Analysis of the gut microbiota profile targeted to multiple hypervariable regions of 16S rRNA in a hypertensive heart failure rat model.

The gut microbiota, comprising a diverse community of microorganisms, significantly influences various aspects of health. Changes in the composition of the gut microbiota are implicated in adverse effects on host physiology, contributing to the pathogenesis of cardiovascular diseases, among others pathological conditions. Understanding the role of the gut microbiota in the context of heart failure is particularly important. In this regard, the spontaneously hypertensive heart failure (SHHF) rat is an adequate experimental model since exhibits many features in common with heart failure (HF) in humans. Recent advancements in next-generation sequencing (NGS) have greatly improved microbiome analysis. However, standardization and the adoption of best practices are essential to mitigate experimental variations across studies. This manuscript outlines a straightforward methodology for analyzing gut microbiota composition in SHHF rat fecal samples using 16S rRNA sequencing, emphasizing the relevance of gut microbiota in heart failure.

Gut Microbiota Signatures with Potential Clinical Usefulness in Colorectal and Non-Small Cell Lung Cancers.

The application of bacterial metagenomic analysis as a biomarker for cancer detection is emerging. Our aim was to discover gut microbiota signatures with potential utility in the diagnosis of colorectal cancer (CRC) and non-small cell lung cancer (NSCLC). A prospective study was performed on a total of 77 fecal samples from CRC and NSCLC patients and controls. DNA from stool was analyzed for bacterial genomic sequencing using the Ion Torrent™ technology. Bioinformatic analysis was performed using the QIIME2 pipeline. We applied logistic regression to adjust for differences attributable to sex, age, and body mass index, and the diagnostic accuracy of our gut signatures was compared with other previously published results. The feces of patients affected by different tumor types, such as CRC and NSCLC, showed a differential intestinal microbiota profile. After adjusting for confounders, Parvimonas (OR = 53.3), Gemella (OR = 6.01), Eisenbergiella (OR = 5.35), Peptostreptococcus (OR = 9.42), Lactobacillus (OR = 6.72), Salmonella (OR = 5.44), and Fusobacterium (OR = 78.9) remained significantly associated with the risk of CRC. Two genera from the Ruminococcaceae family, DTU089 (OR = 20.1) and an uncharacterized genus (OR = 160.1), were associated with the risk of NSCLC. Our two panels had better diagnostic capacity for CRC (AUC = 0.840) and NSLC (AUC = 0.747) compared to the application of two other published panels to our population. Thus, we propose a gut bacteria panel for each cancer type and show its potential application in cancer diagnosis.

Gut microbiota profiles in feces and paired tumor and non-tumor tissues from Colorectal Cancer patients. Relationship to the Body Mass Index.

Colorectal Cancer (CRC) and Obesity constitute two of the most common malignancies in the western world, and previously have been associated with intestinal microbial composition alterations. Our main aim in this study is to provide molecular data on intestinal microbiota patterns in subjects with CRC, as well as to establish possible associations with their Body Mass Index (BMI). A total of 113 samples from 45 subjects were collected and submitted to metagenomics analysis for gut microbiota. This study was performed by 16S ribosomal RNA bacterial gene amplification and sequencing using the Ion Torrent™ technology. The same dominant phyla were observed in feces and colorectal tissues, although a greater proportion of Fusobacteriota was found in tumor samples. Moreover, at the genus level, LEfSe analysis allowed us to detect a significant increase in Fusobacterium and Streptococcus in colorectal tissues with respect to fecal samples, with a significant preponderance of Fusobacterium in tumor tissues. Also, our data revealed relevant associations between gut microbiota composition and tumor location. When comparing bacterial profiles between right and left colon cancers, those from the left-sided colon showed a significant preponderance, among others, of the order Staphylococcales. Moreover, phyla Firmicutes and Spirochaetota were more abundant in the group of right-sided CRCs and phylum Proteobacteria was increased in rectal cancers. In relation to BMI of patients, we detected significant differences in beta diversity between the normal weight and the obese groups of cases. Microbiota from obese patients was significantly enriched, among others, in Bacteroidales. Therefore, our results are useful in the molecular characterization of CRC in obese and non-obese patients, with a clear impact on the establishment of diagnostic and prognosis of CRC.

Gut Microbiota and Derived Short-Chain Fatty Acids Are Linked to Evolution of Heart Failure Patients.

