Association of white matter hyperintensities with low serum 25-hydroxyvitamin D levels

Causal Effect of the 25-Hydroxyvitamin D Concentration on Cerebral Small Vessel Disease: A Mendelian Randomization Study

BACKGROUND

Previous observational studies reported that a lower serum 25-hydroxyvitamin D [25(OH)D] concentration is associated with a higher burden of cerebral small vessel disease (cSVD). The causality of this association is uncertain, but it would be clinically important, given that 25(OH)D can be a target for intervention. We tried to examine the causal effect of 25(OH)D concentration on cSVD-related phenotypes using a Mendelian randomization approach.

METHODS

Genetic instruments for each serum 25(OH)D concentration and cSVD-related phenotypes (lacunar stroke, white matter hyperintensity, cerebral microbleeds, and perivascular spaces) were derived from large-scale genome-wide association studies. We performed 2-sample Mendelian randomization analyses with multiple post hoc sensitivity analyses. A bidirectional Mendelian randomization approach was also used to explore the possibility of reverse causation.

RESULTS

We failed to find any significant causal effect of 25(OH)D concentration on cSVD-related phenotypes (odds ratio [95% CI], 1.00 [0.87-1.16], 1.01 [0.96-1.07], 1.06 [0.85-1.33], 1.00 [0.97-1.03], 1.02 [0.99-1.04], 1.01 [0.99-1.04] for lacunar stroke, white matter hyperintensity, cerebral microbleeds, and white matter, basal ganglia, hippocampal perivascular spaces, respectively). These results were reproduced in the sensitivity analyses accounting for genetic pleiotropy. Conversely, when we examined the effects of cSVD phenotypes on 25(OH)D concentration, cerebral microbleeds were negatively associated with 25(OH)D concentration (0.94 [0.92-0.96]).

CONCLUSIONS

Given the adequate statistical power (>0.8) of the analyses, our findings suggest that the previously reported association between 25(OH)D concentration and cSVD phenotypes might not be causal and partly attributed to reverse causation.

Brain changes in neuroimaging of adult patients with vitamin D deficiency: systematic review protocol

INTRODUCTION

Brain abnormalities detected through neuroimaging are described in patients with vitamin D deficiency, however, it is still not clear which cerebral alterations are more frequent and characteristic in this population. Thus, this review aims to identify and classify which are the main and most frequent brain changes found by neuroimaging in patients with vitamin D deficiency.

METHODS AND ANALYSIS

The study protocol was constructed in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols and the leading research question was formulated through Population, Intervention, Comparator, Outcome, Setting. The evidence will be researched at the following electronic databases: PubMed, PsycINFO, Scopus, Web of Science and EMBASE. Two researchers will work in the selection, analysis and inclusion phases of the articles. In the case of divergence, a third-party reviewer will be contacted. The following studies will be included: (1) cohort studies, case-control studies and cross-sectional studies; (2) studies carried out on patients with serum 25-hydroxyvitamin D levels below 30 ng/mL; (3) studies conducted with an adult population; (4) studies using neuroimaging methods. Articles considered eligible will be analysed by the Newcastle-Ottawa Quality Assessment Scale/cross-section studies to evaluate study quality. The survey will be conducted from June to December 2022.

ETHICS AND DISSEMINATION

The identification of the main and most frequent brain alterations found through neuroimaging in patients with vitamin D deficiency can guide professionals as to the identification which of the main cerebral pathologies detected through neuroimaging are related to vitamin D deficiency, in choosing more sensitive and specific neuroimaging tests to detect these brain changes, in addition to emphasising the importance of monitoring and maintaining adequate serum levels of vitamin D, in order to reduce possible cognitive sequelae. Results will be announced at national and international conferences.

PROSPERO REGISTRATION NUMBER

CRD42018100074.

Impact of 25-Hydroxy Vitamin D on White Matter Hyperintensity in Elderly Patients: A Systematic Review and Meta-Analysis

Some studies show that low serum vitamin D levels are associated with white matter hyperintensity (WMH), while other studies report no association. This meta-analysis aimed to investigate the presence of an association between serum 25-hydroxy vitamin D [25(OH)D] levels and WMH. PubMed, Embase, the Cochrane Library, CNKI, WANFANG, and VIP were searched for available papers published up to December 2020. The outcomes were the odds ratios (ORs) with 95% confidence intervals (CIs) for the association between different vitamin D statuses and WMH. All meta-analyses were performed using a random-effects model. Five studies (4393 patients) were included. Compared with sufficient 25(OH)D levels, 25(OH)D deficiency was not associated with WMH (OR = 1.67, 95%CI: 0.92–3.04; I² = 70.2%, P_{heterogeneity} = 0.009), nor was 25(OH)D insufficiency (OR = 1.21, 95%CI: 0.89–1.65; I² = 48.1%, P_{heterogeneity} = 0.103). A decrease of 25 nmol/L in 25(OH)D levels was associated with WMH (OR = 1.83, 95%CI: 1.34-2.49; I² = 0%, P_{heterogeneity}= 0.512). The sensitivity analyses showed that the results were robust. 25(OH)D deficiency and insufficiency are not associated with WMH. A decrease of 25 nmol/L in 25(OH)D levels was associated with WMH, but this result will have to be confirmed. Prospective trials, both cross-sectional and longitudinal, are necessary to examine the association between 25(OH)D levels and WMH.

