Table 3.
Multivariable adjusted models depicting the association between 25(OH)D levels and the MRI variables
| Model | TBV |
HPV |
WMHV |
WMH (extensive) |
SCI |
|||||
|---|---|---|---|---|---|---|---|---|---|---|
| β ±SE | p | β±SE | p | β ±SE | p | OR (95% CI) | p | OR (95% CI) | p | |
| 25(OH)D as standardized continuous variable | ||||||||||
| 1 | 0.14 ± 0.08 | 0.075 | 0.003 ±0.002 | 0.103 | −0.03± 0.03 | 0.212 | 1.00 (0.84–1.18) | 0.973 | 0.85 (0.71–1.04) | 0.108 |
| 2 | 0.09 ± 0.08 | 0.268 | 0.003 ±0.002 | 0.114 | −0.03± 0.03 | 0.212 | 1.00 (0.84–1.20) | 0.965 | 0.90 (0.74–1.09) | 0.291 |
| 3 | −0.002± 0.09 | 0.984 | 0.002 ±0.002 | 0.299 | −0.03± 0.03 | 0.295 | 1.02 (0.85–1.23) | 0.815 | 0.91 (0.74–1.12) | 0.374 |
| 25(OH) D <10 ng/mL | ||||||||||
| 1 | −0.34 ±0.29 | 0.249 | −0.01 ±0.01 | 0.033 | −0.004± 0.09 | 0.964 | 1.00 (0.53–1.89) | 0.995 | 1.34 (0.73–2.48) | 0.349 |
| 2 | −0.16 ±0.29 | 0.591 | −0.01 ±0.01 | 0.034 | −0.03± 0.10 | 0.778 | 0.96 (0.50–1.84) | 0.896 | 1.12 (0.60–2.11) | 0.721 |
| 3 | 0.04 ± 0.31 | 0.889 | −0.01 ±0.01 | 0.058 | −0.05± 0.10 | 0.621 | 0.90 (0.45–1.81) | 0.773 | 1.18 (0.61–2.27) | 0.629 |
| 25(OH)D < the cohort-specific 20th percentile | ||||||||||
| 1 | −0.36 ±0.20 | 0.073 | −0.01 ±0.004 | 0.111 | 0.01 ±0.06 | 0.869 | 0.88 (0.56–1.39) | 0.585 | 1.03 (0.65–1.63) | 0.908 |
| 2 | −0.23 ±0.20 | 0.248 | −0.01 ±0.004 | 0.112 | 0.01 ±0.07 | 0.829 | 0.89 (0.56–1.41) | 0.619 | 0.92 (0.57–1.46) | 0.717 |
| 3 | −0.09 ±0.22 | 0.687 | −0.005 ±0.005 | 0.296 | −0.01± 0.07 | 0.890 | 0.88 (0.53–1.43) | 0.595 | 0.89 (0.54–1.47) | 0.652 |
| 25(OH)D > the cohort-specific 80th percentile | ||||||||||
| 1 | 0.28 ± 0.20 | 0.163 | 0.002 ±0.004 | 0.633 | −0.07± 0.06 | 0.277 | 0.91 (0.59–1.41) | 0.676 | 0.87 (0.53–1.41) | 0.557 |
| 2 | 0.18 ± 0.20 | 0.362 | 0.002 ±0.004 | 0.713 | −0.08± 0.07 | 0.207 | 0.88 (0.56–1.38) | 0.577 | 0.92 (0.56–1.50) | 0.736 |
| 3 | 0.05 ± 0.21 | 0.822 | −0.000 ±0.004 | 0.921 | −0.08± 0.07 | 0.226 | 0.94 (0.59–1.50) | 0.798 | 0.97 (0.59–1.61) | 0.904 |
Bold highlight denotes p< 0.05; HPV, hippocampal volume; SBI, silent cerebral infarcts; TBV, total brain volume; WMHV, white matter hyperintensity volume. Regression coefficients represent the change in mean of each standardized MRI variable per cohort-specific 1-SD increment in 25(OH)D levels; or by the presence of a 25(OH)D concentration <10 ng/mL; < cohort-specific 20th percentile; or > the cohort-specific 80th percentile. Model 1 adjusts for age, gender, and time from vitamin D measurement to MRI. Model 2 adjusts for the addition of vascular risk factors (smoking, hypertension, diabetes, prevalent cardiovascular disease, and homocysteine). Model 3 adjusts for the addition of BMI and vitamin D supplement use.