Uncomplicated obesity is associated with abnormal aortic function assessed by cardiovascular magnetic resonance

Maternal Hemodynamics from Preconception to Delivery: Research and Potential Diagnostic and Therapeutic Implications: Position Statement by Italian Association of Pre-Eclampsia and Italian Society of Perinatal Medicine

OBJECTIVE

 The Italian Association of Preeclampsia (AIPE) and the Italian Society of Perinatal Medicine (SIMP) developed clinical questions on maternal hemodynamics state of the art.

STUDY DESIGN

 AIPE and SIMP experts were divided in small groups and were invited to propose an overview of the existing literature on specific topics related to the clinical questions proposed, developing, wherever possible, clinical and/or research recommendations based on available evidence, expert opinion, and clinical importance. Draft recommendations with a clinical rationale were submitted to 8th AIPE and SIMP Consensus Expert Panel for consideration and approval, with at least 75% agreement required for individual recommendations to be included in the final version.

RESULTS

 More and more evidence in literature underlines the relationship between maternal and fetal hemodynamics, as well as the relationship between maternal cardiovascular profile and fetal-maternal adverse outcomes such as fetal growth restriction and hypertensive disorders of pregnancy. Experts agreed on proposing a classification of pregnancy hypertension, complications, and cardiovascular states based on three different hemodynamic profiles depending on total peripheral vascular resistance values: hypodynamic (>1,300 dynes·s·cm-5), normo-dynamic, and hyperdynamic (<800 dynes·s·cm-5) circulation. This differentiation implies different therapeutical strategies, based drugs' characteristics, and maternal cardiovascular profile. Finally, the cardiovascular characteristics of the women may be useful for a rational approach to an appropriate follow-up, due to the increased cardiovascular risk later in life.

CONCLUSION

 Although the evidence might not be conclusive, given the lack of large randomized trials, maternal hemodynamics might have great importance in helping clinicians in understanding the pathophysiology and chose a rational treatment of patients with or at risk for pregnancy complications.

KEY POINTS

· Altered maternal hemodynamics is associated to fetal growth restriction.. · Altered maternal hemodynamics is associated to complicated hypertensive disorders of pregnancy.. · Maternal hemodynamics might help choosing a rational treatment during hypertensive disorders..

Prognostic value of triglyceride-glucose index in patients with chronic coronary syndrome undergoing percutaneous coronary intervention

BACKGROUND

The triglyceride-glucose (TyG) index has been proposed as a reliable surrogate marker of insulin resistance and an independent predictor of major adverse cardiovascular events (MACEs). Several recent studies have shown the relationship between the TyG index and cardiovascular outcomes; however, the role of the TyG index in chronic coronary syndrome (CCS) progression has not been extensively assessed especially in population after revascularization. This study aimed to investigate the prognostic value of the TyG index in predicting MACEs in CCS patients undergoing percutaneous coronary intervention (PCI).

METHODS

The data for the study were taken from the Hospital Information System database in China-Japan Friendship Hospital over the period 2019-2021. Eligible participants were divided into groups according to the TyG index tertiles. The Boruta algorithm was performed for feature selection. Multivariate Cox proportional hazards models and restricted cubic spline (RCS) analysis were applied to examine the dose-response relationship between the TyG index and endpoint, and the results were expressed with hazard ratio (HR) and 95% confidence interval (CI) values. The area under the receiver operating characteristic (ROC) curve (AUC), decision curve analysis (DCA), and clinical impact curve (CIC) were plotted to comprehensively evaluate the predictive accuracy and clinical value of the model. The goodness-of-fit of models was evaluated using the calibration curve and χ2 likelihood ratio test.

RESULTS

After applying inclusion and exclusion criteria, 1353 patients with CCS undergoing PCI were enrolled in the study. After adjusting for all confounders, we found that those with the highest TyG index had a 59.5% increased risk of MACEs over the 1-year follow-up (HR 1.595, 95% CI 1.370 ~ 1.855). Using the lowest TyG index tertile as the reference (T1), the fully adjusted HRs (95% CIs) for endpoints was 1.343 (1.054 ~ 1.711) in the middle (T2) and 2.297 (1.842 ~ 2.864) in highest tertile (T3) (P for trend < 0.001). The TyG index had an excellent predictive performance according to the results of AUC 0.810 (0.786, 0.834) and χ2 likelihood ratio test (χ2 = 7.474, P = 0.486). DCA and CIC analysis also suggested a good overall net benefit and clinical impact of the multivariate model. The results in the subgroup analysis were consistent with the main analyses. RCS model demonstrated that the TyG index was nonlinearly associated with the risk of MACEs within one year (P for nonlinear < 0.001).

