Influence of obesity and insulin resistance on left atrial size in children

Obesity-hyperlipidemia, Hypertension, and Left Atrial Enlargement During Stroke in Young Adults

BACKGROUND

This study investigated the association between left atrial enlargement and stroke severity in young adults. We also studied the differences between the normal and left atrial enlargement groups in clinical data.

METHODS

A total of 135 young stroke patients admitted to the Department of Neurology of the Taizhou People's Hospital were recruited from January 2018 to December 2021. The patients were divided into normal and enlarged groups by left atrial size. The relationship between the left atrial diameter and the National Institutes of Health Stroke Scale score was analyzed apart from the differences in clinical variables.

RESULTS

No relationship was observed between the left atrial diameter and the National Institutes of Health Stroke Scale score ( r =-0.045 P =0.603). The univariate analysis of both groups revealed that hypertension ( P =0.004), hyperlipidemia ( P =0.001), body mass index ( P =0.000), obesity ( P =0.015), and not stroke etiologic subtypes were associated with left atrial enlargement. In binary logistic regression analysis models, hyperlipidemia 3.384 (95% CI, 1.536 to 7.452), hypertension 2.661 (95% CI, 1.066 to 6.639), and obesity 2.858 (95% CI, 1.158 to 7.052) were significantly associated with the young stroke of left atrial enlargement.

CONCLUSIONS

In young adults, obesity-hyperlipidemia and hypertension were significantly associated with left atrial enlargement in stroke.

The effect of overweight/obesity on diastolic function in children and adolescents: A meta-analysis

Left ventricular diastolic function (LVDF) is an important marker of early cardiovascular remodelling, which has not been well summarized in young people with overweight/obesity. Weighted, random-effects regression was used to determine the strength of associations of both body mass index (BMI) and homeostatic model assessment of insulin resistance (HOMA-IR) with LVDF measures, adjusting for age and sex. Six databases were searched after PROSPERO registration (CRD42020177470) from inception to July 2020 for studies that compared LVDF between overweight/obesity and control groups aged ≤24 years, yielding 70 studies (9983 individuals). Quality and risk of bias were assessed using NHLBI tools, with scores of good, fair, and poor for 6, 48, and 16 studies, respectively. Increased BMI was associated with worse LVDF in all measures except early mitral inflow deceleration time, with septal early diastolic tissue peak velocity to late diastolic tissue peak velocity ratio having the strongest association (n = 13 studies, 1824 individuals; r = -0.69; P < 0.001). Elevated HOMA-IR was also associated with worse LVDF. Although we could not determine the causality of reduced LVDF in young people, our findings should aid the development of paediatric guidelines for the assessment of LVDF and support further work to address the longitudinal consequences of childhood obesity and IR on LVDF.

Cardiometabolic markers among Argentinean normal weight and overweight children with and without central obesity

BACKGROUND

The association between central obesity and cardiometabolic complications justifies exploring its association in normal-weight and overweight/obese (OW/OB) schoolchildren.

OBJECTIVE

To describe cardiometabolic markers in four groups according to BMI/WC categories: (i) normal weight with central OB; (ii) normal weight without central OB; (iii) OW/OB with central OB and (iv) OW/OB without central OB, in a sample of Argentinean schoolchildren.

METHODS

A cross-sectional study of 1264 Argentinean schoolchildren (624 F), aged 9.5 ± 2.2 years was performed between November 2013 and 2015. Children's anthropometric measures, blood pressure (BP), glucose, lipids, and insulin were measured. Children were divided into four groups: (i) normal weight with central OB; (ii) normal weight without central OB; (iii) OW/OB with central OB and (iv) OW/OB without central OB.

RESULTS

The prevalence of normal-weight children without central OB was 64.3% (796), normal weight with central OB 5% (66), OW/OB without central OB 11% (137), and OW/OB with central OB 21% (265). Normal weight with central OB had significantly higher triglycerides than normal-weight children without central OB (86 vs 70 mg/dL, respectively) and OW/OB children without central OB (81 vs 77 mg/dL). Multiple linear regression analyses showed that age, systolic BP, HDL-C, triglycerides, and maternal WC were significantly associated with children's WC; R2 = 0.50 as well as children's BMI; R2 = 0.37.

CONCLUSION

This study found that children with central OB might be at future higher cardiometabolic risk than those without central OB independently of the presence of OW/OB. However, future longitudinal studies should be performed to confirm these findings.

Dietary factors and their association with childhood obesity in the Middle East: A systematic review

BACKGROUND:

Childhood obesity is a global epidemic that is related to environmental and genetic factors and has adverse consequences throughout life, being obese is a serious health problem in childhood and increases the risk of many co-morbidities.

