomatic Down syndrome; APOE, apolipoprotein E; CAMCOG‐DS, Cambridge Cognitive Examination for Older Adults with Down Syndrome; CSF, cerebrospinal fluid; dDS, Down syndrome with Alzheimer's disease dementia; DS, Down syndrome; GFAP, glial fibrillary acidic protein concentration (pg/mL); HC, euploid cognitively unimpaired controls; IQR, interquartile range; NfL, neurofilament light chain concentration (pg/mL); pDS, prodromal Down syndrome; pTau181, tau phosphorylated at threonine 181 concentration (pg/mL); YKL‐40, chitinase 3‐like 1.