CONCLUSION

The elevated TyG index is associated with an increased risk of cardiovascular events and predicts future MACEs in patients with CCS undergoing PCI independently of known cardiovascular risk factors, indicating that the TyG index may be a potential marker for risk stratification and prognosis in CCS patients undergoing PCI.

Influence of Obesity on Histological Tissue Structure of the Cardiovascular System in Horses

It has been well established that obesity in horses can have a negative impact on their health, including endocrine disturbances. In humans, it is well known that obesity leads to structural and functional changes of the cardiovascular system. The aim of the study was to assess the impact of obesity on the histological structure of the myocardial tissue, as well as great and peripheral arteries in horses. The heart, arteries (aorta, pulmonary artery and palmar arteries) specimens from 7 horses with normal BCS (4–5/9) and 12 extremely obese (BCS 9/9) draft slaughter horses were obtained for histopathological evaluation. The heart tissue and great arteries showed more intense disturbances in the architecture and vacuolization in the aorta in obese horses as compared to the healthy group. The intima in the pulmonary artery, coronary arteries and palmar arteries was thicker in the obese, rather than healthy horses. The palmar arteries in obese horses had a larger lumen diameter and the lumen-to-total diameter ratio as compared to the control group. The presented study showed a significant effect of obesity on the heart as well as the central and peripheral vessels in horses. This forms the basis for a deeper reflection on the impact of obesity on the equine body.

Hemodynamic Assessment of Pregnant People with and without Obesity by Noninvasive Bioreactance: A Pilot Study

Objective  This study aimed to identify cardiovascular differences between pregnant people with and without obesity for trimester-specific changes in hemodynamic parameters using noninvasive cardiac output monitoring (NICOM). Study Design  This study is a pilot prospective comparative cohort between pregnant people with and without obesity. Hemodynamic assessment was performed with NICOM (12-14, 21-23, and 34-36 weeks) during pregnancy. Results  In first trimester, pregnant people with obesity had higher blood pressure, stroke volume (SV), total peripheral resistance index (TPRI), and cardiac output (CO). Pregnant people with obesity continued to have higher SV and cardiac index (second and third trimesters). During the first trimester, body mass index (BMI) positively correlated with SV, TPRI, and CO. Fat mass showed a strong correlation with TPRI. BMI positively correlated with CO during the second trimester and fat mass was positively associated with CO. During the third trimester, TPR negatively correlated with BMI and fat mass. Conclusion  Fat mass gain in the period between the first and second trimesters in addition to the hemodynamic changes due to obesity and pregnancy contribute to some degree of left ventricular diastolic dysfunction which was manifested by lower SVs. Future work should investigate the possible causative role of obesity in the cardiovascular changes identified in people with obesity.

Compliant vascular models 3D printed with the Stratasys J750: a direct characterization of model distensibility using intravascular ultrasound

PURPOSE

The purpose of this study is to evaluate biomechanical accuracy of 3D printed anatomical vessels using a material jetting printer (J750, Stratasys, Rehovot, Israel) by measuring distensibility via intravascular ultrasound.

MATERIALS AND METHODS

The test samples are 3D printed tubes to simulate arterial vessels (aorta, carotid artery, and coronary artery). Each vessel type is defined by design geometry of the vessel inner diameter and wall thickness. Vessel inner diameters are aorta = 30mm, carotid = 7mm, and coronary = 3mm. Vessel wall thickness are aorta = 3mm, carotid = 1.5mm, and coronary = 1mm. Each vessel type was printed in 3 different material options. Material options are user-selected from the J750 printer software graphical user interface as blood vessel wall anatomy elements in 'compliant', 'slightly compliant', and 'rigid' options. Three replicates of each vessel type were printed in each of the three selected material options, for a total of 27 models. The vessels were connected to a flow loop system where pressure was monitored via a pressure wire and cross-sectional area was measured with intravascular ultrasound (IVUS). Distensibility was calculated by comparing the % difference in cross-sectional area vs. pulse pressure to clinical literature values. Target clinical ranges for normal and diseased population distensibility are 10.3-44 % for the aorta, 5.1-10.1 % for carotid artery, and 0.5-6 % for coronary artery.

RESULTS

Aorta test vessels had the most clinically representative distensibility when printed in user-selected 'compliant' and 'slightly compliant' material. All aorta test vessels of 'compliant' material (n = 3) and 2 of 3 'slightly compliant' vessels evaluated were within target range. Carotid vessels were most clinically represented in distensibility when printed in 'compliant' and 'slightly compliant' material. For carotid test vessels, 2 of 3 'compliant' material samples and 1 of 3 'slightly compliant' material samples were within target range. Coronary arteries were most clinically represented in distensibility when printed in 'slightly compliant' and 'rigid' material. For coronary test vessels, 1 of 3 'slightly compliant' materials and 3 of 3 'rigid' material samples fell within target range.

