Serum 25-Hydroxyvitamin D Level and Aortic Intima-Media Thickness in Patients Without Clinical Manifestation of Atherosclerotic Cardiovascular Disease

Serum 25-Hydroxyvitamin D Level Is Positively Associated with Vascular Reactivity Index in Patients with Type 2 Diabetes Mellitus

Circulating 25-hydroxyvitamin D (25(OH)D) significantly influences endothelial function. This study assessed the correlation between serum 25(OH)D and endothelial function using the vascular reactivity index (VRI) in patients with type 2 diabetes mellitus (T2DM). Fasting blood samples from 102 T2DM participants and VRI were assessed. Patients were divided into three categories based on VRI: low (VRI < 1.0), intermediate (1.0 ≤ VRI < 2.0), and good (VRI ≥ 2.0). Among these patients, 30 (29.4%) had poor, 39 (38.2%) had intermediate, and 33 (32.4%) exhibited good vascular reactivity. Higher serum fasting glucose (p = 0.019), glycated hemoglobin (p = 0.009), and urinary albumin-to-creatinine ratio (p = 0.006) were associated, while lower prevalence of hypertension (p = 0.029), lower systolic blood pressure (p = 0.027), lower diastolic blood pressure (p < 0.001), and lower circulation 25(OH)D levels (p < 0.001) were associated with poor vascular reactivity. Significant independent associations between diastolic blood pressure (p = 0.002) and serum 25(OH)D level (p < 0.001) and VRI were seen in T2DM patients according to multivariable forward stepwise linear regression analysis. Serum 25(OH)D positively correlated with VRI values, and lower levels of serum 25(OH)D were linked to endothelial dysfunction in T2DM patients.

25(OH)D level and vascular lesion scores in kidney histopathology as risk-stratification tool for predicting renal progression in people with type 2 diabetes

AIM

To evaluate the potential of the combined individual vascular histopathological lesion and serum 25-hydroxy vitamin D [25(OH)D] level as predictors of outcomes in patients with diabetes and chronic kidney disease.

METHODS

A total of 190 patients with type 2 diabetes and kidney disease stages 1-4 were retrospectively included. Kaplan-Meier analysis and the log-rank test were performed to assess renal survival differences. And the time-dependent receiver operating characteristic analyses were used to characterize the predictive accuracy. Hazard ratios for vascular lesion scores and 25(OH)D levels with renal outcomes were estimated using Cox proportional hazards regression models with follow-up time.

RESULTS

Over a median follow-up of 23.78 (12.61, 37.14) months, 71 patients (37.4 %) experienced the renal outcomes. Enrolled patients with more severe vascular lesions had worse kidney function, heavier proteinuria, lower serum 25(OH)D levels, and higher prevalence of composite kidney outcomes. Baseline serum 25(OH)D was a significant independent risk factor for vascular lesion scores. The effect of serum 25(OH)D level on kidney prognosis was more pronounced in males and those with more exacerbated vascular lesions (score 2). The severity of vascular lesions and serum 25(OH)D levels were associated with unfavorable kidney outcomes. Accordingly, further time-dependent receiver operating characteristic curves confirmed that combined 25(OH)D level and vascular lesion score had a stable and reliable performance in renal outcomes prediction at short and long-term follow-up times.

CONCLUSIONS

25(OH)D level and vascular lesion scores in kidney histopathology could serve as a useful risk-stratification tool for predicting renal progression in patients with type 2 diabetes.

Correlation between Serum 25-Hydroxyvitamin D Level and Peripheral Arterial Stiffness in Chronic Kidney Disease Stage 3-5 Patients

Vitamin D deficiency and high brachial-ankle pulse wave velocity (baPWV) are each independently associated with higher incidence of mortality and cardiovascular (CV) disease or CV events, respectively. This study aimed to evaluate the relationship between serum 25-hydroxyvitamin D levels and baPWV in non-dialysis patients with stage 3−5 chronic kidney disease (CKD). We enrolled 180 CKD patients. A commercial enzyme-linked immunosorbent assay was used to measure 25-hydroxyvitamin D levels. BaPWV values were measured using an automatic pulse wave analyzer. Either left or right baPWV > 18.0 m/s was considered indicative of peripheral arterial stiffness (PAS). In this study, 73 (40.6%) patients were found to have PAS. Compared to those without PAS (control group), patients with PAS were older and had higher incidence of diabetes mellitus, higher systolic and diastolic blood pressure, higher levels of intact parathyroid hormone, and C-reactive protein, and lower levels of 25-hydroxyvitamin D. Multivariate logistic regression analysis found 25-hydroxyvitamin D levels (odds ratio [OR]: 0.895, 95% confidence interval [CI] 0.828−0.968, p = 0.005) and old age (OR: 1.140, 95% CI 1.088−1.194, p < 0.001) to be independently associated with PAS in patients with stage 3−5 CKD. Lower serum 25-hydroxyvitamin D levels and older age were associated with PAS in these patients.