There is a lack of direct evidence regarding gut microbiota dysbiosis and changes in short-chain fatty acids (SCFAs) in heart failure (HF) patients. We sought to assess any association between gut microbiota composition, SCFA production, clinical parameters, and the inflammatory profile in a cohort of newly diagnosed HF patients. In this longitudinal prospective study, we enrolled eighteen newly diagnosed HF patients. At admission and after 12 months, blood samples were collected for the assessment of proinflammatory cytokines, monocyte populations, and endothelial dysfunction, and stool samples were collected for analysis of gut microbiota composition and quantification of SCFAs. Twelve months after the initial HF episode, patients demonstrated improved clinical parameters and reduced inflammatory state and endothelial dysfunction. This favorable evolution was associated with a reversal of microbiota dysbiosis, consisting of the increment of health-related bacteria, such as genus Bifidobacterium, and levels of SCFAs, mainly butyrate. Furthermore, there was a decrease in the abundance of pathogenic bacteria. In vitro, fecal samples collected after 12 months of follow-up exhibited lower inflammation than samples collected at admission. In conclusion, the favorable progression of HF patients after the initial episode was linked to the reversal of gut microbiota dysbiosis and increased SCFA production, particularly butyrate. Whether restoring butyrate levels or promoting the growth of butyrate-producing bacteria could serve as a complementary treatment for these patients deserves further studies.

Non-invasive electromechanical assessment during atrial fibrillation identifies underlying atrial myopathy alterations with early prognostic value.

Electromechanical characterization during atrial fibrillation (AF) remains a significant gap in the understanding of AF-related atrial myopathy. This study reports mechanistic insights into the electromechanical remodeling process associated with AF progression and further demonstrates its prognostic value in the clinic. In pigs, sequential electromechanical assessment during AF progression shows a progressive decrease in mechanical activity and early dissociation from its electrical counterpart. Atrial tissue samples from animals with AF reveal an abnormal increase in cardiomyocytes death and alterations in calcium handling proteins. High-throughput quantitative proteomics and immunoblotting analyses at different stages of AF progression identify downregulation of contractile proteins and progressive increase in atrial fibrosis. Moreover, advanced optical mapping techniques, applied to whole heart preparations during AF, demonstrate that AF-related remodeling decreases the frequency threshold for dissociation between transmembrane voltage signals and intracellular calcium transients compared to healthy controls. Single cell simulations of human atrial cardiomyocytes also confirm the experimental results. In patients, non-invasive assessment of the atrial electromechanical relationship further demonstrate that atrial electromechanical dissociation is an early prognostic indicator for acute and long-term rhythm control.

Coronary microvascular dysfunction is associated with impaired cognitive function: the Cerebral-Coronary Connection study (C3 study).

BACKGROUND: It remains unknown whether the presence of coronary microcirculatory dysfunction (CMD) correlates with its equivalent condition in the brain, cerebral small vessel disease (CSVD). The cerebral-coronary connection (C3), a prospective blinded study, investigated the prevalence of CMD in patients with coronary artery disease (CAD) and its association with CSVD and cognitive function. METHODS AND RESULTS: Patients with documented CAD fulfilling inclusion criteria underwent physiological assessment of epicardial vessels and the microcirculation using intracoronary pressure and Doppler. Coronary microcirculation-related indices included coronary flow reserve (CFR) and hyperaemic microvascular resistance. Brain magnetic resonance imaging, transcranial Doppler (TCD), and neurocognitive examination were performed. Overall, 67 patients were included in the study (mean age 66 years, 73% female). Patients with abnormal CFR (<2.0) (55.2%) showed higher burden of white-matter hyperintensities: 43.2 vs. 20.0% (P = 0.044). After statistical adjustment, low CFR was associated with lower grey matter volume (P = 0.024) and with parameters of white-matter microstructural damage in diffusion-tensor imaging (lower fractional anisotropy and higher mean diffusivity, P = 0.029 and P = 0.032, respectively). Low CFR was associated with higher resistive (P = 0.027) and pulsatility (P = 0.043) values on TCD, and worse neurocognitive test scores (lower mini mental state examination, P = 0.025, and slower Trail Making Test A, P = 0.034). CONCLUSIONS: Coronary microcirculatory dysfunction is frequent in patients with CAD and correlates with CSVD, abnormal cerebral flow haemodynamics, and significant cognitive impairment. These findings support the hypothesis that microvascular dysfunction in the heart and the brain are part of a single pathological process affecting microcirculation in patients with CAD. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT04131075.