CONCLUSIONS

This study suggests that advancements in materials and 3D printing technology introduced with the J750 Digital Anatomy 3D Printer can enable anatomical models with clinically relevant distensibility.

Effects of Exercise and Weight Loss on Proximal Aortic Stiffness in Older Adults With Obesity

BACKGROUND

Obesity may accelerate age-related increases in aortic stiffness. Although aerobic exercise training generally has favorable effects on aortic structure and function, exercise alone may not be sufficient to improve aortic stiffness in older adults with obesity. We determined the effects of aerobic exercise training with and without moderate- to high-caloric restriction (CR) on the structure and function of the proximal aorta in 160 older (65-79 years) men and women with obesity (body mass index=30-45 kg/m²).

METHODS

Participants were randomly assigned to 1 of 3 groups: aerobic exercise training only (treadmill 4 days/week for 30 minutes at 65% to 70% of heart rate reserve; n=56), aerobic exercise training plus moderate CR (n=55), or aerobic exercise training plus more intensive CR (n=49) for 20 weeks. Aortic pulse wave velocity, aortic distensibility, and other measures of aortic structure and function were assessed by cardiovascular magnetic resonance imaging. Pearson correlation coefficients were examined to assess associations between changes in proximal aortic stiffness and changes in fitness, fatness, and other potential confounders.

RESULTS

Weight loss in the aerobic exercise training plus moderate CR (-8.0 kg [95% CI, -9.17 to -6.87]) and aerobic exercise training plus more intensive CR (-8.98 kg [95% CI, -10.23 to -7.73) groups was significantly greater compared with the aerobic exercise training-only group (-1.66 kg [95% CI, -2.94 to -0.38]; P<0.017 for both). There were significant treatment effects for descending aorta distensibility (P=0.008) and strain (P=0.004) and aortic arch pulse wave velocity (P=0.01) with the aerobic exercise training plus moderate CR group having a 21% increase in distensibility (P=0.016) and an 8% decrease in pulse wave velocity (P=0.058). None of the aortic stiffness measures changed significantly in the aerobic exercise training-only or aerobic exercise training plus more intensive CR groups, and there were no significant changes in any other measure of aortic structure or function in these groups. Overall, increases in aortic distensibility were correlated with improvements in body weight and body fat distribution, but these associations were not statistically significant after adjustment for multiple comparisons.

CONCLUSIONS

In older adults with obesity, combining aerobic exercise with moderate CR leads to greater improvements in proximal aortic stiffness than exercise alone. Registration: URL: https://clinicaltrials.gov; Unique identifier: NCT01048736.

A comprehensive study of phospholipid fatty acid rearrangements in metabolic syndrome: correlations with organ dysfunction

The balance within phospholipids (PLs) between saturated fatty acids and monounsaturated or polyunsaturated fatty acids is known to regulate the biophysical properties of cellular membranes. As a consequence, in many cell types, perturbing this balance alters crucial cellular processes, such as vesicular budding and the trafficking/function of membrane-anchored proteins. The worldwide spread of the Western diet, which is highly enriched in saturated fats, has been clearly correlated with the emergence of a complex syndrome known as metabolic syndrome (MetS). MetS is defined as a cluster of risk factors for cardiovascular diseases, type 2 diabetes and hepatic steatosis; however, no clear correlations have been established between diet-induced fatty acid redistribution within cellular PLs and the severity/chronology of the symptoms associated with MetS or the function of the targeted organs. To address this issue, in this study we analyzed PL remodeling in rats exposed to a high-fat/high-fructose diet (HFHF) over a 15-week period. PL remodeling was analyzed in several organs, including known MetS targets. We show that fatty acids from the diet can redistribute within PLs in a very selective manner, with phosphatidylcholine being the preferred sink for this redistribution. Moreover, in the HFHF rat model, most organs are protected from this redistribution, at least during the early onset of MetS, at the expense of the liver and skeletal muscles. Interestingly, such a redistribution correlates with clear-cut alterations in the function of these organs.This article has an associated First Person interview with the first author of the paper.

