HIV-infected patients are at increased risk for cardiovascular disease, which may be mediated in part by inflammation. This study aimed to evaluate the risk factors of carotid plaque, and clinical factors associated with carotid atherosclerosis measured by carotid intima-medial thickness (cIMT) in HIV patients.
Materials and Methods
Clinical and cardiometabolic factors as well as cIMT were prospectively measured in 145 HIV-infected participants who had received combined antiretroviral therapy for ≥6 months. The mean value of the bilateral average cIMT level was used as Mean-IMT in the analysis, and the greatest value among the measured cIMT levels was used as Max-IMT.
Among 145 patients, 34 (23.4%) had carotid plaque. Multivariate logistic regression analysis revealed three independent risk factors of carotid plaque: old age [odds ratio (OR) 6.16, 95% confidence interval (CI) 1.09-34.88; p=0.040], hypertension (OR 12.62, 95% CI 1.72-92.49; p=0.013) and higher low-density lipoprotein cholesterol (LDL-C) (OR 1.08, 95% CI 1.01-1.16; p=0.039). Levels of estimated glomerular filtration rate were inversely associated with Mean-IMT (r=-0.379, p<0.001) and Max-IMT (r=-0.389, p<0.001). Stepwise multivariate regression analyses revealed that age, total cholesterol and fasting glucose were positively correlated with cIMT, independent of other risk factors.
The presence of hypertension, old age and a higher level of LDL-C were independent risk factors of carotid plaque among HIV-infected subjects.
Carotid plaque; carotid artery intima-media thickness; atherosclerosis; combined antiretroviral therapy; HIV infection
Systematic differences between readers or equipment in imaging studies are not uncommon; failure to account for such differences when using Carotid Ultrasonography may introduce bias into associations between carotid intima media thickness (cIMT) and outcomes. We demonstrate the impact of this source of systematic measurement error (SME) using data on 5,521 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) and 661 participants from the Study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM). Participants were between 37 and 78 years old. Two outcomes were considered: (1) the effect of HIV infection on cIMT (between study) and (2) the association of cIMT with cardiovascular events (within study). All estimates were adjusted for demographics (age, gender, and ethnicity) and for traditional cardiovascular disease risk factors (smoking, blood pressure, diabetes and cholesterol). When comparing the FRAM and MESA cohorts to estimate the association of HIV infection on common cIMT, accounting for machine and reader variability (between study variability) reduced the difference associated with HIV infection from +0.080 mm (95% Confidence Interval (CI):0.065–0.095) to +0.037 mm (95% CI:0.003 to 0.072) while internal cIMT declined from +0.254 mm (95% CI:0.205–0.303) to +0.192 mm (95% CI:0.076–0.308). Attenuation of the association between cIMT and cardiovascular endpoints occurred when within study reader variability was not accounted for. The effect of SME due to use of multiple readers or machines is most important when comparisons are made between two different study populations. Within-cohort measurement error dilutes the association with events.
Carotid intima media thickness; Measurement error; Bias; Carotid ultrasonography
Reduced kidney function and albuminuria are associated with higher risk for cardiovascular disease (CVD) and mortality in HIV-infected individuals. We investigated whether reduced estimated glomerular filtration rate (eGFR) and albuminuria are associated with subclinical vascular disease, as assessed by carotid intima-medial thickness (cIMT).
Cross-sectional analysis of 476 HIV-infected individuals without clinical evidence of CVD enrolled in the Fat Redistribution and Metabolic Change in HIV infection (FRAM) study, using multivariable linear regression. eGFRCys and eGFRCr were calculated from cystatin C and creatinine levels. Albuminuria was defined as a positive urine dipstick (≥1+) or urine albumin-to-creatinine ratio ≥30 mg/g. Common and internal cIMT were measured by high-resolution B-mode ultrasound.
In unadjusted analyses, eGFRCys and eGFRCr were strongly associated with common and internal cIMT. Each 10 ml/min/1.73 m2 decrease in eGFRCys and eGFRCr was associated with a 0.008 mm higher common cIMT (p = 0.003, p = 0.01) and a 0.024 and 0.029 mm higher internal cIMT (p = 0.003), respectively. These associations were eliminated after adjustment for age, gender, and race. Albuminuria showed little association with common or internal cIMT in all models.
In HIV-infected individuals without prior CVD, reduced kidney function and albuminuria were not independently associated with subclinical vascular disease, as assessed by cIMT. These results suggest that research should focus on searching for novel mechanisms by which kidney disease confers cardiovascular risk in HIV-infected individuals.
Cystatin C; Intima-medial thickness; HIV; Atherosclerosis; Cardiovascular disease; Kidney
The role of host genetics in the development of subclinical atherosclerosis in the context of HIV infected persons who are being treated with highly active antiretroviral therapy (HAART) is not well understood.