Relationship between the coronary artery calcium quantification and gut microbiota composition in subjects without previous cardiovascular disease: A pilot study. / Relación entre la cuantificación de calcio coronario y la composición de la microbiota intestinal en sujetos sin enfermedad cardiovascular previa: estudio piloto.

AIM: To investigate the relationship between gut microbiota composition and the presence of coronary atherosclerosis assessed by coronary artery calcium (CAC) quantification in individuals without previous cardiovascular disease (CVD). METHODS: We included 20 patients over 18 years of age with no history of CVD who underwent multiple detector-computed tomography. From each patient, a stool sample was obtained to characterize gut microbiota composition by sequencing bacterial 16S ribosomal RNA gene. In addition, circulating levels of TNF-α and IL-1ß, as well as trimethylamine N-oxide (TMAO) were determined in plasma samples by automated ELISA and capillary gas chromatography-mass spectrometry, respectively. RESULTS: The mean age of patients was 63.5 years and 60% were women. Half of patients had CAC >100 (Agatston score), and were characterized by a higher abundance of the phylum Proteobacteria, mainly of bacteria belonging to the families Enterobacteriaceae and than patients with a CAC ≤ 100. Moreover, bacterial genera identified as biomarkers, such as Enterobacter, Escherichia/Shigella y Klebsiella, were positively associated with inflammation levels and with TMAO production. CONCLUSION: Our data shows a gut microbiota profile associated with the presence of coronary calcium in patients without previous CVD. Although there are no strategies to decrease the amount of coronary calcium, gut microbiota is highly malleable by several factors. The possibility of preventing and even intervening CVD progression through strategies targeted gut microbiota is a very attractive idea that deserves further studies.

Microglial CX3CR1 production increases in Alzheimer's disease and is regulated by noradrenaline.

The loss of noradrenergic neurons and subsequent reduction of brain noradrenaline (NA) levels are associated with the progression of Alzheimer's disease (AD). This seems to be due mainly to the ability of NA to reduce the activation of microglial cells. We previously observed that NA induces the production of the chemokine Fractalkine/CX3CL1 in neurons. The activation of microglial CX3CR1, sole receptor for CX3CL1, reduces the activation of microglia, which is known to largely contribute to the neuronal damage characteristic of AD. Therefore, alterations of CX3CR1 production in microglia could translate into the enhancement or inhibition of CX3CL1 anti-inflammatory effects. In order to determine if microglial CX3CR1 production is altered in AD and if NA can control it, CX3CR1 expression and synthesis were analyzed in 5xFAD mice and human AD brain samples. In addition, the effects of NA and its reuptake inhibitor reboxetine were analyzed in microglial cultures and mice respectively. Our results indicate that in AD CX3CR1 production is increased in the brain cortex and that reboxetine administration further increases it and enhances microglial reactivity toward amyloid beta plaques. However, direct administration of NA to primary rat microglia or human HMC3 cells inhibits CX3CR1 production, suggesting that microglia responses to NA may be altered in the absence of CX3CL1-producing neurons or other nonmicroglial external factors.

Identification of a Plasma Microrna Signature as Biomarker of Subaneurysmal Aortic Dilation in Patients with High Cardiovascular Risk.

Patients with subaneurysmal aortic dilation (SAD; 25-29 mm diameter) are likely to progress to true abdominal aortic aneurysm (AAA). Despite these patients having a higher risk of all-cause mortality than subjects with aortic size <24 mm, early diagnostic biomarkers are lacking. MicroRNAs (miRs) are well-recognized potential biomarkers due to their differential expression in different tissues and their stability in blood. We have investigated whether a plasma miRs profile could identify the presence of SAD in high cardiovascular risk patients. Using qRT-PCR arrays in plasma samples, we determined miRs differentially expressed between SAD patients and patients with normal aortic diameter. We then selected 12 miRs to be investigated as biomarkers by construction of ROC curves. A total of 82 significantly differentially expressed miRs were found by qPCR array, and 12 were validated by qRT-PCR. ROC curve analyses showed that seven selected miRs (miR-28-3p, miR-29a-3p, miR-93-3p, miR-150-5p, miR-338-3p, miR-339-3p, and miR-378a-3p) could be valuable biomarkers for distinguishing SAD patients. MiR-339-3p showed the best sensitivity and specificity, even after combination with other miRs. Decreased miR-339-3p expression was associated with increased aortic abdominal diameter. MiR-339-3p, alone or in combination with other miRs, could be used for SAD screening in high cardiovascular risk patients, helping to the early diagnosis of asymptomatic AAA.

