Increased left ventricular mass in obese adolescents*1

Early cardiac dysfunction in obese adolescents with Down syndrome or autism

BACKGROUND

Obesity in adolescents with intellectual and developmental disabilities) occurs at twice the frequency as their typically developing peers. Typically developing adolescents with obesity have abnormal cardiac function (as measured by strain echocardiography) and cardiac mass, but the effects of obesity on cardiac health in adolescents with Down syndrome or autism spectrum disorder are unknown. The purpose of this study was to evaluate the impact of body mass index on cardiac function in adolescents with Down syndrome or autism.

METHODS

Adolescents (age 12-21 years) with Down syndrome (n = 28), autism (n = 33), and age-/sex-matched typically developing controls (n = 15) received an echocardiogram optimised for strain analysis at a single timepoint. Measures of ventricular function, mass, and size were collected. Regression modelling evaluated the impact of body mass index and intellectual and developmental disabilities diagnosis on these cardiac measures.

RESULTS

In regression modelling, an elevated body mass index z-score was associated with diminished systolic biventricular function by global strain (left ventricular longitudinal strain β 0.87, P < 0.001; left ventricular circumferential strain β 0.57, p 0.003; right ventricular longitudinal strain β 0.63, P < 0.001). Diminished left ventricular diastolic function by early diastolic strain rate was also associated with elevated body mass index (global longitudinal end-diastolic strain rate β -0.7, P < 0.001). No association was found between traditional (non-strain) measures of systolic and diastolic ventricular function and body mass index z-score.

CONCLUSIONS

Obesity in adolescents with Down syndrome or autism negatively impacts cardiac function as measured by echocardiographic strain analysis that was not detected by traditional parameters.

The relevance of left ventricular functions to clinical and metabolic characteristics of prepubertal children with obesity

BACKGROUND

Paediatric obesity is a worldwide health burden, with growing evidence linking obesity to myocardial function impairments. The study aims to evaluate left ventricular functions among prepubertal obese children to obesity-related clinical and metabolic parameters.

METHODS

Between June 2019 and March 2020, 40 prepubertal children with obesity were recruited and compared to 40 healthy controls. Patients were assessed for body mass index z scores, waist circumference, body adiposity by bioimpedance analysis, and obesity-related laboratory tests, for example, serum chemerin. Left ventricular functions were assessed using variable echocardiographic modalities, such as M-mode, tissue Doppler, and two-dimensional speckle tracking.

RESULTS

Mean patients' age was 9.25 ± 1.05 years. Left ventricular mass index, E/E', and myocardial performance index were significantly increased in obese children than controls. Although M-mode-derived ejection fraction was comparable in both groups, two-dimensional speckle tracking-derived ejection fraction, global longitudinal strain, and global circumferential strain were significantly lower in cases than controls. Left ventricular mass index displayed a positive correlation with body mass index z score (p = 0.003), fat mass index (p = 0.037), and trunk fat mass (p = 0.021). Global longitudinal strain was negatively correlated with body mass index z score (p = 0.015) and fat mass index (p = 0.016). Serum chemerin was positively correlated with myocardial performance index (p = 0.01).

CONCLUSION

Alterations of left ventricular myocardial functions in prepubertal obese children could be detected using different echocardiographic modalities. Chemerin, body mass index z score, fat mass index, and trunk fat mass were correlated with subclinical left ventricular myocardial dysfunction parameters before puberty. Our results reinforce early and strict management of childhood obesity upon detection of changes in anthropometric and body adiposity indices.

Left Ventricular Measurements and Strain in Pediatric Patients Evaluated for Systemic Hypertension and the Effect of Adequate Anti-hypertensive Treatment

Pediatric hypertension (HTN) is an epidemic that is associated with HTN in adulthood and adverse cardiovascular outcomes. We hypothesized that children with HTN would have left ventricular (LV) hypertrophy and abnormal LV global longitudinal strain (GLS) on echocardiogram and that these values would differ by weight, race, and HTN treatment. Data were collected from first visits to the HTN Program from 12/2011 to 9/2018, excluding patients with cardiac disease or heart transplantation. LV measurements including LV mass index (LVMI), LV GLS, and diastolic indices were compared between groups. Multivariable logistic regression was used to identify risk factors for an abnormal LVMI. There were 212 patients with an interquartile age range of 13-18 years. On univariate analysis, LVMI was higher in hypertensive, obese, and African American patients. LV strain was less negative in obese and African American patients. Adequately treated patients with HTN had a higher LVMI and a higher E/e' ratio compared to patients with no HTN. On multivariate analysis, only obesity was associated with an LVMI ≥ 95th percentile (OR 2.9, 95% CI 1.4, 5.8). LVMI is higher in hypertensive, obese, and African American patients; however, in the multivariate analysis, obesity was the only independent risk factor for an abnormal LVMI. LVMI was still higher in those adequately treated for HTN compared to patients without HTN, possibly due to concomitant obesity. Future studies should focus on subclinical changes in LV performance seen in obese and hypertensive patients and the impact on long-term health.

Multichamber Dysfunction in Children and Adolescents With Severe Obesity: A Cardiac Magnetic Resonance Imaging Myocardial Strain Study

BACKGROUND

In severe obesity, left ventricular (LV) and right ventricular (RV) remodeling and contractile dysfunction have been documented, but less is known regarding left atrial (LA) dysfunction and its association with LV/RV remodeling, especially in children.

PURPOSE

To assess the effects of severe childhood obesity on cardiac function by using multichamber strain analysis with MRI.

STUDY TYPE

Prospective.

SUBJECTS

Forty-five children aged 7-18 years (including 20 with severe obesity, defined as a body mass index values above the 99th percentile).

FIELD STRENGTH

5 T.

SEQUENCE

Steady-state-free-precession (SSFP) images in short-axis views and longitudinal two- and four-chamber views.

ASSESSMENT

Cardiac strain measurements were derived from standard SSFP cine images by using a dedicated MR imaging feature tracking software. Inter- and intra-rater reliability were evaluated.

STATISTICAL TESTS

Independent sample t test, Spearman's correlation coefficient, principal component analysis, Bland-Altman analysis, and intra-class correlation coefficients (ICC). A P value <0.05 was considered statistically significant.

