Vitamin D and cardiovascular disease

Associations of genetically predicted vitamin D status and deficiency with the risk of carotid artery plaque: a Mendelian randomization study

Low concentrations of circulating 25-hydroxy-vitamin D are observationally associated with an increased risk of subclinical atherosclerosis and cardiovascular disease. However, randomized controlled trials have not reported the beneficial effects of vitamin D supplementation on atherosclerotic cardiovascular disease (ASCVD) outcomes. Whether genetically predicted vitamin D status confers protection against the development of carotid artery plaque, a powerful predictor of subclinical atherosclerosis, remains unknown. We conducted a two-sample Mendelian randomization (MR) study to explore the association of genetically predicted vitamin D status and deficiency with the risk of developing carotid artery plaque. We leveraged three genome-wide association studies (GWAS) of vitamin D status and one GWAS of vitamin D deficiency. We used the inverse-variance weighted (IVW) approach as our main method, and MR-Egger, weighted-median, and radialMR as MR sensitivity analyses. We also conducted sensitivity analyses using biologically plausible genetic instruments located within genes encoding for vitamin D metabolism (GC, CYP2R1, DHCR7, CYP24A1). We did not find significant associations between genetically predicted vitamin D status (Odds ratio (OR) = 0.99, P = 0.91) and deficiency (OR = 1.00, P = 0.97) with the risk of carotid artery plaque. We additionally explored the potential causal effect of vitamin D status on coronary artery calcification (CAC) and carotid intima-media thickness (cIMT), two additional markers of subclinical atherosclerosis, and we did not find any significant association (βCAC = - 0.14, P = 0.23; βcIMT = 0.005, P = 0.19). These findings did not support the causal effects of vitamin D status and deficiency on the risk of developing subclinical atherosclerosis.

Role of Vitamin D Deficiency in the Pathogenesis of Cardiovascular and Cerebrovascular Diseases

Deficiency in vitamin D (VitD), a lipid-soluble vitamin and steroid hormone, affects approximately 24% to 40% of the population of the Western world. In addition to its well-documented effects on the musculoskeletal system, VitD also contributes importantly to the promotion and preservation of cardiovascular health via modulating the immune and inflammatory functions and regulating cell proliferation and migration, endothelial function, renin expression, and extracellular matrix homeostasis. This brief overview focuses on the cardiovascular and cerebrovascular effects of VitD and the cellular, molecular, and functional changes that occur in the circulatory system in VitD deficiency (VDD). It explores the links among VDD and adverse vascular remodeling, endothelial dysfunction, vascular inflammation, and increased risk for cardiovascular and cerebrovascular diseases. Improved understanding of the complex role of VDD in the pathogenesis of atherosclerotic cardiovascular diseases, stroke, and vascular cognitive impairment is crucial for all cardiologists, dietitians, and geriatricians, as VDD presents an easy target for intervention.

Effects of preoperative serum vitamin D levels on early clinical function outcomes and the moderate-to-severe pain prevalence in postmenopausal women after primary total knee arthroplasty

OBJECTIVE

To investigate the impact of vitamin D levels on early clinical function outcomes and the potential risk factors of moderate-to-severe pain prevalence in postmenopausal women after primary total knee arthroplasty (TKA).

METHODS

From April 2017 to December 2019, 226 women were retrospectively recruited. The women were divided into two groups based on their preoperative serum 25-hydroxyvitamin D levels: (1) vitamin D-sufficient group (≥30 ng/mL); (2) vitamin D-deficient group (<30 ng/mL). The visual analog scale, Western Ontario and McMaster Arthritis Index score, and Knee Society Score were used to evaluate clinical outcomes. Risk factors for developing postoperative moderate-to-severe knee pain were studied using multivariate binary logistic regression analyses.

RESULTS

There was no significant difference in preoperative clinical function assessment between the two groups. The difference in postoperative Western Ontario and McMaster Arthritis Index score between the two groups was statistically significant (15.3 ± 0.7 vs 15.6 ± 0.7: P = 0.02). However, the differences in postoperative visual analog scale and Knee Society Score scores between the two groups were not significant (P > 0.05). The incidence of postoperative moderate-to-severe pain was 16.4% (95% CI 11.8%-21.9%). Multivariate logistic regression analysis revealed that vitamin D deficiency, smoking, and high body mass index were potential risk factors for moderate-to-severe knee pain in postmenopausal women early after TKA (P < 0.05).

CONCLUSION

Preoperative vitamin D deficiency may adversely affect early functional outcomes in postmenopausal women after TKA. In addition, vitamin D deficiency, smoking, and high body mass index were independent risk factors for moderate-to-severe knee pain after surgery.

