Endothelial Dysfunction in Childhood Infection

Defining the role of host biomarkers in the diagnosis and prognosis of the severity of childhood pneumonia: a prospective cohort study

Reliable tools to inform outpatient management of childhood pneumonia in resource-limited settings are needed. We investigated the value added by biomarkers of the host infection response to the performance of the Liverpool quick Sequential Organ Failure Assessment score (LqSOFA), for triage of children presenting with pneumonia to a primary care clinic in a refugee camp on the Thailand-Myanmar border. 900 consecutive presentations of children aged ≤ 24 months meeting WHO pneumonia criteria were included. The primary outcome was receipt of supplemental oxygen. We compared discrimination of a clinical risk score (LqSOFA) to markers of endothelial injury (Ang-1, Ang-2, sFlt-1), immune activation (CHI3L1, IP-10, IL-1ra, IL-6, IL-8, IL-10, sTNFR-1, sTREM-1), and inflammation (CRP, PCT), and quantified the net benefit of including biomarkers alongside LqSOFA. We evaluated the differential contribution of LqSOFA and host biomarkers to the diagnosis and prognosis of pneumonia severity. 49/900 (5.4%) presentations met the primary outcome. Discrimination of LqSOFA and Ang-2, the best performing biomarker, were comparable (AUC 0.82 [95% CI 0.76-0.88] and 0.81 [95% CI 0.74-0.87] respectively). Combining Ang-2 with LqSOFA improved discrimination (AUC 0.91; 95% CI 0.87-0.94; p < 0.001), and resulted in greater net benefit, with 10-30% fewer children who required oxygen supplementation incorrectly identified as safe for community-based management. Ang-2 had greater prognostic utility than LqSOFA to identify children requiring supplemental oxygen later in their illness course. Combining Ang-2 and LqSOFA could guide referrals of childhood pneumonia from resource-limited community settings. Further work on test development and integration into patient triage is required.

Does endothelial dysfunction correlate with endocrinal abnormalities in patients with polycystic ovary syndrome?

To study and critically analyze the published evidence on correlation of hormonal abnormalities and endothelial dysfunction (ED) in polycystic ovary syndrome (PCOS) through a systematic review. The databases including MEDLINE, PubMed, Up-To-Date, and Science Direct were searched using Medical subject handling terms and free text term keywords such as endocrine abnormalities in PCOS, ED assessment in PCOS, ED in combination with insulin resistance (IR), hyperandrogenism (HA), increased free testosterone, free androgen index (FAI), gonadotrophin levels, luteinizing hormone (LH), prolactin, estrogen, adipocytokines to search trials, and observational studies published from January 1987 to September 2015. Authors of original studies were contacted for additional data when necessary. PCOS increases the risk of cardiovascular disease in women. ED, which is a reliable indicator of cardiovascular risk in general population, is seen in most (but not all) women with PCOS. IR, seen in 70% patients with PCOS, is associated with ED in these women, but patients can have normal endothelial function even in the presence of IR. Free testosterone and FAI are consistently associated with ED, but endothelial function can be normal despite HA. Estradiol (not estrone) appears to be protective against ED though estrone is the predominant estrogen produced in PCOS. Increased levels of adipocytokines (visfatin) are promising in predicting ED and cardiovascular risk. However, more studies are required focusing on direct correlation of levels of prolactin, LH, estrone, and visfatin with ED in PCOS.

Vascular consequences of inflammation: a position statement from the ESH Working Group on Vascular Structure and Function and the ARTERY Society

: Inflammation is a physiological response to aggression of pathogenic agents aimed at eliminating the aggressor agent and promoting healing. Excessive inflammation, however, may contribute to tissue damage and an alteration of arterial structure and function. Increased arterial stiffness is a well recognized cardiovascular risk factor independent of blood pressure levels and an intermediate endpoint for cardiovascular events. In the present review, we discuss immune-mediated mechanisms by which inflammation can influence arterial physiology and lead to vascular dysfunction such as atherosclerosis and arterial stiffening. We also show that acute inflammation predisposes the vasculature to arterial dysfunction and stiffening, and alteration of endothelial function and that chronic inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease and psoriasis are accompanied by profound arterial dysfunction which is proportional to the severity of inflammation. Current findings suggest that treatment of inflammation by targeted drugs leads to regression of arterial dysfunction. There is hope that these treatments will improve outcomes for patients.

Subclinical atherosclerosis in children and adolescents with congenital heart disease

BACKGROUND

Subclinical atherosclerosis in childhood can be evaluated by carotid intima-media thickness, which is considered a surrogate marker for atherosclerotic disease in adulthood. The aims of this study were to evaluate carotid intima-media thickness and, to investigate associated factors.

METHODS

Cross-sectional study with children and adolescents with congenital heart disease (CHD). Socio-demographic and clinical characteristics were assessed. Subclinical atherosclerosis was evaluated by carotid intima-media thickness. Cardiovascular risk factors, such as physical activity, screen time, passive smoke, systolic and diastolic blood pressure, waist circumference, dietary intake, lipid parameters, glycaemia, and C-reactive protein, were also assessed. Factors associated with carotid intima-media thickness were analysed using multiple logistic regression.

RESULTS

The mean carotid intima-media thickness was 0.518 mm and 46.7% had subclinical atherosclerosis (carotid intima-media thickness ≥ 97th percentile). After adjusting for confounding factors, cyanotic CHD (odds ratio: 0.40; 95% confidence interval: 0.20; 0.78), cardiac surgery (odds ratio: 3.17; 95% confidence interval: 1.35; 7.48), and be hospitalised to treat infections (odds ratio: 1.92; 95% confidence interval: 1.04; 3.54) were associated with subclinical atherosclerosis.

CONCLUSION

Clinical characteristics related to CHD were associated with subclinical atherosclerosis. This finding suggests that the presence of CHD itself is a risk factor for subclinical atherosclerosis. Therefore, the screen and control of modifiable cardiovascular risk factors should be made early and intensively to prevent atherosclerosis.

Prediction of disease severity in young children presenting with acute febrile illness in resource-limited settings: a protocol for a prospective observational study

INTRODUCTION

In rural and difficult-to-access settings, early and accurate recognition of febrile children at risk of progressing to serious illness could contribute to improved patient outcomes and better resource allocation. This study aims to develop a prognostic clinical prediction tool to assist community healthcare providers identify febrile children who might benefit from referral or admission for facility-based medical care.

METHODS AND ANALYSIS

This prospective observational study will recruit at least 4900 paediatric inpatients and outpatients under the age of 5 years presenting with an acute febrile illness to seven hospitals in six countries across Asia. A venous blood sample and nasopharyngeal swab is collected from each participant and detailed clinical data recorded at presentation, and each day for the first 48 hours of admission for inpatients. Multianalyte assays are performed at reference laboratories to measure a panel of host biomarkers, as well as targeted aetiological investigations for common bacterial and viral pathogens. Clinical outcome is ascertained on day 2 and day 28.Presenting syndromes, clinical outcomes and aetiology of acute febrile illness will be described and compared across sites. Following the latest guidance in prediction model building, a prognostic clinical prediction model, combining simple clinical features and measurements of host biomarkers, will be derived and geographically externally validated. The performance of the model will be evaluated in specific presenting clinical syndromes and fever aetiologies.

