Cardiovascular dysfunction in obesity and new diagnostic imaging techniques: the role of noninvasive image methods

Impact of body mass index on markers of vascular health in normotensive women with history of pre-eclampsia

OBJECTIVE

Obesity and pre-eclampsia (PE) are both associated with vascular dysfunction, which translates into an increased risk for cardiovascular disease in later life. The aim of this study was to investigate whether there is an interaction between body mass index (BMI) and a history of PE in their effects on vascular health.

METHODS

This was an observational case-control study of 30 women with a history of PE who were compared with 31 age- and BMI-matched controls who had an uncomplicated pregnancy. Flow-mediated dilation (FMD), carotid intima-media thickness (cIMT) and carotid distensibility (CD) were measured 6-12 months postpartum. To evaluate the impact of physical fitness, maximum oxygen uptake capacity was assessed using a standardized maximum exhaustion cycling test using breath-by-breath analysis. To specify further BMI subgroups, metabolic syndrome constituents were assessed in all individuals.

RESULTS

Formerly pre-eclamptic women had significantly lower FMD (5.1 ± 2.1% vs 9.4 ± 3.4%; P < 0.01), higher cIMT (0.59 ± 0.09 vs 0.49 ± 0.07 µm; P < 0.01) and lower CD (1.54 ± 0.37%/10 mmHg vs 1.80 ± 0.39%/10 mmHg; P < 0.01) compared with controls. In our study, population BMI correlated negatively with FMD (P = 0.04) but not with cIMT or CD. BMI and PE did not exhibit an interaction effect on these vascular parameters. Physical fitness was lower in women with a history of PE and in women with higher BMI. Constituents of the metabolic syndrome, including insulin, homeostasis model assessment for insulin resistance (HOMA-ir), triglyceride, microalbuminuria and systolic and diastolic blood pressure, were significantly higher in formerly pre-eclamptic women. BMI affected glucose metabolism but not lipids or blood pressure. BMI and PE positively interacted in their effect on insulin (P = 0.04) and HOMA-ir (P = 0.02).

CONCLUSIONS

Both BMI and a history of PE have negative effects on endothelial function, insulin resistance and physical fitness. In formerly pre-eclamptic women, the effect of BMI on insulin resistance was particularly high, suggesting a synergistic effect. Additionally, independently of BMI, a history of PE was associated with reduced FMD and CD and increased cIMT and blood pressure. Recognizing the cardiovascular risk profile is important for informing patients and encouraging targeted lifestyle modifications. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Left Ventricular Diastolic Dysfunction Among Youth with Obesity and History of Elevated Blood Pressure

OBJECTIVE

To assess prevalence of and factors associated with left ventricular diastolic dysfunction (LVDD) in youth with obesity and elevated blood pressure (BP).

STUDY DESIGN

This was a cross-sectional analysis of baseline and follow-up visits of 83 youth, 5-21 years, evaluated for overweight/obesity and elevated BP in a multidisciplinary clinic. LVDD was defined according to established adult criteria (LVDD_adult; E/A < 1, E/e' > 14, or e'/a' < 0.8) and pediatric criteria (LVDD_peds; E/A <10th percentile, E/e' >99th percentile, or e'/a' <1st percentile) based on data from 103 age-sex matched healthy controls. Baseline factors associated with LVDD_peds were examined using Wilcoxon rank sum and χ² tests. Multiple logistic regression analyses using generalized estimating equations to account for repeated measures evaluated the associations of adiposity and BP with LVDD_peds.

RESULTS

The prevalence of LVDD ranged from 1.2% to 2.7% when we used adult criteria and 19% to 28% when we used pediatric criteria. Those with LVDD_peds were older, predominantly male, and non-African American and had greater weight, BP, BP medication use, and non-high-density lipoprotein cholesterol than those without LVDD_peds. Diastolic BP z score was associated with LVDD_peds by E/A (OR 1.95, 95% CI 1.15-3.32, P = .014) after we adjusted for age, sex, race, BP medications, and body mass index z score.

CONCLUSIONS

LVDD was present in a substantial proportion of youth with overweight/obesity and elevated BP using pediatric criteria. Those with LVDD_peds had significantly greater measures of adiposity and BP compared with those without LVDD_peds, and diastolic BP z score was an independent predictor of LVDD_peds by E/A. These data emphasize the importance of prevention and treatment of cardiovascular disease risk factors in childhood.