The present genome-wide association study (GWAS) is based on 177 HIV-positive Caucasian males receiving HAART who participated in the Fat Redistribution and Metabolic Change in HIV Infection (FRAM) Study. Common and internal carotid intima-media thicknesses (cIMT) measured by B-mode ultrasound were used as a subclinical measure of atherosclerosis. Single nucleotide polymorphisms (SNPs) were assayed using the Illumina HumanCNV370-quad beadchip. Copy Number Variants (CNV) were inferred using a hidden Markov Model (PennCNV). Regression analyses were used to assess the association of common and internal cIMT with individual SNPs and CNVs, adjusting for age, duration of antiretroviral treatment, and principal components to account for potential population stratification.
Two SNPs in tight linkage disequilibrium, rs2229116 (a missense, nonsynonymous polymorphism (IIe to Val)) and rs7177922, located in the Ryanodine receptor (RYR3) gene on chromosome 15 were significantly associated with common cIMT (p-value<1.61×10−7). The RYR gene family has been known to play a role in the etiology of cardiovascular disease and has been shown to be regulated by HIV TAT protein.
These results suggest that in the context of HIV infection and HAART, a functional SNP in a biologically plausible candidate gene, RYR3, is associated with increased common carotid IMT, which is a surrogate for atherosclerosis.
HIV; HAART; atherosclerosis; GWAS; intima-media thickness
Cardiovascular disease (CVD) is an increasing cause of morbidity and mortality in HIV-infected patients. However, it is controversial whether HIV infection contributes to accelerated atherosclerosis independent of traditional CVD risk factors.
Cross-sectional study of HIV-infected and control subjects without pre-existing CVD from the study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM) and the Multi-Ethnic Study of Atherosclerosis (MESA). Pre-clinical atherosclerosis was assessed by carotid intima-medial thickness (IMT) measurements in the internal/bulb and common regions in HIV-infected and control subjects after adjusting for traditional CVD risk factors.
For internal carotid, mean IMT was 1.17±0.50mm for HIV-infected participants and 1.06±0.58mm for controls (p<0.0001). After multivariable adjustment for demographic characteristics, the mean difference of HIV-infected vs. controls was +0.188mm (95%CI 0.113-0.263, p<0.0001). Further adjustment for traditional CVD risk factors modestly attenuated the HIV association (+0.148mm, 95%CI 0.072-0.224, p=0.0001). For the common carotid, HIV infection was independently associated with greater IMT (+0.033mm, 95%CI 0.010, 0.056, p=0.005). The association of HIV infection with IMT was similar to that of smoking which was also associated with greater IMT (internal +0.173mm, common +0.020mm).
Even after adjustment for traditional CVD risk factors, HIV infection was accompanied by more extensive atherosclerosis measured by IMT. The stronger association of HIV infection with IMT in the internal/bulb region compared to the common carotid may explain previous discrepancies in the literature. The association of HIV infection with IMT was similar to that of traditional CVD risk factors, such as smoking.
HIV; carotid IMT; smoking; cholesterol; diabetes; atherosclerosis
HIV-infected patients are at increased risk for cardiovascular disease, which may be mediated in part by inflammation. Surrogate marker studies suggest an increased prevalence of vascular abnormalities in HIV infection. We examined the association of all-cause mortality in HIV-infected patients with carotid artery intima-media thickness (cIMT) and high-sensitivity C-reactive protein (hsCRP).
Design and Methods
Baseline risk factors, cIMT and hsCRP were prospectively measured in 327 HIV-infected participants. Follow-up time with median of 3.1 years was calculated from baseline to death or censored dated 7/31/07. Cox Proportional Hazards models were used to study risk factors associated with mortality.
Thirty eight (11.6 %) of participants have died since study enrollment. CIMT was significantly higher in those who died and decedents were significantly more likely to have cIMT above the 75th percentile. Those who died had higher hsCRP than those alive and more had hsCRP values above 3 mg/L. CD4 count was lower and log10 viral load was higher in decedents, but antiretroviral regimens were similar in both groups. CIMT and hsCRP levels were significantly associated with mortality (HR=2.74, 95% CI 1.26 to 5.97, p=0.01; HR=2.38, 95% CI 1.15 to 4.9, p=0.02).
Our study demonstrated a strong association of carotid IMT and hsCRP with all-cause death in this HIV-infected population despite being similar with respect to exposure to antiretroviral medications. Together these surrogate markers may be indices of chronic inflammation and unfavorable outcomes in HIV-positive patients.
Carotid intima–media thickness (CIMT) and plaque information can improve coronary heart disease (CHD) risk prediction when added to traditional risk factors (TRF). However, obtaining adequate images of all carotid artery segments (A-CIMT) may be difficult. Of A-CIMT, the common carotid artery intima–media thickness (CCA-IMT) is relatively more reliable and easier to measure. We evaluated whether CCA-IMT is comparable to A-CIMT when added to TRF and plaque information in improving CHD risk prediction in the Atherosclerosis Risk in Communities (ARIC) study.