RESULTS

As compared to children without obesity, those with obesity showed significantly reduced LA reservoir function (22.2% ± 6.4% vs. 33.8% ± 9.0%) and contractile function (5.4% ± 3.2% vs. 13.3% ± 8.0%) as well as significantly decreased absolute values for LA longitudinal strain in reservoir and contraction phases and LA radial motion fraction in reservoir and contraction phases. Children with severe obesity showed significantly reduced absolute RV radial motion fraction (-10.6% ± 2.9% vs. -18.2% ± 2.9%) and circumferential strain (-10.6% ± 2.9% vs. -16% ± 2.5%) as well as higher LV mass index (28.7% ± 5.1% vs. 21.7 ± 4.6 g/m² ) along with significantly reduced LV ejection fraction (56.4% ± 3.9% vs. 60% ± 4.1%), LV radial strain (56% ± 6% vs. 61.8% ± 11.3%), and longitudinal strain (-17.8% ± 1.8% vs. -20.3% ± 3.2%). Reliability was good to excellent, with ICC ranging from 79.1% to 97.7%.

DATA CONCLUSION

MR feature-tracking strain analysis revealed multichamber dysfunction in severely obese children with impaired LA reservoir and atrial contraction phases, which suggest an early loss in the compensatory ability of atrial contraction with severe obesity.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 3.

Severe obesity in children as an independent risk factor for perioperative respiratory adverse events during anaesthesia for minor non-airway surgery, a retrospective observational study

Purpose:

The purpose of this article is to quantify grades of obesity and their independent effects on perioperative adverse events in children having ambulatory minor non-airway surgery.

Methods:

After obtaining ethics committee approval, we selected every tenth child aged 2 to 16 years who was identified as having been a day case between January 2012 and December 2014. Weight groups were defined based on age- and gender-specific body mass index (BMI) cutoff points. A sample size of 1102 was calculated to demonstrate a three-fold increase in the primary outcome measure, perioperative respiratory-airway adverse events, among obese children, with a power of 80% and an alpha error of 5%. Chi-squared and Fisher exact tests were used to compare proportions, and independent sample t tests were used to compare means.

Results:

Severely obese children had a significantly higher incidence of perioperative respiratory-airway adverse events when compared to normal-weight children despite no difference in respiratory and other comorbidity. Obese children had higher prevalence of overall medical comorbidities and obstructive sleep apnoea when compared to normal-weight children and there was no significant difference in the incidence of perioperative respiratory-airway adverse events and other outcome measures between obese and normal-weight children.

Conclusions and recommendations:

Severely obese children have a higher risk of perioperative respiratory-airway adverse events even during minor non-airway surgery despite absence of medical comorbidities. We recommend the use of age- and sex- specific BMI cutoffs or BMI percentile charts to identify children who are severely obese to anticipate and prevent major respiratory adverse events.

Overexpressing the novel autocrine/endocrine adipokine WISP2 induces hyperplasia of the heart, white and brown adipose tissues and prevents insulin resistance

WISP2 is a novel adipokine, most highly expressed in the adipose tissue and primarily in undifferentiated mesenchymal cells. As a secreted protein, it is an autocrine/paracrine activator of canonical WNT signaling and, as an intracellular protein, it helps to maintain precursor cells undifferentiated. To examine effects of increased WISP2 in vivo, we generated an aP2-WISP2 transgenic (Tg) mouse. These mice had increased serum levels of WISP2, increased lean body mass and whole body energy expenditure, hyperplastic brown/white adipose tissues and larger hyperplastic hearts. Obese Tg mice remained insulin sensitive, had increased glucose uptake by adipose cells and skeletal muscle in vivo and ex vivo, increased GLUT4, increased ChREBP and markers of adipose tissue lipogenesis. Serum levels of the novel fatty acid esters of hydroxy fatty acids (FAHFAs) were increased and transplantation of Tg adipose tissue improved glucose tolerance in recipient mice supporting a role of secreted FAHFAs. The growth-promoting effect of WISP2 was shown by increased BrdU incorporation in vivo and Tg serum increased mesenchymal precursor cell proliferation in vitro. In contrast to conventional canonical WNT ligands, WISP2 expression was inhibited by BMP4 thereby allowing normal induction of adipogenesis. WISP2 is a novel secreted regulator of mesenchymal tissue cellularity.

Cardiac Abnormalities in Youth with Obesity and Type 2 Diabetes

Childhood obesity has been linked to cardiovascular disease (CVD) risk in adulthood. Of great concern is the expected increase in the population's CVD burden in relation to childhood obesity. This is compounded by the risk related to chronic hyperglycemia exposure in youth with type 2 diabetes. We herein provide an overview of the spectrum of early cardiovascular disease manifestation in youth with obesity and type 2 diabetes, in particular abnormalities in cardiac structure and function. Cardiac remodeling and adverse target organ damage is already evident in the pediatric age group in children with obesity and type 2 diabetes. This supports the importance of intensifying obesity prevention efforts and early intervention to treat comorbidities of obesity in the pediatric age group to prevent cardiac events in early adulthood.

The impact of obesity on the relationship between epicardial adipose tissue, left ventricular mass and coronary microvascular function

Purpose

Epicardial adipose tissue (EAT) has been linked to coronary artery disease (CAD) and coronary microvascular dysfunction. However, its injurious effect may also impact the underlying myocardium. This study aimed to determine the impact of obesity on the quantitative relationship between left ventricular mass (LVM), EAT and coronary microvascular function.

Methods

A total of 208 (94 men, 45 %) patients evaluated for CAD but free of coronary obstructions underwent quantitative [¹⁵O]H₂O hybrid positron emission tomography (PET)/CT imaging. Coronary microvascular resistance (CMVR) was calculated as the ratio of mean arterial pressure to hyperaemic myocardial blood flow.

Results

Obese patients [body mass index (BMI) > 25, n = 133, 64 % of total] had more EAT (125.3 ± 47.6 vs 93.5 ± 42.1 cc, p < 0.001), a higher LVM (130.1 ± 30.4 vs 114.2 ± 29.3 g, p < 0.001) and an increased CMVR (26.6 ± 9.1 vs 22.3 ± 8.6 mmHg×ml⁻¹×min⁻¹×g⁻¹, p < 0.01) as compared to nonobese patients. Male gender (β = 40.7, p < 0.001), BMI (β = 1.61, p < 0.001), smoking (β = 6.29, p = 0.03) and EAT volume (β = 0.10, p < 0.01) were identified as independent predictors of LVM. When grouped according to BMI status, EAT was only independently associated with LVM in nonobese patients. LVM, hypercholesterolaemia and coronary artery calcium score were independent predictors of CMVR.

Conclusion

EAT volume is associated with LVM independently of BMI and might therefore be a better predictor of cardiovascular risk than BMI. However, EAT volume was not related to coronary microvascular function after adjustments for LVM and traditional risk factors.