AIM:

The purpose of this systematic review is to illustrate that dietary factors correlate with obesity among children studied in the Middle East area.

METHODS:

Studies were screened by searching two databases in August 2017 and considered as eligible for inclusion if they: (a) are observational studies, (b) define at least one dietary factor for obese children aged 6-12 years, (c) are undertaken in the Middle East area, and (d) are written in English. The search dependent words and terms used are: diet, nutrition, pediatric obesity, physical activity, Middle East, overweight, children, excess weight, childhood, obesity and dietary factors. Papers were initially evaluated for eligibility based on title and abstract. The full text of articles of studies that met, or appeared to meet, the inclusion criteria, were saved. Quality assessment was conducted using the NIH tool for observational cohort and cross-sectional studies. Out of 730 studies, 4 papers met the inclusion criteria and rated as good quality. These studies were from Iran ( n=2), Saudi Arabia ( n=1) and Lebanon ( n=1) during 2008 and 2016.

RESULTS:

Dietary factors identified were breakfast intake, junk-food consumption, energy intake and micronutrient intake. The present systematic review shows that several dietary behaviors such as missing breakfast, excessive fat and refined carbohydrate intake with low micronutrient intake due to low consumption of fruits, vegetables and milk/diary, are associated with obesity in children in the Middle East.

CONCLUSIONS:

A healthy diet during childhood to control weight and prevent obesity is recommended for a healthy, lifelong adulthood.

Excess weight in children and adolescents is associated with altered subendocardial blood supply among girls but not boys

Subendocardial viability ratio (SEVR) is a reliable index of myocardial supply-workload balance. This study sought to investigate whether overweight/obese children and adolescents have altered SEVR and to identify which are the associated factors. This cross-sectional study involved 789 individuals. Central haemodynamic was measured by radial applanation tonometry. Diastolic time was shorter (496 ± 122 vs 537 ± 140 ms, P = .014) and diastolic pressure-time index was lower (2681 ± 412 vs 2814 ± 423 mm Hg seconds, P = .024) in overweight/obese compared with eutrophic girls. SEVR was lower in girls than in boys (1.34 ± 0.39 vs 1.48 ± 0.41, P = .018) but only among overweight/obese. SEVR may be affected by small variations in the temporal determinants of cardiac cycle.

Magnetic resonance imaging reveals elevated aortic pulse wave velocity in obese and overweight adolescents

The aortic pulse wave velocity (PWV) measured via cardiac magnetic resonance (CMR) can be used to non-invasively assess changes in arterial stiffness and potential underlying vascular dysfunction. This technique could unmask early arterial dysfunction in overweight and obese youth at risk for cardiovascular disease. We sought to determine the association between vascular stiffness, percentage body fat, body mass index (BMI), and cardiac function in adolescents across the weight spectrum through both CMR and standard applanation tonometry (AT)-based PWV measurements. PWV and left-ventricular cardiac function were assessed using 3.0 T CMR in obese and overweight (OB/OW) participants (n = 12) and controls (n = 7). PWV was also estimated via carotid-femoral AT. OB/OW participants did not differ from healthy-weight controls regarding cardiometabolic risk factors or physical activity levels, but there was a trend towards higher levels of triglycerides in obese/overweight participants (P = 0.07). Mean PWV was higher in obese participants when corrected for age and sex (P = 0.01), and was positively associated with BMI (β = 0.51, P = 0.02). PWV estimated through AT was not significantly different between groups. Cardiac function measured by left-ventricular ejection fraction z-score was inversely associated with mean PWV (β = -0.57, P = 0.026). Increasing arterial stiffness and decreasing cardiac function were evident among our overweight and obese cohort. PWV estimated by CMR could detect early increases in arterial stiffness vs. traditional AT measurements of PWV.

Adolescent Body Mass Index and Cardiovascular Disease-Specific Mortality by Midlife

CONTEXT

As opposed to coronary heart disease (CHD) mortality, cardiovascular mortality attributed to non-CHD causes has increased.

OBJECTIVE

To evaluate the association of body mass index (BMI) in late adolescence with mortality attributed to non-CHD cardiovascular sequelae.

DESIGN AND SETTING

A nationwide cohort.

PARTICIPANTS

A total of 2,294,139 adolescents examined between 1967 and 2010.

INTERVENTIONS

Height and weight were measured at age 17. All cardiovascular disease-specific outcomes, coded by the Central Bureau of Statistics from death notifications as the underlying cause of death, were obtained by linkage. Cox hazards models were applied.