ETHICS AND DISSEMINATION

The study has received approval from all relevant international, national and institutional ethics committees. Written informed consent is provided by the caretaker of all participants. Results will be shared with local and national stakeholders, and disseminated via peer-reviewed open-access journals and scientific meetings.

TRIAL REGISTRATION NUMBER

NCT04285021.

Evaluation of the Effect of Essential Hypertension on Elasticity of Ascending Aorta in Type 2 Diabetic Mellitus Patients by Echocardiography

Both essential hypertension (EH) and type 2 diabetes mellitus (T2DM) can impair the elasticity of the ascending aorta. We prospectively enrolled 42 patients with T2DM, 44 patients with EH, 45 patients with T2DM and EH (T2DM + EH), and 41 healthy subjects (HS). They all underwent transthoracic echocardiography to measure ascending aorta inner diameters and a brachial blood pressure measurement to calculate aortic elastic parameters (ie, compliance, distensibility, strain, stiffness index, and Peterson elastic modulus). We found that there were no significant differences as regard with age, sex, body mass index, blood lipids and glucose, carotid atherosclerosis, and ascending aorta inner diameters among the 4 groups. The aortic elastic properties were significantly impaired in T2DM, EH, and T2DM + EH patients compared with the HS, and more impaired in EH and T2DM + EH patients than T2DM patients; there were no significant differences between EH and T2DM + EH patients. Our findings suggest that both T2DM and EH can impair aortic elastic properties. Essential hypertension may play a more important role in the process of ascending aorta sclerosis in patients with T2DM + EH.

Childhood infections and common carotid intima media thickness in adolescence

Atherosclerotic changes can be measured as changes in common carotid intima media thickness (CIMT). It is hypothesised that repeated infection-associated inflammatory responses in childhood contribute to the atherosclerotic process. We set out to determine whether the frequency of infectious diseases in childhood is associated with CIMT in adolescence. The study is part of the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) population-based birth cohort. At age 16 years, common CIMT was measured. We collected general practitioner (GP) diagnosed infections and prescribed antibiotics. Parent-reported infections were retrieved from annual questionnaires. Linear regression analysis assessed the association between number of infections during the first 4 years of life and common CIMT. Common CIMT measurement, GP and questionnaire data were available for 221 participants. No association was observed between the infection measures and CIMT. In a subgroup analysis, significant positive associations with CIMT were observed in participants with low parental education for 2-3 or ⩾7 GP diagnosed infections (+26.4 µm, 95% CI 0.4-52.4 and +26.8 µm, 95% CI 3.6-49.9, respectively) and ⩾3 antibiotic prescriptions (+35.5 µm, 95%CI 15.8-55.3). Overall, early childhood infections were not associated with common CIMT in adolescence. However, a higher number of childhood infections might contribute to the inflammatory process of atherosclerosis in subgroups with low education, this needs to be confirmed in future studies.

Endothelial Nitric Oxide Pathways in the Pathophysiology of Dengue: A Prospective Observational Study

BACKGROUND

Dengue can cause increased vascular permeability that may lead to hypovolemic shock. Endothelial dysfunction may underlie this; however, the association of endothelial nitric oxide (NO) pathways with disease severity is unknown.

METHODS

We performed a prospective observational study in 2 Vietnamese hospitals, assessing patients presenting early (<72 hours of fever) and patients hospitalized with warning signs or severe dengue. The reactive hyperemic index (RHI), which measures endothelium-dependent vasodilation and is a surrogate marker of endothelial function and NO bioavailability, was evaluated using peripheral artery tonometry (EndoPAT), and plasma levels of l-arginine, arginase-1, and asymmetric dimethylarginine were measured at serial time-points. The main outcome of interest was plasma leakage severity.

RESULTS

Three hundred fourteen patients were enrolled; median age of the participants was 21(interquartile range, 13-30) years. No difference was found in the endothelial parameters between dengue and other febrile illness. Considering dengue patients, the RHI was significantly lower for patients with severe plasma leakage compared to those with no leakage (1.46 vs 2.00; P < .001), over acute time-points, apparent already in the early febrile phase (1.29 vs 1.75; P = .012). RHI correlated negatively with arginase-1 and positively with l-arginine (P = .001).

CONCLUSIONS

Endothelial dysfunction/NO bioavailability is associated with worse plasma leakage, occurs early in dengue illness and correlates with hypoargininemia and high arginase-1 levels.

Risk Factors for Peri-Procedural Arterial Ischaemic Stroke in Children with Cardiac Disease

Improved survival of children with congenital heart disease has led to increasing focus on neurodevelopmental outcome, as close to half of the infants undergoing cardiac surgery are affected by neurodevelopmental disability. Stroke is particularly important as it frequently results in permanent neurologic sequelae. The aim of this study was to investigate risk factors for peri-procedural arterial ischaemic stroke (AIS) in children with cardiac disease. A retrospective case-control analysis of children aged <18 years with radiologically confirmed AIS following a cardiac procedure admitted to the Royal Children's Hospital Melbourne between 1993 and 2010. Each case was matched with two controls with similar cardiac diagnosis, procedure type, age and date of procedure. Demographics and peri-procedural data were collected from medical records and departmental database. Fifty-two cases were identified. Multivariable analysis identified post-procedural infection (OR 6.1, CI 1.3-27, p = 0.017) and length of ICU stay (OR 4.0, CI 1.4-11, p = 0.009) as risk factors for AIS. Although the study is limited to a single-centre cohort, length of ICU stay and post-procedural infection were identified as risk factors for AIS. These findings demonstrate these factors to be important areas to focus attention for stroke prevention in children with cardiac disease.

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.

Endothelial Cell Function and Dysfunction in Critically Ill Children

Endothelial cells (ECs) line the lumen of the entire vascular system and actively regulate blood flow; maintain blood fluidity; control water, solute, and macromolecular transfer between blood and tissue; and modulate circulating immune cell recruitment and activation. These vital functions, combined with the broad anatomic distribution of ECs, implicate them in all forms of critical illness. The present article discusses how ECs adapt and break down during the course of critical illness. We first review the biology of ECs, highlighting the vascular segmental differences and their specific roles in the maintenance of homeostasis. We then discuss how ECs acquire new functions to restore local and systemic homeostasis (activation) as well as how breakdowns in EC functions (dysfunction) contribute to local and systemic pathologic responses, with clinical correlations. Lastly, how these processes have been studied in critically ill children is discussed.

Current Understanding of Atherogenesis

Scientific understanding of atherogenesis is constantly developing. From Virchow's observations 160 years ago we now recognize the endothelial response to injury as inflammatory, involved in all stages of atherosclerosis. Endothelial activation may cause reversible injury or dysfunction, or lead to irreparable damage. Indeed, early atherosclerosis is reversible. The introduction of genome-wide association testing has furthered the identification of potentially important genetic variants that help explain the heritability of coronary artery disease as well as spontaneous cases of severe coronary artery disease in patients with otherwise minimal risk factors. However, the mechanisms by which many of the newer variants exert their influence remain unknown.

