Submitted to: Neurology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2009
Publication Date: 1/5/2010
Citation: Buell, J., Dawson-Hughes, B., Scott, T., Weiner, D., Dallal, G., Qiao, W., Bergethon, P., Rosenberg, I., Folstein, M., Patz, S. 2010. 25-Hydroxyvitamin D, dementia, and cerebrovascular pathology in elders receiving home services. Neurology. 74(1):18-26. Interpretive Summary: There is evidence of neuroprotective functions of vitamin D and growing evidence of a potential role of vitamin D in cognitive function. Vitamin D may help prevent neurodegenerative diseases of aging through protection against comorbidities such as cardiovascular and cerebrovascular disease, peripheral artery disease, oxidation and inflammation, and neuronal health. However, there is a paucity of data on the association between biomarkers of vitamin D, cognition, dementia and MRI measures of cerebrovascular disease (CVD). The objectives of the current study were to explore mechanisms through which vitamin D may be involved in neurocognitive function. Using a subset of the population previously studied, we examined associations between vitamin D and diagnoses of neurodegenerative diseases, MRI indicators for vascular brain pathology, and volumetric measures of brain structures in a racially diverse elderly population receiving homecare in Boston, MA. Among 318 participants, the mean age was 73.5, 72.6% were women and 34.3% were black. Vitamin D insufficiency and deficiency were prevalent (44.3% and 15%). 23.9% of participants had dementia, 41 of which were classified as probable Alzheimer’s disease. Vitamin D concentrations were lower in subjects with dementia, and there was a higher prevalence of dementia among participants with vitamin D insufficiency. Vitamin D insufficiency and deficiency was inversely associated with all-cause dementia, Alzheimer’s disease, stroke (with and without dementia symptoms), and MRI indicators of CVD. These findings suggest a potential vasculoprotective role of vitamin D. While the extent to which vitamin D deficiency and cognitive function are related remains unclear, the biological plausibility of this relationship is increasingly supported.
Technical Abstract: Vitamin D deficiency has potential adverse effects on neurocognitive health and subcortical function. However, no studies have examined the association between vitamin D status, dementia, and cranial magnetic resonance imaging (MRI) indicators of cerebrovascular disease (CVD). Cross-sectional investigation of 25-hydroxyvitamin D (25(OH)D), dementia, and MRI measures of CVD in elders receiving homecare (aged 65–99 y) from 2003-07. Among 318 participants, the mean age was 73.5 +/- 8.1 years; 231 (72.6%) were women and 109 (34.3%) were black. 25(OH)D concentrations were deficient (<10 ng/mL) in 14.5% and insufficient (10-20 ng/mL) in 44.3% of participants. There were 76 (23.9%) participants with dementia; 41 of which were classified as probable Alzheimer’s disease. Mean 25(OH)D concentrations were lower in subjects with dementia (16.8 versus 19.9ng/ml; P<0.01). There was a higher prevalence of dementia among participants with 25(OH)D insufficiency (</=20ng/ml)(30.5 vs. 14.5%; P<0.001). 25(OH)D deficiency was associated with increased white matter hyperintensity (WMH) volume (4.9 vs. 2.9 ml; P<0.01), grade (3.0 vs. 2.2; P=0.04), and prevalence of large vessel infarcts (10.1 vs 6.9%; P<0.01). After adjusting for age, race, sex, BMI, and education, 25(OH)D insufficiency (</=20ng/ml) was associated with more than twice the odds of all-cause dementia (OR=2.3; 95% CI:1.2, 4.27), Alzheimer’s disease (OR=2.5; 95%CI:1.1, 6.1) and stroke (with and without dementia symptoms) (OR=2.0; 95%CI: 1.0,4.0). Vitamin D insufficiency and deficiency was inversely associated with all-cause dementia, Alzheimer’s disease, stroke (with and without dementia symptoms), and MRI indicators of CVD. These findings suggest a potential vasculoprotective role of vitamin D.