Table 1 Plasma biomarker levels (pg/mL, mean ± SD) across a 24-h period.
From: P-tau217 and other blood biomarkers of dementia: variation with time of day
Variable | Group | Statistics | Time-point (approximate clock time) | ICC, (95% CI) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 (14:00) | 2 (17:00) | 3 (20:00) | 4 (23:00) | 5 (02:00) | 6 (05:00) | 7 (08:00) | 8 (11:00) | 9 (14:00) | ||||
P-tau217 | Total sample | Mean | 0.789 | 0.686 | 0.767 | 0.671 | 0.674 | 0.670 | 0.653 | 0.612 | 0.654 | 0.97 (0.96, 0.99) |
SD | 0.593 | 0.501 | 0.676 | 0.481 | 0.498 | 0.514 | 0.519 | 0.472 | 0.496 | |||
N | 20 | 20 | 21 | 17 | 17 | 17 | 20 | 17 | 17 | |||
Cognitively intact | Mean | 0.361 | 0.378 | 0.348 | 0.346 | 0.341 | 0.337 | 0.332 | 0.327 | 0.385 | 0.89 (0.74, 0.98) | |
SD | 0.118 | 0.091 | 0.129 | 0.094 | 0.101 | 0.128 | 0.114 | 0.121 | 0.205 | |||
N | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 6 | |||
PLWA | Mean | 1.272 | 1.127 | 1.323 | 1.248 | 1.297 | 1.294 | 1.144 | 1.129 | 1.121 | 0.95 (0.89, 0.99) | |
SD | 0.660 | 0.599 | 0.810 | 0.440 | 0.420 | 0.470 | 0.591 | 0.564 | 0.565 | |||
N | 8 | 7 | 8 | 5 | 5 | 5 | 7 | 5 | 6 | |||
Study partner | Mean | 0.615 | 0.530 | 0.515 | 0.550 | 0.518 | 0.511 | 0.455 | 0.494 | 0.415 | 0.94 (0.85, 0.99) | |
SD | 0.245 | 0.280 | 0.269 | 0.317 | 0.301 | 0.312 | 0.243 | 0.237 | 0.164 | |||
N | 5 | 6 | 6 | 5 | 5 | 5 | 6 | 5 | 5 | |||
Aβ40 | Total sample | Mean | 122.420 | 119.280 | 123.916 | 125.762 | 129.257 | 123.698 | 118.405 | 111.887 | 124.890 | 0.86 (0.77, 0.93) |
SD | 26.665 | 24.698 | 30.104 | 26.949 | 27.169 | 23.497 | 23.771 | 26.566 | 22.899 | |||
N | 20 | 20 | 21 | 17 | 17 | 17 | 20 | 17 | 17 | |||
Cognitively intact | Mean | 117.884 | 118.666 | 121.981 | 128.279 | 128.248 | 124.966 | 114.608 | 106.928 | 124.004 | 0.87 (0.71, 0.97) | |
SD | 32.883 | 30.941 | 33.746 | 27.547 | 32.163 | 26.646 | 26.635 | 25.072 | 26.415 | |||
N | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 6 | |||
PLWA | Mean | 131.905 | 124.608 | 134.932 | 127.641 | 138.823 | 134.975 | 129.656 | 120.552 | 125.563 | 0.84 (0.67, 0.96) | |
SD | 22.686 | 19.975 | 31.770 | 24.622 | 24.064 | 18.901 | 20.061 | 29.313 | 24.201 | |||
N | 8 | 7 | 8 | 5 | 5 | 5 | 7 | 5 | 6 | |||
Study partner | Mean | 113.597 | 113.781 | 111.484 | 120.360 | 121.104 | 110.645 | 109.710 | 110.166 | 125.144 | 0.88 (0.72, 0.98) | |
SD | 23.273 | 24.776 | 21.460 | 33.294 | 24.953 | 20.281 | 22.910 | 29.671 | 22.164 | |||
N | 5 | 6 | 6 | 5 | 5 | 5 | 6 | 5 | 5 | |||
Aβ42 | Total sample | Mean | 7.941 | 8.015 | 8.110 | 8.370 | 8.575 | 8.294 | 7.884 | 7.342 | 8.134 | 0.84 (0.74, 0.92) |
SD | 1.645 | 1.595 | 1.884 | 1.774 | 1.714 | 1.559 | 1.699 | 1.465 | 1.547 | |||
N | 20 | 20 | 21 | 17 | 17 | 17 | 20 | 17 | 17 | |||
Cognitively intact | Mean | 8.303 | 8.477 | 8.591 | 9.192 | 9.299 | 9.111 | 8.276 | 7.769 | 8.769 | 0.83 (0.65, 0.96) | |
SD | 2.036 | 2.060 | 2.448 | 1.699 | 1.994 | 1.886 | 2.038 | 1.514 | 1.607 | |||
N | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 6 | |||
PLWA | Mean | 8.105 | 8.006 | 8.475 | 7.646 | 7.934 | 7.847 | 8.162 | 6.891 | 7.801 | 0.86 (0.7, 0.96) | |
SD | 1.517 | 1.310 | 1.643 | 1.666 | 1.382 | 0.935 | 1.527 | 1.382 | 1.516 | |||
N | 8 | 7 | 8 | 5 | 5 | 5 | 7 | 5 | 6 | |||
Study partner | Mean | 7.171 | 7.488 | 7.062 | 7.943 | 8.202 | 7.596 | 7.104 | 7.194 | 7.773 | 0.82 (0.61, 0.97) | |