Gut Microbiota Profile Identifies Transition From Compensated Cardiac Hypertrophy to Heart Failure in Hypertensive Rats.

Microcirculatory alterations displayed by patients with heart failure (HF) induce structural and functional intestinal changes that may affect normal gut microbial community. At the same time, gut microbiota can influence pathological mechanisms implicated in HF progression. However, it is unknown whether gut microbiota dysbiosis can precede the development of cardiac alterations in HF or it is only a mere consequence. Our aim was to investigate the potential relationship between gut microbiota composition and HF development by comparing spontaneously hypertensive heart failure and spontaneously hypertensive rat models. Gut microbiota from spontaneously hypertensive heart failure, spontaneously hypertensive rat, and normotensive Wistar Kyoto rats at 9 and 19 months of age was analyzed by sequencing the 16S ribosomal RNA gene, and KEGG metabolic pathways associated to 16S profiles were predicted. Beta diversity, Firmicutes/Bacteroidetes ratio, taxonomic abundances, and potential metabolic functions of gut microbiota were significantly different in spontaneously hypertensive heart failure with respect to spontaneously hypertensive rat before (9 months) and after (19 months) cardiac differences were presented. Nine-month-old spontaneously hypertensive heart failure showed a significant increase in the genera Paraprevotella, Oscillospira, Prevotella 9, Faecalitalea, Faecalibacterium, Ruminiclostridium 6, Phascolarctobacterium, Butyrivibrio, Parasutterella, and Parabacteroides compared with both Wistar Kyoto and spontaneously hypertensive rat, while Ruminiclostridium 9, Oscillibacter, Ruminiclostridium, Mucispirillum, Intestinimonas, and Akkermansia were diminished. Of them, Akkermansia, Prevotella 9, Paraprevotella, and Phascolarctobaterium were associated to changes in cardiac structure and function. Our results demonstrate an association between specific changes in gut microbiota and the development of HF in a hypertensive model of HF and further support the intervention to restore gut microbiota as an innovative therapeutic strategy for preventing HF.

The Interaction between Mitochondrial Oxidative Stress and Gut Microbiota in the Cardiometabolic Consequences in Diet-Induced Obese Rats.

BACKGROUND: The objective of this study is to determine the role of mitochondrial oxidative stress in the dysbiosis associated with a high fat diet in rats. In addition, the impact of gut microbiota (GM) in the cardiometabolic consequences of diet-induced obesity in rats has been evaluated. METHODS: Male Wistar rats were fed either a high fat diet (HFD) or a control (CT) one for 6 weeks. At the third week, one-half of the animals of each group were treated with the mitochondrial antioxidant MitoTempo (MT; 0.7 mgKg-1day-1 i.p). RESULTS: Animals fed an HFD showed a lower microbiota evenness and diversity in comparison to CT rats. This dysbiosis is characterized by a decrease in Firmicutes/Bacteroidetes ratio and relevant changes at family and genera compared with the CT group. This was accompanied by a reduction in colonic mucin-secreting goblet cells. These changes were reversed by MT treatment. The abundance of certain genera could also be relevant in the metabolic consequences of obesity, as well as in the occurrence of cardiac fibrosis associated with obesity. CONCLUSIONS: These results support an interaction between GM and mitochondrial oxidative stress and its relation with development of cardiac fibrosis, suggesting new approaches in the management of obesity-related cardiometabolic consequences.

The Impact of Cardiac Lipotoxicity on Cardiac Function and Mirnas Signature in Obese and Non-Obese Rats with Myocardial Infarction.

Cardiac lipotoxicity is involved in the cardiac functional consequences associated with obesity. Therefore, the aim of this study was to explore whether changes in the mitochondrial lipid cardiac profile could reflect differences in cardiac function and structure in obese and non-obese rats with myocardial infarction (MI). Whether these changes can also be reflected in a specific plasma miRNA signature as markers of cardiac damage was also evaluated. Rats were fed with either standard (3.5% fat) or high fat diet (35% fat) for 6 weeks before the induction of MI and sacrificed 4 weeks later. MI showed cardiac lipotoxicity independently of the presence of obesity, although obese and non-obese rats did not present the same cardiac lipid profile at mitochondrial level. Several cardiac lipid species in mitochondria, including cardiolipins and triglycerides, were associated with myocardial fibrosis, with mitochondrial triglyceride levels being independently associated with it; this supports that lipotoxicity can affect cardiac function. MI down-regulated plasma levels of miRNA 15b-5p and 194-5p in obese and non-obese animals, which were associated with cardiac function, mitochondrial lipids and myocardial fibrosis, with miRNA 15b-5p levels being independently associated with cardiac fibrosis. This could support that lipotoxicity could affect heart function by modulating plasma miRNAs.