Effect of physical activity on pulse wave velocity in elderly subjects with normal glucose, prediabetes or Type 2 Diabetes

Carotid-femoral pulse wave velocity ((cf)PWV) is a measure of arterial stiffness, predicting cardiovascular disease. We hypothesized that the amount of physical activity (PA) is correlated with reduced arterial stiffness in Type 2 diabetic (T2D) subjects. 570 subjects from the 1945 Oulu birth cohort were included in the analysis. (cf)PWV was determined by a non-invasive applanation tonometry. Oral glucose tolerance test was performed and LDL and HDL cholesterol analyzed. PA was registered daily with a wrist-worn acceleration meter for two weeks. (cf)PWV values in subjects with impaired glucose metabolism (IGM) and T2D were higher than in normal glycemic subjects (P < 0.001). PA, fasting and 2 h glucose and HbA1c correlated significantly with (cf)PWV, but HDL or LDL cholesterol did not. The 2 h glucose, heart rate and alcohol consumption in T2D subjects had independent effects on (cf)PWV in multiple regression analysis. T2D and IGM were significantly associated to (cf)PWV. Interestingly, lipids did not have an additional effect on (cf)PWV. Subjects walking more than 10 000 steps/day had 0.2 m/s lower (cf)PWV than those walking less than 6000 steps/day. Presence of T2D, elevated heart rate and alcohol consumption in males were associated with increased aortic stiffening in elderly subjects.

Leptin as a Mediator of Obesity-Induced Hypertension

Hypertension and associated cardiovascular diseases represent the most common health complication of obesity and the leading cause of morbidity and mortality in overweight and obese patients. Emerging evidence suggests a critical role for the central nervous system particularly the brain action of the adipocyte-derived hormone leptin in linking obesity and hypertension. The preserved ability of leptin to cause cardiovascular sympathetic nerve activation despite the resistance to the metabolic actions of the hormone appears essential in this pathological process. This review describes the evidence supporting the neurogenic bases for obesity-associated hypertension with a particular focus on the neuronal and molecular signaling pathways underlying leptin's effects on sympathetic nerve activity and blood pressure.

An update on the role of adipokines in arterial stiffness and hypertension

Adipokines are hormones produced by adipocytes and have been involved in multiple pathologic pathways, including inflammatory and cardiovascular complications in essential hypertension. Arterial stiffness is a frequent vascular complication that represents increased cardiovascular risk in hypertensive patients. Adipokines, such as adiponectin, leptin and resistin, might be implicated in hypertension, as well as in vascular alterations associated with this condition. Arterial stiffness has proven to be a predictor of cardiovascular events. Obesity and target-organ damage such as arterial stiffness are features associated with hypertension. This review aims to update the association between adipokines and arterial stiffness in essential and resistant hypertension (RHTN).

Clinical cardiovascular risk during young adulthood in offspring of hypertensive pregnancies: insights from a 20-year prospective follow-up birth cohort

OBJECTIVES

Offspring of hypertensive pregnancies have increased cardiovascular risk factors during childhood. We hypothesised that offspring of hypertensive pregnancies would demonstrate increased clinical levels of hypertension by young adult life, which would be proportional to the severity of the pregnancy complication.

DESIGN

Prospective birth cohort study

SETTING

Tertiary obstetric hospital.

PARTICIPANTS

2868 young adult offspring of women enrolled during pregnancy into the Western Australia Pregnancy Cohort (Raine) Study.

MAIN OUTCOME MEASURES

Cardiovascular risk, including incidence of hypertension and metabolic disease, in those born to hypertensive compared to normotensive pregnancies.

RESULTS

Young adult offspring of hypertensive pregnancies were 2.5 times (95% CI 1.32 to 4.56, p=0.004) more likely to have global lifetime risk (QRISK) scores above the 75th centile. Thirty per cent of 20 year olds with hypertensive blood pressures were born following a hypertensive pregnancy. Pre-eclampsia or hypertension resulting in preterm birth associated with a threefold (95% CI 1.3 to 7.0, p=0.01) greater risk of being hypertensive by age 20 years, with no differences in body mass index. Whereas pregnancy-induced hypertension associated with a smaller 3 ± 1 mm Hg blood pressure rise (p=0.001) and a twofold (95% CI 1.5 to 2.8, p=0.001) greater risk of being obese or overweight. Risk factor associations were consistent throughout early life and independent of other birth-factors.

CONCLUSIONS

Incidence of offspring hypertension was significantly increased in those whose mothers had a more complicated pregnancy history, including preterm birth and pre-eclampsia.

