Endothelial progenitor cells and endothelial microparticles are independent predictors of endothelial function

Surface markers on microparticles involved in obesity-derived diseases

AIMS

This review aimed to investigate the different types of microparticles playing role in obesity-related diseases. Additionally, the factors participating in changing the microparticles amount in obese people will also be discussed.

MATERIAL & METHODS

The authors collected the relevant articles published until 2023 and these are carefully selected from three scientific databases based on keywords.

KEY FINDINGS

It has been revealed that exercise might change the microparticle content in the body. The other factor which participates in obesity process is the oxidative stress which is increased in microparticles. Moreover, the obesity is implicated in metabolic conditions including diabetes and cardiovascular diseases.

SIGNIFICANCE

More than one-third of people on the planet today are known as overweight individuals. Microparticles (MPs) are small membrane-bound vesicles that are found in healthy people's blood and are elevated in patients with pathological conditions such as obesity. MPs mostly come from platelets, leukocytes, endothelial cells, and vascular smooth muscle cells. Considering the effect of obesity on microparticles, these small membrane-bound vesicles might play a crucial role in preventing or treatment of obesity.

Aerobically trained older adults show impaired resting, but preserved exercise-induced circulating progenitor cell count, which was not improved by sprint interval training

Older adults exhibit a reduced number and function of CD34 + circulating progenitor cells (CPC), a known risk factor for cardiovascular disease. Exercise promotes the mobilisation of CPCs from bone marrow, so whether ageing per se or physical inactivity in older age reduces CPCs is unknown. Thus, this study examined the effect of age on resting and exercise-induced changes in CPCs in aerobically trained adults and the effect of 8 weeks of sprint interval training (SIT) on resting and exercise-induced CPCs in older adults. Twelve young (22-34 years) and nine older (63-70 years) adults participated in the study. Blood was sampled pre and immediately post a graded exercise test to exhaustion in both groups. Older participants repeated the process after 8 weeks of SIT (3 × 20 s 'all-out' sprints, 2 × a week). Total CPCs (CD34⁺) and endothelial progenitor cells (EPCs: CD34⁺KDR⁺) were determined by flow cytometry. Older adults exhibited lower basal total CD34⁺ CPCs (828 ± 314 vs. 1186 ± 272 cells·mL^-1, p = 0.0149) and CD34⁺KDR⁺ EPCs (177 ± 128 vs. 335 ± 92 cells·mL^-1, p = 0.007) than younger adults. The maximal exercise test increased CPCs in young (CD34⁺: p = 0.004; CD34⁺KDR⁺: p = 0.017) and older adults (CD34⁺: p < 0.001; CD34⁺KDR⁺: p = 0.008), without difference between groups (p = 0.211). SIT did not alter resting or exercise-induced changes in CPCs in the older cohort (p > 0.232). This study suggests age per se does not impair exercise-induced CPC counts, but does lower resting CPC counts.

Endothelium-derived Microparticles Are Increased in Teenagers With Cobalamin Deficiency

INTRODUCTION

Vitamin B 12 (cobalamin) deficiency may be a significant cause of hyperhomocysteinemia, and high homocysteine (Hcy) levels are associated with an increased risk of cardiovascular disease. Endothelium-derived microparticles (EMPs) are a new marker in endothelial dysfunction and atherosclerosis, which play a role in cardiovascular diseases' pathogenesis. This study aimed to evaluate the EMPs, the markers of endothelial dysfunction and atherosclerosis, and lipid profile in teenagers with cobalamin deficiency.

MATERIALS AND METHODS

This prospective study included 143 teenagers, 75 vitamin B 12 deficient patients and 68 healthy controls between 11 and 18 years of age. Routine laboratory tests, hemogram, vitamin B 12 , folic acid, ferritin, Hcy, lipid profile and EMPs were examined and compared. EMP subgroups were analyzed by flow cytometry method according to the expression of membrane-specific antigens. The microparticles released from the endothelium studied were VE-cadherin (CD144), S-endo1 (CD146), and Endoglin (CD105).

RESULTS

The present study demonstrates that circulating CD105+ EMP, CD144+ EMP, CD146+ EMPs, and Hcy were increased, and high-density lipoprotein (HDL) cholesterol was reduced in teenagers with cobalamin deficiency. Vitamin B 12 showed a negative correlation with EMPs and Hcy, positive correlation with folate and HDL. All EMPs showed a significant positive correlation with triglyceride, vitamin B 12 , and HDL.

CONCLUSION

Vitamin B 12 deficiency may predispose to endothelial damage and atherosclerosis by increasing EMPs and harms lipid metabolism in the long term.

Elevated circulating endothelial microparticles (EMPs) in prepubertal children born preterm

BACKGROUND

Endothelial microparticles (EMPs) act as early biomarkers of endothelial activation and damage. No studies have investigated EMPs in preterm-born individuals.

METHODS

Sixty-three preterm-born children and 52 children born full-term (controls) were studied. Circulating CD62E(+), CD144(+), and CD31(+)/CD42b(-) EMPs were measured in preterm-born children compared to controls; possible associations with cardiovascular risk factors and endothelial function parameters were also assessed.

RESULTS

Circulating CD62E(+), CD144(+), and CD31(+)/CD42b(-) EMPs were significantly higher in preterm-born children compared to controls (p = 0.003, p < 0.001, and p < 0.001, respectively). Preterm birth was recognized as an independent predictor of each EMP subpopulation studied; moreover, the mean pressure and velocity of pulmonary artery were independently correlated with CD62E(+) (β = 0.20, p = 0.04) and CD144(+) EMPs (β = 0.22, p = 0.02), respectively, whereas age (β = 0.21, p = 0.03) and being born SGA (β = 0.26, p = 0.01) correlated independently with CD31(+)/CD42b(-) EMPs in the study population. Furthermore, diastolic blood pressure (β = 0.24, p = 0.04), being born SGA (β = 0.24, p = 0.04) and the hyperemic peak velocity of the brachial artery (β = -0.65, p = 0.02) were independently associated with CD31(+)/CD42b(-) EMPs in the preterm-born group.

CONCLUSION

Circulating EMPs were higher in preterm-born children compared to children born full-term. Whether EMPs could act, in clinical practice, as a complementary tool for non-invasive evaluation of endothelium in preterm-born children, remains under investigation.

IMPACT

Circulating endothelial microparticles (EMPs) are small membrane vesicles released from endothelial cells and they act as novel biomarkers of endothelial activation and damage. No studies have investigated circulating EMPs in preterm-born individuals. Circulating EMPs were significantly higher in prepubertal preterm-born children compared to children born at term. In the preterm-born group, the hyperemic peak velocity of the brachial artery was independently associated with CD31(+)/CD42b(-) EMPs. Whether assessment of circulating EMPs could act, in clinical practice, as a complementary tool for non-invasive evaluation of endothelium in preterm-born children, remains to be defined in future investigations.

