Vitamin D insufficiency and subclinical atherosclerosis in non-diabetic males living with HIV

Prevalence and Predictors of Hypovitaminosis D in Ethiopian HIV-Infected Adults

Background

Hypovitaminosis D is associated with bone fracture and cardiovascular disease in patients receiving antiretroviral therapy. Currently, there are few data on the magnitude of hypovitaminosis D in people living with HIV in Sub-Saharan country. Therefore, the present study determines the magnitude of hypovitaminosis D in people living with HIV and its associated factors in Ethiopia.

Methods

A cross-sectional study was conducted among 171 adult people living with HIV at Debre Berhan Specialized Hospital. Serum vitamin D was measured. Multivariate logistic regression analysis and p-value <0.05 was used to identify the associated factors of hypovitaminosis D.

Results

In the present study, the prevalence of hypovitaminosis D was 129/171 (75.4%), with 11/171 (6.4%) having vitamin D deficiency and 118/171 (69%) having vitamin D insufficiency. Female sex was significantly associated with hypovitaminosis D (AOR: 3.01, 95% CI = 1.381–6.561, P = 0.006).

Conclusion

Our study found a high burden of hypovitaminosis D among adult people living with HIV on antiretroviral therapy. Female sex was associated with hypovitaminosis D.

Carotid artery intima-media thickness in adults receiving long-term home parenteral nutrition

BACKGROUND AND AIMS

Nutrition regimen in parenteral nutrition (PN) patients allows for a control of diet components. This may affect the process of lipid deposition in the vascular wall and change the risk of atherosclerosis. This study aims to examine the effect of long-term PN in adults on carotid intima-media thickness.

METHODS AND RESULTS

Thirty long-term PN patients (15 men and 15 women, mean age 64.7 ± 8.5 years) and thirty healthy volunteers (HV) (15 men and 15 women, mean age 64.9 ± 8.77 years) entered the study. Total amino acid and lipid formulation intake as well as duration of PN were calculated for PN patients. The common carotid artery intima-media thickness (CCA IMT) was examined in both groups. A lower CCA IMT (right/left mean: PN - 776 ± 121 vs HV - 848 ± 121 μm, p < 0.05; right/left maximum CCA IMT: PN - 935 ± 139 vs HV - 1024 ± 135 μm, p < 0.05) in PN patients was observed. A lower serum level of total (PN - 131.43 ± 43.12 vs HV - 209.2 ± 48.01 mg/dl, p < 0.05) and HDL (PN- 44.16 ± 12.45 vs HV - 72.57 ± 25.04 mg/dl, p < 0.05) cholesterol was reported in the PN patients. A correlation between patients' age and CCA IMT was observed in the control group, but not in the PN patients (right/left mean CCA IMT - PN: r = 0.48, p-0.007 vs HV: p-0.073; right/left maximum CCA IMT - PN: r = 0.48, p-0.008, vs HV: p-0.073).

CONCLUSIONS

Long term PN in adults is associated with lower CCA IMT. Long-term PN patients are a unique group in which carotid intima-media thickness does not correlate with the age.

Vitamin D insufficiency is associated with subclinical atherosclerosis in HIV-1-infected patients on combination antiretroviral therapy