The Relationship Between Vitamin D Status and Cardiovascular Diseases

With cardiovascular conditions being a leading cause of mortality and morbidity globally, several studies have identified that there is an important correlation between the level of Vitamin D and cardiovascular diseases, including an increased risk of hypertension, heart failure, and coronary artery diseases. Current published studies are in the form of both in vivo and in vitro studies and they primarily showed the evidence of how Vitamin D can downregulate Renin-Angiotensin-Aldosterone system activity and therefore providing a cardioprotective role. Nevertheless, most of these studies are observational, and there yet to be large-scale randomized controlled trials which would increase the evidence of the findings.This review aims to capture the current evidence of Vitamin D as a metabolite which is critical in reducing cardiovascular conditions and the possible physiological pathways that it works via.

Cohort Study of Nonmelanoma Skin Cancer and the Risk of Exfoliation Glaucoma

PRECIS

In a cohort study of 120,307 participants with 25+ years of follow-up, a history of nonmelanoma skin cancer (NMSC) was associated with a 40% higher exfoliation glaucoma (XFG) risk.

PURPOSE

The purpose of this study was to evaluate the relationship between NMSC (a marker of ultraviolet radiation exposure) and XFG.

METHODS

We performed a cohort study of US women (n=79,102; 1980-2014) and men (n=41,205; 1986-2014), aged 40+ years and at risk for glaucoma who reported eye examinations. From 1984 (women)/1988 (men), we asked about basal cell carcinoma or squamous cell carcinoma history separately; in prior years, we asked about any NMSC history in a single question. Squamous cell carcinoma was confirmed with histopathology reports while basal cell carcinoma and any early (<1984/<1988) NMSC history was self-reported. Incident XFG cases (362 women and 83 men) were confirmed with medical records. Using pooled data, we estimated multivariable-adjusted relative risks [MVRRs; 95% confidence intervals (CIs)] with Cox proportional hazards models that were stratified by age (in mo), 2-year time period at risk and average lifetime residential latitude.

RESULTS

In multivariable-adjusted analyses, we observed a 40% higher XFG risk with any NMSC history (MVRR=1.40; 95% CI=1.08-1.82); the association was observed even with 4 and 8-year lags in NMSC history. Also, the NMSC association was stronger in younger (below 65 y; MVRR=2.56; 95% CI=1.62-4.05) versus older participants (65 y and above; MVRR=1.25; 95% CI=0.94-1.66; P for interaction=0.01) and those living in the northern latitudes (≥42°N; MVRR=1.92; 95% CI=1.28-2.88) versus more southern latitudes (<42°N; MVRR=1.19; 95% CI=0.86-1.66; P for interaction=0.04).

CONCLUSION

NMSC was associated with higher XFG risk, particularly among younger participants and those living in the Northern US.

Functional Nutrients for Epilepsy

Epilepsy is a common neurological disorder of which seizures are a core symptom. Approximately one third of epileptic patients are resistant to antiepileptic drugs and therefore require alternative therapeutic options. Dietary and nutritional supplements can in some cases replace drugs, but with the exception of ketogenic diets, there are no officially recommended dietary considerations for patients with epilepsy. In this review we summarize a selection of nutritional suggestions that have proved beneficial in treating different types of epilepsy. We describe the types of seizures and epilepsy and follow this with an introduction to basic molecular mechanisms. We then examine several functional nutrients for which there is clinical evidence of therapeutic efficacy in reducing seizures or epilepsy-associated sudden death. We also discuss experimental results that demonstrate possible molecular mechanisms elicited by the administration of various nutrients. The availability of multiple dietary and nutritional candidates that show favorable outcomes in animals implies that assessing the clinical potential of these substances will improve translational medicine, ultimately benefitting epilepsy patients.

Parathyroid hormone has an important role in blood pressure regulation in vitamin D-insufficient individuals

OBJECTIVE

The aim of the present study was to evaluate whether vitamin D status is related to blood pressure (BP) in adults.

METHODS

We evaluated the relationship between vitamin D status, intact parathyroid hormone (iPTH) and BP in 332 adults. Anthropometric measurements, BP, and a fasting blood sample was obtained. Participants were stratified into the following BP categories: 1) normal BP; 2) high BP; 3) normal BP through medication. Vitamin D insufficiency was defined as 25-hydroxvitamin D ≤ 75 nmol/L; high iPTH as > 65 pg/mL. The relationships between vitamin D status, iPTH and BP were adjusted for body mass index, waist circumference, blood lipids, physical activity, and sunscreen use.

RESULTS

No differences in prevalences of vitamin D insufficiency and high iPTH were observed among BP groups. No significant association was observed between BP and vitamin D status. Positive correlations were observed between iPTH and systolic BP (r = 0.168; P = 0.002) and between iPTH and diastolic BP (r = 0.168; P = 0.002). iPTH remained correlated with BP even with adjustments.

CONCLUSIONS

The present study contributes to the understanding of calcemic hormones and BP regulation.

