Table 2.
Biochemical Measurements for Study Participants
| Parameters | CH (n=47) | MCI (n=35) | AD (n=26) | P Value |
|---|---|---|---|---|
| Cholesterol efflux (ratio) | 1.56 (0.73)a, b | 0.94 (0.35) | 1.02 (0.43) | <0.001 |
| CSF supernatant PC, ng/mL | 9047 (6668, 11 802)a, b | 7382 (6108, 8717) | 6669 (5506, 8367) | 0.016 |
| CSF nanoparticle PC, ng/mL | 19 (14, 23) | 19 (14, 29) | 18 (14,22) | 0.80 |
| CSF supernatant SM, ng/mL | 2091 (718) | 1837 (643) | 1722 (561) | 0.14 |
| CSF nanoparticle SM, ng/mL | 102 (50) | 90 (35) | 93 (41) | 0.11 |
| Plasma cholesterol, mg/dL | 181 (31) | 180 (39) | 185 (33) | 0.99 |
| CSF cholesterol, μg/mL | 3.49 (0.84) | 3.21 (0.75) | 3.16 (0.56) | 0.04 |
| ApoE levels, μg/mL | 7.2 (2.0) | 7.5 (2.6) | 5.3 (2.1) c | <0.001 |
| ApoA‐I levels, μg/mL | 1.76 (1.3) | 1.74 (1.3) | 1.74 (1.1) | 0.99 |
| CSF PLA2 activity, RFU/min | 887 (233) | 917 (220) | 980 (269) | 0.32 |
| CSF acid sphingomyelinase, RFU/min | 25 (10) | 24 (8) | 15 (6)c | 0.001 |
| CSF neutral sphingomyelinase, RFU/min | 22 (17,26) | 19 (17,24) | 20 (18,24) | 0.38 |
| CSF tau, pg/mL | 275 (154) | 278 (175) | 489 (227)c | <0.001 |
| CSF β‐amyloid 42, pg/mL | 727 (288) | 737 (269) | 522 (223)c | <0.001 |
Data presented as mean (SD) or median (25%, 75% percentile) for nonnormally distributed data. Cholesterol efflux capacity of CSF was measured in all samples and normalized to efflux of 5 μg of purified apoE run in every plate. The 3 groups were compared using a linear regression model. The difference in cholesterol efflux capacity persisted after adjusting for CSF lipids or apolipoprotein levels. AD indicates Alzheimer's disease; CH, cognitively healthy; CSF, cerebrospinal fluid; MCI, mild cognitive impairment; PC, phosphatidylcholine; PLA2, phospholipase A2; RFU, relative fluorescence unit; SM, sphingomyelin.
CH compared with AD, P<0.001.
CH compared with MCI, P<0.001.
AD compared with CH and MCI, P<0.001.