MAIN OUTCOME MEASUREMENTS

Death attributed to fatal arrhythmias, hypertensive heart disease, cardiomyopathies, arterial disease, heart failure, and pulmonary embolism.

RESULTS

During 42,297,007 person-years of follow-up, there were 3178 deaths due to cardiovascular causes, of which 279, 122, 121, 114, 94, and 70 were attributed to the main outcomes, respectively. BMI was positively associated with all study outcomes with hazard ratios (HRs) per unit increment in BMI ranging from 1.09 [95% confidence interval (CI): 1.03 to 1.16] for arterial disease to 1.16 (95% CI: 1.11 to 1.21) for hypertensive heart disease. When BMI was treated as a categorical variable, a graded increase in risk was evident from the high-normal (22.0 to <25.0 kg/m2) to the overweight to the obese categories, with HRs of 1.4, 1.7, and 3.7 for arrhythmias; 1.9, 4.1, and 8.0 for hypertensive heart disease; 1.5, 2.4, and 4.0 for cardiomyopathies, 2.7, 5.0, and 3.5; for arterial disease, 1.7, 2.7, and 5.4 for heart failure; and 1.3, 1.8, and 3.0 for pulmonary embolism. Findings persisted in extensive sensitivity analyses.

CONCLUSIONS

Adolescent BMI within the accepted normal range is associated with non-CHD nonstroke cardiovascular outcomes.

Comparison of echocardiographic findings with laboratory parameters in obese children

Aim The purpose of our study was to evaluate the association between insulin resistance and left ventricular size and function in obese children. Material and methods A total of 79 cases aged 10-16 years and diagnosed with obesity and 79 healthy and non-obese cases as controls were included in the study. Patient and control groups were divided into three groups in terms of age as group 1 (10-12 years), group 2 (12-14 years), and group 3 (14-16 years). Fasting blood glucose, lipid profile, and fasting insulin levels of the cases were assessed. Mitral valve E and A waves, left ventricular ejection fraction, fractional shortening, end-diastolic and end-systolic diameters, left atrium diameter, and septal wall thickness were measured using echocardiography.

RESULTS

Measurements of septal diastolic thicknesses, left atrium diameter, and left ventricular end-systolic diameter of all the three groups obtained by echocardiography were statistically higher compared with the controls. In all the patient groups, the mitral valve E/A ratio was >1. In groups 2 and 3, there was a positive correlation between fasting insulin levels and HOMA-IR and left ventricular end-systolic diameter, end-diastolic diameter, and septal systolic and diastolic wall thicknesses.

CONCLUSION

In paediatric obesity, identification of early cardiac changes will be significant in allowing early diagnosis and treatment of cardiovascular diseases.

Assessment of left ventricular mass index could predict metabolic syndrome in obese children

BACKGROUND

Childhood obesity is a major risk factor for cardiovascular diseases in children and adults.

OBJECTIVES

The purpose of this study was to evaluate the serum leptin level and the cardiac changes in normotensive obese children and to study the relationship between left ventricular mass index (LVMI) and serum leptin with the parameters of metabolic syndrome (MS) in obese children.

METHODS

This study was conducted in al Jeddani Hospital and Ibn Sina College Hospital in Saudi Arabia in the period from July 2012 to December 2013, and included 82 obese children. Their mean age was 10.2 ± 2.8 years; they were divided into 25 obese children with MS and 57 obese children without MS, and 40 healthy age- and sex-matched children were also included in the study as a control group. All children were subjected to clinical assessment including standing height, body weight, body mass index (BMI), waist circumference (WC), and blood pressure measurements. All children received an echocardiographic examination (2-dimensional, M-mode, Doppler, and tissue Doppler echocardiograpy) and laboratory assessment of serum leptin level, fasting glucose, fasting insulin, the homeostatic model assessment for insulin resistance (HOMA) index, total cholesterol, triglycerides, and high- and low-density lipoprotein profile.

RESULTS

BMI, BMI standard deviation score, WC, fasting glucose, fasting insulin, HOMA index and the serum leptin level were significantly higher in obese children compared to control group (p < 0.05). The LVMI were increased in the obese compared to the control group (p < 0.001) while left ventricle systolic and diastolic functions did not differ in obese versus control group (p > 0.05). There was a significant positive correlation between both LVMI and serum leptin level in comparison to BMI, WC, fasting glucose, fasting insulin, HOMA, triglycerides, and low-density lipoprotein in all obese children, especially the MS group. However, there was a significant negative correlation between both LVMI and serum leptin level in comparison to high-density lipoprotein.