Effect of Bariatric Surgery on Cardiovascular Function and Heart Failure Outcomes

In this article, we explore the influence of obesity on cardiovascular health and the role of bariatric surgery in reducing cardiovascular comorbidities, preventing the onset of heart failure and improving mortality and quality of life in those with cardiac dysfunction. We highlight the mechanisms by which obesity leads to cardiovascular remodeling, diastolic dysfunction, and eventual heart failure. These mechanisms include systemic inflammation, local lipotoxicity by way of ectopic fat deposition, and hemodynamic alterations that have significant effects on cardiac structure and function. Bariatric surgery has been shown to reverse these mechanisms, thereby leading to the reversal of adverse cardiac remodeling, improved diastolic function, and in some cases, improved systolic function in patients with systolic heart failure. Most importantly, bariatric surgery leads to significant improvements in cardiovascular outcomes, including the risks of myocardial infarction and stroke, heart failure incidence, and mortality. In patients with heart failure, bariatric surgery has been shown to decrease heart failure exacerbations and admissions and improve quality of life. Furthermore, in advanced heart failure patients, including those requiring mechanical circulatory support, bariatric surgery has been successfully and safely used for weight loss, as a bridge to cardiac transplantation. Therefore, bariatric surgery should be considered as a treatment for conditions ranging from subclinical cardiac dysfunction to symptomatic, advanced heart failure.

Obesity Phenotypes, Diabetes, and Cardiovascular Diseases

This review addresses the interplay between obesity, type 2 diabetes mellitus, and cardiovascular diseases. It is proposed that obesity, generally defined by an excess of body fat causing prejudice to health, can no longer be evaluated solely by the body mass index (expressed in kg/m²) because it represents a heterogeneous entity. For instance, several cardiometabolic imaging studies have shown that some individuals who have a normal weight or who are overweight are at high risk if they have an excess of visceral adipose tissue-a condition often accompanied by accumulation of fat in normally lean tissues (ectopic fat deposition in liver, heart, skeletal muscle, etc). On the other hand, individuals who are overweight or obese can nevertheless be at much lower risk than expected when faced with excess energy intake if they have the ability to expand their subcutaneous adipose tissue mass, particularly in the gluteal-femoral area. Hence, excessive amounts of visceral adipose tissue and of ectopic fat largely define the cardiovascular disease risk of overweight and moderate obesity. There is also a rapidly expanding subgroup of patients characterized by a high accumulation of body fat (severe obesity). Severe obesity is characterized by specific additional cardiovascular health issues that should receive attention. Because of the difficulties of normalizing body fat content in patients with severe obesity, more aggressive treatments have been studied in this subgroup of individuals such as obesity surgery, also referred to as metabolic surgery. On the basis of the above, we propose that we should refer to obesities rather than obesity.

Drug Correction of Vascular Remodeling in Patients with Hypertension: Results of 52-Week Prospective Study ARTERIA-AG

Aim. To study the long-term dynamics of vascular remodeling in patients with hypertension and high and very high cardiovascular risk when statin is added to antihypertensive therapy with a fixed combination of calcium antagonist and angiotensin converting enzyme (ACE) inhibitor.

Material and methods. Hypertensive patients (n=75) with high and very high cardiovascular risk (age 51.5 [44;58] years) were included in the study. Patients were randomized into two groups. The first group (n=36) received a fixed combination of amlodipine and lisinopril in starting dose of 5/10 mg/day. The second group (n=39) received the same antihypertensive therapy and additionally rosuvastatin (20 mg/day). The follow-up period was 52 weeks. The effect of therapy on the following parameters was evaluated: level of office and average daily blood pressure (BP), central BP in the aorta, augmentation index (AIx), pulse wave velocity (PWV), endothelium-dependent brachial artery vasodilation, carotid intima-media complex thickness, carotid arteries plaque height, and blood lipid profile indicators.