Electronic supplementary material

The online version of this article (doi:10.1007/s00259-015-3087-5) contains supplementary material, which is available to authorized users.

Left ventricular diastolic function and cardiometabolic factors in obese normotensive children

BACKGROUND AND AIM

Left ventricular (LV) hypertrophy and diastolic function have been found to be associated with obesity and hypertension in adults. However, there are scarce data about the association of obesity itself to cardiac alteration in children. The aim of this study was to detect early changes in LV structure and function in obese children and whether they are associated with the biomarkers of metabolic risk and endothelial activation.

METHODS AND RESULTS

A total of 130 children aged 7-16 years (88 obese and 42 normal-weight children) were studied. All children had normal resting blood pressure. Two-dimensional ultrasound with M-mode imaging was performed to assess the LV mass index (LVMi), calculated as LV mass/height(2.7), and the peak diastolic of pulmonary venous flow velocity (PVFD). Tissue Doppler imaging was used to analyze ventricular performance through the ratio of the transmitral peak early filling velocity to the early average diastolic peak myocardial velocity (E/E'). The indicators of metabolic control, inflammation, and endothelial cell activation were evaluated. Compared to the controls, the obese subjects had significantly higher LVMi and E/E' and lower PVFD values, the two latest being found especially in severely obese subjects. In the multivariate analysis, the parameters of diastolic function (E/E' and PVFD) were independently associated with obesity, apolipoprotein A1, soluble vascular cell endothelial molecule-1 (sVCAM-1), and retinol-binding protein 4 (RBP4).

CONCLUSION

An echocardiographic evaluation of diastolic function is a useful tool to detect early cardiac changes in obese children. Emergent cardiovascular risk markers such as apolipoprotein A1, RBP4, and sVCAM-1 are associated with the parameters of diastolic function.

Correlation between the morning hypertension on ambulatory blood pressure monitoring and the left ventricular mass in children

PURPOSE

Although high morning blood pressure (BP) is known to be associated with the onset of cardiovascular events in adults, data on its effects in children with hypertension are limited. Our retrospective study aimed to define the clinical characteristics of children with morning hypertension (MH) and to determine its associated factors.

METHODS

We reviewed 31 consecutive patients with hypertension, confirmed by the ambulatory blood pressure monitoring (ABPM). We divided these patients into 2 groups: the MH group (n=21, 67.7%), morning BP above the 95th percentile for age and height (2 hours on average after waking up) and the normal morning BP group (n=10, 32.3%). We compared the clinical manifestations, laboratory results, and echocardiographic findings including left ventricular hypertrophy (LVH) between the groups.

RESULTS

The early/atrial (E/A) mitral flow velocity ratio in the MH group was significantly lower than that in the normal morning BP group. In addition, LV mass was higher in the MH group than in the normal morning BP group, although the difference was not statistically significant. The age at the time of hypertension diagnosis was significantly higher in the MH group than in the normal morning BP group (P=0.003). The incidence of hyperuricemia was significantly higher in the MH group than in the normal morning BP group.

CONCLUSION

Older patients and those with hyperuricemia are at higher risk for MH. The rise in BP in the morning is an important factor influencing the development of abnormal relaxation, as assessed by echocardiography. Clinical trials with longer follow-up periods and larger sample sizes are needed to clarify the clinical significance of MH.

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.

Childhood obesity increases left-ventricular mass irrespective of blood pressure status

Adults with a left-ventricular mass index (LVMI) in grams normalized to height in meters(2.7) (LVMI g/m(2.7)) >51 g/m(2.7) are more prone to cardiovascular and cerebrovascular events. We delineated the odds for cardiac structural sequelae amongst apparently normal white and African-American (AA) children with varying body mass indices (BMI) and office blood pressures. A total of 2,071 children with normal echocardiograms were categorized into risk groups based on BMI and systolic blood pressures (SBPs). Predictors of cardiac sequelae examined were age, sex, race, and z-scores (z) for BMI, SBP, and diastolic blood pressure. Cardiac sequelae measures included (LVMI g/m(2.7)) >51 g/m(2.7), (LVMI) (g/m(2.7)) z, left atrial size (LA(ht)) (mm) z, and relative wall thickness z. Mean age was 14 ± 2 years with 56 % being male and 13 % being AA. Children were divided into "controls" (n = 1,059) and risk groups based on BMI and SBP. Odds ratio for LVMI (g/m(2.7)) > 51.0 g/m(2.7), varied from 5.3 up to 8.5 in children with increased BMI. Both increased BMI and SBP z were associated with increased LVMI (g/m(2.7)) z; however, BMI z had a stronger association. Increased BMI z and AA race were associated with greater LA(ht) (mm) z. AA controls had a nonsignificantly increased LVMI z and a significantly increased LA(ht) (mm) and RWT z. Being overweight or obese is associated with cardiac sequelae in children to the extent known to be associated with adverse outcomes in adults. Healthy AA children have unique cardiac structural differences.

Mechanisms of heart failure in obesity

Heart failure is a leading cause of morbidity and mortality and its prevalence continues to rise. Because obesity has been linked with heart failure, the increasing prevalence of obesity may presage further rise in heart failure in the future. Obesity-related factors are estimated to cause 11% of heart failure cases in men and 14% in women. Obesity may result in heart failure by inducing haemodynamic and myocardial changes that lead to cardiac dysfunction, or due to an increased predisposition to other heart failure risk factors. Direct cardiac lipotoxicity has been described where lipid accumulation in the heart results in cardiac dysfunction inexplicable of other heart failure risk factors. In this overview, we discussed various pathophysiological mechanisms that could lead to heart failure in obesity, including the molecular mechanisms underlying cardiac lipotoxicity. We defined the obesity paradox and enumerated various premises for the paradoxical associations observed in the relationship between obesity and heart failure.