SD | 1.257 | 1.372 | 1.171 | 1.850 | 1.507 | 1.222 | 1.458 | 1.623 | 1.594 | |||
N | 5 | 6 | 6 | 5 | 5 | 5 | 6 | 5 | 5 | |||
Aβ42/Aβ40 | Total sample | Mean | 0.066 | 0.068 | 0.066 | 0.067 | 0.067 | 0.068 | 0.067 | 0.067 | 0.066 | 0.92 (0.87, 0.96) |
SD | 0.011 | 0.011 | 0.010 | 0.009 | 0.009 | 0.009 | 0.009 | 0.011 | 0.010 | |||
N | 20 | 20 | 21 | 17 | 17 | 17 | 20 | 17 | 17 | |||
Cognitively intact | Mean | 0.071 | 0.072 | 0.071 | 0.072 | 0.073 | 0.073 | 0.072 | 0.074 | 0.071 | 0.9 (0.76, 0.98) | |
SD | 0.011 | 0.011 | 0.008 | 0.010 | 0.007 | 0.009 | 0.008 | 0.011 | 0.006 | |||
N | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 6 | |||
PLWA | Mean | 0.062 | 0.065 | 0.064 | 0.060 | 0.057 | 0.059 | 0.063 | 0.058 | 0.063 | 0.95 (0.88, 0.99) | |
SD | 0.012 | 0.014 | 0.013 | 0.008 | 0.005 | 0.008 | 0.010 | 0.010 | 0.014 | |||
N | 8 | 7 | 8 | 5 | 5 | 5 | 7 | 5 | 6 | |||
Study partner | Mean | 0.064 | 0.067 | 0.064 | 0.067 | 0.068 | 0.069 | 0.065 | 0.066 | 0.062 | 0.84 (0.63, 0.97) | |
SD | 0.005 | 0.007 | 0.006 | 0.006 | 0.004 | 0.004 | 0.007 | 0.006 | 0.006 | |||
N | 5 | 6 | 6 | 5 | 5 | 5 | 6 | 5 | 5 | |||
GFAP | Total sample | Mean | 147.624 | 140.967 | 148.273 | 130.534 | 143.213 | 140.273 | 142.536 | 123.011 | 136.349 | 0.9 (0.83, 0.95) |
SD | 77.600 | 68.563 | 89.029 | 71.707 | 75.650 | 70.634 | 68.234 | 63.581 | 69.134 | |||
N | 20 | 20 | 21 | 17 | 17 | 17 | 20 | 17 | 17 | |||
Cognitively intact | Mean | 98.161 | 105.159 | 97.122 | 95.467 | 109.904 | 111.400 | 117.094 | 97.228 | 115.692 | 0.73 (0.49, 0.93) | |
SD | 25.105 | 26.680 | 35.601 | 27.099 | 37.948 | 47.691 | 47.438 | 35.906 | 49.709 | |||
N | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 6 | |||
PLWA | Mean | 196.745 | 185.026 | 204.898 | 180.384 | 195.483 | 197.520 | 182.919 | 166.679 | 177.503 | 0.86 (0.7, 0.96) | |
SD | 90.111 | 80.013 | 99.056 | 75.704 | 93.266 | 74.099 | 76.113 | 71.305 | 75.510 | |||
N | 8 | 7 | 8 | 5 | 5 | 5 | 7 | 5 | 6 | |||
Study partner | Mean | 138.279 | 131.342 | 132.451 | 129.779 | 137.577 | 123.448 | 125.105 | 115.437 | 111.753 | 0.94 (0.85, 0.99) | |
SD | 65.049 | 68.577 | 85.748 | 92.065 | 81.464 | 71.730 | 66.979 | 74.387 | 70.464 | |||
N | 5 | 6 | 6 | 5 | 5 | 5 | 6 | 5 | 5 | |||
NfL | Total sample | Mean | 23.415 | 21.750 | 22.150 | 22.279 | 23.550 | 23.821 | 22.445 | 21.413 | 21.031 | 0,97 (0.94, 0.98) |
SD | 11.023 | 10.870 | 12.087 | 11.539 | 11.638 | 10.991 | 11.922 | 11.171 | 11.601 | |||
N | 20 | 20 | 21 | 17 | 17 | 17 | 20 | 17 | 17 | |||
Cognitively intact | Mean | 17.935 | 17.141 | 16.552 | 17.117 | 17.804 | 18.529 | 17.490 | 17.069 | 17.752 | 0.93 (0.83, 0.98) | |
SD | 7.012 | 5.757 | 7.056 | 6.707 | 5.677 | 6.123 | 6.638 | 5.751 | 7.422 | |||
N | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 6 | |||
PLWA | Mean | 26.948 | 25.942 | 27.439 | 25.279 | 28.854 | 29.074 | 27.455 | 23.782 | 24.570 | 0.87 (0.73, 0.97) | |
SD | 6.569 | 5.243 | 7.881 | 3.200 | 6.131 | 4.028 | 7.119 | 5.320 | 4.383 | |||
N | 8 | 7 | 8 | 5 | 5 | 5 | 7 | 5 | 6 | |||
Study partner | Mean | 25.433 | 22.237 | 21.629 | 26.508 | 26.291 | 25.976 | 22.379 | 25.125 | 20.719 | 0.99 (0.97, 1) | |
SD | 18.582 | 17.933 | 18.676 | 19.356 | 18.801 | 17.930 | 18.892 | 19.079 | 20.258 | |||
N | 5 | 6 | 6 | 5 | 5 | 5 | 6 | 5 | 5 | |||