Effect of intensive multifactorial treatment on vascular progenitor cells in hypertensive patients.

BACKGROUND: Most hypertensive patients, despite a proper control of their cardiovascular risk factors, have cardiovascular complications, evidencing the importance of controlling and/or reversing target-organ damage. In this sense, endothelial dysfunction has been associated with the presence of cardiovascular risk factors and related cardiovascular outcomes. Since hypertension often clusters with other risk factors such as dyslipemia, diabetes and obesity, in this study we have investigated the effect of intensive multifactorial treatment on circulating vascular progenitor cell levels on high-risk hypertensive patients. DESIGN: We included108 hypertensive patients receiving intensive multifactorial pharmacologic treatment and dietary recommendations targeting blood pressure, dyslipemia, hyperglycemia and weight for 12 months. After the treatment period, blood samples were collected and circulating levels of endothelial (CD34+/KDR+, CD34+/VE-cadherin+) and smooth muscle (CD14+/endoglin+) progenitor cells were identified by flow cytometry. Additionally, plasma concentration of vascular endothelial growth factor (VEGF) was determined by ELISA. RESULTS: Most hypertensive patients (61±12 years, 47% men) showed cardiovascular parameters within normal ranges at baseline. Moreover, body mass index and the majority of the biochemical parameters (systolic and diastolic blood pressure, fasting glucose, total cholesterol, HDL-c, LDL-c, creatinine and hs-CRP) significantly decreased overtime. After 12 months of intensive treatment, CD34+/KDR+ and CD14+/endoglin+ levels did not change, but CD34+/VE-cadherin+ cells increased significantly at month 12 [0.9(0.05-0.14)% vs 0.05(0.02-0.09)% P<0.05]. However, VEGF plasma concentration decreased significantly overtime [89.1(53.9-218.7) vs [66.2(47.5-104.6) pg/mL, P<0.05]. CONCLUSIONS: Long-term intensive treatment in hypertensive patients further improves cardiovascular risk and increases circulating EPCs, suggesting that these cells could be a therapeutic target.

Functionally defective high-density lipoproteins are related to heightened T-cell activation in vertically HIV-infected adolescents.

We assessed high-density lipoprotein (HDL) anti-inflammatory properties in a cohort of vertically HIV-infected adolescents. We hypothesized that proatherogenic mechanisms related to inflammation and immune activation during HIV infection may impair HDL functionality and impact on the atherosclerotic burden. Compared with healthy controls, HDL from HIV-infected adolescents presented impaired functionality, as determined by its ability to inhibit monocyte chemotaxis in vitro, which correlated with detectable viral loads (P = 0.044), lower CD4 nadir (P = 0.043), increased levels of CD4 T-cell activation (P = 0.018), higher C-reactive protein (P = 0.009), and a tendency toward thicker carotid intima-media thickness (P = 0.071).

Eplerenone enhances cardioprotective effects of standard heart failure therapy through matricellular proteins in hypertensive heart failure.

AIMS: The addition of an aldosterone receptor antagonist on top of current optimal therapy (based on angiotensin II inhibition) has demonstrated an important clinical benefit in heart failure patients with systolic dysfunction. Whether this finding also applies to heart failure patients with preserved systolic function is unknown. Therefore, we have studied the effect of adding eplerenone to standard pharmacological heart failure therapy (angiotensin-converting enzyme inhibitor/angiotensin receptor blocker and diuretic and ß-blocker) in the progression of heart failure in spontaneously hypertensive heart failure (SHHF) rats. METHODS AND RESULTS: Two-month-old SHHF rats were randomized to receive no treatment (SHHF group), a standard heart failure therapy (quinapril-torasemide-carvedilol; ST-SHHF group), or the combination of eplerenone and standard heart failure therapy (Eple+ST-SHHF group) for 20 months. Untreated SHHF was characterized by progressive left ventricular hypertrophy, fibrosis, and myocardial contractile and relaxation abnormalities, leading to pulmonary congestion. Despite similar blood pressure control, the addition of eplerenone to standard heart failure therapy further prevented left ventricular hypertrophy, contractile and relaxation alterations, and pulmonary congestion than standard heart failure therapy alone. ST-SHHF and Eple + ST-SHHF rats showed similar inhibition of structural extracellular matrix proteins collagen I, collagen III and fibronectin and metalloproteinase (MMP)-2, MMP-7, MMP-12, and MMP-13. However, only the coadministration of eplerenone with standard heart failure therapy normalized the expression of matricellular proteins thrombospondin 1, tenascin C, periostin, and secreted protein acidic rich in cysteine/osteonectin to values comparable to normotensive rats. CONCLUSION: In a hypertensive heart failure rat model, the addition of eplerenone to conventional heart failure therapy further improves cardiac structural and functional parameters, delaying the progression of heart failure. These beneficial effects of eplerenone were associated with normalization of matricellular protein expression.