Methods and results
Ten-year CHD risk prediction models using TRF alone, TRF + A-CIMT + plaque, and TRF + CCA-IMT + plaque were developed for the overall cohort, men, and women. The area under the receiver operator characteristic curve (AUC), per cent individuals reclassified, net reclassification index (NRI), and model calibration by the Grønnesby–Borgan test were estimated. There were 1722 incident CHD events in 12 576 individuals over a mean follow-up of 15.2 years. The AUC for TRF only, TRF + A-CIMT + plaque, and TRF + CCA-IMT + plaque models were 0.741, 0.754, and 0.753, respectively. Although there was some discordance when the CCA-IMT + plaque- and A-CIMT + plaque-based risk estimation was compared, the NRI and clinical NRI (NRI in the intermediate-risk group) when comparing the CIMT models with TRF-only model, per cent reclassified, and test for model calibration were not significantly different.
Coronary heart disease risk prediction can be improved by adding A-CIMT + plaque or CCA-IMT + plaque information to TRF. Therefore, evaluating the carotid artery for plaque presence and measuring CCA-IMT, which is easier and more reliable than measuring A-CIMT, provide a good alternative to measuring A-CIMT for CHD risk prediction.
CIMT; Plaque; Risk prediction
Carotid intima-media thickness (cIMT) is an independent predictor of cardiovascular risk. Furthermore, ethnicity and gender-specific normative data are required to assess cIMT, which are not available for Andean-Hispanics. In addition, data regarding correlates of subclinical atherosclerosis in ethnic population are needed.
We studied 1448 adults enrolled in a population-based study in Peru. cIMT and carotid plaque were measured with high-resolution ultrasonography. A healthy reference sample (n=472) with no cardiovascular disease, normal weight and normal metabolic parameters was selected to establish normative cIMT values. Correlates of abnormal cIMT and carotid plaque were assessed in the entire population.
In the reference sample, 95th-percentile cIMT values were both age and gender-dependent. In stepwise regression, selected predictors of increasing cIMT were: older age, impaired fasting glucose, diabetes mellitus, higher systolic blood pressure, higher LDL-cholesterol, smoking and male gender. Predictors of carotid plaque included older age, male gender, higher systolic blood pressure, lower diastolic blood pressure and higher LDL-cholesterol. HDL-cholesterol and C-reactive protein were not associated with cIMT or carotid plaque. The lack of association with HDL-cholesterol was confirmed using high performance liquid chromatography.
We present ethnic-specific cutoffs for abnormal cIMT applicable to Andean-Hispanics and correlates of subclinical atherosclerosis in this population. Pending longitudinal studies, our data supports several risk associations seen in other populations and can be used to identify Andean-Hispanics at increased risk for atherosclerotic cardiovascular disease. The lack of association between HDL-C and cIMT or carotid plaque in this population requires further investigation.
carotid intima-media thickness; Andean-Hispanics; definitions; cardiovascular disease; Latin America
to determine the prevalence of asymptomatic ischemic heart disease (IHD) in HIV patients by myocardial perfusion scintigraphy (MPS) and to determine the value of coronary artery calcium score (CACS), carotid intima-media thickness (cIMT) and pericardial fat volume as screening tools for detection of IHD in subjects with HIV.
Patients with HIV seem prone to early development of IHD.
105 consecutive HIV patients (mean age 47.4 years; mean duration of HIV 12.3 years; mean CD4+ cell count 636×106/L; all receiving antiretroviral therapy) and 105 controls matched for age, gender and smoking status, without history of IHD were recruited. MPS, CACS, cIMT, pericardial fat volume, and cardiovascular risk scores were measured.
HIV patients demonstrated higher prevalence of perfusion defects than controls (18% vs. 0%; p<0.001) despite similar risk scores. Of HIV patients with perfusion defects, 42% had a CACS = 0. CACS and cIMT were similar in HIV patients and controls. HIV patients on average had 35% increased pericardial fat volume and increased concentration of biomarkers of atherosclerosis in the blood. HIV patients with myocardial perfusion defects had increased pericardial fat volume compared with HIV patients without perfusion defects (314±43 vs. 189±12 mL; p<0.001).
HIV patients had an increased prevalence of silent IHD compared to controls as demonstrated by MPS. The finding was strongly associated with pericardial fat volume, whereas cardiovascular risk scores, cIMT and CACS seem less useful as screening tools for detection of myocardial perfusion defects in HIV patients.
Vascular morbidity and mortality due to cardiovascular disease (CVD) are high after ischemic stroke at a young age. Data on carotid intima-media thickness (cIMT) as marker of atherosclerosis are scarce for young stroke populations. In this prospective case–control study, we examined cIMT, the burden of vascular risk factors (RF) and their associations among young and middle-aged ischemic stroke patients and controls. We aimed to detect clinical and sub-clinical arterial disease.
This study was conducted in 150 patients aged 15–60 years and 84 controls free of CVD. We related RF to ultrasonographic B-mode cIMT-measurements obtained from 12 standardized multiangle measurements in the common carotid artery (CCA), carotid bifurcation (BIF) and internal carotid artery (ICA).
RF burden was higher among patients than among controls (p < 0.001). In multivariate analyses of all 234 participants, increased cIMT was associated with age in each carotid segment. Incident stroke was associated with increased ICA-IMT. ICA-IMT increase was associated with a family history of CVD among patients aged 15–44 years, and with RF at mid-age. The overall cIMT difference between patients and controls was 12% for CCA, 17% for BIF and 29% for ICA. Further, increased CCA-IMT was associated with male sex and hypertension. Increased BIF-IMT was associated with dyslipidemia, coronary heart disease and smoking. Increased ICA-IMT was associated with dyslipidemia and stroke.