Objectives: Vitamin D insufficiency has been associated with faster progression of atherosclerosis and increased cardiovascular disease risk, but limited data are available in HIV-infected people. So, we examined potential correlation between vitamin D status and atherosclerosis in people living with HIV.Methods: A cross-sectional study was performed including adult HIV-infected patients on stable antiretroviral therapy, aged 40-60 years, and with a recent carotid ultrasonography. Subclinical atherosclerosis was defined as a carotid intima-media thickness (IMT) ≥0.9 mm at any site. Patients with diabetes mellitus or atherosclerotic cardiovascular disease were excluded.Results: On the whole, 188 patients were enrolled: 86.2% were men and the mean age was 49.1 years. The mean CD4 T lymphocyte count was 567 cells/mm³, 176 (93.6%) had plasma HIV RNA <20 copies/mL, 51.1% were smoker, 29.2% had hypertension, 27.7% metabolic syndrome, and 44.7% LDL cholesterol >150 mg/dL. The mean serum concentration of vitamin D was 35.2 ng/mL, and 84 (44.6%) patients had a vitamin D insufficiency (<30 ng/mL). Subclinical atherosclerosis was reported in 105 (55.8%) and the mean vitamin D concentration was significantly lower among patients with subclinical atherosclerosis than among those without (18.2 vs 41.3 ng/mL, p < 0.001). Moreover, the multivariate linear regression analysis adjusted by confounding factors showed an independent association between subclinical atherosclerosis and vitamin D insufficiency, age >50 years, smoking, hypertension, metabolic syndrome, higher BMI, higher LDL cholesterol, longer duration of HIV infection, lower nadir CD4 cell count, and longer exposure to boosted protease inhibitors.Conclusion: In our study, vitamin D insufficiency is significantly associated with subclinical atherosclerosis, so its role in HIV-associated cardiovascular disease should be further evaluated as a possible target for intervention.

Association of Low Vitamin D with Complications of HIV and AIDS: A literature Review

With the advent of combination antiretroviral therapy (cART), the survival of HIV patients has improved dramatically, but the complications of the disease and treatment have become an important issue in the management of HIV patients. Vitamin-D deficiency is common in HIV patients. Low vitamin-D is associated with different comorbidities in the HIV uninfected general population. In this review, we first briefly describe vitamin D synthesis and mechanism of action and we focus on the epidemiological and clinical data dealing with the relationship between vitamin D deficiency in HIV infection with several comorbidities which has been found to be increasingly common in patients living with HIV infection. We searched the PubMed database using the keywords "HIV," "vitamin D" and other common disorders or conditions that are relatively common in HIV infection. The other conditions included in the search were osteoporosis and fracture, cardiovascular disease, diabetes and insulin resistance, active tuberculosis, hepatitis-C co-infection, and HIV disease progression. Articles presenting original data as well as systematic reviews and met analysis related to HIV population were included in our analysis. Vitamin-D deficiency seems to be associated with several adverse outcomes in HIV patients but a definite cause and effect relationship with vitamin-D is yet to be confirmed in most of the cases. However, the literature supporting the efficacy of vitamin-D supplementation is lacking.

High Irisin levels in nondiabetic HIV-infected males are associated with insulin resistance, nonalcoholic fatty liver disease, and subclinical atherosclerosis

OBJECTIVE

HIV infection is associated with an increased risk of cardiovascular disease. Irisin is a miokyne secreted by skeletal muscle, which may influence insulin homeostasis, nonalcoholic fatty liver disease (NAFLD) and atherosclerosis. Our objective was to evaluate the relationships between serum irisin, insulin homeostasis, NAFLD and subclinical atherosclerosis in HIV-infected males.

DESIGN

Cross-sectional study in a cohort of HIV-infected patients.

PATIENTS

Inclusion criteria: men older than 18 years; antiretroviral therapy (ART) -naïve or on effective ART (<50 HIV-1 RNA copies/mL) without changes in the previous 6 months; no diabetes or hepatitis C.

MEASUREMENTS

Irisin was measured by enzymatic immunoassay (Phoenix Pharmaceuticals), insulin sensitivity by homeostasis model assessment of insulin resistance (HOMA-IR), as well as the 2-hour continuous infusion of glucose with model assessment (CIGMA-HOMA). Hepatic steatosis was measured by 1-H magnetic resonance spectroscopy, subclinical atherosclerosis by evaluation of carotid intima-media thickness (C-IMT), measured by Ultrasonography.

RESULTS

Eight nine men (age 42.0 ± 8.3 years, duration of HIV infection 7.9 ± 5.6 years, CD4 count 547 ± 279 cells/mL) were included. Circulating irisin was positively related to HOMA-IR and CIGMA-HOMA, hepatic triglyceride content, and to VAT/SAT ratio. Higher irisin concentrations were associated with higher C-IMT, although this association did not persist in multivariate analysis. Lipodystrophy and a higher baseline PAI-1 concentration were independently associated with C-IMT.