Vitamin D and white matter hyperintensities: results of the population-based Heinz Nixdorf Recall Study and 1000BRAINS

BACKGROUND AND PURPOSE

Cross-sectional studies showed an inverse association between serum 25-hydroxyvitamin D (25OHD) and white matter hyperintensities (WMHs) whereas the few longitudinal studies did not. The association between baseline 25OHD and WMHs at 10-year follow-up in the Heinz Nixdorf Recall Study plus 1000BRAINS was investigated.

METHODS

Data of 505 participants (49% women, 56.2 ± 6.6 years) with 25OHD at baseline (2000-2003) and WMH volume and grade of WMHs using the Fazekas classification at 10-year follow-up were analysed. The association between deseasonalized 25OHD and the base-10 logarithm of WMH volume was evaluated by multiple linear regression, adjusted for age, sex, education, smoking, alcohol consumption, sports, diabetes mellitus, systolic blood pressure and total cholesterol. β-estimators were transformed back (10^β ). Using multiple logistic regression, odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated to evaluate the association between deseasonalized 25OHD and Fazekas grades (0, absence and 1, punctate foci vs. 2, beginning and 3, large confluence).

RESULTS

Mean 25OHD was 17.0 ± 8.2 ng/ml, and mean deseasonalized 25OHD was 16.9 ± 7.5 ng/ml. Mean WMH volume was 16.6 ± 17.4 ml, range 1-132 ml. Most grade 2-3 WMHs were found to be periventricular (39% of the participants), parietal (32%) and frontal (31%) (temporal 6%, occipital 3%). The linear regression showed an inverse association between 25OHD and WMH volume. On average, a 25OHD increase of 1 ng/ml was associated with a reduced WMH volume by a factor of 0.99 (95% CI 0.98; 1.00) (fully adjusted). There was also some indication for an inverse association between 25OHD and extent of periventricular (OR 0.98 [95% CI 0.96; 1.01]), frontal (0.99 [0.97; 1.02]) and parietal (0.98 [0.95; 1.00]) WMHs according to the Fazekas classification.

CONCLUSIONS

Lower 25OHD may be a risk factor for the occurrence of WMHs.

Neuroimaging changes associated with vitamin D Deficiency - a narrative review

ABSTRACTEmerging evidence suggests the role of vitamin D in brain health and its implication in the pathogenesis of cognitive impairment. The Aim of this review is to summarize current evidence on neuroimaging changes seen in vitamin D deficient individuals. Cross-sectional and longitudinal studies have consistently found an association between low serum 25 hydroxyvitamin D and cognitive impairment. Furthermore, investigating the association between serum 25 hydroxyvitamin D and neuroimaging abnormalities could provide an insight into the potential mechanisms underlying the association with cognitive impairment. Animal studies have demonstrated structural changes in the cerebral cortex and hippocampus of vitamin D deficient mice. Neuroimaging studies of the brain have shown increased white matter hyperintensities in periventricular, cortical, and juxtacortical areas and grey matter atrophy of the hippocampus, anterior cingulate cortex, and left calcarine sulcus in elderly with vitamin D deficiency.

Vitamin D, Folate, and Cobalamin Serum Concentrations Are Related to Brain Volume and White Matter Integrity in Urban Adults

Background and objectives: Lower vitamin status has been linked to cognitive deficits, pending mechanistic elucidation. Serum 25-hydroxyvitamin D [25(OH)D], folate and cobalamin were explored against brain volumes and white matter integrity (WMI).

Methods: Two prospective waves from Healthy Aging in Neighborhoods of Diversity Across the Life Span (HANDLS) study were primarily used [Baltimore, City, MD, 2004–2015, N = 183–240 urban adults (Age_v1: 30–64 years)]. Serum vitamin 25-hydroxyvitamin D [25(OH)D], folate and cobalamin concentrations were measured at visits 1 (v₁: 2004–2009), while structural and diffusion Magnetic Resonance Imaging (sMRI/dMRI) outcomes were measured at vscan: 2011–2015. Top 10 ranked adjusted associations were corrected for multiple testing using familywise Bonferroni (FWER < 0.05) and false discovery rates (FDR, q-value < 0.10).

Results: We found statistically significant (FWER < 0.05; β±SE) direct associations of 25(OH)D(v₁) with WM volumes [overall: +910 ± 336/males: +2,054 ± 599], occipital WM; [overall: +140 ± 40, males: +261 ± 67 and Age_v1 > 50 years: +205 ± 54]; parietal WM; [overall: +251 ± 77, males: +486 ± 129 and Age_v1 > 50 years: +393 ± 108] and left occipital pole volume [overall: +15.70 ± 3.83 and above poverty: 19.0 ± 4.3]. Only trends were detected for cobalamin exposures (q < 0.10), while serum folate (v₁) was associated with lower mean diffusivity (MD) in the Anterior Limb of the Internal Capsule (ALIC), reflecting greater WMI, overall, while regional FA (e.g., cingulum gyrus) was associated with greater 25(OH)D concentration.