Abnormal systolic and diastolic myocardial function in obese asymptomatic adolescents

Structural and functional cardiac changes are known in obese adults. We aimed to assess the relationship between body mass index (BMI) and cardiac function in overweight and obese asymptomatic adolescents. Ninety three healthy adolescents, aged 12.6 ± 1.2 years, received weight, height, BMI, waist, hips, waist/hips ratio assessment, hematology and biochemistry tests and an echocardiogram. Based on BMI, subjects were divided into: lean (L, n=32), overweight (Ov, n=33) and obese (Ob, n=32). Interventricular septal and LV posterior wall thickness were increased parallel to the BMI (L: 0.84 ± 0.1cm, Ov: 0.88 ± 0.1cm, Ob: 0.96 ± 0.1cm, p<0.001, and L: 0.78 ± 0.1cm, Ov: 0.8 ± 0.1cm, Ob: 0.94 ± 0.1cm, p<0.001, respectively) as were relative wall thickness (RWT) and mass index (LVMI) (L: 0.34 ± 0.05, Ov: 0.34 ± 0.05, Ob: 0.40 ± 0.04, p<0.001, and L: 47.7 ± 8.4 g/m(2), Ov: 51.9 ± 8.3g/m(2), Ob: 65.2 ± 13.3g/m(2), p=0<001, respectively). LV early diastolic (E') lateral and septal velocities (L: 15.3 ± 3.9 cm/s, Ov: 13.6 ± 4 cm/s, Ob: 10.5 ± 3.4 cm/s, p<0.001, and L: 12.2 ± 2.3 cm/s, Ov: 11.1 ± 2.4 cm/s, Ob: 9.8 ± 3.1cm/s, p=0.003, respectively), and systolic (S') velocities (L: 9.2 ± 1.4 cm/s, Ov: 9.3 ± 2.3 cm/s, Ob: 8.04 ± 1.5 cm/s, p=0.018, and L: 9.05 ± 2.3 cm/s, Ov: 9 ± 2.4 cm/s, Ob: 7.6 ± 1.1cm/s, p=0.014, respectively) were all reduced, only in obese adolescents. LV lateral E' (r=-0.44, p<0.001) and S' (r=-0.29, p=0.005) correlated with BMI. In asymptomatic adolescents, LV wall is thicker and diastolic function impaired and correlate with BMI. These findings demonstrate early cardiac functional disturbances which might explain the known obesity risk for cardiac disease.

Increased rate of arterial stiffening with obesity in adolescents: a five-year follow-up study

Background

We prospectively and longitudinally determined the effects of childhood obesity on arterial stiffening and vascular wall changes. Changes in arterial stiffness measured as pulse wave velocity (PWV) and vascular morphology of the radial (RA) and dorsal pedal arteries (DPA) were examined in obese adolescents compared to lean subjects in a 5-year follow-up study.

Methodology/Principal Findings

A total of 28 obese subjects and 14 lean controls participated in both baseline (14 years old) and follow-up studies. PWV was measured by tonometer (SphygmoCor®) and recorded at RA and carotid artery, respectively. Intima thickness (IT), intima-media thickness (IMT) and RA and DPA diameters were measured using high-resolution ultrasound (Vevo 770™). Over the course of 5 years, PWV increased by 25% in the obese subjects as compared to 3% in the controls (p = 0.01). Diastolic blood pressure (DBP) increased by 23% in the obese subjects as opposed to 6% in controls (p = 0.009). BMI increased similarly in both groups, as did the IT and IMT. The change in PWV was strongly associated to the baseline BMI z -score (r = 0.51, p<0.001), as was the change in DBP (r = 0.50, p = 0.001).

Conclusions/Significance

During the transition from early to late adolescence, there was a general increase in arterial stiffness, which was aggravated by childhood obesity. The increase in arterial stiffness and DBP after 5 years was closely correlated to the baseline BMI z -score, indicating that childhood obesity has an adverse impact on vascular adaptation.

Improved outcomes in paediatric anaesthesia: contributing factors

PURPOSE

To discuss developments in paediatric anaesthesia and explore the factors which have contributed to improved anaesthetic-related patient outcomes.

METHODS

Narrative review of findings in the literature retrieved from MEDLINE/Pubmed and manual search.

RESULTS

Adverse perioperative outcomes related to anaesthesia have been extensively debated over the past few decades, with studies implicating factors such as major human error and equipment failure. Case series and event registries have enlightened physicians on sources of error and patient risk factors such as extremes of age, comorbidity and emergent circumstances. Anaesthetic-related deaths in children fell from 6.4 per 10,000 anaesthetics in the early 1950s to as low as 0.1 per 10,000 anaesthetics by the end of the century. Advances in anaesthetic agents, techniques, monitoring technologies and training programmes in paediatric anaesthesia play a vital role in driving this downward trend.

CONCLUSION

Despite substantial progress, there is still much room for improvement in areas such as adverse-event reporting, anaesthetic-related risk and late neurocognitive outcomes. Systematic reviews comparing paediatric patient outcomes after neuroaxial block versus general anaesthesia are currently unavailable. The future of paediatric anaesthesia will most likely be influenced by much-needed large prospective studies, which can provide further insight into patient safety and service delivery.

High physiological omega-3 Fatty Acid supplementation affects muscle Fatty Acid composition and glucose and insulin homeostasis in obese adolescents

Obese adolescents have high concentrations of saturated fatty acids and low omega-3 long-chain polyunsaturated fatty acids (LCUFAs) in plasma phospholipids. We aimed to investigate effects of omega-3 LCPUFA supplementation to obese adolescents on skeletal muscle lipids and glucose and insulin homeostasis. Twenty-five obese adolescents (14–17 years old, 14 females) completed a randomized double-blind crossover study supplying capsules containing either 1.2 g omega-3 LCPUFAs or placebo, for 3 months each with a six-week washout period. Fasting blood glucose, insulin, leptin, adiponectin, and lipids were measured. Intravenous glucose tolerance test (IVGTT) and euglycemic-hyperinsulinemic clamp were performed, and skeletal muscle biopsies were obtained at the end of each period. The concentrations of EPA, DHA, and total omega-3 PUFA in muscle phospholipids increased in both sexes. In the females, omega-3 LCPUFA supplementation improved glucose tolerance by 39% (P = 0.04) and restored insulin concentration by 34% (P = 0.02) during IVGTT. Insulin sensitivity improved 17% (P = 0.07). In males, none of these parameters was influenced by omega-3 supplementation. Thus, three months of supplementation of omega-3 LCPUFA improved glucose and insulin homeostasis in obese girls without influencing body weight.

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.

Childhood obesity and future cardiac risk: what should physicians be looking for?

Obesity increases the risk for future health problems, including cardiovascular disease, Type 2 diabetes, certain forms of cancer, orthopedic issues, nonalcoholic fatty liver disease, depression and psychosocial issues. Prevention and screening children should begin in infancy with parental education on the importance of healthy eating habits and daily physical activity. Early detection of at-risk behaviors, family risk factors and trends towards obesity should be assessed at every healthy-child visit by plotting height and weight in infants and toddlers and measuring BMI, starting at 2 years of age. Blood pressure monitoring should be a routine part of the physical examination in children over the age of 3 years. At-risk children with a BMI over the 85th percentile or with high-risk family histories should be screened for the potential health problems associated with childhood obesity. Early intervention and treatment using a staged approach with family involvement is important. Close monitoring with frequent follow-up visits increase the potential for successful intervention.