Clinical Use of Cardiac Magnetic Resonance in Systemic Heart Disease

A systemic disease is one that affects a number of organs and tissues, or the body as a whole. Systemic diseases include endocrine, metabolic, nutritional, multisystem (rheumatic) and HIV disease. Cardiovascular involvement is a common and underestimated problem in systemic diseases, and may present with disease associated cardiac involvement at diagnosis or later in the course of the systemic disease. The cardiac involvement in these diseases is usually silent or oligo-symptomatic and includes different pathophysiological mechanisms such as, myocardial inflammation, infarction, diffuse, subendocardial vasculitis, valvular disease and different patterns of fibrosis. Furthermore, acuity of heart involvement may be underestimated due to non-specific cardiac signs, and finally, most of patients are female and unable to exercise, due to arthritis or muscular discomfort/weakness or may have limited acoustic window, due to increased breast size. Cardiovascular magnetic resonance (CMR), due to its ability to reliably assess cardiac anatomy, function, inflammation, stress perfusion-fibrosis, aortic distensibility, and iron and fat deposition, constitutes an excellent tool for early diagnosis of heart involvement, risk stratification, treatment evaluation and long-term follow-up of patients with cardiac disease due to systemic diseases.

Body Fat Is Associated With Reduced Aortic Stiffness Until Middle Age

Obesity is a major risk factor for cardiometabolic disease, but the effect of body composition on vascular aging and arterial stiffness remains uncertain. We investigated relationships among body composition, blood pressure, age, and aortic pulse wave velocity in healthy individuals. Pulse wave velocity in the thoracic aorta, an indicator of central arterial stiffness, was measured in 221 volunteers (range, 18–72 years; mean, 40.3±13 years) who had no history of cardiovascular disease using cardiovascular MRI. In univariate analyses, age ( r =0.78; P <0.001) and blood pressure ( r =0.41; P <0.001) showed a strong positive association with pulse wave velocity. In multivariate analysis, after adjustment for age, sex, and mean arterial blood pressure, elevated body fat% was associated with reduced aortic stiffness until the age of 50 years, thereafter adiposity had an increasingly positive association with aortic stiffness (β=0.16; P <0.001). Body fat% was positively associated with cardiac output when age, sex, height, and absolute lean mass were adjusted for (β=0.23; P =0.002). These findings suggest that the cardiovascular system of young adults may be capable of adapting to the state of obesity and that an adverse association between body fat and aortic stiffness is only apparent in later life.

Polycystic ovary syndrome and obesity do not affect vascular parameters related to early atherosclerosis in young women without glucose metabolism disturbances, arterial hypertension and severe abnormalities of lipid profile

The aim of this study was to evaluate the influence of polycystic ovary syndrome (PCOS) and obesity on vascular parameters related to early atherosclerosis (VP-EA) [brachial flow-mediated dilation (FMD), carotid intima-media thickness (CIMT) and carotid arterial compliance (CAC)] in women with minor cardiovascular risk factors (CVRFs). Twenty-five young women with PCOS and 23 eumenorrheic women matched for body mass index (BMI) were studied. The women were subdivided according to BMI and PCOS status, and comparisons were done between PCOS and Control group, regardless of BMI, and between Obese and Lean group, regardless of the presence of PCOS. Insulin resistance was higher in PCOS-group than in control-group and in obese-group than in lean-group. The median of all VP-EA evaluated were similar between PCOS-group and Control-group [FMD: 6.6 versus 8.4% (p = NS); CIMT: 48.0 versus 47.0 mm.10-2 (p = NS); CAC: 6.2 versus 5.6N-1.m4.10-10 (p = NS)] and between obese-group and lean-group [FMD: 7.8 versus 6.6% (p = NS); CIMT: 48.0 versus 47.0 mm.10-2 (p = NS); CAC: 5.7 versus 6.3N-1.m4.10-10 (p = NS)]. These results suggest that PCOS and obesity do not affect VP-EA in women with minor CVRFs.

Increasing plasma free fatty acids in healthy subjects induces aortic distensibility changes seen in obesity

BACKGROUND

Elevated free fatty acid (FFA) levels are known to impair aortic elastic function. In obesity, FFA levels are elevated and aortic distensibility (AD) reduced in a pattern that predominantly affects the distal aorta. Despite this, the role of FFAs in obesity-related aortic stiffness remains unclear.

METHODS AND RESULTS

Using vascular MRI, we aimed to determine if (1) FFA level correlated with AD in obesity; and (2) whether elevating FFA acutely and subacutely in normal-weight subjects reproduced the distal pattern of AD change in obesity. To do this, regional AD was recorded in 35 normal-weight and 70 obese subjects and then correlated with FFA levels. When compared with normal weight, obesity was associated with reduced AD in a pattern predominantly affecting the distal aorta (ascending aorta by -22%, proximal descending aorta by -25%, and abdominal aorta by -35%; P<0.001). After controlling for age, blood pressure, and body mass index, FFA levels remained negatively correlated with abdominal AD (r=-0.43, P<0.01). In 2 further normal-weight groups, AD was recorded before and after elevation of FFA levels with intralipid infusion (by +535%, n=9) and a 5-day high-fat, low-carbohydrate diet (by +48%, n=14).