High circulating levels of CD62E+ and CD31+/Annexin V+ endothelium-derived microparticles in children with overweight/obesity: Evidence of early vascular damage

BACKGROUND

Obesity perturbs endothelium integrity, leading to endothelial activation, which predisposes the release of endothelium-derived microparticles (EMP). We measured the CD31⁺/annexin V⁺ and CD62E⁺ EMP levels to improve our understanding of their contribution to endothelial damage in children with overweight/obesity.

SUBJECT AND METHODS

In this cross-sectional study, 107 children with normal weight and 35 children with overweight/obesity were evaluated. Anthropometric measurement, blood pressure, biochemical profile was performed. Standardized flow cytometry methods were used to identify and quantify circulating CD31⁺/annexin V⁺ and CD62E⁺ EMP.

RESULTS

Children with overweight/obesity had significantly higher circulating levels of CD31⁺/annexin V⁺ (750 [600]) and CD62E⁺ (1400 [700]) EMP than those with normal weight (P < 0.001 for both). We found that EMP levels were positively correlated with body mass index (BMI), waist circumference, blood pressure, total cholesterol, low-density lipoprotein cholesterol (LDLc), and triglycerides. The multivariable logistic regression model revealed that the risks of having high EMP levels (> 75th percentile) were high in children with both large waist circumference and elevated LDLc level. Receiver operating characteristic (ROC) curves demonstrated that the LDLc levels showed significantly greater discrimination than waist circumference for both CD31⁺/annexin V⁺ (P = 0.031) as CD62E⁺ EMPs (P = 0.041).

CONCLUSIONS

Children with overweight/obesity have high circulating CD31⁺/annexin V⁺ and CD62E⁺ EMP levels, which may be an early sign of endothelial apoptosis and inflammatory activation in response to injury. These EMP levels were positively associated with several cardiometabolic risk factors. Our data underscore the negative influence of high-risk metabolic profiles on endothelial integrity in the early stages of childhood obesity.

Probabilistic risk and benefit assessment of nitrates and nitrites by integrating total diet study-based exogenous dietary exposure with endogenous nitrite formation using toxicokinetic modeling

The impacts of dietary nitrates and nitrites on human health have been a controversial topic for many years. However, the risk and benefit assessment of nitrates and nitrites is complicated by the large variation in nitrate and nitrite intake among people and the endogenous nitrite formation in the body. This study conducted a probabilistic risk-benefit assessment of dietary nitrates and nitrites based on internal dose by integrating exogenous and endogenous exposures with human trial data on cardiovascular benefits. A total diet study was carried out to quantify the age-specific dietary intakes of nitrates and nitrites. A previously well-validated human toxicokinetic model was used to predict internal doses for different age groups. In addition, the integrated approach was applied to different populations from different countries/regions based on reported exposure estimates to conduct a comprehensive risk-benefit assessment of dietary nitrates and nitrites. The results demonstrated that vegetable consumption was the main contributor to the internal nitrate and nitrite levels in all age groups. Exposure to nitrates and nitrites exceeding acceptable daily intakes in a variety of foods showed cardiovascular benefits. The probabilistic risk assessment showed that the exposure to nitrates and nitrites did not pose an appreciable health and safety risk. Therefore, the present results suggest that dietary nitrates and nitrites have clear cardiovascular benefits that may outweigh potential risks. Our analysis contributes significantly to addressing the controversy regarding risks and benefits from dietary nitrates and nitrites, and our approach could be applied to other dietary constituents with the potential for both risks and benefits.

Latest Advances in Endothelial Progenitor Cell-Derived Extracellular Vesicles Translation to the Clinic

Almost all nucleated cells secrete extracellular vesicles (EVs) that are heterogeneous spheroid patterned or round shape particles ranging from 30 to 200 nm in size. Recent preclinical and clinical studies have shown that endothelial progenitor cell-derived EVs (EPC-EVs) have a beneficial therapeutic effect in various diseases, including cardiovascular diseases and kidney, and lung disorders. Moreover, some animal studies have shown that EPC-EVs selectively accumulate at the injury site with a specific mechanism of binding along with angiogenic and restorative effects that are superior to those of their ancestors. This review article highlights current advances in the biogenesis, delivery route, and long-term storage methods of EPC-EVs and their favorable effects such as anti-inflammatory, angiogenic, and tissue protection in various diseases. Finally, we review the possibility of therapeutic application of EPC-EVs in the clinic.

Type 1 diabetes patients increase CXCR4+ and CXCR7+ haematopoietic and endothelial progenitor cells with exercise, but the response is attenuated

Exercise mobilizes angiogenic cells, which stimulate vascular repair. However, limited research suggests exercise-induced increase of endothelial progenitor cell (EPCs) is completely lacking in type 1 diabetes (T1D). Clarification, along with investigating how T1D influences exercise-induced increases of other angiogenic cells (hematopoietic progenitor cells; HPCs) and cell surface expression of chemokine receptor 4 (CXCR4) and 7 (CXCR7), is needed. Thirty T1D patients and 30 matched non-diabetes controls completed 45 min of incline walking. Circulating HPCs (CD34⁺, CD34⁺CD45^dim) and EPCs (CD34⁺VEGFR2⁺, CD34⁺CD45^dimVEGFR2⁺), and subsequent expression of CXCR4 and CXCR7, were enumerated by flow cytometry at rest and post-exercise. Counts of HPCs, EPCs and expression of CXCR4 and CXCR7 were significantly lower at rest in the T1D group. In both groups, exercise increased circulating angiogenic cells. However, increases was largely attenuated in the T1D group, up to 55% lower, with CD34⁺ (331 ± 437 Δcells/mL vs. 734 ± 876 Δcells/mL p = 0.048), CD34⁺VEGFR2⁺ (171 ± 342 Δcells/mL vs. 303 ± 267 Δcells/mL, p = 0.006) and CD34⁺VEGFR2⁺CXCR4⁺ (126 ± 242 Δcells/mL vs. 218 ± 217 Δcells/mL, p = 0.040) significantly lower. Exercise-induced increases of angiogenic cells is possible in T1D patients, albeit attenuated compared to controls. Decreased mobilization likely results in reduced migration to, and repair of, vascular damage, potentially limiting the cardiovascular benefits of exercise.Trial registration: ISRCTN63739203.

