TABLE 2.
Interaction between vitamin B-12 and UMFA status in relation to the odds of a low cognitive score1
| Low vitamin B-12 status | Normal vitamin B-12 status | ||||
|---|---|---|---|---|---|
| Cognitive test | UMFA ≤ 1 nmol/L | UMFA > 1 nmol/L | UMFA ≤ 1 nmol/L | UMFA > 1 nmol/L | P-interaction |
| DSST < 34 | |||||
| Subjects, n | 204 | 139 | 1182 | 732 | |
| % with outcome (95% CI) | 14.2 (9.3, 21.1) | 22.1 (15.3, 30.7) | 12.1 (9.6, 15.1) | 9.4 (7.6, 11.6) | |
| OR (95% CI) | 1 (reference) | 2.16 (1.05, 4.47) | 1 (reference) | 0.74 (0.51, 1.08) | 0.0071 |
| DSST < 40 | |||||
| Subjects, n | 204 | 139 | 1182 | 732 | |
| % with outcome (95% CI) | 26.2 (20.2, 33.2) | 29.9 (23.0, 38.0) | 19.3 (16.3, 22.8) | 16.0 (13.2, 19.3) | |
| OR (95% CI) | 1 (reference) | 1.31 (0.70, 2.47) | 1 (reference) | 0.74 (0.54, 1.03) | 0.1347 |
| CERAD-WL < 17 | |||||
| Subjects, n | 205 | 143 | 1210 | 744 | |
| % with outcome (95% CI) | 26.9 (19.6, 35.7) | 26.3 (18.5, 36.0) | 18.9 (16.2, 22.0) | 20.0 (15.6, 25.3) | |
| OR (95% CI) | 1 (reference) | 0.79 (0.41, 1.51) | 1 (reference) | 0.93 (0.60, 1.43) | 0.6567 |
| CERAD-DR < 5 | |||||
| Subjects, n | 205 | 143 | 1210 | 742 | |
| % with outcome (95% CI) | 23.4 (17.2, 31.1) | 28.5 (18.6, 41.0) | 19.4 (16.2, 23.0) | 18.5 (14.9, 22.7) | |
| OR (95% CI) | 1 (reference) | 1.01 (0.45, 2.28) | 1 (reference) | 0.73 (0.54, 0.98) | 0.4367 |
| AF < 14 | |||||
| Subjects, n | 205 | 141 | 1210 | 739 | |
| % with outcome (95% CI) | 25.7 (18.1, 35.2) | 33.2 (24.4, 43.4) | 17.4 (14.8, 20.4) | 18.6 (15.3, 22.5) | |
| OR (95% CI) | 1 (reference) | 1.33 (0.76, 2.33) | 1 (reference) | 1.04 (0.74, 1.46) | 0.4176 |
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 UMFA from a previous NHANES analysis was used as a cutoff (26). 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; UMFA, unmetabolized folic acid.