CONCLUSION

Assessment of LVMI as routine echocardiographic examinations and serum leptin level might be a feasible and reliable method for the evaluation of obesity and its related cardiovascular risks during childhood that can predict metabolic syndrome and insulin resistance.

Increased left atrial size in obese children and its association with insulin resistance: a pilot study

Subclinical cardiac abnormalities represent predisposing factors for cardiovascular disease (CVD) in obese subjects. The aim of this study was to evaluate early cardiac abnormalities in obese youth and the potential association with insulin resistance (IR). Thirty obese (12 males (M)/18 females (F); age = 11.5 ± 2.4 years; body mass index (BMI)-standard deviation score (SDS) = +2.1 ± 0.5) and 15 normal weight (10 M/5 F; age = 12.8 ± 3.1 years; BMI-SDS = +0.3 ± 0.9) children and adolescents underwent Doppler two-dimensional echocardiographic assessments of left atrial (LA) and ventricular (LV) geometry and LV diastolic function (peak early [E] and late waves, E wave deceleration time, myocardial flow velocities). Homeostasis model assessment of IR (HOMA-IR) was used as an IR index. LA size was increased in obese children, as indicated by higher LA diameter (4.9 ± 0.5 vs 4.1 ± 0.4 cm, p < 0.001), area (14.3 ± 2.5 vs 10.7 ± 2.0 cm(2), p < 0.001), and volume (33.8 ± 10.6 vs 23.7 ± 6.4 ml, p = 0.003). LV mass was also increased in obese children (87.0 ± 16.6 vs 68.8 ± 13.2 g, p = 0.003), who also showed subtle diastolic dysfunctions, as indicated by higher values of E (97.1 ± 14.3 vs 86.2 ± 11.9 cm/s, p = 0.02). All the above parameters were significantly associated with BMI-SDS (p < 0.05). In addition, HOMA-IR was independently associated with LA diameter, area, and volume (β = 0.314, p = 0.040; β = 0.415, p = 0.008; β = 0.535, p = 0.001).

CONCLUSION

Obese children feature increased LA size, which emerged to be mainly correlated to, and possibly driven by IR, suggesting an increased CVD risk.

WHAT IS KNOWN

Left atrial and ventricular alterations have been reported in obese adults, and they represent predisposing factors for cardiovascular disease. There is some evidence suggesting that obese children show increased left ventricular mass and also increased atrial size, although with conflicting results.

WHAT IS NEW

Obese normotensive children showed a moderately increased atrial size, subtle alterations in left cardiac diastolic function, and ventricular mass. An association between insulin resistance and left cardiac changes was found, although its mechanism remains to be determined.

Relation of left atrial stiffness to insulin resistance in obese children: Doppler strain imaging study

BACKGROUND

The main objective of the study was to assess the strain measures (peak systolic longitudinal strain [LAS] and stiffness index [LASt]) and their relation to insulin resistance in obese children.

METHODS AND RESULTS

Eighty obese children (body mass index was 28.2 ± 3.1) and 60 age-matched healthy nonobese children were recruited. Conventional, tissue Doppler imaging LAS and LASt were measured for all children using 2D speckle tracking imaging (2DSI). Insulin resistance was assessed for obese children. Mean LAS was lower, and mean LASt was higher in obese children as compared to control group (11.3 + 2.2 vs. 38.2 + 11.6, P < 0.001, and 1.12 ± 0.23 vs. 0.21 ± 0.11, P < 0.001, respectively). LASt was significantly correlated with insulin resistance (P < 0.0001), and a value of >1.0 of LASt was the best cutoff value which can predict insulin resistance in obese children with a sensitivity of 92% and specificity of 86%.

CONCLUSIONS

LAS and LASt differed significantly in obese and nonobese children, in spite of normal left ventricular systolic and diastolic functions. LAS and LASt were associated with insulin resistance in obese children.

Lifetime risk: childhood obesity and cardiovascular risk

In a recent report, the worldwide prevalence of childhood obesity was estimated to have increased by 47% between 1980 and 2013. As a result, substantial concerns have been raised about the future burden of cardiovascular (CV) disease that could ensue. The purpose of this review is to summarize and interpret (i) the evidence linking early life obesity with adverse changes in CV structure and function in childhood, (ii) the lifetime risk for CV disease resulting from obesity in childhood, and (iii) the potential effects of lifestyle interventions in childhood to ameliorate these risks.