Ischemic stroke is associated with increased ICA-IMT, related to a family history of CVD among patients aged <45 years, and to increasing RF burden with increasing age. Preventive strategies and aggressive RF treatment are indicated to avoid future cardiovascular events.
NOR-SYS is registered in ClinicalTrials.gov (NCT01597453).
Young stroke; Ischemic stroke; Risk factors; Carotid intima-media thickness; Atherosclerosis; Ultrasound
To assess the association of HIV infection, HIV disease parameters (including CD4+ T-cell counts, HIV viral load, and AIDS) and antiretroviral medication use with subclinical carotid artery atherosclerosis.
Cross-sectional study nested within a prospective cohort study
Among participants in the Women's Interagency HIV Study (1,331 HIV-infected women, 534 HIV-uninfected women) and Multicenter AIDS Cohort Study (600 HIV-infected men, 325 HIV-uninfected men), we measured subclinical carotid artery lesions and common carotid artery intima-media thickness (CIMT) using B-mode ultrasound. We estimated adjusted mean CIMT differences and prevalence ratios (PRs) for carotid lesions associated with HIV-related disease and treatments, with multivariate adjustment to control for possible confounding variables.
Among HIV-infected individuals, a low CD4+ T cell count was independently associated with an increased prevalence of carotid lesions. Compared to the reference group of HIV-uninfected individuals, the adjusted PR for lesions among HIV-infected individuals with CD4+ T-cell count <200 cells/mm3 was 2.00 (95% confidence interval 1.22, 3.28) in women and 1.74 (95% confidence interval 1.04, 2.93) in men. No consistent association of antiretroviral medications with carotid atherosclerosis was observed, except for a borderline significant association between protease inhibitor use and carotid lesions in men (with no association among women). History of clinical AIDS and HIV viral load were not significantly associated with carotid atherosclerosis.
Beyond traditional cardiovascular disease risk factors, low CD4+ T-cell count is the most robust risk factor for increased subclinical carotid atherosclerosis in HIV-infected women and men.
Upper body fat is associated with increased cardiometabolic risk. More recently, neck circumference (NC) and/or neck fat have been associated with hyperlipidemia, impaired glucose homeostasis, and hypertension. The objective of this study was to determine whether this relationship is evident in HIV-infected individuals, who often exhibit changes in relative fat distribution, and to determine whether NC is independently associated with carotid intima-media thickness (cIMT) in HIV and non–HIV-infected patients.
RESEARCH DESIGN AND METHODS
Body composition, including anthropometrics, visceral adipose tissue assessment by CT, and metabolic parameters, including lipids, cIMT, and oral glucose tolerance test, were measured in 174 men and women with HIV infection and 154 non–HIV-infected subjects. NC was measured in triplicate inferior to the laryngeal prominence.
In univariate analysis, NC was significantly and positively related to blood pressure, hemoglobin A1c, glucose, and insulin and significantly and negatively related to HDL cholesterol in HIV-infected individuals and HIV-negative control subjects. NC was significantly associated with cIMT in univariate regression analysis among HIV-infected (r = 0.21, P = 0.006) and non–HIV-infected (r = 0.31, P = 0.0001) patients. This relationship remained significant among non–HIV-infected patients (R2 = 0.45, P < 0.001) but not HIV-infected patients in multivariate modeling controlling for age, sex, race, smoking hypertension, glucose, and lipids.
Among both HIV and non–HIV-infected patients, increased NC is strongly associated with decreased HDL and impaired glucose homeostasis. Among non–HIV-infected subjects, NC also predicts increased cIMT when controlling for traditional risk factors.
Relationship of hepatitis C virus (HCV) infection with an increased risk of cardiovascular disease (CVD) in HIV-infected patients remains controversial. We evaluated endothelial function and subclinical atherosclerosis in HIV-infected patients with and without HCV.
Flow-mediated dilatation (FMD) of the brachial artery and circulating levels of cell adhesion molecules (CAM) were measured in HCV/HIV-coinfected and HIV-monoinfected patients. Subclinical atherosclerosis was assessed by carotid intima-media thickness (cIMT).
63 (31%) HCV/HIV-coinfected and 138 (69%) HIV-monoinfected patients were included. Median soluble vascular CAM-1 (sVCAM-1) and intercellular CAM-1 (sICAM-1) levels were significantly higher in HIV/HCV-coinfected patients (P < 0.001 for both cases). Median (interquartile range) FMD was 6.21% (2.86-9.62) in HCV/HIV-coinfected and 5.54% (2.13-9.13) in HIV-monoinfected patients (P = 0.37). Adjustment for variables associated with HCV and FMD disclosed similar results. FMD correlated inversely with cIMT and age. Carotid IMT did not differ between HCV/HIV-coinfected and HIV-monoinfected patients in unadjusted (0.61 [0.55-0.65] mm vs 0.60 [0.53-0.72] mm; P = 0.39) or adjusted analyses.