Family Income and Material Deprivation: Do They Matter for Sleep Quality and Quantity in Early Life? Evidence From a Longitudinal Study

Introduction

The aim of this article is to investigate the determinants of sleeping patterns in children up to age 9 on a large and geographically homogeneous sample of British children and parents, focusing in particular on the role of economic and social factors, specifically on income.

Aims and Methods

The data of this study come from the Avon Longitudinal Study of Parents and Children, a long-term health research project that recruited over 14000 pregnant women who were due to give birth between April 1991 and December 1992 in Bristol and its surrounding areas, including some of Somerset and Gloucestershire. Logistic regression models for the sleep problem dummies and log-linear models for the sleep quantity.

Results

One additional item in the material deprivation index is associated to an increase of around 10-20% in the odds of having at least 1 sleep problem. Similarly, children from the richest families are less likely to have any sleep problem up to 115 months (around 20% reduction in the odds). Mother's characteristics (i.e., education and mental health in the pregnancy period) are also significant predictors. Sleep quantity does not vary much and is not sensitive to socioeconomic factors.

Conclusion

Exposure to income-related inequalities affects child sleep. Further research is needed to understand if sleep in early life influences future health and economic trajectories.

Impaired flow-mediated dilation in hospitalized patients with community-acquired pneumonia

BACKGROUND

Community-acquired pneumonia (CAP) is complicated by cardiovascular events as myocardial infarction and stroke but the underlying mechanism is still unclear. We hypothesized that endothelial dysfunction may be implicated and that endotoxemia may have a role.

METHODS

Fifty patients with CAP and 50 controls were enrolled. At admission and at discharge, flow-mediated dilation (FMD), serum levels of endotoxins and oxidative stress, as assessed by serum levels of nitrite/nitrate (NOx) and isoprostanes, were studied.

RESULTS

At admission, a significant difference between patients with CAP and controls was observed for FMD (2.1±0.3 vs 4.0±0.3%, p<0.001), serum endotoxins (157.8±7.6 vs 33.1±4.8pg/ml), serum isoprostanes (341±14 vs 286±10 pM, p=0.009) and NOx (24.3±1.1 vs 29.7±2.2μM). Simple linear correlation analysis showed that serum endotoxins significantly correlated with Pneumonia Severity Index score (Rs=0.386, p=0.006). Compared to baseline, at discharge CAP patients showed a significant increase of FMD and NOx (from 2.1±0.3 to 4.6±0.4%, p<0.001 and from 24.3±1.1 to 31.1±1.5μM, p<0.001, respectively) and a significant decrease of serum endotoxins and isoprostanes (from 157.8±7.6 to 55.5±2.3pg/ml, p<0.001, and from 341±14 to 312±14 pM, p<0.001, respectively). Conversely, no changes for FMD, NOx, serum endotoxins and isoprostanes were observed in controls between baseline and discharge. Changes of FMD significantly correlated with changes of serum endotoxins (Rs=-0.315; p=0.001).

CONCLUSIONS

The study provides the first evidence that CAP is characterized by impaired FMD with a mechanism potentially involving endotoxin production and oxidative stress.

Association between human immunodeficiency virus infection and arterial stiffness in children

Background Human immunodeficiency virus infection (HIV) is associated with increased cardiovascular risk and adverse cardiovascular outcome in adults. Early recognition of changes in vascular properties might prove essential in cardiovascular prevention in HIV-infected patients. We investigated the relations between HIV infection and arterial stiffness in children. Methods This cross-sectional study included 51 HIV-infected and 52 healthy children (age 3.2-14.5 years, 49 males). All infected children had acquired HIV by vertical transmission and were receiving antiretroviral therapy at time of assessment. Arterial stiffness was measured by pulse wave velocity and aortic augmentation index, using the Arteriograph system (Tensiomed Kft, Budapest, Hungary). We applied multivariable general linear modeling to evaluate the relationship between HIV infection and arterial stiffness with further adjustment for confounders and possible intermediary variables. Findings represent mean group differences with 95% confidence intervals and p values. Results Aortic augmentation index was higher by 9.0% (5.6-12.5, p < 0.001) in HIV-infected than in healthy children. Adjustment for blood pressure, protease inhibitor use, biomarkers for level of inflammation, lipid- and glucose-metabolism, as possible intermediary variables, did not appreciably alter the results. There were no significant differences in pulse wave velocity between HIV-infected and healthy children (mean difference 0.28 m/s, -0.14-0.69, p = 0.19). Conclusion HIV-infected children have an increased aortic augmentation index, compared to healthy children. Early cardiovascular assessment may be important in targeted prevention for HIV-infected children.

Assessment of Endothelial Dysfunction With Adhesion Molecules in Patients With Celiac Disease

OBJECTIVES

Celiac disease (CD) is a systemic immune disorder. We assessed serum levels of adhesion molecules as a marker of endothelial dysfunction in patients with CD at first diagnosis and in those on a gluten-free diet.

METHODS

Sixty-five patients with CD (mean age 6.74 ± 4.6 years) and 51 age- and sex-matched control patients participated in the present case-controlled, prospective clinical study. Serum levels of vascular adhesion molecule-1, intercellular adhesion molecule-1, endothelial selectin, vascular endothelial cadherin, high-sensitivity C-reactive protein, and homocysteine levels were measured.

RESULTS

Average soluble vascular adhesion molecule-1 (CD vs control group: 1320 ± 308 vs 1120 ± 406 ng/mL, P = 0.006), soluble intercellular adhesion molecule-1 (336 ± 99 vs 263 ± 67 ng/mL, P = 0.025), and soluble endothelial selectin (113.9 ± 70 vs 76.9 ± 32 ng/mL, P = 0.007) levels were significantly higher in cases of newly diagnosed CD than in the control group. Soluble vascular adhesion molecule-1 (1050 ± 190 ng/mL) and soluble endothelial selectin (68.7 ± 45 ng/mL) levels in patients with CD, who were fully compliant with a gluten-free diet, were significantly lower than that in those newly diagnosed as having CD (P = 0.003 and P = 0.0012, respectively).

CONCLUSIONS

These results show that serum adhesion molecule levels are higher in patients with CD. Some of the risks associated with endothelial dysfunction may be related to CD and these risks can be reduced with an appropriate and fully controlled diet.

Infections in early life and premature acute coronary syndrome: A case-control study

BACKGROUND

Infections in young children may affect the vasculature and initiate early atherosclerosis. Whether infections experienced in childhood play a part in adult clinical cardiovascular disease remains unclear. We investigated the association between infections in early life and the occurrence of premature coronary heart disease.

METHODS

We conducted a population-based case-control study of 153 patients with a first acute coronary syndrome before the age of 56 years and 153 age- and sex-matched controls. Any history of severe infections in childhood and adolescence was obtained, together with clinical and laboratory measurements and other cardiovascular risk factors. We developed an infection score for the overall burden of early life infections. Conditional logistic regression was used to assess the associations.