Associations of cardiac structure with obesity, blood pressure, inflammation, and insulin resistance in African-American adolescents

To determine if obesity, blood pressure (BP), markers of inflammation, and insulin resistance are associated with cardiac structure in African-American adolescents, a cross-sectional study was performed on a cohort oversampled for high BP and obesity. Measurements included the following: anthropometrics, BP, homeostasis model assessment (HOMA) to assess insulin resistance, high-sensitivity C-reactive protein, and plasma adipokines (adiponectin, interleukin-6, plasminogen activator inhibitor-1). Echocardiogram measurements were left-ventricular mass index (LVMI) (g/m(2.7)), LV relative wall thickness (LVRWT), left-atrial diameter index [LADI (mm/m)], and LV diastolic time intervals. LADI (r (2) = 0.25) was associated with body mass index (BMI) systolic BP (SBP) and female sex. LVMI (r (2) = 0.35) variation was associated with BMI SBP, heart rate, age, and male sex. LVRWT (r (2) = 0.05) was associated with HOMA. Tissue diastolic intervals were not associated with any risk factor. Inflammatory markers and adipokines were associated with BMI but were not independently associated with any echocardiographic measures. In African-American adolescents, BMI and SBP, but not inflammatory markers or adipokines, are important correlates of LA size and LVM.

Myocardial tissue remodeling in adolescent obesity

BACKGROUND

Childhood obesity is a significant risk factor for cardiovascular disease in adulthood. Although ventricular remodeling has been reported in obese youth, early tissue-level markers within the myocardium that precede organ-level alterations have not been described.

METHODS AND RESULTS

We studied 21 obese adolescents (mean age, 17.7±2.6 years; mean body mass index [BMI], 41.9±9.5 kg/m(2), including 11 patients with type 2 diabetes [T2D]) and 12 healthy volunteers (age, 15.1±4.5 years; BMI, 20.1±3.5 kg/m(2)) using biomarkers of cardiometabolic risk and cardiac magnetic resonance imaging (CMR) to phenotype cardiac structure, function, and interstitial matrix remodeling by standard techniques. Although left ventricular ejection fraction and left atrial volumes were similar in healthy volunteers and obese patients (and within normal body size-adjusted limits), interstitial matrix expansion by CMR extracellular volume fraction (ECV) was significantly different between healthy volunteers (median, 0.264; interquartile range [IQR], 0.253 to 0.271), obese adolescents without T2D (median, 0.328; IQR, 0.278 to 0.345), and obese adolescents with T2D (median, 0.376; IQR, 0.336 to 0.407; P=0.0001). ECV was associated with BMI for the entire population (r=0.58, P<0.001) and with high-sensitivity C-reactive protein (r=0.47, P<0.05), serum triglycerides (r=0.51, P<0.05), and hemoglobin A1c (r=0.76, P<0.0001) in the obese stratum.

CONCLUSIONS

Obese adolescents (particularly those with T2D) have subclinical alterations in myocardial tissue architecture associated with inflammation and insulin resistance. These alterations precede significant left ventricular hypertrophy or decreased cardiac function.

Relations of circulating resistin and adiponectin and cardiac structure and function: the Framingham Offspring Study

Obesity is associated with pathological cardiac remodeling and risk of heart failure (HF). Adipocytokines (ADKs) may mediate the increased risk of cardiovascular disease associated with excess adiposity. Yet data relating ADKs to cardiac remodeling phenotypes are sparse. We related two circulating ADKs, resistin and adiponectin, to three important echocardiographic markers of cardiac remodeling, left ventricular mass (LVM), left atrial diameter (LAD), and LV fractional shortening (LVFS) in 2,615 participants (mean age 61 years, 55% women) in the Framingham Offspring Study. Adiponectin concentrations were inversely related to LVM in multivariable linear regression models adjusting for key clinical correlates including BMI (regression coefficient per s.d.-increment in ln-adiponectin = -3.37, P = 0.02; P for trend across quartiles = 0.02). Adiponectin was not associated with LAD or LVFS (P > 0.56). Resistin concentrations were inversely related to LVFS (regression coefficient per s.d.-increment in ln-resistin = -0.01, P = 0.03; P for trend across quartiles = 0.04). Resistin was not associated with LVM or LAD (P > 0.05). In our moderate-sized, community-based sample, higher circulating concentrations of adiponectin and resistin were associated with lower LVM and lower LVFS, respectively. In conclusion, these associations identify potential mechanisms by which excess adiposity may mediate adverse cardiac remodeling and HF risk.

