Table 4.
Association Between Folate, Vitamin B12, and Homocysteine and Attention-Specific and Global Cognitive Decline in the Newcastle 85+ Study
| Biomarker | Change Over Time, β (SE); P | Intercept, β (SE); P | Biomarker × Time, β (SE); P |
|---|---|---|---|
| Global cognitive function (SMMSE) | |||
| RBC folate, nmol/L | |||
| Q2 (612–870) | −1.69 (0.18); <.001 | +0.57 (0.42); .17 | −0.38 (0.51); .46 |
| Q3 (870–1280) | +0.61 (0.42); .15 | −0.88 (0.49); .08 | |
| Q4 (>1280) | +1.02 (0.43); .02 | +0.13 (0.51); .80 | |
| Plasma vitamin B12, pmol/L | |||
| Q2 (170–232) | −1.68 (0.18); <.001 | +0.62 (0.42); .14 | +0.50 (0.49); .30 |
| Q3 (232–325) | −0.15 (0.43); .73 | −0.55 (0.50); .27 | |
| Q4 (>325) | +0.54 (0.43); .21 | +0.15 (0.51); .77 | |
| tHcy, μmol/L | |||
| Q2 (13.5–16.7) | −1.68 (0.18); <.001 | −0.53 (0.41); .20 | +0.26 (0.49); .60 |
| Q3 (16.7–21.4) | −0.74 (0.43); .08 | +0.96 (0.50); .06 | |
| Q4 (>21.4) | −1.05 (0.46); .02 | +0.35 (0.53); .50 | |
| Focused attention (PoA, ms) | |||
| RBC folate, nmol/L | |||
| Q2 (612–870) | +104 (15); <.001 | +19 (62); .76 | −10 (43); .82 |
| Q3 (870–1280) | +20 (63); .75 | +98 (42); .02 | |
| Q4 (>1280) | −45 (63); .48 | +27 (43); .52 | |
| Plasma vitamin B12, pmol/L | |||
| Q2 (170–232) | +105 (15); <.001 | −95 (62); .13 | +40 (42); .34 |
| Q3 (232–325) | −41 (62); .52 | +26 (43); .55 | |
| Q4 (>325) | −114 (64); .07 | +35 (43); .42 | |
| tHcy, μmol/L | |||
| Q2 (13.5–16.7) | +105 (15); <.001 | +108 (61); .08 | −110 (42); .01 |
| Q3 (16.7–21.4) | +53 (63); .40 | −93 (42); .03 | |
| Q4 (>21.4) | +81 (68); .23 | −100 (44); .02 | |
| Sustained attention (CoA, ms) | |||
| RBC folate, nmol/L | |||
| Q2 (612–870) | −1.26 (0.30); <.001 | 0.91 (1.20); .45 | −0.34 (0.84); .69 |
| Q3 (870–1280) | −1.27 (1.22); .30 | −0.45 (0.83); .58 | |
| Q4 (>1280) | +1.00 (1.23); .41 | −1.07 (0.84); .21 | |
| Plasma vitamin B12, pmol/L | |||
| Q2 (170–232) | −1.27 (0.30); <.001 | +0.76 (1.21); .53 | −0.45 (0.81); .58 |
| Q3 (232–325) | −1.00 (1.22); .41 | −0.62 (0.83); .45 | |
| Q4 (>325) | −0.32 (1.24); .80 | −0.75 (0.84); .37 | |
| tHcy, μmol/L | |||
| Q2 (13.5–16.7) | −1.27 (0.30); <.001 | +0.38 (1.18); .75 | +1.65 (0.82); .04 |
| Q3 (16.7–21.4) | +1.58 (1.22); .20 | +2.19 (0.83); .01 | |
| Q4 (>21.4) | +0.04 (1.32); .98 | +1.58 (0.87); .07 | |
| RTV | |||
| RBC folate, nmol/L | |||
| Q2 (612–870) | +0.021 (0.008); .01 | +0.017 (0.026); .52 | −0.037 (0.022); .09 |
| Q3 (870–1280) | +0.043 (0.027); .10 | +0.001 (0.021); .97 | |
| Q4 (>1280) | −0.019 (0.027); .49 | +0.028 (0.022); .20 | |
| Plasma vitamin B12, pmol/L | |||
| Q2 (170–232) | +0.021 (0.008); .01 | +0.015 (0.026); .58 | +0.001 (0.021); .95 |
| Q3 (232–325) | +0.034 (0.027); .20 | −0.017 (0.021); .44 | |
| Q4 (>325) | +0.010 (0.027); .72 | −0.015 (0.022); .49 | |
| tHcy, μmol/L | |||
| Q2 (13.5–16.7) | +0.021 (0.008); .01 | +0.016 (0.026); .53 | +0.035 (0.028); .22 |
| Q3 (16.7–21.4) | +0.018 (0.027); .49 | +0.030 (0.030); .31 | |
| Q4 (>21.4) | +0.034 (0.029); .24 | +0.042 (0.031); .18 | |
Q, quartile.
For all models, Q1 (<612 nmol/L RBC folate, <170 pmol/L plasma vitamin B12, and <13.5 tHcy, respectively) was used as the reference (0.00). Models are adjusted for alcohol intake, smoking status, APOE genotype (rs429358 and rs7412), sex, education, BMI, depression, hypertension, diabetes type 1 and 2, history of cardiovascular diseases, and physical activity. RBC folate and plasma vitamin B12 models were additionally adjusted for tHcy and the homocysteine model for renal impairment. Higher scores in the SMMSE and CoA, and lower scores in PoA and RTV tests represent better performance.