Results. A significant decrease in office and average daily BP was found in both groups: from 171.5 (152;194)/104.5 (97;112) to 140.0 (129;154)/87.0 (83;95) mm Hg and from 142.1 (135;153)/86.7 (83;97) to 124.6 (119;133)/76.5 (73;80) mm Hg, respectively, in the 1st group; from 169.5 (160;190)/103.5 (95;109) to 135.0 (125;141)/83.0 (77;88) mm Hg and from 139.9 (136;152)/86.2 (80;92) to 125.1 (118;134)/74.0 (70;81) mm Hg, respectively, in the 2nd group (p<0.001 for all changes). The frequency of reaching the target office BP level was higher in the 2nd group (p=0.031). Significant decrease in total cholesterol by 33.1% and low-density lipoprotein cholesterol by 50.0% was observed in the group 2. Central BP in the aorta decreased in both groups; the degree of central BP reduction did not differ significantly. AIx decreased from 36.5 (24;41)% to 25.0 (15;36)% (p=0.04) in the 1st group and from 36.0 (30;41)% to 24.0 (20;32)% in the 2nd group (p<0.0001) with a more pronounced decrease in AIx after 24 weeks of therapy (-4.8% and -9.4%, respectively, p=0.036). This trend continued at the end of the observation (-6.4% and -10.8%, respectively, p=0.08). Carotid-femoral and carotid-radial PWV decreased only in the 2nd group from 9.5 (8.2;10.7) to 8.3 (7.6;8.9) m/s (p=0.003) and from 9,6 (8.5;10.6) to 8.4 (7.9;9.3) m/s (p=0.01), respectively. A significant decrease in the thickness of the intima-media from 1.08 (1.0;1.2) to 1.02 (0.9;1.1) cm (p<0.0001) and the height of the plaque from 2.2 (2,2;1.7) to 2.1 (2.1;1.7) mm (p=0.001) was found in the 2nd group.

Conclusion. Addition of rosuvastatin to the fixed combination of amlodipine and lisinopril in treatment of hypertensive patients with high and very high cardiovascular risk was accompanied by a more frequent (compared with amlodipine and lisinopril only) achievement of the target office BP level and more pronounced reduction in the following indicators: augmentation index, carotid-femoral and carotid-radial PWV, intima-media thickness, plaque height, total cholesterol and low density lipoprotein cholesterol blood levels.

Overview of Epidemiology and Contribution of Obesity and Body Fat Distribution to Cardiovascular Disease: An Update

Obesity is recognized as a heterogeneous condition in which individuals with similar body mass index may have distinct metabolic and cardiovascular risk profiles. Susceptibility to obesity-related cardiometabolic complications is not solely mediated by overall body fat mass, but is largely dependent upon individual differences in regional body fat distribution and ability of subcutaneous adipose tissue to expand. The present review will discuss to what extent the individual variation in body fat distribution is one of the clinical key variables explaining the metabolic heterogeneity of obesity and its related cardiovascular risk. We will present the evidence for the complex nature of the relationship between obesity and cardiovascular disease, outline our current understanding of the mechanisms involved, and identify future direction of research pertinent to this interaction.

Body Mass Index Is Associated With Microvascular Endothelial Dysfunction in Patients With Treated Metabolic Risk Factors and Suspected Coronary Artery Disease

BACKGROUND

Obesity is key feature of the metabolic syndrome and is associated with high cardiovascular morbidity and mortality. Obesity is associated with macrovascular endothelial dysfunction, a determinant of outcome in patients with coronary artery disease. Here, we compared the influence of obesity on microvascular endothelial function to that of established cardiovascular risk factors such as diabetes mellitus, hypertension, hypercholesterolemia, and smoking in patients with suspected coronary artery disease.

METHODS AND RESULTS

Endothelial function was assessed during postocclusive reactive hyperemia of the brachial artery and downstream microvascular beds in 108 patients who were scheduled for coronary angiography. In all patients, microvascular vasodilation was assessed using peripheral arterial tonometry; laser Doppler flowmetry and digital thermal monitoring were performed. Body mass index was significantly associated with decreased endothelium-dependent vasodilatation measured with peripheral arterial tonometry (r=0.23, P=0.02), laser Doppler flowmetry (r=0.30, P<0.01), and digital thermal monitoring (r=0.30, P<0.01). In contrast, hypertension, hypercholesterolemia, and smoking had no influence on microvascular vasodilatation. Especially in diabetic patients, endothelial function was not significantly reduced (control versus diabetes mellitus, mean±SEM or median [interquartile range], peripheral arterial tonometry: 1.90±0.20 versus 1.67±0.20, P=0.19, laser Doppler flowmetry: 728% [interquartile range, 427-1110] versus 589% [interquartile range, 320-1067] P=0.28, and digital thermal monitoring: 6.6±1.0% versus 2.5±1.7%, P=0.08). In multivariate linear regression analysis, body mass index was the only risk factor that significantly attenuated endothelium-dependent vasodilatation using all 3 microvascular function tests.