CD34+ progenitors are predictive of mortality and are associated with physical activity in cardiovascular disease patients

BACKGROUND AND AIMS

Circulating progenitor cells (CPCs) play an important role in vascular repair and can influence cardiovascular (CV) health and longevity. Exercise is known to modulate these cells via mobilization from the bone marrow. The primary aims of this study were to evaluate the association of CPCs with mortality and explore the association between physical activity (PA) and CPCs.

METHODS

1751 individuals from the Framingham Offspring cohort (66 ± 9 years [40-92 years], 54% female) were included in the study. CPCs (CD34^+, CD34⁺CD133⁺, CD34⁺CD133⁺KDR⁺) were measured by flow cytometry. Multivariable Cox regression analyses were performed to investigate relationship of CPCs with future CV event and mortality. Multivariate regression analyses were performed to determine the relationship between self-reported PA and CPC counts.

RESULTS

Following adjustment for standard risk factors, there was an inverse association between CD34⁺ CPCs and all-cause mortality (hazard ratio (HR) per unit increase in CD34⁺, 0.79; 95% CI 0.64-0.98, p = 0.036). CD34⁺CD133⁺ CPCs were inversely associated with CV mortality (HR 0.63, 95% CI 0.44-0.91, p = 0.013). Associations of CD34⁺ and CD34⁺CD133⁺ with mortality were strongest in participants with pre-existing CVD. PA was associated with CD34⁺ CPCs only in CVD participants (PA Index: β = 0.176, p = 0.003; moderate-to-vigorous [MVPA]: β = 0.159, p = 0.007). This relationship was maintained after adjustment for confounding variables.

CONCLUSIONS

A higher number of CD34⁺ and CD34⁺ CD133⁺ CPCs was inversely associated with all-cause and CV mortality. These associations were strongest in participants with CVD. PA is independently associated with CD34⁺ CPCs in individuals with CVD only, suggestive of greater benefit for this population group.

Increased circulating endothelial progenitor cells (EPCs) in prepubertal children born prematurely: a possible link between prematurity and cardiovascular risk

BACKGROUND

Endothelial progenitor cells (EPCs) ensure vascular integrity and neovascularization. No studies have investigated EPCs in preterm-born children beyond infancy.

METHODS

One hundred and thirty-six prepubertal children were enrolled: 63 preterm and 73 born at term (controls). Circulating CD34(+)/VEGFR-2(+)/CD45(-) and CD34(+)/VEGFR-2(+)/CD45dim EPCs were measured in preterm-born children compared to controls. Body mass index (BMI), waist-to-hip ratio (WHR), neck circumference, systolic and diastolic blood pressure (SBP and DBP, respectively), fasting glucose, insulin, lipid profile, common carotid and abdominal aortic intima-media thickness (cIMT and aIMT, respectively), endothelium-dependent brachial artery flow-mediated dilation (FMD), and echocardiographic parameters were also assessed.

RESULTS

Circulating CD34(+)/VEGFR-2(+)/CD45(-) and CD34(+)/VEGFR-2(+)/CD45dim EPCs were significantly higher in preterm-born children compared to controls (p < 0.001 and p < 0.001, respectively). In total study population and in the preterm-born group, EPCs were significantly lower in children born to mothers with gestational diabetes compared to non-diabetic mothers. Prematurity was associated with higher WHR, neck circumference, SBP, DBP, cIMT, aIMT, mean pressure, and velocity of pulmonary artery; the peak velocity of the brachial artery was significantly lower in children born prematurely. In multiple regression analysis, preterm birth and maternal gestational diabetes were recognized as independent predictors of EPCs.

CONCLUSIONS

Circulating EPCs were increased in prepubertal preterm-born children in comparison with peers born full-term. Maternal gestational diabetes was associated with a decrease in EPCs.

IMPACT

Mounting evidence supports the adverse effect of prematurity on cardiovascular health. However, the underlying mechanisms that could lead to endothelial dysfunction in preterm-born individuals are not fully understood. Endothelial progenitor cells (EPCs) ensure vascular integrity, normal endothelial function and neovascularization. No studies have investigated the EPCs counts in peripheral blood beyond infancy in children born prematurely. Circulating EPCs were significantly higher in preterm-born prepubertal children compared to controls, thus indicating that prematurity is possibly associated with endothelial damage. In total study population and in the preterm-born group, maternal gestational diabetes was associated with decreased EPCs concentrations.

Endothelial impairment evaluation by peripheral arterial tonometry in pediatric endocrinopathies: A narrative review

Endothelial dysfunction (ED) is characterized by an imbalance between vasodilator and vasoconstriction agents. Several pathological conditions clinically diagnosed in childhood and adolescence are characterized by ED and increased risk for early development of microangiopathic and macroangiopathic impairment, in particular type 1 diabetes mellitus (T1DM), T2DM, obesity, metabolic syndromeand pituitary dysfunction associated to various endocrinopathies. More recently insulin resistance following chemotherapy or radiotherapy for tumors, bone marrow transplantation for hematological malignancies (i.e., cancer survivors), or immunosuppressive treatment for solid organ transplantation has been observed. Assessment of ED by means of non-invasive techniques is the gold standard for early ED detection before clinical manifestation. It is aimed to recognize patients at risk and to avoid the development and progression of more serious illnesses. Reactive hyperemia-peripheral artery tonometry is a noninvasive technique to assess peripheral endothelial function by measuring modifications in digital pulse volume during reactive hyperemia, and represents a non-invasive, reproducible and operator-independent tool able to detect precocious ED. This narrative review aimed to provide an overview of the most important papers regarding ED detection by EndoPat 2000 in children and adolescents with different endocrine diseases. A comprehensive search of English language articles was performed in the MEDLINE database without using other search filters except the publication interval between 2005 and 2020.

Body mass index percentiles and elevated blood pressure among children and adolescents

It is well established that obesity is associated with an increased risk of elevated and high blood pressure (BP) in children and adolescents. However, it is uncertain whether there is an increase in the risk of elevated and high BP associated with an increase of body mass index (BMI) among children and adolescents whose BMI is in the accepted normal range. Data were available for 58 899 children and adolescents aged 6-17 years from seven national cross-sectional surveys in China, India, Iran, Korea, Poland, Tunisia, and the United States. The subjects were divided into eight percentile subgroups according to their BMI levels based on the World Health Organization recommendations. Elevated BP and high BP were defined using the 2016 international child BP criteria. Compared with the reference subgroup of the 5th-24th percentiles, the odds ratios (ORs) for high BP were 1.27 (95% confidence interval [CI], 1.14-1.41; P < 0.001) in the 25th-49th percentile subgroup, 1.55 (95% CI, 1.39-1.73; P < 0.001) in the 50th-74th percentile subgroup, and 2.17 (95% CI, 1.92-2.46; P < 0.001) in the 75th-84th percentile subgroup, respectively, after adjustment for sex, age, race/ethnicity, height and country. Additionally, the corresponding ORs for elevated BP were 1.21 (95% CI, 1.10-1.32; P < 0.001), 1.55 (95% CI, 1.42-1.69; P < 0.001), and 1.80 (95% CI, 1.62-2.01; P < 0.001), respectively. In conclusion, a BMI in the 25th-84th percentiles, within the accepted normal weight range, was associated with an increased risk of elevated and high BP among children and adolescents. It is important for children and adolescents to keep a BMI at a low level in order to prevent and control hypertension.