HCV infection was associated with higher levels of sICAM-1 and sVCAM-1, but no evidence of increased subclinical atherosclerosis was found when endothelial function was evaluated through FMD, or when assessing the cIMT.
Carotid intima-media thickness (CIMT) can be reliably determined in vivo by carotidian ultrasound and is an accessible and reliable method to assess subclinical atherosclerosis. Available epidemiological data showed that CIMT is significantly correlated with future cardiovascular events. However it has limited value to help risk stratification on top of standard risk-derived functions such as Framingham risk score. It is particularly useful in individuals classified as being at intermediate or high risk by the presence of multiple conventional risk factors.
CIMT has a class IIa (LOE: B) reccommendation for cardiovascular risk assessment according to the practice guidelines published in 2010, emphasizing the presence of high risk if the common carotid artery intima–media thickness is above the 75th percentile. There is no indication to measure IMT in patients with full-blown atherosclerotic carotid disease, although carotidian ultrasound still remains a very useful tool to assess the severity of disease even in these subjects.
Progression of CIMT (also associated with increasing age) can be delayed by some drugs (statins, colestipol and niacin) and by risk factors modification. However, there is no consistent data demonstrating a link between progression of CIMT and coronary and cerebral events. Subsequently, studies using CIMT progression as primary outcome to indicate the influence of a certain therapy on cardiovascular risk are inherently misleading as suggested in the recently published ACC/AHA Guidelines.
rheumatoid arthritis; inflammation; metabolic syndrome; accelerated atherosclerosis
Single nucleotide polymorphisms in the 5,10-methylenetetrahydrofolate reductase (MTHFR), vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), monocyte chemoattractant protein-1 (MCP-1) and apolipoprotein E (ApoE) genes appear to be a genetic risk factor for atherosclerosis. Common carotid intima-media thickness (cIMT) provides information on the severity of atherosclerosis.
To investigate the relationship between cIMT and gene polymorphisms associated with atherosclerosis in Turkish patients with coronary artery disease (CAD).
Sixty-two patients with angiographically diagnosed stable CAD were divided into two groups according to their cIMT values (group 1: n=35, cIMT of 1 mm or greater; group 2: n=27, cIMT of less than 1 mm). MTHFR 677 C/T, VEGF–460 C/T, eNOS 894 G/T, MCP-1–2518 A/G and ApoE (E2, E3 and E4) gene polymorphisms (where A is adenine, C is cytosine, G is guanine and T is thymine) were analyzed by polymerase chain reaction and restriction fragment length polymorphism. Evaluations of cardiovascular risk factors and coronary atherosclerotic lesions were performed in all patients. Serum homocysteine and high-sensitivity C-reactive protein were measured and compared between the two groups.
Serum high-sensitivity C-reactive protein (P=0.04) and homocysteine (P=0.006) levels were higher in group 1 than in group 2. The ratio of multivessel CAD and previous myocardial infarction was significantly higher in group 1 than in group 2 (P=0.014). In the study population, no significant difference in cIMT was observed according to the polymorphisms studied. Only hyperhomocysteinemia (OR 1.17 [95% CI 1.01 to 1.35], P=0.033) and previous myocardial infarction (OR 3.76 [95% CI 1.10 to 12.81], P=0.034) maintained a significant correlation with cIMT on multiple logistic regression analysis.
cIMT is increased in patients with hyperhomocysteinemia, inflammation and extended CAD. MTHFR 677 C/T, VEGF–460 C/T, eNOS 894 G/T, MCP-1–2518 A/G and ApoE single nucleotide polymorphisms were not associated with increased cIMT.
Atherosclerosis-related genes; Carotid intima-media thickness; Coronary artery disease; Homocysteine
HIV infection is associated with dyslipidaemia and increased risk of cardiovascular disease. The effects of HIV infection and antiretroviral treatment on surrogate markers of atherosclerosis, and lipoprotein metabolism were evaluated in a 12 month prospective study.
Methods and Results
Treatment-naive HIV patients were recruited into one of three groups: untreated HIV infection not likely to require initiation of antiretroviral therapy (ART) for at least 12 months; initiating treatment with non nucleoside reverse transcriptase inhibitor-containing ART regimen and initiating treatment with protease inhibitor-containing ART regimen. The patients underwent assessment of carotid intima-media thickness (cIMT), pulse wave velocity (PWV), brachial flow-mediated dilation (FMD) and variables of plasma lipoprotein metabolism at baseline and 12 months. The findings were compared with published values for age and sex matched HIV-negative healthy subjects in a cross-sectional fashion. cIMT and FMD were lower while PWV was higher in HIV-patients compared with HIV-negative individuals; none of the markers changed significantly during 12 months follow up. HIV patients had hypoalphalipoproteinemia and elevated plasma levels of lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein. The only significant changes in lipid-related variables were elevation of total cholesterol and triglycerides in patients treated with PI-containing regimen and elevation of plasma LCAT levels in patients treated with NNRTI-containing regimen. The ability of whole and apoB-depleted plasma to effect cholesterol efflux was not impaired in all three groups.