Effects of caloric restriction on cardiovascular aging in non-human primates and humans

Approximately one in three Americans has some form of cardiovascular disease (CVD), accounting for one of every 2.8 deaths in the United States in 2004. Two of the major risk factors for CVD are advancing age and obesity. An intervention able to positively impact both aging and obesity, such as caloric restriction (CR), may prove extremely useful in the fight against CVD. CR is the only environmental or lifestyle intervention that repeatedly has been shown to increase maximum life span and to retard aging in laboratory rodents. This article reviews evidence that CR in nonhuman primates and people has a positive effect on risk factors for CVD.

Effect of valsartan on left ventricular anatomy and systolic function and aortic elasticity

The objective of the study was to examine the effect of a 6-month daily treatment with 160 mg valsartan, an angiotensin II receptor blocker, on the left ventricular systolic function and aortic elasticity of patients with type 2 diabetes mellitus (T2DM) and healthy subjects. This was a prospective, randomized, double-blind, placebo-controlled crossover study. Thirteen healthy control subjects and 11 patients with T2DM were enrolled in the study. Eight control subjects and 4 T2DM patients completed the study. Cardiovascular magnetic resonance was used to evaluate the effect of valsartan on the left ventricular function and aortic elasticity. At baseline, T2DM patients had increased left ventricular mass (P = .006) when compared with the healthy controls. In the T2DM patients, treatment with valsartan, in comparison with receiving placebo, resulted in a reduction of aortic radius (P = .026) and wall thickness (P = .032) of the ascending aorta. In the abdominal aorta, valsartan treatment, when compared with placebo treatment, reduced the arterial compliance (P = .014) in the T2DM patients. Valsartan treatment for 6 months decreased the diameter and wall thickness of the ascending aorta in patients with T2DM, but may decrease AC of the abdominal aorta.

Left ventricular hypertrophy is associated with obesity, male gender, and symptoms in healthy adolescents

Obesity has been found to be associated with left ventricular (LV) hypertrophy (LVH). However, the occurrence of LVH in obese teenagers who are involved in sport programs has not been studied. The objective of this study was to evaluate the prevalence of LVH and its correlation with obesity, gender, and symptoms in teenage athletes. We used echocardiographic database of 1,500 adolescences between the ages of 12 and 20 years who were actively involved in school sport programs. We evaluated associations between obesity and LVH (defined as LV wall thickness (LVWT)) >12 mm, or LV mass (LVM) >215 g or relative wall thickness (RWT) >0.43) and physical symptoms. Using univariate and multivariate analysis, male gender was associated with increased LVWT (multivariate odds ratio (OR) 4.87, confidence interval (CI) 2.41-9.82). Obesity was associated with parameters of LVH using univariate and multivariate analysis. (LVM > 215 g) occurred in 10.32% of obese athletes vs. 0.2% (1/445) of controls, (OR 51.33, CI 6.05-433.8), P < 0.001, LVWT >12 mm occurred in 16.5% of obese students vs. 3.6% of controls (OR 5.2, CI 2.7-10.1, P < 0.001), RWT >0.43 occurred in 41.4% of obese students vs. 15.7% of controls (OR 3.78, CI 2.11-6.76, P < 0.001). After adjusting for age and gender, reported history of shortness of breath (SOB), fatigue and leg edema were also significantly more prevalent in obese students and in students with LVH. In conclusion obesity is associated with LVH in a population of healthy teenagers actively involved in sport programs. Furthermore, the presence of LVH was independently associated with many physical symptoms suggesting negative effect of LVH on myocardial function.

Uric acid and left ventricular hypertrophy in Japanese men

BACKGROUND

Experimental studies have reported that allopurinol protects hypertensive rats from left ventricular hypertrophy (LVH) with negligible effects on blood pressure (BP). Uric acid (UA) was thought to induce cardiomyocyte growth and interstitial fibrosis of the heart, partly via activation of the renin-angiotensin system. In the present study, the relationship between serum UA levels and electrocardiographically-diagnosed LVH (ECG-LVH) was examined in Japanese men not taking medication for hypertension (HTN), which could confound the association.

METHODS AND RESULTS

A total of 3,305 male workers aged 35-66 years (mean age+/-SD, 48.0+/-7.1) were studied. LVH was defined as meeting the ECG criteria (ie, Sokolow-Lyon voltage and/or Cornell voltage QRS duration product). Subjects were divided into 3 groups by tertile of serum UA level. The highest tertile (UA range 0.39-0.65 mmol/L or 6.6-11.0 mg/dl) had a significantly increased prevalence of LVH compared with the lowest tertile independent of age, body mass index, serum creatinine level, HTN, diabetes and hyperlipidemia (odds ratio 1.58, 95% confidence interval 1.23-2.02, P<0.001). Similar results were obtained in both the normal and high BP subgroups.

CONCLUSIONS

UA concentration independently and positively associated with ECG-LVH in Japanese men.

Cardiovascular Risks Associated With Obesity in Children and Adolescents

Introduction: The aim of this paper is to review the cardiovascular (CVS) risks associated with obesity in children and adolescents. Both short-term and long-term CVS consequences, the mechanisms of how these develop and the measures that can alter or reverse these CVS events are reviewed. Materials and Methods:Selected publications include original articles and review papers that report on studies of CVS risks and consequences related to childhood obesity. Some papers that contain data from adults studies are also included if the contents help to explain some underlying mechanisms or illustrate the continuation of related CVS changes into adulthood. Results: Obese children and adolescents have an increased risk for CVS complications that include elevation of blood pressure, clustering of CVS risk factors (Metabolic Syndrome), changes to arterial wall thickness, elasticity and endothelium, as well as changes in left ventricular structure and function. Some of these cardiovascular problems may be initiated or potentiated by obstructive sleep apnoea that can accompany obesity in children. Many of such changes have been noted to reverse or improve with weight reduction. Conclusions:Early development of CVS risks in obese children and the possible continuation of CVS complications into adulthood have been observed. Obstructive sleep apnoea in obese children can further contribute to such CVS risks. These findings underscore the importance of prevention of childhood obesity as a priority over management of obesity in children. The prevalence of obesity has risen by three-folds or more in many countries since 1980. In 2005, it was estimated that globally there are about 1.6 billion overweight adults and at least 400 million of them are obese. This increase in the prevalence of adults being overweight and obese comes with a heavy price. The cost of healthcare has significantly increased and is expected to increase even more because of the close association between obesity and various chronic diseases. Key words: Endothelial function, Hypertension, Metabolic syndrome, Obstructive sleep apnoea

Obese children show increased intimal wall thickness and decreased pulse wave velocity

OBJECTIVE

Childhood obesity confers an increased risk of vascular changes and adult cardiovascular disease. Using a high-resolution ultrasound technique that enables separation of intimal and medial layers, we examined the intimal thickness (IT) and intimal-medial thickness (IMT) of radial (RA) and dorsal pedal (DPA) arteries and the pulse wave velocity (PWV) in overweight/obese children and adolescents and in healthy subjects.