CONCLUSIONS

Higher body mass index is associated with reduced endothelial function in patients with suspected coronary artery disease, even after adjustment for treated diabetes mellitus, hypertension, hypercholesterolemia, and smoking.

Association between markers of endothelial dysfunction and early signs of renal dysfunction in pediatric obesity and type 1 diabetes

BACKGROUND

To evaluate whether circulating markers of endothelial dysfunction, such as intercellular adhesion molecule-1 (ICAM-1) and myeloperoxidase (MPO), are increased in youth with obesity and in those with type 1 diabetes (T1D) at similar levels, and whether their levels are associated with markers of renal function.

METHODS

A total of 60 obese youth [M/F: 30/30, age: 12.5 ± 2.8 yr; body mass index (BMI) z-score: 2.26 ± 0.46], 30 with T1D (M/F: 15/15; age: 12.9 ± 2.4 yr; BMI z-score: 0.45 ± 0.77), and 30 healthy controls (M/F: 15/15, age: 12.4 ± 3.3 yr, BMI z-score: -0.25 ± 0.56) were recruited. Anthropometric measurements were assessed and a blood sample was collected to measure ICAM-1, MPO, creatinine, cystatin C and lipid levels. A 24-h urine collection was obtained for assessing albumin excretion rate (AER).

RESULTS

Levels of ICAM-1 and MPO were significantly higher in obese [ICAM-1: 0.606 (0.460-1.033) µg/mL; MPO: 136.6 (69.7-220.8) ng/mL] and T1D children [ICAM-1: 0.729 (0.507-0.990) µg/mL; MPO: 139.5 (51.0-321.3) ng/mL] compared with control children [ICAM-1: 0.395 (0.272-0.596) µg/mL MPO: 41.3 (39.7-106.9) ng/mL], whereas no significant difference was found between T1D and obese children. BMI z-score was significantly associated with ICAM-1 (β = 0.21, p = 0.02) and MPO (β = 0.41, p < 0.001). A statistically significant association was also found between ICAM-1 and markers of renal function (AER: β = 0.21, p = 0.03; e-GFR: β = 0.19, p = 0.04), after adjusting for BMI.

CONCLUSIONS

Obese children have increased markers of endothelial dysfunction and early signs of renal damage, similarly to children with T1D, confirming obesity to be a cardiovascular risk factor as T1D. The association between ICAM-1 with e-GFR and AER confirm the known the association between general endothelial and renal dysfunction.

Early changes in adipokines from overweight to obesity in children and adolescents

OBJECTIVE

Childhood obesity has been associated with metabolic syndrome and cardiovascular diseases. This study aimed to compare plasma levels of traditional metabolic markers, adipokines and soluble tumor necrosis factor receptor type 1 (sTNFR1) in overweight, obese and lean children. We also assessed the relationships of these molecules with classical metabolic risk factors.

METHODS

This study included 104 children and adolescents, which were grouped as: lean (n=24), overweight (n=30), and obese subjects (n=50). They were subjected to anthropometrical, clinical and laboratorial measurements. All measurements were compared between groups. Correlation analyses were also performed to evaluate the association between clinical data, traditional metabolic markers, adipokines and sTNFR1.

RESULTS

Fasting glucose, insulin, homeostatic model assessment of insulin resistance (HOMA-IR), LDL-cholesterol and triglycerides were comparable in lean, overweight and obese subjects. Plasma levels of sTNFR1 were similar in lean and overweight subjects, but significantly increased in obese group. Leptin, adiponectin and resistin levels did not differ when overweight were compared to obese subjects. However, all adipokines differed significantly when lean subjects were compared to overweight and obese individuals. Plasma levels of adiponectin were negatively correlated with body mass index (BMI), whereas leptin, resistin and sTNFR1 concentrations positively correlated with BMI.

CONCLUSION

Our results showed significant differences in circulating levels of the evaluated markers when lean, overweight and obese individuals were compared, suggesting that these biomarkers may change from lean to overweight and from overweight to obesity.