The impact of visceral fat and levels of vitamin D on coronary artery calcification

OBJECTIVE

To evaluated calcification of the coronary arteries and its association with visceral fat and 25-hydroxyvitamin D (25(OH)D) serum levels.

METHODS

A cross sectional study involving 140 individuals without any previous diagnosis of cardiovascular disease. A biochemical analysis of vitamin D serum levels was carried out, as well as computed tomography to measure coronary artery calcium score and visceral adipose tissue.

RESULTS

The mean age of the individuals was 55.9 (±12.4). Coronary artery calcium was observed in 40.7% of the population. Vitamin D presented median serum levels of 30.4 ng/ml (IQ24.5-39.1), with 14,1 and 33.7% of the individuals presenting deficiency and insufficiency, respectively. In the univariate analysis, the calcium score was more prevalent in aged patients (p<0.01), in hypertensive individuals (p<0.01), in diabetics (p=0.02), and in those with a higher concentration of VAT (p=0.02). In the adjusted analysis, it was found that the highest concentration of VAT (OR: 4.0; 95%CI 1.4-11.7), hypertension (OR: 4.8; 95%CI 1.5-15.3), and age (OR: 10.4; 95%CI 3.9-27.6) were predictors of subclinical atherosclerosis, regardless of body mass index, diabetes, and 25OHD.

CONCLUSIONS

Excess visceral fat was associated with subclinical atherosclerosis, regardless of other risk factors for cardiovascular disease. Serum levels of 25OHD were not associated with CAD in its early stages.

Vitamin D and its correlation with blood lipids and intima-media thickness in term infants

Introduction

Background: an association between low 25(OH)D levels and blood lipids has been identified in children, adolescents, and adults but not in the early stages of life, and a relation to carotid and aortic intima-media thickness has not been well studied and is controversial. Objective: to identify whether 25(OH)D levels are correlated with blood lipids and aortic and carotid intima-media thickness in infants aged 3 to 9 months. Methods: a cross-sectional study was conducted in 109 healthy term infants between the ages of 3 and 9 months. Serum vitamin D [25(OH)D], total cholesterol, HDL-cholesterol, non-HDL-cholesterol, and aortic and carotid intima-media thickness were measured. Feeding method, vitamin D supplementation, and sun exposure habits were recorded. Results: only 2.8 % (n = 3) and 10.1 % (n = 14) had vitamin D deficiency and insufficiency, respectively. Infants with inadequate levels of vitamin D were younger (< 6 months) (p = 0.004), and a lower percentage of their body surface area was exposed to the sun (p = 0.006). A significant positive correlation was found between 25(OH)D levels and non-HDL-cholesterol in the infants that consumed breastmilk substitutes (rho = 0.600, p < 0.001) or were partially breastfed (rho = 0.371, p = 0.026), whereas a positive correlation was found with total cholesterol in the infants receiving breastmilk substitutes (rho = 0.618, p < 0.001). No significant correlation was found between vitamin D and aortic or carotid intima-media thickness. Conclusions: there was a positive correlation between 25(OH)D levels and both total and non-HDL-cholesterol only in infants receiving breastmilk substitutes. The frequency of vitamin D deficiency and insufficiency was low.

Vitamin D as A Protector of Arterial Health: Potential Role in Peripheral Arterial Disease Formation

Atherosclerotic occlusive diseases and aneurysms that affect large and medium-sized arteries outside the cardiac and cerebral circulation are collectively known as peripheral arterial disease (PAD). With a rise in the rate of aging population worldwide, the number of people diagnosed with PAD is rapidly increasing. The micronutrient vitamin D is an important steroid hormone that acts on many crucial cellular mechanisms. Experimental studies suggest that optimal levels of vitamin D have beneficial effects on the heart and blood vessels; however, high vitamin D concentrations have been implicated in promoting vascular calcification and arterial stiffness. Observations from various clinical studies shows that deficiency of vitamin D has been associated with a greater risk of PAD. Epidemiological studies have often reported an inverse relation between circulating vitamin D status measured in terms of 25-hydroxivitamin D [25(OH)D] levels and increased cardiovascular disease risk; however, randomized controlled trials did not show a consistent positive effect of vitamin D supplementation on cardiovascular disease risk or events. Even though PAD shares all the major risk factors with cardiovascular diseases, the effect of vitamin D deficiency in PAD is not clear. Current evidence suggests a strong role of vitamin D in promoting genomic and epigenomic changes. This review summarises the current literature that supports the notion that vitamin D deficiency may promote PAD formation. A better understanding of underlying pathological mechanisms will open up new therapeutic possibilities which is the main unmet need in PAD management. Furthermore, epigenetic evidence shows that a more holistic approach towards PAD prevention that incorporates a healthy lifestyle, adequate exercise and optimal nutrition may be more effective in protecting the genome and maintaining a healthy vasculature.