CONCLUSIONS

In male HIV patients without diabetes, higher irisin concentrations are positively associated with insulin resistance, NAFLD and subclinical atherosclerosis. However, waist-hip-ratio is the main determinant of insulin resistance, and PAI-1 and lipodystrophy were the strongest determinants of IMT in this population.

Impact of circulating bacterial DNA in long-term glucose homeostasis in non-diabetic patients with HIV infection: cohort study

In HIV-infected patients, the damage in the gut mucosal immune system is not completely restored after antiretroviral therapy (ART). It results in microbial translocation, which could influence the immune and inflammatory response. We aimed at investigating the long-term impact of bacterial-DNA translocation (bactDNA) on glucose homeostasis in an HIV population. This was a cohort study in HIV-infected patients whereby inclusion criteria were: patients with age >18 years, ART-naïve or on effective ART (<50 HIV-1 RNA copies/mL) and without diabetes or chronic hepatitis C. Primary outcome was the change in HbA1c (%). Explanatory variables at baseline were: bactDNA (qualitatively detected in blood samples by PCR [broad-range PCR] and gene 16SrRNA - prokaryote), ART exposure, HOMA-R and a dynamic test HOMA-CIGMA [continuous infusion of glucose with model assessment], hepatic steatosis (hepatic triglyceride content - 1H-MRS), visceral fat / subcutaneous ratio and inflammatory markers. Fifty-four men (age 43.2 ± 8.3 years, BMI 24.9 ± 3 kg/m², mean duration of HIV infection of 8.1 ± 5.3 years) were included. Baseline HbA1c was 4.4 ± 0.4% and baseline presence of BactDNA in six patients. After 8.5 ± 0.5 years of follow-up, change in HbA1c was 1.5 ± 0.47% in patients with BactDNA vs 0.87 ± 0.3% in the rest of the sample p < 0.001. The change in Hba1c was also influenced by protease inhibitors exposure, but not by baseline indices of insulin resistance, body composition, hepatic steatosis, inflammatory markers or anthropometric changes. In non-diabetic patients with HIV infection, baseline bacterial translocation and PI exposure time were the only factors associated with long-term impaired glucose homeostasis.

Vitamin D and progression of carotid intima-media thickness in HIV-positive Canadians

OBJECTIVES

Based on a growing body of evidence implicating low vitamin D status in the development of cardiovascular disease (CVD), we hypothesized that in Canadian HIV-positive adults, low 25-hydroxyvitamin D (25(OH)D) concentration would be associated with increased subclinical vascular disease progression.

METHODS

We prospectively studied the relationship between baseline 25(OH)D and subsequent progression of carotid intima-media thickness (CIMT) between 2002 and 2011, in the Canadian HIV Vascular Study using stored blood specimens.

RESULTS

Of the 128 participants, 89.1% were men, the mean age (standard deviation [SD]) was 46.5 (8.2) years, 93.8% were white, and 36.7% were current smokers. Mean (SD) annual CIMT follow-up was 5.9 (1.8) years (maximum 8.5 years), providing approximately 750 patient-years of follow-up. Mean (SD) CIMT progression was 0.027 (0.030) mm/year. Mean (SD) 25(OH)D was 95.0 (46.9) nmol/L. Only 13.3% of participants were vitamin D deficient (25(OH)D < 50 nmol/L), whereas 61.7% had a 25(OH)D exceeding the sufficiency threshold (75 nmol/L). Vitamin D quartiles were inversely associated with body mass index (BMI) (P = 0.034), total cholesterol to high-density lipoprotein (HDL) cholesterol ratio (P = 0.001) and parathyroid hormone concentration (P = 0.003), but not efavirenz exposure (P = 0.141). In linear regression analyses, baseline 25(OH)D as a continuous variable was inversely associated with CIMT progression in univariable (P < 0.001) and multivariable (P < 0.001) models.