This study did not find evidence for rapid progression of subclinical atherosclerosis and deterioration of dyslipidaemia in HIV patients within 1 year.
HIV; atherosclerosis; lipoproteins; cholesterol metabolism
Human immunodeficiency virus (HIV)–infected patients are at increased risk of cardiovascular disease, which may be related to chronic inflammation and endothelial dysfunction despite virological control with antiretroviral therapy. The relationship between carotid intima-media thickness (IMT), a surrogate marker for cardiovascular disease, proinflammatory cytokines, and endothelial activation markers has not been fully explored in HIV-infected patients who are receiving antiretroviral therapy.
We conducted a prospective, cross-sectional, observational study of treated HIV-infected patients and healthy control subjects to evaluate the relationship between carotid IMT, proinflammatory cytokines, endothelial activation biomarkers, and metabolic parameters in treated HIV-infected patients, compared with healthy control subjects.
We enrolled 73 HIV-infected patients and 21 control subjects. Common carotid artery and internal carotid artery IMT measurements, as well as tumor necrosis factor–α, high-sensitivity C-reactive protein, inter-leukin-6, myeloperoxidase, and soluble vascular cell adhesion molecule-1 levels were higher in the HIV-infected group. High-sensitivity C-reactive protein was the only biomarker that was positively correlated with carotid IMT in both groups. In the HIV-infected group, soluble vascular cell adhesion molecule–1 was positively correlated with all inflammatory cytokine levels. In multiple regression analysis, soluble vascular cell adhesion molecule–1, myeloperoxidase, and tumor necrosis factor–α levels were all associated with internal carotid artery IMT in the HIV-infected group, whereas age was associated with both common carotid artery and internal carotid artery IMT.
Enhanced endothelial activation, inflammation, and increased carotid IMT occur in HIV-infected patients despite antiretroviral therapy. Inflammatory markers are associated with endothelial activation, and both are associated with internal carotid artery IMT, supporting a potential role of inflammation in endothelial activation and cardiovascular disease in HIV infection.
To evaluate associations between traditional cardiovascular disease (CVD) risk factors, inflammatory markers, and markers of HIV disease activity with ultrasonographic measures of CVD risk in patients with HIV who are not receiving antiretroviral therapy (ART).
Cross-sectional, baseline evaluation of ART-naïve HIV-infected individuals without known CVD or diabetes mellitus enrolled in a randomized ART treatment trial.
Prior to ART initiation, carotid artery intima-media thickness (CIMT) and brachial artery flow-mediated dilation (FMD) were measured. Additional parameters included CD4 cell count, HIV viral load, body composition, lipoproteins, and inflammatory markers. Associations with common CIMT, bifurcation CIMT, presence of carotid artery lesions, and brachial artery FMD were evaluated.
The 331 enrolled subjects were a median (1st–3rd quartile) of 36 (28–45) years old. Common and bifurcation CIMT values were higher and lesions more prevalent with older age (p <0.001). FMD was lower with older age (p =0.009). Those with a Framingham Risk Score >6%/10 years (N =44) had higher common and bifurcation CIMT (p <0.001), carotid lesion prevalence (p <0.001), and lower FMD (p =0.035). Independent associations with common CIMT were identified for increasing age, height, weight, small LDL particles, and black race; these were similar for bifurcation CIMT. Presence of carotid artery lesions was associated with increasing age, presence of metabolic syndrome, interleukin-6, and lower HIV-1 RNA.
In a contemporary cohort of ART-naive HIV-infected individuals, ultrasonographic measures of CVD risk were more strongly associated with traditional risk factors than CD4 cell counts, HIV replication, or inflammatory markers.
atherosclerosis; carotid arteries; endothelial function; human immunodeficiency virus; inflammation
HIV-infected patients have low vitamin D levels as well as an increase in cardiovascular (CVD) risk. We examined the relationship between vitamin D and three markers of arterial dysfunction among HIV-infected individuals on stable antiretroviral (ARV) therapy. Levels of 25-hydroxyvitamin D [25(OH)D] were assessed by chemiluminescent immunoassay (DiaSorin) in 100 enrollees into the Hawaii Aging with HIV-Cardiovascular Cohort Study, a cohort of HIV-infected subjects age ≥40 years on stable (≥6 months) ARV therapy. The relationships between 25(OH)D levels and brachial artery flow-mediated dilation (FMD), right common carotid artery intima-media thickness (cIMT), and coronary artery calcium (CAC) were examined. Analytical methods included Pearson's correlations, Kruskal–Wallis tests, relative risks, and linear regression models. The cohort was 86% male and 60% white with a median age of 52 years and CD4 of 510 cells/mm3. The median (Q1, Q3) level of 25(OH)D was 27.9 ng/ml (21.8, 38.3). There were 72 FMD, 50 cIMT, and 90 CAC measurements available for analyses. A significant correlation was observed between 25(OH)D levels and FMD (r=0.30, p=0.01) but not with cIMT (r=−0.05, p=0.76). In a linear regression model, Framingham risk score attenuated the relationship between FMD and 25(OH)D. Those with lower 25(OH)D levels were at slightly higher risk of having CAC (RR=1.02, p=0.04). Among those with CAC, lower 25(OH)D levels were not associated with higher CAC scores (p=0.36). Lower vitamin D levels are associated with evidence of subclinical arterial dysfunction in HIV-infected individuals. The significance of these findings warrants further investigation.