RESULTS

Infections experienced in early life increased the risk of acquiring acute coronary syndrome at a young age with an odds ratio (OR) of 2.67 (95% confidence interval (CI) 1.47-4.83, p = 0.001). After adjustments for traditional risk factors, lifestyle, dietary patterns, socio-economic status and parental history of cardiovascular events, these associations remained significant and changed only slightly. There was an indication for an interaction between infections in early life and current cardiovascular risk (Framingham Risk Score (FRS); p-interaction = 0.052). Within participants with a low FRS (<10%), the OR of early life infection for acute coronary syndrome was 1.49 (95% CI 0.72-3.08, p = 0.283); within participants with an intermediate FRS (10-20%), the OR was 4.35 (95% CI 1.60-11.84, p = 0.004); and within participants with a high FRS (>20%), the OR 10.00 (95% CI 1.21-82.51, p = 0.032).

CONCLUSION

Infections in early life may partly explain premature coronary heart disease in adulthood and may potentiate traditional cardiovascular risk factor effects.

A qualitative investigation of the role of the family in structuring young people's alcohol use

BACKGROUND

Few qualitative studies have investigated young people's perspectives around influences on substance use. We aimed to examine young people's understandings, attitudes and experiences around alcohol, tobacco and cannabis use and factors influencing substance use behaviour.

METHODS

Qualitative interview study involving 28 young people (13 males and 15 females) aged 18-20 years, recruited purposively on the basis of substance use, who were participating in the Avon Longitudinal Study of Parents and Children. Interviews were conducted at participants' homes or at local cafés. Audio data were transcribed verbatim, systematically coded and analysed inductively using a constant comparative approach.

RESULTS

Parental attitudes and behaviours and the nature of communication emerged as critical factors structuring young people's alcohol use. Initiation of alcohol use was frequently mediated by parents early in adolescence, with the home recounted as a primary site of early drinking experiences. Later in adolescence, young people perceived a more permissive stance towards alcohol use, with broad acceptance of high levels of consumption and recognition of drinking as a cultural norm during adolescence. In contrast, young people reported a more prohibitive and discouraging stance from their parents towards tobacco and cannabis use, and the use of these substances appeared to be of greater parental concern.

CONCLUSIONS

Interventions involving parents or guardians have a critical role to play in the prevention of harms arising from alcohol use during adolescence. However, such interventions are needed in conjunction with individual, school, community and environmental interventions to shift cultural norms across the population and to facilitate effective prevention.

Infectious diseases are associated with carotid intima media thickness in adolescence

OBJECTIVE

Inflammatory risk factors in childhood, e.g. obesity, impact on carotid artery intima media thickness (CIMT), an early indicator of atherosclerosis. Little is known on potential infectious origins in childhood. We investigated the association between number of reported different childhood infectious diseases and CIMT in adolescence.

STUDY DESIGN

288 SAPALDIA offspring (8-21years) underwent a clinical examination in 2010-2011: anthropometry, blood pressure, CIMT, blood draw (cardiovascular biomarkers, cotinine). Offspring and parents gave information on individuals' and family health, child's vaccination status, infectious diseases and other early life factors. Life-time prevalence of bronchitis, pneumonia, tonsillitis, otitis, mononucleosis, meningitis, appendicitis, and scarlet fever were investigated, separately, and as cumulative infectious disease score. Multilevel adjusted linear regression analysis on the association between subjects' CIMT average and infectious diseases score was performed, stratifying by sex.

RESULTS

Youth (mean age 14.8 yrs; 53% female) reported on average 1.3 of the listed infectious diseases; 22% boys and 15% girls reported ≥3 infectious diseases (p = 0.136). Two-thirds were vaccinated according to recommendations (boys 56%, girls 61.5%, p = 0.567). Sex-stratified analyses yielded significantly increased CIMT in boys with ≥3 infectious diseases vs. none (0.046 mm, 95%CI 0.024; 0.068). In girls, the effect was of same direction but statistically non-significant (0.011 mm, 95%CI -0.015; 0.036).

CONCLUSION

The SAPALDIA Youth study complements current evidence on infectious origins of atherosclerosis in adults. The larger effects observed in boys may relate to a higher vulnerability of the vasculature and/or to infectious pathogens. Our data are suggestive of an early impact of childhood infectious diseases on vascular health.

Measurement of brachial artery endothelial function using a standard blood pressure cuff

The integrity of endothelial function in major arteries (EFMA) is a powerful independent predictor of heart attack and stroke. Existing ultrasound-based non-invasive assessment methods are technically challenging and suitable only for laboratory settings. EFMA, like blood pressure (BP), is both acutely and chronically affected by factors such as lifestyle and medication. Consequently, laboratory-based measurements cannot fully gauge the effects of medical interventions on EFMA. EFMA and BP have, arguably, comparable (but complementary) value in the assessment of cardiovascular health. Widespread deployment of EFMA assessment is thus a desirable clinical goal. To this end, we propose a device based on modifying the measurement protocol of a standard electronic sphygmomanometer. The protocol involves inflating the cuff to sub-diastolic levels to enable recording of the pulse waveform before and after vasodilatory stimulus. The mechanical unloading of the arterial wall provided by the cuff amplifies the distension that occurs with each pulse, which is measured as a pressure variation in the cuff. We show that the height of the rising edge of each pulse is proportional to the change in lumen area between diastole and systole. This allows the effect of vasodilatory stimuli on the artery to be measured with high sensitivity. We compare the proposed cuff flow-mediated dilation (cFMD) method to ultrasound flow-mediated dilation (uFMD). We find significant correlation (r = 0.55, p = 0.003, N = 27) between cFMD- and uFMD-based metrics obtained when the release of a 5 min cuff occlusion is employed to induce endothelial stimulus via reactive hyperemia. cFMD is approximately proportional to the square of uFMD, representing a typical increase in sensitivity to vasodilation of 300-600%. This study illustrates the potential for an individual to conveniently measure his/her EFMA by using a low-cost reprogrammed home sphygmomanometer.

Childhood hospitalisation with infection and cardiovascular disease in early-mid adulthood: a longitudinal population-based study

Background

Pathogen-specific and overall infection burden may contribute to atherosclerosis and cardiovascular disease (CVD), but the effect of infection severity and timing is unknown. We investigated whether childhood infection-related hospitalisation (IRH, a marker of severity) was associated with subsequent adult CVD hospitalisation.

Methods

Using longitudinal population-based statutorily-collected administrative health data from Western Australia (1970-2009), we identified adults hospitalised with CVD (ischaemic heart disease, ischaemic stroke, and peripheral vascular disease) and matched them (10:1) to population controls. We used Cox regression to assess relationships between number and type of childhood IRH and adulthood CVD hospitalisation, adjusting for sex, age, Indigenous status, socioeconomic status, and birth weight.

Results

631 subjects with CVD-related hospitalisation in adulthood (≥ 18 years) were matched with 6310 controls. One or more childhood (< 18 years) IRH was predictive of adult CVD-related hospitalisation (adjusted hazard ratio, 1.3; 95% CI 1.1-1.6; P < 0.001). The association showed a dose-response; ≥ 3 childhood IRH was associated with a 2.2 times increased risk of CVD-related hospitalisation in adulthood (adjusted hazard ratio, 2.2; 95% CI 1.7-2.9; P < 0.001). The association was observed across all clinical diagnostic groups of infection (upper respiratory tract infection, lower respiratory tract infection, infectious gastroenteritis, urinary tract infection, skin and soft tissue infection, and other viral infection), and individually with CVD diagnostic categories (ischaemic heart disease, ischaemic stroke and peripheral vascular disease).