METHODS AND RESULTS

IT and IMT of RA and DPA and PWV were measured in 33 obese children and adolescents (13.9+/-1.6 years) and in 18 matched lean controls (14.3+/-2.2). Increased RA IT was found in the obese group, whereas no differences in RA IMT or medial thickness were observed. Obese females accounted for the entire difference in RA IT (P=0.04). DPA IT was inversely correlated with HDL cholesterol in the obese group (-0.56, P=0.0089). PWV was lower in the obese group than in the lean group (6.2+/-0.8 versus 7.0+/-0.9 m s(-1), respectively; P=0.001).

CONCLUSIONS

Obese children and adolescents, primarily females, present with increased RA IT. The decreased PWV in the obese versus lean subjects might reflect general vasodilatation.

Associations among obesity, blood pressure, and left ventricular mass

OBJECTIVES

To measure resting and ambulatory systemic blood pressure (BP) and left ventricular mass (LVM) in prepubertal obese and lean children and to determine their relationships.

STUDY DESIGN

Cross-sectional study including 44 obese and 22 lean prepubertal children (mean age 8.8 +/- 1.5 years). We measured casual and 24-hour ambulatory BP, LVM and LVM index (LVMI) by echocardiography, and whole body lean tissue and fat mass by dual-energy X-ray absorptiometry.

RESULTS

Mean 24-hour systolic BP (124.8 +/- 14.2 vs 105.5 +/- 8.8 mm Hg), diastolic BP (72.8 +/- 7.3 vs 62.7 +/- 3.8 mm Hg), and LVMI (36.1 +/- 5.8 vs 30.9 +/- 5.7, g x m(-2.7)) were significantly higher in obese than in lean subjects. Systolic ambulatory hypertension was present in 47.6% of obese children, and casual BP was normal in 55% of those cases. Body fatness, lean tissue mass, and 24-hour BP correlated positively with LVMI. When adjusted for body fatness, LVMI was only associated with 24-hour systolic BP (adjusted R(2) = 15.9%; P = .001).

CONCLUSIONS

Ambulatory systemic hypertension and increased LVM are found in obese children. Left ventricular mass is partially determined by systemic BP. We conclude that prevention and treatment of childhood obesity should be initiated as early as possible to prevent the premature development of hypertension and end-stage organ damage.

Effect of Obesity on Left Ventricular Structure and Myocardial Systolic Function: Assesment by Tissue Doppler Imaging and Strain/Strain Rate Imaging

BACKGROUND

Obesity is associated with heart failure, cardiovascular morbidity, and mortality. A direct effect of weight on left ventricle (LV) structure and myocardial function is not well-established.

AIM

The aim of our study is to determine the effect of obesity on LV morphology and systolic function by using LV standard Doppler echocardiographic indices, myocardial Doppler imaging and strain/strain rate imaging indices.

METHODS

We studied 33 obese and 34 age, sex-adjusted control subjects who had no other pathological conditions. Standard transthoracic Doppler echocardiographical measurements, reconstructed spectral pulsed wave tissue Doppler velocities, strain and strain rate imaging of six different myocardial regions were obtained. Peak systolic velocity (SR), peak systolic strain (I), peak systolic strain rate (SR) for each region and as a global systolic longitidunal LV function mean of peak systolic strain of six myocardial regions (glsca) were compared.

RESULTS

Age, body surface area, blood pressure, and heart rate were comparable between the two groups. Obese subjects had significantly increased LV end-diastolic volume, septal wall thickness, left atrial diameter, and decreased transmitral early to late diastolic velocity ratio. In obese subjects, reconstructed spectral pulsed-wave tissue Doppler analysis showed significantly decreased basal lateral peak systolic (Sm) velocity (6.68 +/- 1.89 vs. 8.08 +/- 2.50, P < 0.05), mid lateral Sm (5.01 +/- 2.17 vs. 6.78 +/- 3.22, P < 0.05). Differences in regional strain rate (mid septal SR, 1.45 +/- 0.23 vs. 1.63 +/- 0.18, P < 0.05), regional strain (basal septum I, 19.13 +/- 3.83 vs. 22.09 +/- 4.60, P < 0.05; mid-septum I, 18.03 +/- 2.91 vs. 20.25 +/- 4.77, P < 0.05; radial I, 27.50 +/- 7.32 vs. 35.53 +/- 9.48, P < 0.05), and global strain (glsca, 19.38 +/- 1.34 vs. 21.24 +/- 2.82, P < 0.05) were identified between obese and the referent subjects.

CONCLUSIONS

Obesity is associated with morphologic alterations in left ventricle and left atrium and subclinical changes in left ventricle systolic function which can be detected by strain and strain rate imaging even without overt heart disease.

Cardiovascular effects of sibutramine in the treatment of obese adolescents: results of a randomized, double-blind, placebo-controlled study

BACKGROUND

Adolescent obesity is a major public health problem. Treatment options in addition to behavioral therapy could include pharmacotherapy with sibutramine.

OBJECTIVES

Concerns regarding increases in blood pressure and heart rate after sibutramine treatment in some adult patients precipitated the present analysis, which evaluated the cardiovascular safety of sibutramine plus a behavioral therapy program in obese adolescents.

PATIENTS AND METHODS

With this 12-month, randomized, double-blind, placebo-controlled trial in 33 US clinics we studied 498 adolescents aged 12 to 16 years with multiethnic backgrounds and BMIs of 28.1 to 46.3 kg/m2.