HIV-seropositive patients are at higher risk for atherosclerosis than HIV-seronegative persons. This has been variably attributed to antiretroviral drug toxicity, immunodeficiency, and/or HIV-associated inflammation. To evaluate the contributions of these factors to HIV-associated atherosclerosis, we assessed carotid artery intima-media thickness (IMT) in a diverse cohort of HIV-seronegative and seropositive adults, including a unique group of HIV-infected patients who were untreated, had undetectable viral loads and had preserved CD4+ T cell counts (HIV controllers).
Methods and Results
Carotid IMT was measured in 494 subjects, including 33 HIV controllers and 93 HIV-seronegative controls. HIV controllers had higher IMT than seronegative controls even after adjustment for traditional risk factors (p=0.003). IMT in controllers was similar to antiretroviral-untreated patients with detectable viremia. Across all subjects, IMT was strongly associated with the presence of HIV disease rather than viral load or CD4+ T cell count. C-reactive protein was higher in HIV controllers than HIV-seronegative persons. Antiretroviral drug exposure was also associated with higher IMT.
Increased atherosclerosis with HIV infection can occur in the absence of antiretroviral therapy, detectable viremia, or overt immunodeficiency. Chronic inflammation—which is higher in controllers than in HIV-uninfected persons—may account for early atherosclerosis in these patients.
To investigate the effects of aging and smoking on carotid intima-media thickness (cIMT) among patients with and without HIV.
Data from a community sample of HIV-infected and HIV-uninfected participants were analyzed. Carotid intima-media thickness was measured via carotid ultrasound and smoking history was obtained via patient interview.
Data on 166male and female participants with stable HIV-infection and 152 healthy HIV-uninfected participants were analyzed. Among the HIV-infected and HIV-uninfected participants, a significant association was observed between age and cIMT [r=0.51, P<0.0001 (HIV), r=0.39, P<0.0001, (non-HIV)], and between smoking burden and cIMT [r=0.42, P<0.0001 (HIV), r=0.24, P=0.003 (non-HIV)]. In multivariate regression modeling among all participants (HIV and non-HIV), a significant three-way interaction was observed between age, smoking burden, and HIV status with respect to cIMT (P<0.010), controlling for gender, race and traditional cardiovascular disease (CVD) risk factors, such that increased cIMT was associated with increased smoking burden and age to a greater degree among HIV-infected vs. HIV-uninfected participants. Among HIV-infected participants a significant interaction between smoking burden and age with respect to cIMT was seen (P=0.027), controlling for race, gender, CVD risk factors, immunological function and antiretroviral therapy use.
A significant interaction between HIV, age and smoking on cIMT was observed, suggesting that HIV-infection modifies the relationship of age and smoking on cIMT in this population. These findings emphasize the need to encourage smoking cessation in this population, due to its deleterious effect on subclinical atherosclerosis in older HIV-infected patients.
HIV; Aging; Cardiovascular Diseases; Smoking
Carotid artery intima-media thickness progression is associated with human immunodeficiency virus replication as well as with exposure to certain antiretroviral therapy regimens.
Background. Persons with human immunodeficiency virus (HIV) infection are at risk for premature cardiovascular disease (CVD). Predictors of atherosclerotic disease progression in contemporary patients have not been well described.
Methods. Using data from a prospective observational cohort of adults infected with HIV (Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy), we assessed common carotid artery intima-media thickness (CIMT) at baseline and year 2 by ultrasound. We examined HIV-associated predictors of CIMT progression after adjusting for age, sex, race/ethnicity, body mass index, smoking, hypertension, diabetes, low-density lipoprotein cholesterol level, and baseline CIMT using linear regression.
Results. Among 389 participants (median age at baseline, 42 years; male sex, 77%; median CD4+ cell count at baseline, 485 cells/mm3; 78% receiving antiretroviral therapy), the median 2-year CIMT change was 0.016 mm (interquartile range, −0.003 to 0.033 mm; P < .001). Lesser CIMT progression was associated with a suppressed viral load at baseline (−0.009 mm change; P = .015) and remaining virologically suppressed throughout follow-up (−0.011 mm change; P < .001). After adjusting for additional risk factors and a suppressed viral load during follow-up, nonnucleoside reverse transcriptase inhibitor versus protease inhibitor exposure was associated with lesser CIMT progression (−0.011 mm change; P = .02).
Conclusions. Suppressing HIV replication below clinical thresholds was associated with less progression of atherosclerosis. The proatherogenic mechanisms of HIV replication and the net CVD benefit of different antiretroviral drugs should be a focus of future research.