Conclusions

Severe childhood infection is associated with CVD hospitalisations in adulthood in a dose-dependent manner, independent of population-level risk factors.

Childhood infections and trauma as risk factors for stroke

Stroke is as common as brain tumor in children. The etiology of childhood arterial ischemic stroke (AIS) appears to be multifactorial, resulting from the interaction between genetic predisposition and environmental triggers. The risk factors for AIS in children are markedly different from the atherosclerotic risk factors in adults. Trauma and infections have been identified as associations in previous studies and are exposures of particular interest because of their increased prevalence in the children. The aim of this review article is to provide an overview of the research studies that have addressed the role of infections and trauma in pediatric AIS.

The ACE I/D polymorphism is associated with nitric oxide metabolite and blood pressure levels in healthy Mexican men

The I/D insertion/deletion polymorphism of the angiotensin-converting enzyme has been related to hypertension. This polymorphism also seems to have gender related implications. Angiotensin II contributes to the production and release of oxygen reactive species that react with nitric oxide, inactivating its effects.

OBJECTIVE

To establish whether the ACE I/D polymorphism correlates with nitric oxide plasma metabolites in healthy men and women.

METHODS

Among 896 subjects between 18 and 30 years of age range, 138 fulfilled inclusion criteria. The polymorphism was identified by polymerase chain reaction, and blood nitric oxide metabolites were analyzed following the method described by Bryan.

RESULTS

Both systolic and diastolic arterial pressures were higher in men than in women (107/67 vs. 101/65 mm Hg, p<0.001). In terms of the ACE gene, there were differences in the concentration of nitric oxide metabolites in men with the I/D and D/D genotypes when compared to carriers of the I/I genotype (33.55 and 29.23 vs. 53.74 pmol/ml; p=<0.05), while there were no significant differences in women when compared by genotype. Men with the D/D genotype had higher systolic blood pressure than I/D carriers (111 vs. 104 mm Hg, p<0.05). We observed no arterial blood pressure differences in women when grouped by ACE genotype.

CONCLUSIONS

The ACE D/D genotype was associated with nitric oxide metabolite levels and systolic blood pressure in clinically healthy men while it had no effect in women.

Interleukin-1 and acute brain injury

Inflammation is the key host-defense response to infection and injury, yet also a major contributor to a diverse range of diseases, both peripheral and central in origin. Brain injury as a result of stroke or trauma is a leading cause of death and disability worldwide, yet there are no effective treatments, resulting in enormous social and economic costs. Increasing evidence, both preclinical and clinical, highlights inflammation as an important factor in stroke, both in determining outcome and as a contributor to risk. A number of inflammatory mediators have been proposed as key targets for intervention to reduce the burden of stroke, several reaching clinical trial, but as yet yielding no success. Many factors could explain these failures, including the lack of robust preclinical evidence and poorly designed clinical trials, in addition to the complex nature of the clinical condition. Lack of consideration in preclinical studies of associated co-morbidities prevalent in the clinical stroke population is now seen as an important omission in previous work. These co-morbidities (atherosclerosis, hypertension, diabetes, infection) have a strong inflammatory component, supporting the need for greater understanding of how inflammation contributes to acute brain injury. Interleukin (IL)-1 is the prototypical pro-inflammatory cytokine, first identified many years ago as the endogenous pyrogen. Research over the last 20 years or so reveals that IL-1 is an important mediator of neuronal injury and blocking the actions of IL-1 is beneficial in a number of experimental models of brain damage. Mechanisms underlying the actions of IL-1 in brain injury remain unclear, though increasing evidence indicates the cerebrovasculature as a key target. Recent literature supporting this and other aspects of how IL-1 and systemic inflammation in general contribute to acute brain injury are discussed in this review.

Adverse effects of maternal lead levels on birth outcomes in the ALSPAC study: a prospective birth cohort study

OBJECTIVE

To study the associations of prenatal blood lead levels (B-Pb) with pregnancy outcomes in a large cohort of mother-child pairs in the UK.

DESIGN

Prospective birth cohort study.

SETTING

Avon area of Bristol, UK.

POPULATION

Pregnant women enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC).

METHODS

Whole blood samples were collected and analysed by inductively coupled plasma dynamic reaction cell mass spectrometry (n = 4285). Data collected on the infants included anthropometric variables and gestational age at delivery. Linear regression models for continuous outcomes and logistic regression models for categorical outcomes were adjusted for covariates including maternal height, smoking, parity, sex of the baby and gestational age.

MAIN OUTCOME MEASURES

Birthweight, head circumference and crown-heel length, preterm delivery and low birthweight.

RESULTS

The mean blood lead level (B-Pb) was 3.67 ± 1.47 μg/dl. B-Pb ≥ 5 μg/dl significantly increased the risk of preterm delivery (adjusted odds ratio [OR] 2.00 95% confidence interval [95% CI] 1.35-3.00) but not of having a low birthweight baby (adjusted OR 1.37, 95% CI 0.86-2.18) in multivariable binary logistic models. Increasing B-Pb was significantly associated with reductions in birth weight (β -13.23, 95% CI -23.75 to -2.70), head circumference (β -0.04, 95% CI -0.07 to -0.06) and crown-heel length (β -0.05, 95% CI -0.10 to -0.00) in multivariable linear regression models.

CONCLUSIONS

There was evidence for adverse effects of maternal B-Pb on the incidence of preterm delivery, birthweight, head circumference and crown-heel length, but not on the incidence of low birthweight, in this group of women.

Is susceptibility to chronic rheumatic heart disease determined in early infancy? An analysis of mortality in Britain during the 20th century

BACKGROUND

The reason why some individuals but not others are susceptible to rheumatic fever and chronic rheumatic heart disease is not understood. Because of the substantial evidence that poverty is an important determinant of the disease and must operate in early life, we have investigated the role of the early environment in an ecological study using 20(th) century mortality as an index of disease prevalence.

METHODS

We analysed 37,321 deaths from rheumatic heart disease in England and Wales during 1968-78. We compared the geographical distribution of deaths with previous infant mortality records from 1911 onwards. These records included details of mortality at different ages and from different causes. They also included data on housing and population density.

RESULTS

Mortality from rheumatic heart disease showed a strong correlation with past infant mortality that was consistently stronger with postneonatal mortality (deaths from one month to one year) than with neonatal mortality (deaths during the first month of life). Areas with high infant mortality from diarrhoea or bronchitis had the highest subsequent mortality from rheumatic heart disease. Although rheumatic heart disease was linked with early overcrowding, regression analyses suggested that overcrowding could not per se explain the infant mortality associations.

CONCLUSIONS

Chronic rheumatic heart disease may have its origins in early infancy. Our findings raise the possibility that susceptibility to rheumatic fever and rheumatic heart disease may be linked with infection in the postneonatal period. Alternatively, they may be explained by the operation of environmental factors that both predispose to infection in infancy and the subsequent liability to heart disease.

Allergies are associated with arterial changes in young children

BACKGROUND

Inflammation is important in atherosclerosis development. Whether common causes of inflammation, such as allergies and infections, already exert this influence in early childhood is unknown. The objective of this study was to investigate the association between both allergies and infections with children's vasculature.