Blood Flow Restriction Exercise Attenuates the Exercise-Induced Endothelial Progenitor Cell Response in Healthy, Young Men

Endothelial progenitor cells (EPCs) are a vasculogenic subset of progenitors, which play a key role in maintenance of endothelial integrity. These cells are exercise-responsive, and thus exercise may play a key role in vascular repair and maintenance via mobilization of such cells. Blood flow restriction exercise, due to the augmentation of local tissue hypoxia, may promote exercise-induced EPC mobilization. Nine, healthy, young (18–30 years) males participated in the study. Participants undertook 2 trials of single leg knee extensor (KE) exercise, at 60% of thigh occlusion pressure (4 sets at 30% maximal torque) (blood flow restriction; BFR) or non- blood flow restriction (non-BFR), in a fasted state. Blood was taken prior, immediately after, and 30 min after exercise. Blood was used for the quantification of hematopoietic progenitor cells (HPCs: CD34⁺CD45^dim), EPCs (CD34⁺VEGFR2⁺/CD34⁺CD45^dimVEGFR2⁺) by flow cytometry. Our results show that unilateral KE exercise did not affect circulating HPC levels (p = 0.856), but did result in increases in both CD34⁺VEGFR2⁺ and CD34⁺CD45^dimVEGFR2⁺ EPCs, but only in the non-BFR trial (CD34⁺VEGFR2⁺: 269 ± 42 cells mL^-1 to 573 ± 90 cells mL^-1, pre- to immediately post-exercise, p = 0.008; CD34⁺CD45^dimVEGFR2⁺: 129 ± 21 cells mL^-1 to 313 ± 103 cells mL^-1, pre- to 30 min post-exercise, p = 0.010). In conclusion, low load BFR exercise did not result in significant circulating changes in EPCs in the post-exercise recovery period and may impair exercise-induced EPC mobilization compared to non-BFR exercise.

Detrimental Impact of Low Birth Weight on Circulating Number and Functional Capacity of Endothelial Progenitor Cells in Healthy Children: Role of Angiogenic Factors

OBJECTIVE

To provide a comprehensive assessment of the relationship of birth weight with both endothelial progenitor cell function and angiogenic factors in children.

STUDY DESIGN

Anthropometric measures, biochemical profile, endothelial progenitor cell number, endothelial progenitor cell colony-forming units, vascular endothelial growth factor-A, and nitric oxide plasma levels of 58 children aged 7-11 years were determined.

RESULTS

A positive correlation was observed between birth weight and circulating endothelial progenitor cell number (r= 0.461; P= .001), endothelial progenitor cell colony-forming units (r= 0.512; P < .001), vascular endothelial growth factor-A (r= 0.407; P= .002), and nitric oxide (r= 0.547; P < .001) levels, whereas the adjustment for prematurity, family history of cardiovascular disease, and systolic blood pressure levels did not modify these associations.

CONCLUSION

Low birth weight was associated with a decrease in the circulating/functional capacity of endothelial progenitor cells among healthy children, independent of traditional cardiovascular risk factors. This detrimental impact was accompanied by lower circulating levels of angiogenic factors.

Effect of an 8-Week Individualized Training Program on Blood Biomarkers, Adipokines and Endothelial Function in Obese Young Adolescents with and without Metabolic Syndrome

Obesity is a chronic condition whose incidence is growing due to lack of exercise and frequent nutrition disorders. Childhood obesity has reached epidemic proportions worldwide. One of the best treatment methods is physical training. However, conflicting results have been reported regarding its clinical effectiveness. These contrasting findings may be due to the type and intensity of the adopted physical training program. Therefore, the purpose of the current study was to investigate the effect of an 8-week individualized physical training program on endothelial function, blood biomarkers and adipokine levels in obese adolescents with and without metabolic syndrome (MS). One-hundred-and-twenty-two obese adolescents (71 obese without MS and 51 obese with MS) aged 14 ± 2 years were included in this study. The 8-week individualized training program decreased glucose, triglycerides, total cholesterol, low-density lipoprotein cholesterol and leptin in obese subjects with and without MS. However, adiponectin and endothelial-dependent vasodilatation increased in the follow-up study in both groups. Taken together, the findings suggest that individualized training program is an effective means for the treatment of obesity and MS in pediatric populations.

Endothelial Microparticles and Vascular Endothelial Growth Factor in Patients With Head and Neck Cancer Undergoing Radiotherapy or Radiochemotherapy

BACKGROUND

Endothelial microparticles (EMPs) released from activated or apoptotic endothelial cells may play a role in coagulation and thrombus formation. However, there is insufficient evidence regarding the impact of EMPs on angiogenesis in patients with cancer.

MATERIALS AND METHODS

Sixteen patients with head and neck cancer (HNC) undergoing radiotherapy/radiochemotherapy (RT/RCT) and 10 healthy controls were studied. Serum EMPs were counted by flow cytometry, and vascular endothelial growth factor (VEGF) was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The mean EMP level was significantly higher in patients with HNC before RT/RCT (1,601±1,479 EMP/μl) compared to the control group (782±698 EMP/μl). The number of EMPs was not notably increased after RT/RCT (1,629±769 EMP/μl). There was no significant correlation between the plasma EMP number and concentration of VEGF before (r=0.131; p=0.625), 1 day after (r=-0.042, p=0.874), nor 3 months after RT/RCT (r=0.454, p=0.076).

CONCLUSION

Released EMPs may not influence promotion of neovascularization in patients with HNC.

Molecular Mechanisms Underpinning Microparticle-Mediated Cellular Injury in Cardiovascular Complications Associated with Diabetes

Microparticles (MPs) are small vesicles shed from the cytoplasmic membrane of healthy, activated, or apoptotic cells. MPs are very heterogeneous in size (100–1,000 nm), and they harbor proteins and surface antigens specific to cells they originate from. Virtually, all cells can shed MPs, and therefore, they can be found in all body fluids, but also entrapped in tissues. Of interest and because of their easy detection using a variety of techniques, circulating MPs were recognized as biomarkers for cell activation. MPs were also found to mediate critical actions in intercellular communication and transmitting biological messages by acting as paracrine vehicles. High plasma numbers of MPs were reported in many cardiovascular and metabolic disturbances that are closely associated with insulin resistance and low-grade inflammation and have been linked to adverse actions on cardiovascular function. This review highlights the involvement of MPs in cardiovascular complications associated with diabetes and discusses the molecular mechanisms that underpin the pathophysiological role of MPs in the onset and progression of cellular injury in diabetes.