Conclusions: Among urban adults, serum 25(OH)D status was consistently linked to larger occipital and parietal WM volumes and greater region-specific WMI. Pending longitudinal replication of our findings, randomized controlled trials of vitamin D supplementation should be conducted against brain marker outcomes.

Association of serum cystatin C with white matter abnormalities in patients with amnestic mild cognitive impairment

Aim

White matter hyperintensities (WMH) on MRI have been reported to be a risk factor for the conversion from mild cognitive impairment (MCI) to Alzheimer's disease, although the reason remains unclear. In the present study, we hence investigated the associations between WMH volumes and cognitive function, blood levels of various molecules, and the presence of lifestyle‐associated diseases in patients with amnestic MCI.

Methods

The initial data of 38 patients with amnestic MCI and 10 normal control individuals were analyzed. The volumes of periventricular hyperintensities (PVH) and deep WMH (DWMH) were measured on T2 fluid‐attenuated inversion recovery using the imaging software, 3D Slicer; and the association between PVH/DWMH volumes and cognitive function, blood levels of molecules (such as cystatin C [CysC], 25‐hydroxyvitamin D and homocysteine) and the presence of lifestyle‐associated diseases (such as hypertension, hyperlipidemia and diabetes mellitus) were analyzed.

Results

In the MCI group, the PVH volume : intracranial volume ratio significantly correlated with Trail Making Test‐A/B scores and CysC level by Pearson's analysis, and the PVH volume : intracranial volume ratio significantly correlated with only CysC levels, whereas the DWMH volume : intracranial volume ratio did not correlate with any items at all by linear multiple regression analysis.

Conclusions

PVH volume was closely associated with frontal lobe dysfunction, particularly with attention and executive dysfunction. Serum CysC level was associated with PVH volume, which suggests that CysC might be a useful marker for determining treatment strategies for white matter abnormalities in amnestic MCI. Geriatr Gerontol Int 2019; 19: 1036–1040.

Examining the relationship between nutrition and cerebral structural integrity in older adults without dementia

The proportion of adults aged 60 years and over is expected to increase over the coming decades. This ageing of the population represents an important health issue, given that marked reductions to cerebral macro- and microstructural integrity are apparent with increasing age. Reduced cerebral structural integrity in older adults appears to predict poorer cognitive performance, even in the absence of clinical disorders such as dementia. As such, it is becoming increasingly important to identify those factors predicting cerebral structural integrity, especially factors that are modifiable. One such factor is nutritional intake. While the literature is limited, data from available cross-sectional studies indicate that increased intake of nutrients such as B vitamins (for example, B6, B12 and folate), choline, n-3 fatty acids and vitamin D, or increased adherence to prudent whole diets (for example, the Mediterranean diet) predicts greater cerebral structural integrity in older adults. There is even greater scarcity of randomised clinical trials investigating the effects of nutritional supplementation on cerebral structure, though it appears that supplementation with B vitamins (B6, B12 and folic acid) or n-3 fatty acids (DHA or EPA) may be beneficial. The current review presents an overview of available research examining the relationship between key nutrients or adherence to select diets and cerebral structural integrity in dementia-free older adults.

Vitamin D and Risk of Neuroimaging Abnormalities

Vitamin D deficiency has been linked with an increased risk of incident all-cause dementia and Alzheimer’s disease. The aim of the current study was to explore the potential mechanisms underlying these associations by determining whether low vitamin D concentrations are associated with the development of incident cerebrovascular and neurodegenerative neuroimaging abnormalities. The population consisted of 1,658 participants aged ≥65 years from the US-based Cardiovascular Health Study who were free from prevalent cardiovascular disease, stroke and dementia at baseline in 1992–93. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were determined by liquid chromatography-tandem mass spectrometry from blood samples collected at baseline. The first MRI scan was conducted between 1991–1994 and the second MRI scan was conducted between 1997–1999. Change in white matter grade, ventricular grade and presence of infarcts between MRI scan one and two were used to define neuroimaging abnormalities. During a mean follow-up of 5.0 years, serum 25(OH)D status was not significantly associated with the development of any neuroimaging abnormalities. Using logistic regression models, the multivariate adjusted odds ratios (95% confidence interval) for worsening white matter grade in participants who were severely 25(OH)D deficient (<25 nmol/L) and deficient (≥25–50 nmol/L) were 0.76 (0.35–1.66) and 1.09 (0.76–1.55) compared to participants with sufficient concentrations (≥50 nmol/L). The multivariate adjusted odds ratios for ventricular grade in participants who were severely 25(OH)D deficient and deficient were 0.49 (0.20–1.19) and 1.12 (0.79–1.59) compared to those sufficient. The multivariate adjusted odds ratios for incident infarcts in participants who were severely 25(OH)D deficient and deficient were 1.95 (0.84–4.54) and 0.73 (0.47–1.95) compared to those sufficient. Overall, serum vitamin D concentrations could not be shown to be associated with the development of cerebrovascular or neurodegenerative neuroimaging abnormalities in Cardiovascular Health Study participants.