DESIGN

This was a longitudinal study in a general population cohort.

METHODS

In 390 five-year-olds of the WHISTLER (Wheezing-Illnesses-Study-LEidsche-Rijn) birth cohort, carotid intima-media thickness (CIMT) and arterial stiffness were obtained ultrasonographically. Physician-diagnosed allergies and infections and recent prescriptions of systemic antihistamines and antibiotics were obtained, as well as parental history of allergies. General linear regression was performed with vascular characteristics as dependent variables and measures of inflammation as independent variables.

RESULTS

Having both a positive parental history of allergy and an allergy diagnosis showed 15.0 µm (95% confidence interval (CI): 2.3-27.8, p = 0.02) larger CIMT than not having such history and diagnosis. Having a positive parental history of allergy only showed 11.9 µm (0.87-23.0, p = 0.04) larger CIMT. Recent use of antihistamines and antibiotics showed 18.8 µm (1.6-35.9, p = 0.03) and 16.1 µm (4.5-27.7, p = 0.01) larger CIMT, respectively. Childhood infections were not clearly related to vascular parameters. Neither allergy nor infections were associated with arterial stiffness.

CONCLUSION

An allergic predisposition is already associated with thicker arterial walls in early childhood.

High levels of mannose-binding lectin are associated with lower pulse wave velocity in uraemic patients

Background

Uraemia is associated with a highly increased risk of cardiovascular disease. Mannose-binding lectin (MBL) has been shown to be involved in cardiovascular pathophysiology and a protective effect of MBL is suggested. The purpose of the present study was to evaluate a potential impact of MBL on vascular parameters in uraemic patients.

Methods

A cohort of 98 patients with end stage renal disease (ESRD) awaiting kidney transplantation had pulse wave velocity (PWV) and augmentation index (AIX) examined by tonometry and endothelial dependent flow-mediated (FMD) and endothelial independent nitroglycerin-induced (NID) dilatory capacities of the brachial artery measured by ultrasound. An oral glucose tolerance test (OGTT) was performed and serum levels of MBL were measured using Luminex xMAP bead array technology.

Results

The cohort was divided in two groups according to MBL-concentration below or above the median concentration. These groups were comparable regarding age, BMI, and duration of ESRD. PWV was significantly lower in the group with high MBL levels compared to the group with low MBL levels and trends toward better AIX and higher insulin sensitivity (ISI) was also seen in the group with high MBL levels. No difference was seen in FMD and NID.

Conclusions

High levels of MBL are associated with lower PWV and the use of antihypertensive drugs in a cohort of patients with ESRD awaiting kidney transplantation suggesting a beneficial role of high levels of MBL on arterial stiffness in uraemia.

Impact of non-cardiovascular surgery on reactive hyperaemia and arterial endothelial function

Vascular reactivity is a surrogate marker for atherosclerosis and is predictive of cardiovascular outcome. Non-cardiovascular surgery is associated with perioperative cardiovascular complications in high-risk patients. To evaluate the impact of non-cardiovascular surgery on reactive hyperaemia and arterial endothelial function and to investigate the relationships between endothelial dysfunction and invasive (laparotomy) or minimally invasive (laparoscopic) surgery, we prospectively evaluated 106 patients undergoing abdominal surgery under general anaesthesia (71 laparotomy, 35 laparoscopy). Measurements of blood pressure, heart rate and pain (on a visual analogue scale (VAS)) were undertaken. Brachial endothelium-dependent flow-mediated dilation (FMD), endothelium-independent dilation, nitroglycerin (NTG)-induced dilation and reactive hyperaemia were measured with high-resolution B-mode ultrasound on preoperative Day 1 (baseline), as well as 2 h and 1 and 7 days postoperatively. Blood pressure and heart rate were significantly higher 2 h postoperatively. Pain, as measured on the VAS, was higher (P < 0.01) and reactive hyperaemia and FMD were significantly lower (P < 0.001) at 2 h and 1 day postoperatively compared with values at baseline and on postoperative Day 7. By postoperative Day 7, FMD had recovered to baseline levels. Patients undergoing laparoscopic surgery had less FMD reduction on Days 1 and 7 (7.5 ± 1.5% and 7.9 ± 1.5%, respectively) compared with those undergoing laparotomy (6.4 ± 1.6% (P = 0.001) and 7.0 ± 1.6% (P = 0.006), respectively), consistent with potential cardiovascular benefit. Responses to NTG were stable throughout. Backward multivariate linear regression analysis indicated that FMD was independently related to age and VAS (model R = 0.486; F = 6.4; P < 0.001). Reactive hyperaemia and arterial endothelial function are significantly reduced in the early postoperative period, particularly after laparotomy compared with laparoscopy, which may be related to postoperative cardiovascular events.

Aortic intima-media thickness measured by trans-abdominal ultrasound as an early life marker of subclinical atherosclerosis

Atherosclerosis is a chronic inflammatory process that begins in early life. Improved identification of markers of early atherosclerosis via neonatal aortic intima-media thickness (aIMT) measurement may allow the development of interventions to prevent or reduce later cardiovascular disease.

CONCLUSION

Using aIMT, studies have shown that antenatal factors such as intra-uterine growth retardation, prematurity, maternal factors and inflammation are associated with early cardiovascular changes.

Chickenpox and risk of stroke: a self-controlled case series analysis

Children who experience chickenpox are at a 4-fold increased risk of ischemic stroke in the subsequent 6 months. The evidence is less strong for adults, possibly due to mechanistic differences in the role of inflammation in adult stroke risk.

Background. There is good evidence that respiratory and other infections that cause systemic inflammation can trigger strokes; however, the role of specific infections is unclear. Case reports have highlighted chickenpox as a possible risk factor for arterial ischemic stroke, particularly in children, but rigorous studies are needed to determine and quantify any increased risk.

Methods. We used anonymized electronic health records totaling >100 million person-years of observation from 4 UK primary care databases to identify individuals who had documented clinical chickenpox and a stroke or transient ischemic attack (TIA). Self-controlled case series methods were used to quantify any increased risk of first stroke or TIA in the 0–6 and 7–12 months following chickenpox compared to other observed time periods. We analyzed data within each database, and performed meta-analyses to obtain summary age-adjusted incidence ratios (IRs) separately for adults and children.

Results. Five hundred sixty eligible individuals (including 60 children) were identified who experienced chickenpox and a stroke or TIA during follow-up. Among children, there was a 4-fold increased risk of stroke in the 0–6 months after chickenpox (summary IR = 4.07; 95% confidence interval [CI], 1.96–8.45; I² = 0%). Among adults, there was a less marked increased risk with moderate between-database heterogeneity (random-effects summary IR = 2.13; 95% CI, 1.05–4.36; I² = 51%). There was no significant increased risk of stroke in the 7–12 months after chickenpox in children or adults, nor was there evidence of increased risk of TIA in either time period.

Conclusions. Our study provides new evidence that children who experience chickenpox are at increased risk of stroke in the subsequent 6 months.