CONCLUSIONS

Both intralipid infusion and a low-carbohydrate diet resulted in reduced abdominal AD (infusion -22%, diet -28%; both P<0.05), reproducing the distal pattern AD reduction seen in obesity. These findings suggest that elevated FFA impair AD in obesity and provide a potential therapeutic target to improve aortic elastic function in obesity.

Impaired endothelial responses in apparently healthy young people associated with subclinical variation in blood pressure and cardiovascular phenotype

BACKGROUND

A phenomenon of endothelial impairment, independent of classical cardiovascular risk factors, has been observed in young people. We identified subjects with persistently reduced, or declining, endothelial function during adolescence and early adulthood, without apparent cardiovascular risk, and investigated the clinical relevance of this finding.

METHODS

Endothelial vasomotor responses were assessed by brachial artery flow-mediated dilatation (FMD) at age 15 years in 47 subjects (22 males) who returned for a repeated measurement at age 25. Subjects underwent quantification of left ventricular mass (LVM) and function by cardiovascular magnetic resonance, central arterial stiffness by applanation tonometry, and common carotid artery intima-media thickness using ultrasound on their visit at age 25.

RESULTS

Individuals with low average FMD over 10-year period, although normotensive, had 5 mm Hg higher systolic blood pressure and, significantly greater LVM (73.48 ± 7.73 vs. 56.25 ± 9.54 g/m(2), P = 0.0001), carotid intima-media thickness (cIMT) (0.53 ± 0.06 vs. 0.47 ± 0.04 mm, P = 0.03), and pulse wave velocity (5.97 ± 0.63 vs. 5.29 ± 0.59 m/s, P = 0.02) than those with higher endothelial responses. Subjects with the greatest decline in FMD over 10 years had a significant increase in mean arterial pressure but similar cardiovascular phenotype.

CONCLUSION

Persistently reduced, or declining, endothelial function during adolescence, in the absence of overt cardiovascular disease, is a sensitive early marker associated with subclinical changes in blood pressure (BP) and an adverse cardiovascular phenotype. The findings highlight the potential importance of endothelial responses during adolescence in primary prevention strategies for hypertension.

Comparison of echotracking and magnetic resonance assessment of abdominal aorta distensibility and relationships with pulse wave velocity

Arterial distensibility can be measured either by echotracking or by nuclear magnetic resonance (MRI). Little information, however, is available on the comparison between the two methods and on the relationships between the results obtained with the two approaches and the arterial stiffness gold standard measurement, i.e., pulse wave velocity (PWV). In 28 normotensive subjects (age 33.0 ± 10.4 years, mean ± SD) we measured aortic diameter 1 cm above iliac bifurcation, aortic pulse pressure by tonometry and calculated arterial distensibility via the Reneman formulae for both methods. Aortic diameter and aortic distensibility were not superimposable and higher values were systematically detected with the MRI approach than with the ultrasound one. However, PWV showed a significant correlation with aortic distensibility values obtained by both methods (r = 0.50 and r = 0.49, p < 0.05). These data provide evidence that MRI-measured distensibility value is higher than that obtained via echotracking. The significant correlation with PWV, however, suggests that both methods can be regarded as valuable approaches. Considering the greater economic cost and the lower availability in daily clinical and research practice of MRI, echotracking ultrasonography can be regarded as a reliable and feasible method to assess aortic distensibility.

Open questions about metabolically normal obesity

Subsets of obese subjects without any cardiometabolic risk factors have been repeatedly described. This raises questions whether obesity 'per se' enhances the risk for cardiovascular or metabolic diseases and whether healthy obese subjects would benefit from a medical treatment. In order to answer these questions, as a first step, an expert consensus should be reached for the definition of metabolic normality. In fact, up to now, different parameters related to the metabolic syndrome and/or to insulin sensitivity have been utilized across studies. Once an agreement is reached, population-based studies should be undertaken to establish the incidence of metabolic normality among obese subjects. Furthermore, many other parameters such as age, sex, race, fat distribution and physical activity should be monitored to obtain results representative of a general population. Longitudinal studies aimed at investigating the evolution of the cardiometabolic profile of healthy obese subjects are also needed. In conclusion, data from the literature strongly suggest that a regular surveillance of the cardiometabolic parameters and a prevention of any further weight gain should be applied to healthy obese individuals, whereas possible benefits of a weight loss treatment are still a matter of debate.

