TABLE 3.
Interaction between vitamin B-12 and total folate status in relation to the odds of a low cognitive score1
| Low vitamin B-12 status | Normal vitamin B-12 status | ||||
|---|---|---|---|---|---|
| Cognitive test | Total folate ≤ 74.1 nmol/L | Total folate > 74.1 nmol/L | Total folate ≤ 74.1 nmol/L | Total folate > 74.1 nmol/L | P-interaction |
| DSST < 34 | |||||
| Subjects, n | 289 | 54 | 1501 | 411 | |
| % with outcome (95% CI) | 18.5 (13.8, 24.2) | 13.0 (7.1, 22.7) | 11.4 (9.4, 13.8) | 9.7 (7.4, 12.5) | |
| OR (95% CI) | 1 (reference) | 0.68 (0.27, 1.74) | 1 (reference) | 0.87 (0.58, 1.32) | 0.6235 |
| DSST < 40 | |||||
| Subjects, n | 289 | 54 | 1501 | 411 | |
| % with outcome (95% CI) | 28.3 (23.0, 34.3) | 25.5 (16.1, 37.8) | 18.4 (15.7, 21.5) | 16.7 (12.9, 21.4) | |
| OR (95% CI) | 1 (reference) | 0.94 (0.27, 3.26) | 1 (reference) | 0.95 (0.65, 1.39) | 0.9956 |
| CERAD-WL < 17 | |||||
| Subjects, n | 291 | 57 | 1529 | 423 | |
| % with outcome (95% CI) | 24.3 (19.1, 30.4) | 36.7 (25.1, 50.0) | 18.9 (15.8, 22.3) | 21.0 (17.0, 25.6) | |
| OR (95% CI) | 1 (reference) | 1.78 (0.88, 3.59) | 1 (reference) | 1.04 (0.75, 1.44) | 0.1823 |
| CERAD-DR < 5 | |||||
| Subjects, n | 291 | 57 | 1528 | 422 | |
| % with outcome (95% CI) | 23.3 (18.3, 29.1) | 35.4 (20.7, 53.5) | 19.6 (16.5, 23.1) | 17.5 (13.4, 22.5) | |
| OR (95% CI) | 1 (reference) | 1.66 (0.64, 4.30) | 1 (reference) | 0.68 (0.47, 0.98) | 0.0815 |
| AF < 14 | |||||
| Subjects, n | 289 | 57 | 1529 | 418 | |
| % with outcome (95% CI) | 26.2 (20.0, 33.5) | 40.6 (28.5, 54.0) | 18.5 (15.8, 21.4) | 16.2 (12.6, 20.6) | |
| OR (95% CI) | 1 (reference) | 1.93 (1.08, 3.45) | 1 (reference) | 0.78 (0.54, 1.13) | 0.0078 |
1
Low serum vitamin B-12 status is defined as either serum vitamin B-12 < 150 pmol/L or MMA > 271 nmol/L. The 75th percentile of serum total folate concentration was used as a cutoff. The multiple logistic regression models were adjusted for age group, sex, race/Hispanic origin, education level, heavy drinking, smoking, and fasting hour. AF, animal fluency test; CERAD-DR, Consortium to Establish a Registry for Alzheimer's Disease Delayed Recall test; CERAD-WL, Consortium to Establish a Registry for Alzheimer's Disease Word Learning test; DSST, Digit Symbol Substitution Test.