Hypovitaminosis D and mild hypocalcaemia are highly prevalent among young Vietnamese children and women and related to low dietary intake

Introduction

In many developing countries including Vietnam, data are lacking on vitamin D and calcium deficiencies whereas those deficiencies can play an important role in the development of bone health and possibly non-communicable diseases. The purpose of this study was to determine the overall prevalence of vitamin D and calcium deficiencies in women and young children and their nutritional related risk factors.

Methods

A cross-sectional study conducted among 595 women of reproductive age and 532 children <5 years from 19 provinces of Vietnam. For each individual, data concerning daily diet, socioeconomic group, anthropometric status were obtained, and plasma concentrations of calcium and vitamin D were measured.

Results

The prevalence of hypovitaminosis D status was very high, with the prevalence of vitamin D deficiency (25(OH)D<30 nmol/L) and insufficiency (25(OH)D between 30–49.9 nmol/L) being 17% and 40% in women and 21% and 37% in children, respectively. Using more liberal cut-off of 75 nmol/L, approximately 90% of the women and children were classified as having hypovitaminosis D. Overweight/obese women had a 2 times lower risk (OR = 0.46, [0.24–0.90]) for vitamin D deficiency than non-overweight and non-obese women. No participant had severe calcium deficiency but moderate and mild hypocalcaemia (plasma calcium concentrations between 1.15-0.9 mmol/L for mild deficiency and between 0.9-0.8 mmol/L for moderate deficiency) affected respectively 14% and 83% of the women with 97% of the children having mild hypocalcaemia. Women and children consumed about 1% of the Institute of Medicine (IOM) recommended nutrient intake (RNI) for vitamin D and less than 43% of the RNI for calcium.

Conclusion

Our study suggests that calcium and vitamin D deficiencies represent a major public health concern in Vietnam. Thus, actions to improve the vitamin D and calcium status of the Vietnamese population should be considered.

Association between serum levels of 25-hydroxyvitamin D and osteoarthritis: a systematic review

OBJECTIVE

To systematically review the evidence for association between serum 25-hydroxyvitamin D (25-(OH)D) and OA and the effect of vitamin D therapy on OA.

METHODS

An English Medline, EMBASE and Cochrane Library search for vitamin D and OA from January 1980 to June 2012 was performed. Randomized controlled trials (RCTs), cohort, case-control and cross-sectional studies in adults were included. The methodological quality of the selected studies was assessed and a best-evidence synthesis was used to summarize the results due to the heterogeneity of the studies.

RESULTS

Of the 86 evaluated articles, 2 RCTs and 13 observational studies were included in the final analyses. The number of participants ranged from 64 to 1644 (0-100% women). The RCTs were only reported in abstract form and showed inconsistent results, most likely due to variations in their study design. There was insufficient or limited evidence for associations between 25-(OH)D and hand or hip OA. For knee radiographic OA as assessed by the Kellgren and Lawrence (KL) score, there was moderate evidence showing that low levels of 25-(OH)D were associated with increased progression of radiographic OA. Strong evidence for an association between 25-(OH)D and cartilage loss was apparent when joint space narrowing and changes in cartilage volume were considered collectively as cartilage loss.

CONCLUSION

25-(OH)D appears to be implicated in structural changes of knee OA rather than symptoms, and further well-designed RCTs are required to determine whether vitamin D supplementation can slow disease progression. There is insufficient evidence for other sites.

Pre-diagnostic plasma 25-hydroxyvitamin D levels and risk of non-melanoma skin cancer in women

BACKGROUND

Recent reports have shown that vitamin D status was inversely associated with the risk of various cancers. However, few studies examined the association between vitamin D levels and risk of skin cancer.

METHODS

We prospectively evaluated the association between baseline plasma 25(OH)D levels and the risk of incident squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) among 4,641 women from the Nurses' Health Study (NHS) and the NHS II with 510 incident BCC cases and 75 incident SCC cases. We used multivariate logistic regression models to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Plasma 25(OH)D levels were positively associated with risk of BCC after adjusting for age at blood draw, season of blood draw, lab batch, hair color, burning tendency, the number of sunburns, and ultra-violet B flux of residence at blood collection. Women in the highest quartile of 25(OH)D had more than 2-fold increased risk of BCC compared with women in the lowest quartile (OR = 2.07, 95% CI = 1.52-2.80, P for trend <0.0001). We also found a significantly positive association between plasma 25(OH)D levels and SCC risk after adjusting for the same covariates (OR, highest vs. lowest quartile = 3.77, 95% CI = 1.70-8.36, P for trend= 0.0002).

CONCLUSION

In this prospective study of women, plasma vitamin D levels were positively associated with non-melanoma skin cancer risk. Considering that most circulating vitamin D is due to sun exposure, the positive association between plasma vitamin D and non-melanoma skin cancer is confounded by sun exposure. Our data suggest that one-time measurement of plasma vitamin D levels may reasonably reflect long-term sun exposure and predict the risk of non-melanoma skin cancer.