RESULTS

The subjects were randomly assigned to behavioral therapy plus 10 mg of sibutramine or behavioral therapy plus placebo daily. At the end point, there was a mean treatment group difference in BMI of 2.6 kg/m2 in favor of sibutramine. Small mean decreases in blood pressure and pulse rate were seen in both sibutramine and placebo groups at the end point (systolic blood pressure: -2.1 vs -2.1 mmHg; diastolic blood pressure: -0.1 vs -1.1 mmHg; pulse rate: -0.2 vs -1.8 bpm). In both treatment groups, these reductions in vital signs were greater at the end point when BMI reduction was > or = 5% compared with < 5%.

CONCLUSIONS

Sibutramine may have some direct cardiovascular effects on obese adolescents. These cardiovascular effects may be balanced by a reduction in BMI, which, in adolescents, seems to be greater than that observed in adults.

Left ventricular hypertrophy in hypertensive adolescents: analysis of risk by 2004 National High Blood Pressure Education Program Working Group staging criteria

The National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents recently recommended staging hypertension (HTN) in children and adolescents based on blood pressure severity. The use of blood pressure staging and its corresponding therapeutic approach was examined in this pooled analysis assessing the risk for end-organ damage, specifically left ventricular hypertrophy among hypertensive adolescents stratified by working group criteria. Newly diagnosed hypertensive adolescents and normotensive control subjects similar in age, race/ethnicity, gender, and body mass index completed casual and 24-hour ambulatory blood pressure measurements, M-mode echocardiography, and fasting serum laboratories. Hypertensive subjects had higher insulin and cholesterol but similar glucose levels as compared with control subjects. Among subjects with stage 1 HTN by casual blood pressure, 34% had white-coat HTN as opposed to 15% of stage 2 hypertensive subjects. Of the subjects with normal casual measurements, 20% had HTN by ambulatory monitoring. Subjects with stage 2 HTN by casual measurement alone (odds ratio: 4.13; 95% CI: 1.04 to 16.48) and after 24-hour ambulatory confirmation (odds ratio: 7.23; 95% CI: 1.28 to 40.68) had increased odds for left ventricular hypertrophy. In addition, the risk for left ventricular hypertrophy was similar for subjects with masked and confirmed stage 1 HTN, whereas subjects with white-coat HTN had a risk comparable to normotensive subjects. Thus, recommendations that adolescents with stage 2 HTN by casual measurements alone receive medication initially along with therapeutic lifestyle counseling are reasonable, though ambulatory blood pressure monitoring remains a valuable tool for evaluating children with stage 2 HTN, because >10% have white-coat HTN.

24-h Systolic blood pressure and heart rate recordings in lean and obese adolescents

OBJECTIVE

We assessed the hypothesis that differences in day and night-time systolic blood pressure (SBP) and heart rate (HR) recordings were smaller in obese versus lean children and adolescents, and whether measurements obtained during a school week or during weekends or holidays influenced these nocturnal falls. We also wanted to determine whether the results were influenced by gender.

METHODS

Ambulatory 24-h BP and HR measurements were performed in 80 subjects, 51 girls and 29 boys. Lean (n = 25) and obese (n = 55) subjects were classified according to body mass index (BMI)-standard deviation (SD) criteria. Forty-eight subjects had their 24-h recordings performed during a school week and 32 during leisure time.

RESULTS

The SBP nocturnal dipping response was less pronounced in obese subjects (16.2 +/- 6.3 mmHg) compared with lean controls (21.1 +/- 5.7 mmHg) (P < 0.01) of which the girls constituted most of the difference. HR change between day and night was similar in both groups being approximately 15 b/min. A small but statistical negative correlation was observed between BMI-SD and nocturnal fall in SBP (r = -0.3, P = 0.0065). In all subjects, regardless of BMI-SD, daytime SBP was higher when readings were obtained during a school week (123 +/- 7 mmHg) than during weekends or holidays (119 +/- 7 mmHg) (P = 0.029).

CONCLUSION

Obese children and adolescents showed smaller nocturnal falls in SBP compared with lean subjects. This pattern may cause increased cardiovascular loading; thus, it may reflect an early sign of high blood pressure development and adds to cardiovascular risk in young obese individuals.

Relation of increase in adiposity to increase in left ventricular mass from childhood to young adulthood

This study evaluated the influence of adiposity on the progression of left ventricular (LV) mass from childhood to adulthood and the relation of LV mass to insulin resistance in young adulthood. One hundred thirty-two healthy children recruited into a longitudinal study at a mean age of 13 years and reevaluated at 27 years, at which time insulin resistance studies were also performed, were studied. Echocardiographic assessment of LV mass was made and indexed for height. Body mass index (BMI) at 13 years was highly correlated with BMI at 27 years, as was LV mass index at 13 and 27 years. The cross-sectional correlation of LV mass index and BMI at 13 years (r = 0.38, p < 0.0001) had strengthened considerably by 27 years (r = 0.55, p < 0.0001). A BMI increase > or = 5.5 kg/m2 from 13 to 27 years was associated with a significantly greater increase in the LV mass index (p < 0.0001) than a BMI change < 5.5 kg/m2, and this relation was similar in children who were thin and heavy at baseline. In young adulthood, the relation of LV mass index to lean mass was weaker than that of LV mass index to fat mass. The association of LV mass with insulin resistance was dependent on adiposity. In conclusion, adiposity and LV mass are related in childhood, and this association tracks and becomes stronger in young adulthood. Moreover, the increase in LV mass from childhood to young adulthood is related to the degree of increase in BMI, independent of BMI at 13 years, suggesting that an excessive increase in LV mass could be limited by controlling gain in body fat during adolescence.

Modeling physiological and anthropometric variables known to vary with body size and other confounding variables

This review explores the most appropriate methods of identifying population differences in physiological and anthropometric variables known to differ with body size and other confounding variables. We shall provide an overview of such problems from a historical point of view. We shall then give some guidelines as to the choice of body-size covariates as well as other confounding variables, and show how these might be incorporated into the model, depending on the physiological dependent variable and the nature of the population being studied. We shall also recommend appropriate goodness-of-fit statistics that will enable researchers to confirm the most appropriate choice of model, including, for example, how to compare proportional allometric models with the equivalent linear or additive polynomial models. We shall also discuss alternative body-size scaling variables (height, fat-free mass, body surface area, and projected area of skeletal bone), and whether empirical vs. theoretical scaling methodologies should be reported. We shall offer some cautionary advice (limitations) when interpreting the parameters obtained when fitting proportional power function or allometric models, due to the fact that human physiques are not geometrically similar to each other. In conclusion, a variety of different models will be identified to describe physiological and anthropometric variables known to vary with body size and other confounding variables. These include simple ratio standards (e.g., per body mass ratios), linear and additive polynomial models, and proportional allometric or power function models. Proportional allometric models are shown to be superior to either simple ratio standards or linear and additive polynomial models for a variety of different reasons. These include: 1) providing biologically interpretable models that yield sensible estimates within and beyond the range of data; and 2) providing a superior fit based on the Akaike information criterion (AIC), Bayes information criterion (BIC), or maximum log-likelihood criteria (resulting in a smaller error variance). As such, these models will also: 3) naturally lead to a more powerful analysis-of-covariance test of significance, which will 4) subsequently lead to more correct conclusions when investigating population (epidemiological) or experimental differences in physiological and anthropometric variables known to vary with body size.