Ezetimibe inhibits PMA-induced monocyte/macrophage differentiation by altering microRNA expression: a novel anti-atherosclerotic mechanism.

Ezetimibe, a selective inhibitor of intestinal cholesterol absorption, effectively reduces plasma cholesterol both in monotherapy or combined with a statin. However, its effect on atherosclerosis plaque progression is certainly unknown. MicroRNAs are short non-encoding RNA molecules dynamically implicated in monocytic differentiation which is considered an essential process during atherosclerosis development. The purpose of this study was to investigate the effect of ezetimibe on monocyte/macrophage differentiation as well as the implication of microRNAs (miRNAs) in this process. THP-1 differentiation with PMA became cells adherent to the plastic surface, and induced the expression of macrophage surface markers (CD11a, CD11b and ICAM-1) and miR-155, miR-222, miR-424 and miR-503. In the presence of ezetimibe, the adhesive capacity of THP-1 cells was decreased in a dose-dependent manner (P<0.05) and the expression of CD11a, CD11b and ICAM-1 was almost totally inhibited (P<0.05). The expression of miR-155, miR-222, miR-424 and miR-503 was reduced by 55%, 100%, 75% and 100%, respectively (P<0.05). Further mechanistic studies demonstrated that ezetimibe suppressed the PMA-induced phosphorylation of ERK/MAPK and inhibited the NF-κB activity, which are upstream signalling molecules in the differentiation process. In conclusion, ezetimibe inhibits PMA-induced THP-1 cell differentiation into macrophage-like cells in association with the inhibition of miRNA pathways. Our study suggests that inhibition of miRNAs might form a novel mechanism of anti-atherosclerotic effect of ezetimibe.

Association of HIV-Infection and antiretroviral therapy with levels of endothelial progenitor cells and subclinical atherosclerosis.

BACKGROUND: Although in the general population circulating vascular progenitor cell levels have been implicated in the homeostasis of the vascular wall through differentiation into endothelium and/or smooth muscle cells, it has not yet been assessed in HIV-infected patients. We herein investigated the number of progenitor cell subpopulations in HIV-infected patients and its relationship to carotid intima-media thickness (c-IMT). METHODS: Blood samples were collected from 200 HIV-infected patients and CD34/KDR, CD34/VE-cadherin, and CD14/Endoglin progenitor cells were identified by flow cytometry. c-IMT was determined by ultrasonography. A group of 27 healthy subjects was used as control group. RESULTS: In our population (20 ART-naive patients and 180 treated patients), traditional cardiovascular risk factors were not found predictive of vascular progenitor cell levels. However, antiretroviral therapy (ART)-treatment was identified as the main predictive value for low CD34/KDR cells and high CD14/Endoglin cells after adjustment by cardiovascular risk factors (age, sex, hypertension, diabetes, and hyperlipidaemia) and HIV-related characteristics (HIV duration and ART treatment). Low levels of circulating CD34/KDR or CD34/VE-cadherin endothelial progenitor cells tended to be associated with increased c-IMT. However, a positive association was found between CD14/Endoglin cells and c-IMT. Low number of CD34/KDR cells was also associated with the longest exposure to nucleoside reverse transcriptase inhibitors and/or protease inhibitors. CONCLUSIONS: ART exposure is the main predictor of circulating vascular progenitor cell levels. However, their levels are only partially associated with high c-IMT in HIV-infected patients. ART has already been found to have proatherogenic effect, but our data first describe its relationship with vascular progenitor cells and c-IMT.