The effect of obesity and weight loss on aortic pulse wave velocity as assessed by magnetic resonance imaging

Obesity is an escalating global health problem associated with both an increased risk of death and an increased risk of cardiovascular events. Our goal was to use magnetic resonance imaging (MRI) to determine the effect of obesity and weight loss, in the absence of the traditional cardiovascular risk factors, on aortic pulse wave velocity (PWV) a reliable, reproducible, and accurate clinical measure of aortic stiffness linked to increased mortality. Fifty obese (BMI 38.3 ± 6.8 kg/m(2)) and eighteen normal-weight controls (BMI 22.0 ± 1.7 kg/m(2)) with no identifiable cardiovascular risk factors underwent vascular MRI to assess PWV between the ascending aorta at the level of the pulmonary artery and the abdominal aorta (AA). Twenty-eight subjects underwent repeat imaging after a 1-year period of weight loss. Both groups were well matched for age, systolic blood pressure, fasting glucose, and total cholesterol. Obesity was associated with a 14% increase in PWV (P = 0.021), and with elevated C-reactive protein (CRP) (P < 0.01) and leptin levels (P < 0.001) factors known to cause increase arterial stiffness. Weight loss (average 50% excess weight) was associated with a 14% improvement in PWV (P = 0.03), and with reductions in serum leptin levels (P < 0.01). Obesity, in the absence of the traditional cardiovascular risk factors, is associated with increased aortic PWV, a noninvasive clinical measure of aortic stiffness independently predictive of cardiovascular mortality. Significant weight loss results in improvements in aortic PWV. This may provide a potential link between both obesity and increased mortality, and the reduction in mortality that occurs with weight loss.

Increased arterial stiffness and impaired endothelial function in nonalcoholic Fatty liver disease: a pilot study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease both in the general and pediatric population and has been associated with increased cardiovascular risk. Arterial function and early atherosclerotic changes are markers of cardiovascular disease and independent predictors of the corresponding risk. Through a global approach, we investigated the relationships between NAFLD and functional arterial changes and early atherosclerosis.

METHODS

A total of 23 consecutive patients (mean age 55 ± 14 years, 11 males) with biopsy evidence of NAFLD and 28 control subjects matched for age, gender, body mass index, and other cardiovascular risk factors participated in the study.

RESULTS

Compared to controls, NAFLD subjects had significantly higher carotid-femoral pulse wave velocity (PWV; 8.2 ± 1.3 m/s vs. 6.9 ± 1.3 m/s, P = 0.001), higher carotid intima-media thickness (IMT; 0.79 ± 0.18 mm vs. 0.67 ± 0.13 mm, P = 0.01), and reduced flow-mediated dilatation (FMD; 1.92 ± 2.11% vs. 4.8 ± 2.43%, P < 0.001). In multivariable analysis, presence of NAFLD was an independent determinant of both PWV and FMD, whereas leptin was an independent determinant of PWV (B = 0.036, P < 0.05), and adiponectin was independently associated with FMD (B = 0.104, P < 0.05). In addition, histological activity of liver disease expressed by the global Brunt Grade was associated independently with FMD (B = -1.054, P < 0.05).

CONCLUSIONS

NAFLD is associated with arterial stiffness and endothelial dysfunction. Given the important independent prognostic role of these arterial indexes, these findings have important implications for increased cardiovascular risk in patients with NAFLD.

Mechanism of impaired baroreflex sensitivity in Wistar rats fed a high-fat and -carbohydrate diet

Both high-fat and high-carbohydrate diets have been considered in association with the impairment of baroreflex sensitivity. However, the mechanisms are unclear. In the present study, the effects of a complex high-fat and high-carbohydrate diet (HFCD) on baroreflex circuitry were investigated. A HFCD emulsion was formulated and orally administered to rats for 30 d. Rats were then anaesthetised and baroreflex sensitivity was measured following intravenous injection of phenylephrine (PE) and sodium nitroprusside (SNP) at various doses. Morphological changes of the brainstem were detected by transmission electron microscopy. Baroreflex sensitivity-associated gene and protein expression was determined by quantitative RT-PCR and Western blot analysis. We found that: (1) the HFCD significantly attenuated heart rate responses to arterial blood pressure (ABP) increases induced by PE, but had no effect on heart rate responses to ABP decreases induced by SNP; (2) the HFCD induced medullary sheath thickening, myelinated nerve atrophy and hyaloplasm dissolving; (3) protein levels of substance P, calcitonin gene-related peptide, GlutR2 and γ-aminobutyric acid A receptors were all markedly decreased in the brainstems of rats administered with the HFCD. These findings conclude that a HFCD could impair the baroreflex sensitivity of rats. Remodelled morphology and decreased neurotransmitters and receptors in the domains of the nucleus tractus solitarii and nucleus ambiguus are participating in this process.