Body fat, abdominal fat, and body fat distribution is related to left atrial diameter in young children

In adults, the size of the left atria (LA) has important prognostic information. In obese adults, adolescents and children enlargement of LA have been observed. This has not been investigated on a population-based level in young children. We therefore assessed if total body fat mass (TBF), abdominal fat, and body fat distribution were related to LA diameter. Cross-sectional study of 244 children (boys = 137 and girls n = 107) aged 8-11 years, recruited from an urban population-based cohort. Dual-energy X-ray absorptiometry (DXA) measured total lean body mass, TBF, and abdominal fat mass (AFM). Body fat was also calculated as a percentage of body mass (BF%). Body fat distribution (AFM/TBF) was calculated. Echocardiography was performed with two-dimensional guided M-mode. LA diameter was measured and left ventricular mass (LVM) was calculated. Systolic blood pressure and diastolic blood pressure were measured and maturity assessed according to Tanner. There were significant (P < 0.05) univariate correlations for all children between TBF (r = 0.40), BF% (r = 0.32), AFM (r = 0.41), and AFM/TBF (r = 0.41) vs. LA diameter. Multiple regression analyses with the inclusion of possible confounders such as lean body mass, blood pressure, gender, age, and Tanner stage revealed that TBF, AFM, and AFM/TBF were all independently related to LA diameter. Differences in the different body fat measurements explained 6-9% of the variance in LA size. These results demonstrated that both total body fat, AFM, and body fat distribution are already at a young age negatively and independently associated to LA diameter.

Association between left atrial size and measures of adiposity among normal adolescent boys

Obesity (OB) in adults is associated with insulin resistance, hypertension, and left atrial (LA) enlargement. This study aimed to determine the association between LA size and (1) different components of the metabolic syndrome (body mass index [BMI], waist circumference [WC], insulin levels, lipid levels, and blood pressure), and (2) left ventricular (LV) diameters and diastolic function. Data were collected cross-sectionally from 142 healthy adolescent boys age 16.8 ± 2.0 years in 2009. Measurements of BMI, WC, blood pressure, lipid profile, and insulin were performed. Mode M, two-dimensional Doppler echocardiography was performed. Measurements of LA area, LV end diastolic diameter (EDD), end systolic diameter (ESD), posterior wall, interventricular septum (IVS), and shortening fraction were performed. Tisular Doppler of the diastolic mitral annular E wave (DTE) and A wave (DTA) and the ratio of maximal early diastolic filling wave velocity to maximal early diastolic myocardial velocity (E/e') were recorded. The study group included 38 OB boys (26.8%) and 32 overweight boys (22.5%). Significant univariate association was found between LA area and BMI (r = 0.61), WC (r = 0.56), systolic blood pressure (r = 0.21), insulinemia (r = 0.28), high-density lipoprotein-cholesterol (HDL-C) (r = -0.24), triglycerides (r = 0.20), EDD (r = 0.25), LV posterior wall (r = 0.25), IVS (r = 0.25), DTE (r = 0.27), DTA (r = 0.30), and E/e' (r = -0.28). Multiple linear regression analysis showed that LA area was associated with BMI (B = 0.61; R (2) = 0.47) adjusted for confounding variables. In adolescents, BMI and WC were significantly associated with LA, suggesting that OB could be associated with LA enlargement as early as adolescence.

Newer Doppler echocardiography techniques in assessment of heart function in obese patients

Obesity is one of the major health problems of modem society. The prevalence of this condition has increased at an alarming rate, especially the most severe form (body mass index >40 kg/m2). The cardiovascular problems that generally accompany obesity are the focus of a large number of studies. Conventional echogram and more current modalities, such as tissue Doppler, strain and strain rate are valuable tools for the detection of subclinical dysfunction and the early diagnosis and treatment of patients.

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

Obesity is a major public health problem affecting adults and children in both developed and developing countries. This condition often leads to metabolic syndrome, which increases the risk of cardiovascular disease. A large number of studies have been carried out to understand the pathogenesis of cardiovascular dysfunction in obese patients. Endothelial dysfunction plays a key role in the progression of atherosclerosis and the development of coronary artery disease, hypertension and congestive heart failure. Noninvasive methods in the field of cardiovascular imaging, such as measuring intima-media thickness, flow-mediated dilatation, tissue Doppler, and strain, and strain rate, constitute new tools for the early detection of cardiac and vascular dysfunction. These techniques will certainly enable a better evaluation of initial cardiovascular injury and allow the correct, timely management of obese patients. The present review summarizes the main aspects of cardiovascular dysfunction in obesity and discusses the application of recent noninvasive imaging methods for the early detection of cardiovascular alterations.