Methodological considerations and practical recommendations for the application of peripheral arterial tonometry in children and adolescents

Endothelial dysfunction is recognized as the primum movens in the development of atherosclerosis. Its crucial role in both cardiovascular morbidity and mortality has been confirmed. In the past, research was hampered by the invasive character of endothelial function assessment. The development of non-invasive and feasible techniques to measure endothelial function has facilitated and promoted research in various adult and paediatric subpopulations. To avoid user dependence of flow-mediated dilation (FMD), which evaluates nitric oxide dependent vasodilation in large vessels, a semi-automated, method to assess peripheral microvascular function, called peripheral arterial tonometry (Endo-PAT(®)), was recently introduced. The number of studies using this technique in children and adolescents is rapidly increasing, yet there is no consensus with regard to either measuring protocol or data analysis of peripheral arterial tonometry in children and adolescents. Most paediatric studies simply applied measuring and analysing methodology established in adults, a simplification that may not be appropriate. This paper provides a detailed description of endothelial function assessment using the Endo-PAT for researchers and clinicians. We discuss clinical and methodological considerations and point out the differences between children, adolescents and adults. Finally, the main aim of this paper is to provide recommendations for a standardised application of Endo-PAT in children and adolescents, as well as for population-specific data analysis methodology.

Differences between blood donors and a population sample: implications for case-control studies

BACKGROUND

Selecting appropriate controls for studies of genetic variation in case series is important. The two major candidates involve the use of blood donors or a random sample of the population.

METHODS

We compare and contrast the two different populations of controls for studies of genetic variation using data from parents enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). In addition we compute different biases using a series of hypothetical assumptions.

RESULTS

The study subjects who had been blood donors differed markedly from the general population in social, health-related, anthropometric, and personality-related variables. Using theoretical examples, we show that blood donors are a poor control group for non-genetic studies of diseases related to environmentally, behaviourally, or socially patterned exposures. However, we show that if blood donors are used as controls in genetic studies, these factors are unlikely to make a major difference in detecting true associations with relatively rare disorders (cumulative incidence through life of <10%). Nevertheless, for more common disorders, the reduction in accuracy resulting from the inclusion in any control population of individuals who have or will develop the disease in question can create a greater bias than can socially patterned factors.

CONCLUSIONS

Information about the medical history of a control and the parents of the control (as a proxy for whether the control will develop the disease) is more important with regard to the choice of controls than whether the controls are a random population sample or blood donors.

Endothelial cell death and intimal foam cell accumulation in the coronary artery of infected hypercholesterolemic minipigs

Apoptosis of endothelial cells (ECs) has been suggested to play a role in atherosclerosis. We studied the synergism of hypercholesterolemia with Chlamydia pneumoniae and influenza virus infections on EC morphology and intimal changes in a minipig model. The coronary artery was excised at euthanasia (19 weeks of age) and serial sections were processed for the detection of EC apoptosis, histology, and transmission electron microscopy (TEM) studies. There was a significantly higher number of TUNEL-positive ECs in infected compared to noninfected groups [0.2942 % (interquartile ranges (IR), 0.2941; n = 26) versus 0 % (IR, 0; n = 12), p < 0.01]. Caspase-3 staining was negative. Cholesterol diet together with infections induced widening of the subendothelial space and appearance of increased numbers of foam cells. TEM revealed degenerative changes in cytoplasmic organelles and signs of EC necrosis. In conclusion, infection leads to an increase in coronary EC death and seems to exacerbate cholesterol-induced intimal thickening and foam cell accumulation.

Assessment of endothelial dysfunction in childhood obesity and clinical use

The association of obesity with noncommunicable diseases, such as cardiovascular complications and diabetes, is considered a major threat to the management of health care worldwide. Epidemiological findings show that childhood obesity is rapidly rising in Western society, as well as in developing countries. This pandemic is not without consequences and can affect the risk of future cardiovascular disease in these children. Childhood obesity is associated with endothelial dysfunction, the first yet still reversible step towards atherosclerosis. Advanced research techniques have added further insight on how childhood obesity and associated comorbidities lead to endothelial dysfunction. Techniques used to measure endothelial function were further brought to perfection, and novel biomarkers, including endothelial progenitor cells, were discovered. The aim of this paper is to provide a critical overview on both in vivo as well as in vitro markers for endothelial integrity. Additionally, an in-depth description of the mechanisms that disrupt the delicate balance between endothelial damage and repair will be given. Finally, the effects of lifestyle interventions and pharmacotherapy on endothelial dysfunction will be reviewed.

Inflammatory activation: cardiac, renal, and cardio-renal interactions in patients with the cardiorenal syndrome

Although inflammation is a physiologic response designed to protect us from infection, when unchecked and ongoing it may cause substantial harm. Both chronic heart failure (CHF) and chronic kidney disease (CKD) are known to cause elaboration of several pro-inflammatory mediators that can be detected at high concentrations in the tissues and blood stream. The biologic sources driving this chronic inflammatory state in CHF and CKD are not fully established. Traditional sources of inflammation include the heart and the kidneys which produce a wide range of pro-inflammatory cytokines in response to neurohormones and sympathetic activation. However, growing evidence suggests that non-traditional biomechanical mechanisms such as venous and tissue congestion due to volume overload are also important as they stimulate endotoxin absorption from the bowel and peripheral synthesis and release of pro-inflammatory mediators. Both during the chronic phase and, more rapidly, during acute exacerbations of CHF and CKD, inflammation and congestion appear to amplify each other resulting in a downward spiral of worsening cardiac, vascular, and renal functions that may negatively impact patients' outcome. Anti-inflammatory treatment strategies aimed at attenuating end organ damage and improving clinical prognosis in the cardiorenal syndrome have been disappointing to date. A new therapeutic paradigm may be needed, which involves different anti-inflammatory strategies for individual etiologies and stages of CHF and CKD. It may also include specific (short-term) anti-inflammatory treatments that counteract inflammation during the unsettled phases of clinical decompensation. Finally, it will require greater focus on volume overload as an increasingly significant source of systemic inflammation in the cardiorenal syndrome.

Endothelial dysfunction and cardiovascular disease in early-stage chronic kidney disease: cause or association?

Chronic kidney disease (CKD) is strongly associated with cardiovascular disease (CVD); a graded inverse relationship between estimated glomerular filtration rate (eGFR) and cardiovascular event rates has emerged from large-scale observational studies. Chronic kidney disease is also associated with endothelial dysfunction (ED) although the precise relationship with GFR and the "threshold" at which ED begins are contentious. Abnormal endothelial function is certainly present in late-stage CKD but data in early-stage CKD appear confounded by disease states such as diabetes and hypertension which themselves promote ED. Thus, the direct effect of a reduction in GFR on endothelial function and, therefore, cardiovascular (CV) risk is far from completely established. In human studies, the precise duration of kidney impairment is seldom known and the onset of CVD often insidious, making it difficult to determine exactly when CVD first appears in the context of CKD. Kidney donors provide a near-ideal experimental model of CKD; subjects undergo an acute change from normal to modestly impaired renal function at the time of nephrectomy and lack the confounding co-morbidity that has made observational studies of CKD patients so challenging to interpret. By examining changes in endothelial function in living kidney donors before and after nephrectomy, useful insight might be gained into the pathophysiology of CVD in CKD and help determine whether targeting ED or the renal disease itself has the potential to reduce CV risk.

Where are we heading with noninvasive clinical vascular physiology? Why and how should we assess endothelial function?