CONCLUSIONS

Baseline 25(OH)D was associated with CIMT progression in this relatively vitamin D replete, predominately white and male, Canadian HIV-positive population. Future research needs to establish causality as this may warrant more targeted screening or supplementation.

Impact of Vitamin D deficiency on subclinical carotid atherosclerosis: a pooled analysis of cohort studies

CONTEXT

Vitamin D deficiency patients have an increased cardiovascular (CV) morbidity and mortality. Carotid intima-media thickness (IMT) and carotid plaques are markers of subclinical atherosclerosis and predictors of CV events.

OBJECTIVE

To perform a meta-analysis of studies evaluating the impact of Vitamin D deficiency on common carotid artery IMT (CCA-IMT) and on the prevalence of carotid plaques.

DATA SOURCES

Studies were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases.

RESULTS

Twenty-one studies (3,777 Vitamin D deficiency patients and 4,792 controls) with data on CCA-IMT and 6 studies (1,889 Vitamin D deficiency patients and 2,883 controls) on the prevalence of carotid plaques were included. Compared to controls, Vitamin D deficiency patients showed a significantly higher CCA-IMT (mean difference [MD]: 0.043 mm; 95%CI: 0.030, 0.056; P<0.001), and an increased prevalence of carotid plaques (Odds Ratio [OR]: 2.29, 95%CI: 1.03-5.11; P=0.043) with an attributable risk of 35.9%. When selecting studies specifically including patients with diabetes, the prevalence of carotid plaques in Vitamin D deficiency patients than in controls resulted higher (OR: 3.27; 95%CI: 1,62-6.62; P=0.001). A significant difference in CCA-IMT was confirmed when comparing patients with Vitamin D insufficiency to controls (MD: 0.011; 95%CI: 0.010-0.012, P<0.001). Sensitivity analyses substantially confirmed results and regression models showed that with the exception of LDL-cholesterol, HDL-cholesterol, triglycerides and the prevalence of hypercholesterolemia, all the other clinical and demographic co-variates significantly impacted on the difference in CCA-IMT between Vitamin D deficiency patients and controls.

CONCLUSIONS

Both Vitamin D deficiency and Vitamin D insufficiency are associated with subclinical atherosclerosis, potentially suggesting an increased CV risk in these clinical settings.

Environmental Factors Related to Pulmonary Tuberculosis in HIV-Infected Patients in the Combined Antiretroviral Therapy (cART) Era

The aim of our study was to evaluate the seasonal variations and whether short-term exposure to environmental risk factors, such as climate and air pollution, is associated with PTB-related hospital admissions in human immunodeficiency virus (HIV)-infected patients in Spain during the era of combined antiretroviral therapy (cART). A retrospective study was carried out using data from the Minimum Basic Data Set (MBDS) and the State Meteorological Agency (AEMET) of Spain. The primary outcome variable was hospital admissions with PTB diagnosis. The environmental risk factors evaluated were season, temperature, humidity, NO2, SO2, O3, PM10, and CO. Overall, HIV-infected patients had a lower frequency of PTB-related hospital admissions in summer (22.8%) and autumn (22.4%), but higher values in winter (26.6%) and spring (28.2%). Using a Bayesian temporal model, PTB-related hospital admissions were less frequent in summer-autumn and more abundant in winter-spring during the first years of follow-up. During the later years of follow-up, the seasonal trends continued resulting in the lowest values in autumn and the highest in spring. When considering short-term exposure to environmental risk factors, lower temperatures at 1 week (odds ratio (OR) = 1.03; p = 0.008), 1.5 weeks (OR = 1.03; p<0.001), 2 weeks (OR = 1.04; p<0.001), and 3 weeks (OR = 1.03; p<0.001) prior to PTB admission. In addition, higher concentration of NO2 at the time of admission were significantly associated with higher likelihoods of PTB-related hospital admission in HIV-infected patients when 1.5 weeks (OR = 1.1; p = 0.044) and 2 weeks (OR = 1.21; p<0.001) were used as controls. Finally, higher concentration of SO2 at 1.5 weeks prior to PTB admission was significantly associated with a higher likelihood of PTB-related hospital admissions (OR = 0.92; p = 0.029). In conclusion, our data suggest an apparent seasonal variation in hospital admissions of HIV-infected patients with a PTB diagnosis (summer/autumn vs. winter/spring), as well as a link to short-term exposure to environmental risk factors, such as temperature and ambient NO2 and SO2.