Longer Sleep Duration and Endothelial Cell Health Among a Multiethnic Sample of Adolescents

OBJECTIVE

Adverse endothelial cell health, an early pathogenic process underlying atherosclerosis and cardiovascular disease, is evident in childhood and adolescence. Sleep duration, a modifiable cardiovascular health behavior, may be an important cardiovascular disease prevention target that may affect endothelial cell health. We examined the associations of longer sleep duration with endothelial cell injury among youth.

METHODS

In a multiethnic sample of 235 children (63.0% female, mean age = 13.9 years), we conducted multivariable linear regressions to test the cross-sectional association of sleep duration and circulating levels of endothelial cell-derived microparticles (EMPs), phenotypic for endothelial cell activation and apoptosis (CD62E+ EMPs, CD31+/CD42b- EMPs, and CD31+/Annexin V+ EMPs). Sleep duration and EMPs were both treated as continuous variables. Models were adjusted for age, sex, race, pubertal status, household economic resources, and waist circumference.

RESULTS

Overall, 69.2% had short sleep duration (<8 hours of sleep per night). Longer sleep duration was significantly associated with lower levels of CD62E+ EMPs and CD31+/CD42b- EMPs. A 60-minute increase in sleep duration was associated with an 8.40 (95% confidence interval = -205.20 to -1.80, p = .046) decrease in CD62E+ EMPs and a 9.00 (95% confidence interval = -153.60 to -9.60, p = .027) decrease in CD31+/CD42b- EMPs. Sleep duration was not associated with CD31+/Annexin V+ EMPs.

CONCLUSIONS

Our results support the hypothesis that sleeping longer has beneficial effects on endothelial cell health during childhood. Primordial prevention efforts might incorporate sleep extension to offset cardiovascular risk in youth.

Potential Cellular and Biochemical Mechanisms of Exercise and Physical Activity on the Ageing Process

Exercise in young adults has been consistently shown to improve various aspects of physiological and psychological health but we are now realising the potential benefits of exercise with advancing age. Specifically, exercise improves cardiovascular, musculoskeletal, and metabolic health through reductions in oxidative stress, chronic low-grade inflammation and modulating cellular processes within a variety of tissues. In this this chapter we will discuss the effects of acute and chronic exercise on these processes and conditions in an ageing population, and how physical activity affects our vasculature, skeletal muscle function, our immune system, and cardiometabolic risk in older adults.

Endothelial Regenerative Capacity and Aging: Influence of Diet, Exercise and Obesity

Background:

The endothelium plays an important role in cardiovascular regulation, from blood flow to platelet aggregation, immune cell infiltration and demargination. A dysfunctional endo-thelium leads to the onset and progression of Cardiovascular Disease (CVD). The aging endothelium displays significant alterations in function, such as reduced vasomotor functions and reduced angio-genic capabilities. This could be partly due to elevated levels of oxidative stress and reduced endothe-lial cell turnover. Circulating angiogenic cells, such as Endothelial Progenitor Cells (EPCs) play a significant role in maintaining endothelial health and function, by supporting endothelial cell prolifera-tion, or via incorporation into the vasculature and differentiation into mature endothelial cells. Howev-er, these cells are reduced in number and function with age, which may contribute to the elevated CVD risk in this population. However, lifestyle factors, such as exercise, physical activity obesity, and dietary intake of omega-3 polyunsaturated fatty acids, nitrates, and antioxidants, significantly af-fect the number and function of these circulating angiogenic cells.

Conclusion:

This review will discuss the effects of advancing age on endothelial health and vascular regenerative capacity, as well as the influence of diet, exercise, and obesity on these cells, the mecha-nistic links and the subsequent impact on cardiovascular health

Extracellular vesicles and microvascular pathology: Decoding the active dialogue

Extracellular vesicles (EV) are a heterogeneous collection of membrane-surrounded structures released from all studied cells, under both physiological and pathological conditions. These nano-size vesicles carry complex cargoes including different classes of proteins, lipids and nucleic acids and are known to act as a communication and signalling vesicles in various cellular process. In addition to their role in development and progression of pathological disorders which make them potentially great biomarkers, EV have beneficial effects, as they take part in homeostasis. In this review we have analysed the evidence for the role of microvesicles and exosomes secreted from other cells on microvascular endothelium (EV uptake) as well as the role of endothelial-derived vesicles on their neighbouring and distant cells (EV release).

Lower resting and exercise-induced circulating angiogenic progenitors and angiogenic T cells in older men

Aging is associated with a dysfunctional endothelial phenotype as well as reduced angiogenic capabilities. Exercise exerts beneficial effects on the cardiovascular system, possibly by increasing/maintaining the number and/or function of circulating angiogenic cells (CACs), which are known to decline with age. However, the relationship between cardiorespiratory fitness (CRF) and age-related changes in the frequency of CACs, as well as the exercise-induced responsiveness of CACs in older individuals, has not yet been determined. One-hundred seven healthy male volunteers, aged 18-75 yr, participated in study 1. CRF was estimated using a submaximal cycling ergometer test. Circulating endothelial progenitor cells (EPCs), angiogenic T cells (T_ANG), and their chemokine (C-X-C motif) receptor 4 (CXCR4) cell surface receptor expression were enumerated by flow cytometry using peripheral blood samples obtained under resting conditions before the exercise test. In study 2, 17 healthy men (8 young men, 18-25 yr; 9 older men, 60-75 yr) were recruited, and these participants undertook a 30-min cycling exercise bout at 70% maximal O₂ consumption, with CACs enumerated before and immediately after exercise. Age was inversely associated with both CD34⁺ progenitor cells ( r² = -0.140, P = 0.000) and T_ANG ( r² = -0.176, P = 0.000) cells as well as CXCR4-expressing CACs (CD34⁺: r² = -0.167, P = 0.000; EPCs: r² = -0.098, P = 0.001; T_ANG: r² = -0.053, P = 0.015). However, after correcting for age, CRF had no relationship with either CAC subset. In addition, older individuals displayed attenuated exercise-induced increases in CD34⁺ progenitor cells, T_ANG, CD4⁺, T_ANG, and CD8⁺CXCR4⁺ T_ANG cells. Older men display lower CAC levels, which may contribute to increased risk of cardiovascular disease, and older adults display an impaired exercise-induced responsiveness of these cells. NEW & NOTEWORTHY Older adults display lower circulating progenitor cell and angiogenic T cell counts compared with younger individuals independently of cardiometabolic risk factors and cardiorespiratory fitness. Older adults also display impaired exercise-induced mobilization of these vasculogenic cells.

