Table 1.
Statistical Dataa
| Characteristic | Value |
|---|---|
| No. of subjects | |
| With BDS | 122 |
| With ADL | 115 |
| Total visits (% retrospective, ie, prior to blood drawing) | |
| With BDS | 919 (55) |
| With ADL | 730 (38) |
| Age at baseline, mean (SD) [range], y | 73.3 (8.2) [47–89] |
| Duration of Alzheimer disease at baseline, mean (SD) [range], y | 3.2 (2.1) [0.7–12.4] |
| Educational achievement, mean (SD) [range], y | 13.6 (3.1) [3–20] |
| Sex, No. (%) | |
| Males with BDS | 55 (45) |
| Males with ADL | 55 (48) |
| Females with BDS | 67 (55) |
| Females with ADL | 60 (52) |
| Age at onset of AD, mean (SD) [range], y | 70.2 (8.4) [44–87] |
| No. of visits across time per person, mean (SD) [range] | |
| BDS | 7.5 (4.4) [2–26] |
| ADL | 6.3 (3.2) [2–20] |
| Interval between visits, mean (SD) [range] | |
| BDS | 6 mo (4 mo) [2 wk-3 y] |
| ADL | 9 mo (7 mo) [3 mo-6 y] |
| No. of years in study, mean (SD) [range] | 4.2 (2.6) [2 wk-14 y] |
| No. of years to blood draw after baseline | 2.7 (2.2) [0–12] |
| Test score, mean (SD) [range] | |
| BDS at baseline | 9.1 (5) [0–29] |
| BDS at blood drawing | 14.6 (7.6) [3–32] |
| ADL at baseline | 25.4 (16.5) [0–73] |
| ADL at blood drawing | 43 (23) [6–87] |
| Biochemical data, mean (SD) [range]b | |
| Aβ40 level, pmol/L | 51.5 (17.8) [12–110] |
| Aβ42 level, pmol/L | 7 (3.6) [2–22] |
| tHcy level, µmol/L | 9 (3.2) [4–24] |
| Vitamin B12 level, pg/mL | 600 (309) [187–1870] |
| Folic acid level, ng/mL | 13.9 (9.9) [3–68] |
| hsCRP level, mg/L | 2.5 (4.5) [0.1–34.6] |
| Genetic data | |
| APOE genotype, No. (%) | |
| APOE ε4 carrier | 83 (68) |
| No APOE ε4 allele | 36 (30) |
| Information unavailable | 3 (2) |
Abbreviations: Aβ40 and Aβ42, amyloid β-protein 40 and 42, respectively; ADL, Weintraub Activities of Daily Living Scale; APOE, apolipoprotein E; BDS, Blessed Dementia Scale; hsCRP, high-sensitivity C-reactive protein; tHcy, total homocysteine.
SI unit conversions: To convert vitamin B12 to picomoles per liter, multiply by 0.7378; to convert folic acid to nanomoles per liter, multiply by 2.266; to convert hsCRP to nanomoles per liter, multiply by 9.524.
Except where noted, data pertain to the data set used in analysis of the BDS; values for the ADL data set were virtually the same, except where indicated.
Aβ40, Aβ42, hsCRP, and tHcy levels were significantly (P < .05) intercorrelated (r = 0.18–0.69), as were vitamin B12 and tHcy levels (r = −0.36) and vitamin B12 and folic acid levels (r = 0.30).