Pro-Inflammatory Markers in Relation to Cardiovascular Disease in HIV Infection. A Systematic Review

Background

In the past years many inflammatory markers have been studied in association with clinically manifest cardiovascular disease (CVD) and carotid intima-media thickness (CIMT) in HIV-infected patients, to obtain insights in the increased cardiovascular risk observed in HIV infection. This systematic review provides an oversight of the current knowledge.

Methods

A search was performed in PubMed, Embase and Cochrane in July 2014, identifying all articles from 1996 onwards addressing the relation between inflammatory markers and CVD or CIMT in HIV-positive adults. Two authors, using predefined criteria, independently conducted the selection of articles, critical appraisal and extraction of the data. Analysis was focused on the immune markers that were most frequently assessed. The review protocol was registered in the PROSPERO database at 11 July 2014 (registration number CRD42014010516). This review was performed according to the PRISMA guideline.

Findings

Forty articles were selected; eight addressing cardiovascular disease (CVD) and thirty-two addressing CIMT. C-reactive protein (CRP), interleukin-6 (IL-6) and d-dimer were assessed most frequently in relation to the occurrence of CVD; in four out of eight studies. All three markers were positively related to CVD in three out of four studies. Studies addressing CIMT were too heterogeneous with respect to patient populations, inflammatory markers, CIMT measurement protocols and statistical methods to allow for a formal meta-analysis to obtain summary statistics. CRP, IL-6 and soluble vascular cell adhesion molecule (sVCAM-1) were the most studied markers in relation to CIMT. None of the inflammatory markers showed an association with CIMT.

Interpretation

This review showed a relation between some inflammatory markers and CVD, however, no consistent relation is observed for CIMT. Statistical approaches that yields effect estimates and standardized CIMT protocols should be chosen. Further research should focus on prospective studies and a selected set of inflammatory markers.

Causes of changes in carotid intima-media thickness: a literature review

Atherosclerosis causes significant morbidity and mortality. Carotid intima-media thickness (CIMT) predicts future cardiovascular and ischaemic stroke incidence. CIMT, a measure of atherosclerotic disease, can be reliably determined in vivo by carotid ultrasound. In this review, we determined that CIMT is associated with traditional cardiovascular risk factors such as age, sex, race, smoking, alcohol consumption, habitual endurance exercise, blood pressure, dyslipidemia, dietary patterns, risk-lowering drug therapy, glycemia, hyperuricemia, obesity-related anthropometric parameters, obesity and obesity-related diseases. We also found that CIMT is associated with novel risk factors, including heredity, certain genotypic indices, anthropometric cardiovascular parameters, rheumatoid arthritis, immunological diseases, inflammatory cytokines, lipid peroxidation, anthropometric hemocyte parameters, infectious diseases, vitamin D, matrix metalloproteinases, and other novel factors and diseases. However, the conclusions are inconsonant; the underlying causes of these associations remain to be further explored.

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.

Vitamin D Deficiency in HIV Infection: Not Only a Bone Disorder

Hypovitaminosis D is a worldwide disorder, with a high prevalence in the general population of both Western and developing countries. In HIV patients, several studies have linked vitamin D status with bone disease, neurocognitive impairment, depression, cardiovascular disease, high blood pressure, metabolic syndrome, type 2 diabetes mellitus, infections, autoimmune diseases like type 1 diabetes mellitus, and cancer. In this review, we focus on the most recent epidemiological and experimental data dealing with the relationship between vitamin D deficiency and HIV infection. We analysed the extent of the problem, pathogenic mechanisms, clinical implications, and potential benefits of vitamin D supplementation in HIV-infected subjects.