Microvascular endothelial function in Japanese early adolescents

Endothelial dysfunction is the early predictive factor for the development of atherosclerosis and future cardiovascular diseases in adulthood. The prevalence of endothelial dysfunction in children and early adolescents is increasing worldwide. Peripheral arterial tonometry is a noninvasive technique for assessing peripheral microvascular function and is used as a validated marker of endothelial function. We assessed anthropometric parameters, blood pressure, arterial stiffness, and peripheral endothelial function in 157 Japanese early adolescents (75 boys and 82 girls). We measured peripheral endothelial function by using peripheral arterial tonometry to determine the reactive hyperemia index, and assessed the association of reactive hyperemia index with parameters of anthropometry and arterial stiffness. The mean reactive hyperemia index of all subjects was 1.85 ± 0.6, and there was no difference of reactive hyperemia index according to sex. Reactive hyperemia index was significantly associated with systolic and diastolic blood pressures, and had no correlation with anthropometric parameters and arterial stiffness markers. The reactive hyperemia index values among Japanese early adolescents were similar to those reported in previous studies on children and early adolescents. This noninvasive technique may be useful for the assessment of microvascular endothelial function among children and early adolescents.

Methods to evaluate arterial structure and function in children - State-of-the art knowledge

BACKGROUND

With increasing rates of hypertension, obesity, and diabetes in the pediatric population, wide available, and reproducible methods are necessary to evaluate arterial structure and function in children and adolescents.

METHODS

MEDLINE/Pubmed was searched for articles published in years 2012-2017 on methodology of, current knowledge on, and limitations of the most commonly used methods to evaluate central, proximal and coronary arteries, as well as endothelial function in pediatric patients.

RESULTS

Among 1528 records screened (including 1475 records from years 2012 to 2017) 139 papers were found suitable for the review. Following methods were discussed in this review article: ultrasound measurements of the intima-media thickness, coronary calcium scoring using computed tomography, arterial stiffness measurements (pulse wave velocity and pulse wave analysis, carotid artery distensibility, pulse pressure, and ambulatory arterial stiffness index), ankle-brachial index, and methods to evaluate vascular endothelial function (flow-mediated vasodilation, peripheral arterial tonometry, Doppler laser flowmetry, and cellular and soluble markers of endothelial dysfunction).

CONCLUSIONS

Ultrasonographic measurement of carotid intima-media thickness and measurement of pulse wave velocity (by oscillometry or applanation tonometry) are highly reproducible methods applicable for both research and clinical practice with proved applicability for children aged ≥6 years or with height ≥120cm. Evaluation of ambulatory arterial stiffness index by ambulatory blood pressure monitoring is another promising option in pediatric high-risk patients. Clearly, further studies are necessary to evaluate usefulness of these and other methods for the detection of subclinical arterial damage in children.

Effect of Intensive Periodontal Therapy on Blood Pressure and Endothelial Microparticles in Patients With Prehypertension and Periodontitis: A Randomized Controlled Trial

BACKGROUND

Although some studies show a positive association between periodontitis and blood pressure (BP) elevation, research on the effect of intensive periodontal treatment on decline in BP levels and endothelial microparticles (EMPs) without any antihypertensive management is lacking. Therefore, the present clinical trial explores whether intensive periodontal therapy would lower BP levels and EMPs of patients with prehypertension with periodontitis.

METHODS

From a total 107 patients, 95 underwent randomization (47 assigned to control-treatment [CT] group and 48 assigned to intensive-treatment [IT] group) and completed the trial. Patients received intervention for 4 consecutive weeks and were followed for 6 months. Levels of BP and EMPs were evaluated at baseline and 1, 3, and 6 months after intervention.

RESULTS

Periodontal conditions were significantly improved (P <0.05) 6 months after intensive periodontal treatment. In parallel, the primary outcomes including systolic and diastolic BP and EMPs were markedly reduced in the IT group compared with the CT group (absolute difference: 12.57 and 9.65 mm Hg and 581.59/μL, respectively; 95% confidence intervals: 10.45 to 14.69, 7.06 to 12.24, and 348.12 to 815.06, respectively; P <0.05). Reduction in BP levels and EMPs was related to improvement in probing depth (r = 0.358, 0.363, and 0.676, respectively, by the Pearson product-moment correlation; P = 0.009, 0.008, and P <0.001, respectively).

CONCLUSION

To the best knowledge of the authors, the present study demonstrates for the first time that intensive periodontal intervention without any antihypertensive medication therapy may be an effective means to lower levels of BP and EMPs in patients with prehypertension with periodontitis.

Immune biomarkers in the spectrum of childhood noncommunicable diseases

A biomarker is an accurately and reproducibly quantifiable biological characteristic that provides an objective measure of health status or disease. Benefits of biomarkers include identification of therapeutic targets, monitoring of clinical interventions, and development of personalized (or precision) medicine. Challenges to the use of biomarkers include optimizing sample collection, processing and storage, validation, and often the need for sophisticated laboratory and bioinformatics approaches. Biomarkers offer better understanding of disease processes and should benefit the early detection, treatment, and management of multiple noncommunicable diseases (NCDs). This review will consider the utility of biomarkers in patients with allergic and other immune-mediated diseases in childhood. Typically, biomarkers are used currently to provide mechanistic insight or an objective measure of disease severity, with their future role in risk stratification/disease prediction speculative at best. There are many lessons to be learned from the biomarker strategies used for cancer in which biomarkers are in routine clinical use and industry-wide standardized approaches have been developed. Biomarker discovery and validation in children with disease lag behind those in adults; given the early onset and therefore potential lifelong effect of many NCDs, there should be more studies incorporating cohorts of children. Many pediatric biomarkers are at the discovery stage, with a long path to evaluation and clinical implementation. The ultimate challenge will be optimization of prevention strategies that can be implemented in children identified as being at risk of an NCD through the use of biomarkers.