Continued Interest and Controversy: Vitamin D in HIV

PURPOSE OF REVIEW

Vitamin D (VitD) deficiency is highly prevalent among HIV-infected individuals. Given the overlapping risk for several chronic disease and immunomodulatory outcomes from both long-standing HIV and VitD deficiency, there is great interest in clarifying the clinical role of VitD for this population.

RECENT FINDINGS

Recent studies have expanded our knowledge regarding the epidemiology and mechanisms of VitD deficiency-associated outcomes in the setting of HIV. Clinical trials focusing on VitD supplementation have demonstrated a positive impact on bone mineral density in subgroups of HIV-infected individuals initiating ART or on suppressive ART regimens; however, significant heterogeneity exists between studies and data are less consistent with other clinical outcomes. Further research is needed to clarify uncertainly in several domains, including identifying patients at greatest risk for poor outcomes from VitD deficiency, standardizing definitions and measurement techniques, and better quantifying the benefits and risks of VitD supplementation across different demographic strata for skeletal and extra-skeletal outcomes.

Associations between vitamin D status and atherosclerosis among Inuit in Greenland

BACKGROUND AND AIMS

Low levels of vitamin D are suspected to be a risk factor for cardiovascular disease and atherosclerosis. The aim of this study was to assess the prevalence of subclinical atherosclerosis among Inuit in Greenland, and to evaluate the association with vitamin D status. We hypothesized that low vitamin D status could be associated with higher carotid intima-media thickness (IMT) as a marker of atherosclerosis.

METHODS

756 adults from the Inuit Health in Transition (IHIT) study carried out in Greenland in the period 2005-2010 were included. A blood sample donated in 1987 was available for a sub-sample of 102 individuals. Serum 25(OH)D3 from the IHIT study and the 1987 survey was used as a measure of vitamin D status. IMT measurements were conducted by ultrasound scanning. The prevalence of atherosclerosis was estimated, and the association between serum 25(OH)D3 and IMT measurements was examined by linear regression.

RESULTS

The overall prevalence of subclinical atherosclerosis was 20.1% (n = 152). The linear regression analyses indicated a weak positive association between serum 25(OH)D3 level and IMT measurements from the IHIT study, though not statistically significant after adjustment for potential confounders (β = 0.35% per 10 nmoL/L 25(OH)D3, p = 0.06). Linear regression analyses of the association between serum 25(OH)D3 level in the 1987 survey and IMT measurements also indicated a positive, though not statistically significant, association after adjustment (β = 0.07% per 10 nmoL/L 25(OH)D3, p = 0.86).

CONCLUSIONS

Our findings did not support the hypothesis of an association between low vitamin D levels and risk of atherosclerosis.

The Role of Vitamin D in Diabetes and Cardiovascular Disease: An Updated Review of the Literature

The dietary reference values for Vitamin D were set primarily considering its role in bone health, but with the discovery of Vitamin D receptors throughout body tissues, new links with other health conditions are now studied, such as for diabetes and cardiovascular diseases (CVD). This paper shall analyze and examine all new research studies carried out, especially in 2013–2015 regarding diabetes mellitus (DM) and cardiovascular diseases (CVD). Vast research has been carried out to establish strong relationship between Vitamin D serum levels, supplementation, diabetes, and CVD. However, the results from researches identified in this paper are disputable. Benefits of Vitamin D adequate levels were recognized from gestational period until later in disease development such as diabetes and/or CVD, but since not all studies are in agreement further investigation is suggested. Researches conducting large randomized controlled trials, exploring range of supplement doses, with variable baseline serum Vitamin D levels, and inclusion of array of associated parameters, are still required to conduct large-scale analysis and draw conclusion as a risk factor. Until then it is possible to conclude that maintenance of serum Vitamin D levels holds advantageous aspects in diabetic and cardiovascular conditions, and people should strive to attain them.