Beneficial cardiovascular effects of bariatric surgical and dietary weight loss in obesity

OBJECTIVES

We hypothesized that, in obese persons without comorbidities, cardiovascular responses to excess weight are reversible during weight loss by either bariatric surgery or diet.

BACKGROUND

Obesity is associated with cardiac hypertrophy, diastolic dysfunction, and increased aortic stiffness, which are independent predictors of cardiovascular risk.

METHODS

Thirty-seven obese (body mass index 40 +/- 8 kg/m(2)) and 20 normal-weight subjects (body mass index 21 +/- 2 kg/m(2)) without identifiable cardiac risk factors underwent cardiac magnetic resonance imaging for the assessment of the left and right ventricles and of indexes of aortic function. Thirty of the obese subjects underwent repeat imaging after 1 year of significant weight loss, achieved in 17 subjects by diet and in 13 subjects by bariatric surgery. Seven obese subjects underwent repeat imaging after 1 year of continued obesity.

RESULTS

Left and right ventricular masses were significantly increased, left ventricular diastolic function impaired, and aortic distensibility reduced in the obese. Both diet and bariatric surgery led to comparable, significant decreases in left and right ventricular masses, end-diastolic volume, and diastolic dysfunction, and an increase in aortic distensibility at all levels of the aorta, most pronounced distally (e.g., distal descending aorta 5.1 +/- 1.8 mm Hg(-1) x 10(-3) before weight loss and 6.8 +/- 2.5 mm Hg(-1) x 10(-3) after weight loss; p < 0.001). No improvements were observed in continued obesity.

CONCLUSIONS

Irrespective of method, 1 year of weight loss leads to partial regression of cardiac hypertrophy and to reversal of both diastolic dysfunction and aortic distensibility impairment. These findings provide a potential mechanism for the reduction in mortality seen with weight loss.

Healthy obesity

PURPOSE OF REVIEW

To introduce the healthy obese phenotype, characterized by favorable cardiometabolic risk factors despite excess adipose tissue. The epidemiology of the healthy obese phenotype is presented, including associated risk of cardiovascular disease (CVD), and potential biologic mechanisms which may give rise to the phenotype are discussed.

RECENT FINDINGS

Although it appears that approximately 30% of obese individuals maintain healthy cardiometabolic profiles, little published data exist examining the healthy obese phenotype. The healthy obese do not appear to be at increased risk of incident CVD events compared with at-risk obese, and the location of adipose tissue and the metabolic characteristics of the fat in a given location, including the presence of ectopic fat and associated adipocytokine response, may give rise to the phenotype. Recent data also suggest that weight loss among healthy obese may adversely impact their favorable cardiometabolic profile.

SUMMARY

A high prevalence of the healthy obese phenotype has been reported, and these individuals appear to be at no increased risk of CVD. Further research is needed into the mechanisms that allow these individuals to maintain low risk of CVD despite excess adiposity and appropriate weight loss recommendations for this group.

Vascular function assessed with cardiovascular magnetic resonance predicts survival in patients with advanced chronic kidney disease

BACKGROUND

Increased arterial stiffness is associated with mortality in patients with chronic kidney disease. Cardiovascular magnetic resonance (CMR) permits assessment of the central arteries to measure aortic function.

METHODS

We studied the relationship between central haemodynamics and outcome using CMR in 144 chronic kidney disease patients with estimated glomerular filtration rate <15 ml/min (110 on dialysis). Aortic distensibilty and volumetric arterial strain were calculated from cross sectional aortic volume and pulse pressure measured during the scan.

RESULTS

Median follow up after the scan was 24 months. There were no significant differences in aortic distensibilty or aortic volumetric arterial strain between pre-dialysis and dialysis patients. Aortic distensibilty and volumetric arterial strain negatively correlated with age. Aortic distensibilty and volumetric arterial strain were lower in diabetics, patients with ischaemic heart disease and peripheral vascular disease. During follow up there were 20 deaths. Patients who died had lower aortic distensibilty than survivors. In a survival analysis, diabetes, systolic blood pressure and aortic distensibilty were independent predictors of mortality. There were 12 non-fatal cardiovascular events during follow up. Analysing the combined end point of death or a vascular event, diabetes, aortic distensibilty and volumetric arterial strain were predictors of events.

CONCLUSION

Deranged vascular function measured with CMR correlates with cardiovascular risk factors and predicts outcome. CMR measures of vascular function are potential targets for interventions to reduce cardiovascular risk.