Effects of a dietary strawberry powder on parameters of vascular health in adolescent males

Previous studies have shown that the intake of freeze-dried strawberry powder (FDSP) improves select markers of cardiovascular health in adults with cardiovascular risk factors; however, whether these improvements can be observed in at-risk adolescents is unknown. A randomised, double-blind, cross-over study enrolled twenty-five overweight or obese males, aged 14-18 years, to consume 50 g of a FDSP or a control powder, daily for 1 week. Before and after each test period, measures of microvascular function, plasma nitrate/nitrite, platelet reactivity and blood lipids were collected at baseline and acutely 1 h after FDSP intake. Acute plasma nitrate/nitrite levels increased 1 h after consuming the FDSP during Study Visit 1 before daily FDSP intake (P<0·001) and during Study Visit 2 after 1 week of FDSP intake (P<0·001) compared with control powder intake. As a group, fasting nitrate/nitrite levels did not significantly change after 1 week of control or FDSP intake. However, for those individuals where fasting nitrate levels increased after short-term FDSP intake compared with controls, an increase in reactive hyperaemia index (RHI) was observed (P=0·014), whereas RHI was unchanged in those individuals who did not have a significant increase in nitrate (P=0·396). Taken together, these data support the concept that strawberries can provide vascular health benefits to heavier adolescent males.

Circulating microparticles as a predictor of vascular properties in patients on mechanical circulatory support; hype or hope?

Microparticles are small circulating vesicles originating from circulatory system and vascular wall cells released during their activation or damage. They possess different roles in regulation of endothelial function, inflammation, thrombosis, angiogenesis, and in general, cellular stress. Microparticles are the subject of intensive research in pulmonary hypertension, atherosclerotic disease, and heart failure. Another recently emerging role is the evaluation of the status of vasculature in end-stage heart failure patients treated with implantable ventricular assist devices. In patients implanted as destination therapy, assessment of the long-term effect of currently used continuous-flow left ventricular assist devices (LVADs) on vasculature might be of critical importance. However, unique continuous flow pattern generated by LVADs makes it difficult to assess reliably the vascular function with most currently used methods, based mainly on ultrasound detection of changes of arterial dilatation during pulsatile flow. In this respect, the measurement of circulating microparticles as a marker of vascular status may help to elucidate both short- and long-term effects of LVADs on the vascular system. Because data regarding this topic are very limited, this review is focused on the advantages and caveats of the circulating microparticles as markers of vascular function in patients on continuous-flow LVADs.

Association of CD34/CD133/VEGFR2-Positive Cell Numbers with Eicosapentaenoic Acid and Postprandial Hyperglycemia in Patients with Coronary Artery Disease

OBJECTIVES

Circulating endothelial progenitor cells (EPCs), which have the ability to differentiate into mature endothelial cells, can elicit angiogenesis, vasculogenesis and vessel repair in cardiac ischemia and vascular injuries caused by endothelial damage. Serum 1,5-anhydro-d-glucitol (1,5-AG), which is a useful clinical marker of postprandial hyperglycemia, eicosapentaenoic acid (EPA), and arachidonic acid (AA) are newly identified risk factors for coronary artery disease (CAD). However, no previous study has reported the associations between EPCs and 1,5-AG, EPA, and AA levels in CAD patients with type 2 diabetes mellitus (DM).

METHODS

Peripheral EPCs, assessed as CD34+ cells co-expressing CD133 and vascular endothelial growth factor receptor-2, were studied in 76 CAD patients (mean age, 69.2±11.3years) with DM. Serum 1,5-AG, EPA, and AA levels were measured.

RESULTS

EPC numbers showed a significant association with 1,5-AG and HbA1c (r=0.290; p=0.037 and r=-0.328; p=0.011, respectively). In addition, there were significant associations between EPC numbers and EPA and body mass index (BMI) (r=0.354; p=0.027 and r=-0.402; p=0.002, respectively). In multiple linear regression analysis, HbA1c, BMI, and EPA values had significant associations with EPC numbers (β=-0.316, 95% confidence interval (CI) -0.256 to -0.008, p=0.037; β=-0.413, 95% CI -0.099 to -0.017, p=0.007; and β=0.400, 95% CI 0.004 to 0.002, p=0.010, respectively).

CONCLUSIONS

EPC number is associated with HbA1c, 1,5-AG, EPA, and BMI values, suggesting that postprandial hyperglycemia and n-3 polyunsaturated fatty acids contribute to EPC recruitment in CAD patients with type 2 DM.

Childhood obesity-related endothelial dysfunction: an update on pathophysiological mechanisms and diagnostic advancements

Childhood obesity jeopardizes a healthy future for our society's children as it is associated with increased cardiovascular morbidity and mortality later on in life. Endothelial dysfunction, the first step in the development of atherosclerosis, is already present in obese children and may well represent a targetable risk factor. Technological advancements in recent years have facilitated noninvasive measurements of endothelial homeostasis in children. Thereby this topic ultimately starts to get the attention it deserves. In this paper, we aim to summarize the latest insights on endothelial dysfunction in childhood obesity. We discuss methodological advancements in peripheral endothelial function measurement and newly identified diagnostic markers of vascular homeostasis. Finally, future challenges and perspectives are set forth on how to efficiently tackle the catastrophic rise in cardiovascular morbidity and mortality that will be inflicted on obese children if they are not treated optimally.

Non-invasive assessment of endothelial function in children with obesity and lipid disorders

BACKGROUND

Digital tonometry is designed to non-invasively screen for endothelial dysfunction by the detection of impaired flow-induced reactive hyperaemia in the fingertip. We determined whether digital reactive hyperaemia correlated with risk factors for atherosclerosis in two groups of children at increased risk for endothelial dysfunction.

METHODS

A total of 15 obese children and 23 non-obese, dyslipidaemic children, 8-21 years of age, were enrolled, and their medical histories, anthropometric measurements, carotid wall thickness by means of ultrasonography, and fasting blood samples for cardiovascular risk factors were obtained. The standard endoPAT index of digital reactive hyperaemia was modified to reflect the true peak response or the integrated response of the entire post-occlusion period. In each group, age, sex, pubertal status, carotid wall thickness, and multiple cardiovascular risk factors were tested as predictors of endothelial dysfunction.

RESULTS

In the non-obese, dyslipidaemic group, but not in the obese group, both indices strongly correlated with height (r=0.55, p=0.007, by peak response) followed by weight, waist circumference, and age. In both groups, neither index of reactive hyperaemia significantly correlated with any other cardiovascular risk factor.

CONCLUSIONS

Contrary to the known age-related increase in atherosclerosis, digital reactive hyperaemia increased with age and its correlates in non-obese, dyslipidaemic children and was not related to other cardiovascular risk factors in either group. The reason for the lack of this relationship with age in obese children is unknown. The age-dependent physiology of digital microvascular reactivity and the endothelium-independent factors controlling the peak hyperaemic response need further study in children with a wide age range.

