TABLE 1.
Baseline characteristics of OPEN study participants by allocated treatment1
| Vitamin B-12 | Placebo | |
| Participants, n | 99 | 102 |
| Sex, M, n (%) | 46 (46.5) | 48 (47.1) |
| Age | ||
| Age, y | 79.9 ± 3.52 | 80.1 ± 3.7 |
| 75–79, n (%) | 56 (56.6) | 57 (55.9) |
| ≥80, n (%) | 43 (43.4) | 45 (44.1) |
| Education | ||
| Age at leaving, y | 18.3 ± 5.3 | 17.8 ± 6.6 |
| No qualifications, n (%) | 21 (21.4) | 33 (33.0) |
| Basic or clerical, n (%) | 16 (16.3) | 18 (18.0) |
| Advanced or university, n (%) | 33 (33.7) | 19 (19.0) |
| Other, n (%) | 28 (28.6) | 30 (30.0) |
| Vascular health | ||
| Myocardial infarction in 5 y, n (%) | 1 (1.0) | 4 (3.9) |
| Stroke in 5 y, n (%) | 1 (1.0) | 0 |
| BMI, kg/m2 | 27.0 ± 5.6 | 27.5 ± 5.3 |
| <18.5, n (%) | 1 (1.0) | 0 |
| ≥30, n (%) | 18 (18.2) | 25 (24.8) |
| Mini-Mental State Examination score | 29 (28–29)3 | 29 (28–29) |
| Current prescription drugs,4 n (%) | ||
| Statins | 32 (38.1) | 35 (44.9) |
| Proton-pump inhibitors | 26 (31.0) | 27 (34.6) |
| Other relevant | 1 (1.2) | 2 (2.6) |
| Dietary pattern, n (%) | ||
| >1 portion meat/wk | 69 (73.4) | 70 (72.2) |
| >1 portion oily fish/wk | 16 (18.0) | 22 (23.4) |
| >1 portion white fish/wk | 21 (21.9) | 18 (18.8) |
| >1 portion eggs/wk | 47 (48.5) | 38 (39.2) |
| Daily alcohol | 33 (34.4) | 35 (35.4) |
| Blood biochemical measure | ||
| Participants, n | 86 | 84 |
| Vitamin B-12, pmol/L | 222.9 (197.4–268.9) | 228.0 (194.7–271.0) |
| Holotranscobalamin, pmol/L | 50.4 (38.2–68.3) | 48.8 (39.8–62.9) |
| Homocysteine, μmol/L | 15.9 (14.0–18.9) | 16.3 (13.3–19.9) |
| Folate, nmol/L | 17.7 (10.8–25.4) | 17.5 (11.8–25.4) |
| Hemoglobin, g/L | 139.8 ± 11.1 | 138.9 ± 12.9 |
1
OPEN, Older People and Enhanced Neurological Function.
2
Mean ± SD (all such values).
3
Median; IQR in parentheses (all such values).
4
Drug categories were as follows: statins (simvastatin, atorvastatin, pravastatin, and rosuvastatin); proton-pump inhibitors (omeprazole, lansoprazole, esomeprazole, rabeprazole, and pantoprazole); and other relevant drugs (amiodarone and metronidazole).