There are several invasive and noninvasive methods available to the clinical researcher for the assessment of endothelial function. The first investigations in humans involved invasive pharmacological vascular function testing, which have been used to gain a detailed understanding of the mechanisms involved in the pathogenesis of endothelial dysfunction and atherosclerosis as well as novel targets for intervention. Techniques for endothelial function testing have evolved over time from these invasive methods, which, by their nature, are restricted to small studies in the research laboratory, to more standardized noninvasive methods, which are suitable for use in large prospective cohort studies and clinical trials. This paper describes currently available methods for assessment of endothelial function and their potential application in cardiovascular research and clinical practice.

Hospitalization for infection and risk of acute ischemic stroke: the Cardiovascular Health Study

BACKGROUND AND PURPOSE

Little is known about the acute precipitants of ischemic stroke, although evidence suggests infections contribute to risk. We hypothesized that acute hospitalization for infection is associated with the short-term risk of stroke.

METHODS

The case-crossover design was used to compare hospitalization for infection during case periods (90, 30, or 14 days before an incident ischemic stroke) and control periods (equivalent time periods exactly 1 or 2 years before stroke) in the Cardiovascular Health Study, a population-based cohort of 5888 elderly participants from 4 US sites. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated by conditional logistic regression. Confirmatory analyses assessed hazard ratios of stroke from Cox regression models, with hospitalization for infection as a time-varying exposure.

RESULTS

During a median follow-up of 12.2 years, 669 incident ischemic strokes were observed in participants without a baseline history of stroke. Hospitalization for infection was more likely during case than control time periods; for 90 days before stroke, OR=3.4 (95% CI, 1.8 to 6.5). The point estimates of risks were higher when we examined shorter intervals: for 30 days, OR=7.3 (95% CI, 1.9 to 40.9), and for 14 days, OR=8.0 (95% CI, 1.7 to 77.3). In survival analyses, risk of stroke was associated with hospitalization for infection in the preceding 90 days, adjusted hazard ratio=2.4 (95% CI, 1.6 to 3.4).

CONCLUSIONS

Hospitalization for infection is associated with a short-term increased risk of stroke, with higher risks observed for shorter intervals preceding stroke.

Infection-induced coronary dysfunction and systemic inflammation in piglets are dampened in hypercholesterolemic milieu

The synergism of infection with conventional cardiovascular risk factors in atherosclerosis is much debated. We hypothesized that coronary arterial injury correlates with infection recurrence and pathogen burden and is further aggravated by hypercholesterolemia. Forty-two Göttingen minipigs were assigned to repeated intratracheal inoculation of PBS, Chlamydia pneumoniae (Cpn), or both Cpn and influenza virus at 8, 11, and 14 wk of age. Animals were fed either standard or 2% cholesterol diet (chol-diet). At 19 wk of age coronary vasomotor responses to acetylcholine (ACh) and adenosine were assessed in vivo and blood and tissue samples were collected. Nonparametric tests were used to compare the groups. In cholesterol-fed animals, total cholesterol/HDL was significantly increased in infected animals compared with noninfected animals [3.13 (2.17–3.38) vs. 2.03 (1.53–2.41), respectively; P = 0.01]. C-reactive protein (CRP) rose in infected animals [10.60 (4.96–18.00) vs. 2.47 (1.44–3.01) μg/ml in noninfected; P < 0.01] without significant difference between the mono- and coinfected groups. Among coinfected animals, both CRP and haptoglobin were lower in those fed chol-diet than in those fed standard diet ( P < 0.05). The vasoconstricting response to ACh was most prominent in coinfected animals {769.3 (594–1,129) cm; P = 0.03 vs. noninfected [342 (309–455) cm] and P = 0.07 vs. monoinfected [415 (252.5–971.8) cm]}. Among monoinfected animals, similar to CRP, a trend for less vasoconstriction was observed in those fed chol-diet ( P = 0.08). Coinfection of piglets appears to be associated with more pronounced coronary muscarinic vasomotor dysfunction. In monoinfected animals, use of chol-diet seems to dampen both coronary dysfunction and systemic inflammation induced by infection.

Early life socioeconomic adversity is associated in adult life with chronic inflammation, carotid atherosclerosis, poorer lung function and decreased cognitive performance: a cross-sectional, population-based study

BACKGROUND

Socioeconomic gradients in health persist despite public health campaigns and improvements in healthcare. The Psychosocial and Biological Determinants of Ill-health (pSoBid) study was designed to uncover novel biomarkers of chronic disease that may help explain pathways between socioeconomic adversity and poorer physical and mental health.

METHODS

We examined links between indicators of early life adversity, possible intermediary phenotypes, and markers of ill health in adult subjects (n = 666) recruited from affluent and deprived areas. Classical and novel risk factors for chronic disease (lung function and atherosclerosis) and for cognitive performance were assessed, and associations sought with early life variables including conditions in the parental home, family size and leg length.

RESULTS

Associations were observed between father's occupation, childhood home status (owner-occupier; overcrowding) and biomarkers of chronic inflammation and endothelial activation in adults (C reactive protein, interleukin 6, intercellular adhesion molecule; P < 0.0001) but not number of siblings and leg length. Lung function (forced expiratory volume in 1 second) and cognition (Choice Reaction Time, the Stroop test, Auditory Verbal Learning Test) were likewise related to early life conditions (P < 0.001). In multivariate models inclusion of inflammatory variables reduced the impact and independence of early life conditions on lung function and measures of cognitive ability. Including variables of adult socioeconomic status attenuated the early life associations with disease biomarkers.

CONCLUSIONS

Adverse levels of biomarkers of ill health in adults appear to be influenced by father's occupation and childhood home conditions. Chronic inflammation and endothelial activation may in part act as intermediary phenotypes in this complex relationship. Reducing the 'health divide' requires that these life course determinants are taken into account.

Infectious burden: a new risk factor and treatment target for atherosclerosis

Atherosclerosis is a chronic inflammatory process, and several common bacterial and viral infections have been hypothesized to contribute to the inflammation of the vascular wall that leads to atherosclerosis. More recently, investigators have found preliminary evidence that the aggregate burden of these chronic infections, rather than any single organism, may contribute to atherosclerosis and risk of clinical vascular events, including ischemic stroke. This aggregate burden of infections, which has been variably labeled "infectious burden" or "pathogen burden," may be associated with stroke through mechanisms independent of atherosclerosis, as well, including platelet aggregation and endothelial dysfunction. Host factors, moreover, may interact with infectious burden to modify the risk of disease associated with these infections. Currently there is no commonly accepted group of organisms or method of assessing infectious burden, and not all studies confirm an association of infection and stroke risk. Nonetheless, if infectious burden does play a role in atherosclerosis or stroke, it is plausible that preventive anti-infective treatment, such as vaccination, or antibiotics, would reduce the risk of incident or recurrent stroke. While influenza vaccination has been recommended to prevent recurrence among those with coronary disease, similar recommendations for stroke patients have not yet been made. Large scale randomized clinical trials of macrolide antibiotics for coronary patients, moreover, have been negative. Further studies are needed, however, to determine whether an association between infectious burden and stroke exists, and whether infectious burden may be a target for intervention.