Relations of circulating resistin and adiponectin and cardiac structure and function: the Framingham Offspring Study

Obesity is associated with pathological cardiac remodeling and risk of heart failure (HF). Adipocytokines (ADKs) may mediate the increased risk of cardiovascular disease associated with excess adiposity. Yet data relating ADKs to cardiac remodeling phenotypes are sparse. We related two circulating ADKs, resistin and adiponectin, to three important echocardiographic markers of cardiac remodeling, left ventricular mass (LVM), left atrial diameter (LAD), and LV fractional shortening (LVFS) in 2,615 participants (mean age 61 years, 55% women) in the Framingham Offspring Study. Adiponectin concentrations were inversely related to LVM in multivariable linear regression models adjusting for key clinical correlates including BMI (regression coefficient per s.d.-increment in ln-adiponectin = -3.37, P = 0.02; P for trend across quartiles = 0.02). Adiponectin was not associated with LAD or LVFS (P > 0.56). Resistin concentrations were inversely related to LVFS (regression coefficient per s.d.-increment in ln-resistin = -0.01, P = 0.03; P for trend across quartiles = 0.04). Resistin was not associated with LVM or LAD (P > 0.05). In our moderate-sized, community-based sample, higher circulating concentrations of adiponectin and resistin were associated with lower LVM and lower LVFS, respectively. In conclusion, these associations identify potential mechanisms by which excess adiposity may mediate adverse cardiac remodeling and HF risk.

Echocardiographic measurement of epicardial adipose tissue in obese children

The echocardiographic measurement of epicardial adipose tissue (EAT) has been suggested as an easy method for evaluation of the visceral adipose tissue and its related cardiovascular risks in adults. However, a direct effect of obesity on cardiac function is not well established, and echocardiographic EAT thickness has not been studied in children. The aims of this study were to evaluate cardiac function and echocardiographic EAT thickness and to correlate EAT with the other echocardiographic findings in obese children. The study population included 106 obese and 62 lean children. Echocardiographic indexes of systolic and diastolic function were obtained. We measured EAT thickness on the free wall of the right ventricle from parasternal long-axis views. The septal and posterior wall thicknesses, relative wall thickness, left atrial diameter, and left ventricular mass were increased (p = 0.001) in obese children. However, systolic and diastolic functions of the left ventricle were normal in the patients. The obese children had a significantly thicker EAT (p = 0.001) compared to the lean subjects. EAT thickness correlated significantly with body mass index (r = 0.50, p = 0.001), left atrial diameter (r = 0.37, p = 0.001), and left ventricular mass (r = 0.33, p = 0.001). In conclusion, the present study demonstrates a close relationship between EAT thickness and obesity in children. Assessment of EAT thickness in routine echocardiographic examinations might be used as a feasible and reliable method for the evaluation of obesity and its related cardiovascular risks during childhood.

Longitudinal tracking of left atrial diameter over the adult life course: Clinical correlates in the community

BACKGROUND

Increased left atrial diameter (LAD) is associated with elevated risk of atrial fibrillation (AF) and cardiovascular disease. Information is limited regarding the short- or long-term correlates of LAD.

METHODS AND RESULTS

We evaluated clinical correlates of LAD for a 16-year period in 4403 Framingham Study participants (mean age, 45 years; 52% women; median observations/participant=3) using multilevel modeling. We related age, sex, body mass index (BMI), systolic and diastolic blood pressure (BP), diabetes, and antihypertensive treatment to LAD. Sex-specific growth curves for LAD were estimated for individuals with low, intermediate, and high risk factor burden. We also related risk factors to changes in LAD during a 4-year period in 3365 participants. Age, male sex (3.83 mm compared to women), greater BMI, higher systolic BP (0.24 mm per 10 mm Hg increment), and antihypertensive treatment (0.54 mm) were associated positively with LAD (P<0.001). Men had a greater increase in LAD with BMI than women (2.02 versus 1.77 mm in women, per 5-unit increment), and individuals receiving antihypertensive treatment experienced a greater increase in LAD with age (0.95 versus 0.63 mm per 10-year age increment) when compared with those not receiving antihypertensive treatment. Overall, greater risk factor burden was positively associated with LAD. These risk factors were also associated positively with 4-year change in LAD (P<0.001).

CONCLUSIONS

Our longitudinal study of a large community-based sample identified higher BP and greater BMI as key modifiable correlates of LAD, suggesting that maintaining optimal levels of these risk factors through the life course may prevent atrial remodeling and AF.

Impact of continuous positive airway pressure treatment on left atrial volume and function in patients with obstructive sleep apnoea assessed by real-time three-dimensional echocardiography

Background:

Obstructive sleep apnoea (OSA) has been reported as a predictor of left ventricle (LV) diastolic dysfunction and left atrium (LA) remodelling. The aim of this study is to evaluate the impact of OSA treatment with a continuous positive airway pressure device (CPAP) on the LA volume and function, as well as on the LV diastolic function.