Impact of Obesity on Cardiac Geometry and Function in a Population of Adolescents

OBJECTIVES

The goal here was to examine left ventricular (LV) geometry and function in a large, unselected group of adolescents with different degrees of abnormal body build, and verify whether possibly higher LV mass is compensatory for increased cardiac workload.

BACKGROUND

There is little information on how much the excess of body weight impacts LV geometry and function in populations of adolescents.

METHODS

Anthropometric, laboratory, and Doppler echocardiographic parameters of cardiac geometry and function were obtained in 460 adolescent participants (age 14 to 20 years, 245 female participants, 27 hypertensive, 10 with diabetes) from the Strong Heart Study. Body build was classified based on 85th and 95th percentiles of body mass index (BMI)-for-age charts.

RESULTS

Range of BMI was 16.3 to 56.5 kg/m2 (28.8 +/- 8.3 kg/m2); 114 participants (24.9%) fell within the 85th percentile of BMI distribution (normal weight [NW]), 113 (24.6%) fell between 85th and 95th percentile (overweight [OW]), and 223 (48.5%) fell above the 95th percentile (obese [OB]). Obese participants were older than OW and NW subjects (p < 0.01), without differences in heart rate. Both OW and OB had greater LV diameter and mass than NW (all p < 0.05). Left ventricular hypertrophy was more prevalent in the OB (33.5%) and OW (12.4%), as compared with NW participants (3.5%; p < 0.001), largely compensating increased cardiac workload. However, OB subjects had four-fold higher probability of carrying an LV mass exceeding values compensatory for their cardiac workload (p < 0.001), a feature associated with lower ejection fraction, myocardial contractility, and greater force developed by left atrium to complete LV filling (all p < 0.05).

CONCLUSIONS

While in OW adolescents increased levels of LV mass are appropriate to compensate their higher hemodynamic load, in OB increase in LV mass exceeds this need and is associated with mildly reduced LV myocardial performance and increased left atrial force to contribute to LV filling.

Association of the Ghrelin Receptor Gene Region With Left Ventricular Hypertrophy in the General Population

Growth hormone (GH) can influence left ventricular myocardial growth, structure, and function. The GH secretagogue receptor (GHSR, ghrelin receptor) is known to be involved in GH release and is expressed in the myocardium. We hypothesized that genetic variants within the GHSR are associated with parameters of left ventricular mass (LVM) and geometry. Ten single-nucleotide polymorphisms (SNPs) covering the gene region were genotyped in 1230 members of the general population (Monitoring Trends and Determinants on Cardiovascular Diseases Augsburg Echocardiographic Substudy). Linkage disequilibrium analysis revealed a linkage disequilibrium block consisting of 5 SNPs forming 2 common haplotypes. One haplotype was found significantly more often in subjects without left ventricular hypertrophy ([LVH] 69% versus 59%; permutated P =0.0015), whereas the second haplotype was significantly more frequent in individuals with LVH (32% versus 26%; P =0.019). Homozygous subjects presented with an increase of risk with respect to all heart size parameters. A significantly increasing frequency of the risk haplotype could be observed from the lowest (20.9%) to the highest quintile (31.0%) of gender-specific LVM distributions ( P =0.0096). We found association of the minor alleles of individual single nucleotide polymorphisms contributing to the haplotypes with higher LVM indices, septal wall thickness, and different LVH criteria consistent in men and women in matched cases and controls (LVM, women: 144.8±30.9 [noncarrier] versus 171.3±36.0 [homozygous], P =0.001; men: 186.7±42.4 versus 236.3±64.5, P =0.002). These data suggest that common variants in the GHSR region are associated with parameters of LVM and geometry independent of blood pressure and body mass in the general population and, thus, may be involved in the pathogenesis of LVH.

Determination of the ability of high-frequency ECG to estimate left ventricular mass in humans, determined by magnetic resonance imaging

BACKGROUND

Previous studies have shown a significantly higher correlation between left ventricular mass index (LVMi) and high-frequency QRS components (HF-QRS) than between LVMi and QRS amplitudes in the standard frequency range in rabbits. The purpose of the present study was to compare ECG measurements from standard and high-frequency ranges with left ventricular mass (LVM) and LVMi determined by magnetic resonance imaging in humans.

METHODS

Sixty-two normal subjects were studied. Signal-averaged ECGs from the 12 standard leads were analysed in the standard frequency range (0.05-150 Hz), in the middle (25-100 Hz) and high end (50-150 Hz) of the standard frequency range and in the 150-250 Hz range. Root-mean square (RMS) values from the HF-QRS and QRS amplitude measurements from the standard ECGs were compared with LVM and LVMi.

RESULTS

The correlations between LVMi and HF-QRS were similar to those between LVMi and standard ECG. When regarding LVM, however, the correlations found in the standard ECG were higher than those found in HF-QRS.

CONCLUSIONS

Contrary to previous results in animals, we found in humans no better correlation between HF-QRS and LVM/LVMi than between standard ECG and LVM/LVMi.

Therapy Insight: weight-loss surgery and major cardiovascular risk factors

Weight-loss surgery is an effective treatment for severe, medically complicated and refractory obesity. It reverses, eliminates or significantly ameliorates major cardiovascular risk factors related to obesity. In a large proportion of patients, the therapy produces significant weight loss, reduces the risk of disability and premature death, and improves quality of life. Surgical treatment by gastric-restrictive and malabsorptive procedures started several decades ago in the US. Since the 1970s, accrued clinical experience and advances in technology, particularly in minimally invasive surgical approaches, have changed this therapy. Some procedures have evolved, whereas others have become obsolete. Today's weight-loss operations are safe, effective and potentially life-saving options for severely obese cardiology patients. This review describes weight-loss surgery procedures and their effects on cardiovascular risk factors.