Insights into the molecular mechanisms of diabetes-induced endothelial dysfunction: focus on oxidative stress and endothelial progenitor cells

Diabetes mellitus is a heterogeneous, multifactorial, chronic disease characterized by hyperglycemia owing to insulin insufficiency and insulin resistance (IR). Recent epidemiological studies showed that the diabetes epidemic affects 382 million people worldwide in 2013, and this figure is expected to be 600 million people by 2035. Diabetes is associated with microvascular and macrovascular complications resulting in accelerated endothelial dysfunction (ED), atherosclerosis, and cardiovascular disease (CVD). Unfortunately, the complex pathophysiology of diabetic cardiovascular damage is not fully understood. Therefore, there is a clear need to better understand the molecular pathophysiology of ED in diabetes, and consequently, better treatment options and novel efficacious therapies could be identified. In the light of recent extensive research, we re-investigate the association between diabetes-associated metabolic disturbances (IR, subclinical inflammation, dyslipidemia, hyperglycemia, dysregulated production of adipokines, defective incretin and gut hormones production/action, and oxidative stress) and ED, focusing on oxidative stress and endothelial progenitor cells (EPCs). In addition, we re-emphasize that oxidative stress is the final common pathway that transduces signals from other conditions-either directly or indirectly-leading to ED and CVD.

Vascular Ageing and Exercise: Focus on Cellular Reparative Processes

Ageing is associated with an increased risk of developing noncommunicable diseases (NCDs), such as diabetes and cardiovascular disease (CVD). The increased risk can be attributable to increased prolonged exposure to oxidative stress. Often, CVD is preceded by endothelial dysfunction, which carries with it a proatherothrombotic phenotype. Endothelial senescence and reduced production and release of nitric oxide (NO) are associated with “vascular ageing” and are often accompanied by a reduced ability for the body to repair vascular damage, termed “reendothelialization.” Exercise has been repeatedly shown to confer protection against CVD and diabetes risk and incidence. Regular exercise promotes endothelial function and can prevent endothelial senescence, often through a reduction in oxidative stress. Recently, endothelial precursors, endothelial progenitor cells (EPC), have been shown to repair damaged endothelium, and reduced circulating number and/or function of these cells is associated with ageing. Exercise can modulate both number and function of these cells to promote endothelial homeostasis. In this review we look at the effects of advancing age on the endothelium and these endothelial precursors and how exercise appears to offset this “vascular ageing” process.

Endothelial progenitor cell phenotype and function are impaired in childhood-onset systemic lupus erythematosus

OBJECTIVE

Systemic lupus erythematosus (SLE) is characterized by increased cardiovascular risk in adult-onset and childhood-onset SLE. Type I interferons (IFNs) appear to play a prominent role in premature vascular damage in adult-onset SLE, at least in part, by inducing impairments in the phenotype and function of endothelial progenitor cells (EPCs), thereby hampering vascular repair. It is not clear whether EPC dysfunction is present in childhood-onset SLE in association with a type I IFN signature.

METHODS

The phenotype and numbers of EPCs were quantified in patients with childhood-onset SLE, patients with juvenile idiopathic arthritis (JIA), and matched healthy control subjects. In a separate cohort of patients with childhood-onset SLE, markers of subclinical atherosclerosis and endothelial dysfunction were quantified using standardized protocols and analyzed for associations with serum type I IFN activity.

RESULTS

EPC numbers and function were significantly decreased in patients with childhood-onset SLE compared with patients with JIA and healthy control subjects. Serum from patients with childhood-onset SLE impaired differentiation of EPCs into mature endothelial cells in healthy controls, and this effect was blocked by inhibition of the type I IFN pathway. Type I IFN activity in serum was not significantly associated with subclinical atherosclerosis and endothelial function in patients with childhood-onset SLE.

CONCLUSION

As in adult-onset SLE, childhood-onset SLE is characterized by phenotypic and functional EPC abnormalities, which are likely triggered by type I IFNs. Although cross-sectional analysis revealed no global association between type I IFN signatures and vascular measures of subclinical atherosclerosis, longitudinal assessments are needed to evaluate whether progression of vascular damage in patients with childhood-onset SLE is associated with type I IFNs, as observed in patients with adult-onset SLE.

The real face of endothelial progenitor cells - Circulating angiogenic cells as endothelial prognostic marker?

Endothelial progenitor cells (EPCs) have been extensively studied for almost 19 years now and were considered as a potential marker for endothelial regeneration ability. On the other hand, circulating endothelial cells (CEC) were studied as biomarker for endothelial injury. Yet, in the literature, there is also huge incoherency in regards to terminology and protocols used. This results in misleading conclusions on the role of so called "EPCs", especially in the clinical field. The discrepancies are mainly due to strong phenotypic overlap between EPCs and circulating angiogenic cells (CAC), therefore changes in "EPC" terminology have been suggested. Other factors leading to inconsistent results are varied definitions of the studied populations and the lack of universal data reporting, which could strongly affect data interpretation. The current review is focused on controversies concerning the use of "EPCs"/CAC and CEC as putative endothelial diagnostic markers.

Diet, exercise, and endothelial function in obese adolescents

BACKGROUND AND OBJECTIVES

Endothelial dysfunction is the first, although reversible, sign of atherosclerosis and is present in obese adolescents. The primary end point of this study was to investigate the influence of a multicomponent treatment on microvascular function. Additional objectives and end points were a reduced BMI SD score, improvements in body composition, exercise capacity, and cardiovascular risk factors, an increase in endothelial progenitor cells (EPCs), and a decrease in endothelial microparticles (EMPs).

METHODS

We used a quasi-randomized study with 2 cohorts of obese adolescents: an intervention group (n = 33; 15.4 ± 1.5 years, 24 girls and 9 boys) treated residentially with supervised diet and exercise and a usual care group (n = 28; 15.1 ± 1.2 years, 22 girls and 6 boys), treated ambulantly. Changes in body mass, body composition, cardiorespiratory fitness, microvascular endothelial function, and circulating EPCs and EMPs were evaluated after 5 months and at the end of the 10-month program.

RESULTS

Residential intervention decreased BMI and body fat percentage, whereas it increased exercise capacity (P < .001 after 5 and 10 months). Microvascular endothelial function also improved in the intervention group (P = .04 at 10 months; + 0.59 ± 0.20 compared with + 0.01 ± 0.12 arbitrary units). Furthermore, intervention produced a significant reduction in traditional cardiovascular risk factors, including high-sensitivity C-reactive protein (P = .012 at 10 months). EPCs were increased after 5 months (P = .01), and EMPs decreased after 10 months (P = .004).

CONCLUSIONS

A treatment regimen consisting of supervised diet and exercise training was effective in improving multiple adolescent obesity-related end points.