Methods:

In total, 56 OSA patients were studied. All patients underwent real-time three-dimensional (RT3DE) and two-dimensional echocardiogram with tissue Doppler evaluation in order to estimate LA volumes, function and LV diastolic performance. A total of 30 patients with an apnoea-hypopnoea index greater than 20 were randomly selected to receive sham CPAP (n = 15) or effective CPAP (n = 15) for 24 weeks. They underwent echo examination on three different occasions: at baseline, after 12 weeks and 24 weeks of CPAP or sham CPAP.

Results:

In the effective CPAP group we observed the following changes from the baseline to the 24-week echo evaluation: (a) a reduction in the E/E′ ratio (10.3 (1.9) to 7.9 (1.3), p = 0.03); (b) an increase in the LA passive emptying fraction (28.8% (11.9%) to 46.8% (9.3%), p = 0.01); and (c) a reduction in the LA active emptying fraction (42.7% (11.5%) to 25.7 (15.7), p<0.01). In the sham group, there were no changes from the baseline to the 24-week echo. We found a positive correlation between 24 week/baseline LA active emptying volume and 24 week/baseline E/E′ ratios (r = 0.40, p<0.05) and a negative correlation between 24 week/baseline LA passive emptying volume and 24 week/baseline E/E′ ratios (r = −0.53, p<0.05). No significant changes were found on LA total emptying fraction.

Conclusion:

CPAP improved LV diastolic function and LA passive emptying, but not LA structural variables in OSA patients.

Trial registration number:

NCT00768807.

Cardiac markers of pre-clinical disease in adolescents with the metabolic syndrome: the strong heart study

OBJECTIVES

Our aim was to evaluate the impact of metabolic syndrome (MetS) on cardiac phenotype in adolescents.

BACKGROUND

A high prevalence of MetS has been reported in adolescents.

METHODS

Four hundred forty-six nondiabetic American Indian adolescents (age 14 to 20 years, 238 girls) underwent clinical evaluation, laboratory testing, and Doppler echocardiography. Age- and gender-specific partition values were used to define obesity and hypertension. Metabolic syndrome was defined according to Adult Treatment Panel III criteria, modified for adolescents. Left ventricular (LV) hypertrophy and left atrial (LA) dilation were identified using age- and gender-specific partition values.

RESULTS

One hundred eleven participants met criteria for MetS. They had a similar age and gender distribution as non-MetS participants. Analysis of covariance, controlling for relevant confounders, demonstrated that participants with MetS had higher LV, LA, and aortic root diameters, higher LV relative wall thickness, and greater LV mass index. Accordingly, MetS participants showed higher prevalences of LV hypertrophy (43.2% vs. 11.7%) and LA dilation (63.1% vs. 21.9%, both p < 0.001) compared with non-MetS participants. In addition, MetS was associated with a reduction in midwall shortening, lower transmitral mitral early to atrial peak velocity ratio, and mildly prolonged mitral early deceleration time (all p < 0.05). In multiple regression analysis, independently of demographics, obesity, blood pressure, and single metabolic components of MetS, clustered MetS was associated with a 2.6-fold higher likelihood of LV hypertrophy and a 2.3-fold higher likelihood of LA dilation (both p < or = 0.02).

CONCLUSIONS

In a population sample of adolescents, MetS is associated with higher prevalences of LV hypertrophy and LA dilation and with reduced LV systolic and diastolic function, independently of individual MetS components.

Cardiac remodeling in obesity

The dramatic increase in the prevalence of obesity and its strong association with cardiovascular disease have resulted in unprecedented interest in understanding the effects of obesity on the cardiovascular system. A consistent, but puzzling clinical observation is that obesity confers an increased susceptibility to the development of cardiac disease, while at the same time affording protection against subsequent mortality (termed the obesity paradox). In this review we focus on evidence available from human and animal model studies and summarize the ways in which obesity can influence structure and function of the heart. We also review current hypotheses regarding mechanisms linking obesity and various aspects of cardiac remodeling. There is currently great interest in the role of adipokines, factors secreted from adipose tissue, and their role in the numerous cardiovascular complications of obesity. Here we focus on the role of leptin and the emerging promise of adiponectin as a cardioprotective agent. The challenge of understanding the association between obesity and heart failure is complicated by the multifaceted interplay between various hemodynamic, metabolic, and other physiological factors that ultimately impact the myocardium. Furthermore, the end result of obesity-associated changes in the myocardial structure and function may vary at distinct stages in the progression of remodeling, may depend on the individual pathophysiology of heart failure, and may even remain undetected for decades before clinical manifestation. Here we summarize our current knowledge of this complex yet intriguing topic.