Increased regional deformation of the left ventricle in normal children with increased body mass index: implications for future cardiovascular health

The prevalence of obesity continues to increase in the developing world. The effects of obesity on the cardiovascular system include changes in systolic and diastolic function. More recently obesity has been linked with impairment of longitudinal myocardial deformation properties in children. We sought to determine the effect of increased body mass index (BMI) on cardiac deformation in a group of children taking part in the population-based Southampton Women's Survey to detect early cardiovascular changes associated with increasing BMI before established obesity. Sixty-eight children at a mean age of 9.4 years old underwent assessment of longitudinal myocardial deformation in the basal septal segment of the left ventricle (LV) using two-dimensional speckle tracking echocardiography. Parameters of afterload and preload, which may influence deformation, were determined from cardiac magnetic resonance imaging. BMI was determined from the child's height and weight at the time of echocardiogram. Greater pediatric BMI was associated with greater longitudinal myocardial deformation or strain in the basal septal segment of the LV (β = 1.6, p < 0.001); however, this was not related to contractility or strain rate in this part of the heart (β = 0.001, p = 0.92). The end-diastolic volume of the LV increased with increasing BMI (β = 3.93, p < 0.01). In young children, regional deformation in the LV increases with increasing BMI, whilst normal contractility is maintained. This effect may be explained by the increased preload of the LV associated with increased somatic growth. The long-term implications of this altered physiology need to be followed-up.

Therapeutic approach in the improvement of endothelial dysfunction: the current state of the art

The endothelium has a central role in the regulation of blood flow through continuous modulation of vascular tone. This is primarily accomplished by balanced release of endothelial relaxing and contractile factors. The healthy endothelial cells are essential for maintenance of vascular homeostasis involving antioxidant, anti-inflammatory, pro-fibrinolytic, anti-adhesive, or anticoagulant effects. Oppositely, endothelial dysfunction is primarily characterized by impaired regulation of vascular tone as a result of reduced endothelial nitric oxide (NO) synthase activity, lack of cofactors for NO synthesis, attenuated NO release, or increased NO degradation. So far, the pharmacological approach in improving/reversal of endothelial dysfunction was shown to be beneficial in clinical trials that have investigated actions of different cardiovascular drugs. The aim of this paper was to summarize some of the latest clinical findings related to therapeutic possibilities for improving endothelial dysfunction in different pathological conditions. In the majority of presented clinical investigations, the assessment of improvement or reversal of endothelial dysfunction was performed through the flow-mediated dilatation measurement, and in some of those endothelial progenitor cells' count was used for the same purpose. Still, given the fast and continuous development of this field, the evidence acquisition included the MEDLINE data base screening and the selection of articles published between 2010 and 2012.

Assessing pre-clinical ventricular dysfunction in obese children and adolescents: the value of speckle tracking imaging

AIMS

Obesity has become a major health problem worldwide. Cardiovascular abnormalities have been described not only in obese adults but also in obese children and adolescents. The aim of the present study was to investigate left and right, systolic and diastolic ventricular dysfunction in obese paediatric patients without comorbidities using 2D speckle tracking longitudinal strain.

METHODS AND RESULTS

Doppler echocardiogram was performed on 50 obese children and adolescents with body mass index (BMI) above the 95th percentile (OG) and 46 non-obese sex- and age-matched controls (CG). Systolic and diastolic functions of both ventricles were investigated through conventional Doppler echocardiography. Tissue Doppler imaging (TDI), colour Doppler myocardial imaging (CDMI), and two-dimensional (2D) speckle tracking were also used to analyse ventricular performance in both groups. Left-ventricular (LV) ejection fraction was similar between groups (68.2 ± 6.2 vs. 68.3 ± 5.3, P = 0.931). Left-ventricular diastolic parameters did not differ between groups, except for a lower mitral A wave (61.6 ± 13.0 vs. 51.9 ± 10.0 cm/s, P > 0.001) and higher E/A ratio (1.8 ± 0.5 vs. 2.1 ± 0.4, P = 0.007) in the controls. Left-ventricular global strain was lower in the OG by both methods (CDMI: 22.0 ± 2.8 vs. 24.6 ± 2.7%, P = 0.020; 2D speckle tracking: 18.4 ± 1.6 vs. 20.4 ± 1.7%, P < 0.001). In multivariate analysis, 2D longitudinal global strain correlated negatively with BMI, r = -0.433, p = 0.002.

CONCLUSION

Although EF was not different between the two groups, LV 2D speckle tracking longitudinal strain was lower in the obese group, even in the absence of other comorbidities, indicating that obesity effects on LV function is an early finding in obesity.