The increased immune activation and inflammation of chronic HIV-infection and the characteristic dyslipidemias associated with HIV infection and antiretroviral therapy (ART) contribute to an increased risk of atherosclerotic vascular disease among HIV-infected adults. There is an emerging need to understand determinants of cardiovascular disease (CVD) among individuals aging with HIV in sub-Saharan Africa. We determined the prevalence of subclinical atherosclerosis [carotid intima media thickness (CIMT) ≥0.78 mm] and its correlation with traditional CVD risk factors among HIV-infected adults.
In a cross-sectional study, HIV-infected adults (ART-naïve and ART-treated) were consecutively selected from patients' enrollment registers at two large HIV clinics at Mulago Hospital, Kampala, Uganda. We measured traditional CVD risk factors including age, biophysical profile, fasting blood sugar and serum lipid profile as well as biomarkers of inflammation. High resolution ultrasound was used to measure common carotid CIMT.
Of 245 patients, Median age [Interquartile range (IQR)] 37 years (31–43), 168 (69%) were females; and 100 (41%) were ART-treated for at least 7 years. Overall, 34/186 (18%) had subclinical atherosclerosis; of whom 15/108 (14%) were ART-naïve whereas 19/78 (24%) were ART-treated. Independent predictors of subclinical atherosclerosis included age [odds ratio (OR) 1.83 per 5-year increase in age; 95% confidence interval (CI) 1.24–2.69; p = 0.002], body mass index (BMI); OR 1.15; CI 1.01–1.31; p = 0.041 and high low density lipoprotein (LDL) [OR 2.99; CI 1.02–8.78, p = 0.046]. High sensitivity C-reactive protein (hsCRP) was positively correlated with traditional cardio-metabolic risk factors including waist circumference (r = 0.127, p = 0.05), triglycerides (r = 0.19, p = 0.003) and Total Cholesterol: High Density Lipoprotein ratio (TC:LDL) (r = 0.225, p<0.001).
The prevalence of subclinical atherosclerosis was 18% among HIV-infected adults in Uganda. Traditional CVD risk factors were associated with subclinical atherosclerosis. We recommend routine assessment of traditional CVD risk factors within HIV care and treatment programs in sub-Saharan Africa.
Diabetes is associated with atherogenic risk factors. Hypertension has a major influence on cardiovascular disease in diabetic patients. Ambulatory blood pressure monitoring (ABPM) is useful for identifying nocturnal hypertension. Carotid intima-media thickness (cIMT) is a good measure for identifying subclinical atherosclerosis. This study aimed to evaluate whether nocturnal hypertension affects atherosclerosis in children and adolescents with type 1 diabetes and to investigate the relationship between atherogenic risk factors and cIMT.
RESEARCH DESIGN AND METHODS
ABPM and cIMT were measured in 82 diabetic children and adolescents. We reviewed the hemoglobin A1c levels, 24-h urine microalbumin excretion, lipid profiles, and duration of diabetes. Nocturnal hypertension was defined as hypertension observed only at night.
Forty-three (52%) subjects were hypertensive, and 30 subjects were classified as having nocturnal hypertension. cIMT was higher in the nocturnal hypertensive group than in the normotensive group (0.44 ± 0.03 vs. 0.42 ± 0.04 mm, P = 0.026). Among children and adolescents with nonhypertensive blood pressure levels in clinic blood pressure monitoring, cIMT and daytime blood pressure were higher in the nocturnal hypertensive group. All ABPM parameters were significantly related to cIMT in multiple linear regression analysis.
This study showed significantly increased cIMT and daytime blood pressure in diabetic children and adolescents with nocturnal hypertension. ABPM may be a useful method for detecting the macrovascular complications of type 1 diabetes. Longitudinal studies are needed to find the causes of nocturnal hypertension and to evaluate the effect of nocturnal hypertension on atherosclerosis in type 1 diabetes.
Rheumatoid arthritis (RA) patients have increased mortality and morbidity as a result of cardiovascular and cerebrovascular disease. What is not clear, however, is either how early accelerated atherosclerosis begins in RA or how soon risk factors must be rigorously controlled. Furthermore, given the strong relationship of vascular disease to RA mortality and of inflammation to the accelerated atherosclerosis associated with RA, it is important to evaluate indices that could serially and noninvasively quantify atherosclerotic disease in RA patients. The carotid intima-media thickness (cIMT) and plaque, measured by ultrasound, correlate closely with direct measurement of the local and systemic atherosclerotic burden. To investigate the presence of subclinical atherosclerosis in the early stages of RA, the cIMT and plaque were measured using carotid duplex scanning in 40 RA patients with disease duration < 12 months and in 40 control subjects matched for age, sex and established cardiovascular risk factors. Patients with RA had significantly higher average cIMT values and more plaque than the control group (cIMT 0.64 ± 0.13 mm versus 0.58 ± 0.09 mm, respectively; P = 0.03). In RA patients, the cIMT was predicted by age and C-reactive protein level at first presentation to the clinic (R2 = 0.64). C-reactive protein was associated with age of disease onset and history of smoking. Since inflammation has been shown to predate onset of clinical RA, the accelerated atherogenic process related to inflammation may precede RA symptom onset.