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

Association between insulin resistance and cardiac remodeling in HER2-positive breast cancer patients: a real-world study

BACKGROUND

Insulin resistance is an overlapping risk factor for both heart and breast cancer, while its interaction with cardiotoxicity in breast cancer (BC) patients is not clear. This study investigated the impact of insulin resistance on cardiac remodeling in patients with human epidermal growth factor receptor 2 (HER2)-positive BC during and after trastuzumab therapy in real-world clinical practice.

METHODS

HER2-positive BC patients who received trastuzumab treatment between December 2012 and December 2017 were reviewed and 441 patients with baseline metabolic indices and serial echocardiographic measurements (baseline, 6, 12, and 18 months) after trastuzumab therapy initiation were included. Repeated measurement analysis of variance was used to evaluate temporal trends in multiparameter echocardiography. Linear mixed model was applied to further evaluate the role of insulin resistance in forementioned changes. Correlation of homeostasis model assessment-estimated insulin resistance (HOMA-IR) and triglyceride-glucose index (TyG) levels to changes in echocardiography parameters was explored.

RESULTS

Of 441 patients (mean age 54 ± 10 [SD] years), 61.8% received anthracycline-based chemotherapy, 33.5% received left-sided radiotherapy, 46% received endocrine therapy. No symptomatic cardiac dysfunction was observed over the therapy course. A total of 19 (4.3%) participants experienced asymptomatic cancer therapy-related cardiac dysfunction (CTRCD), and the peak onset time was 12 months after the initiation of trastuzumab. Albeit relatively low CTRCD incidence, cardiac geometry remodeling, especially left atrial (LA) dilation over therapy was notable and was more severe in high HOMA-IR and TyG level groups (P < 0.01). Noteworthy, a partial reversibility of cardiac remodeling was observed with treatment cessation. Additionally, HOMA-IR level positively correlated to changes in LA diameter from baseline to 12 months (r = 0.178, P = 0.003). No significant association (all P > 0.10) was detected between HOMA-IR or TyG level and dynamic left ventricular parameter evaluation. Multivariate linear regression analysis demonstrated that higher HOMA-IR level was an independent determinant for LA enlargement in BC patients during anti-HER2 targeted therapy course after adjusting for confounding risk factors (P = 0.006).

CONCLUSION

Insulin resistance was associated with left atrial adverse remodeling (LAAR) in HER2-positive BC patients that received standard trastuzumab therapy, indicating that insulin resistance could be a supplementation to baseline cardiovascular risk stratification proforma for HER2-targeted antitumor therapies.

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.

Composition and Functions of the Gut Microbiome in Pediatric Obesity: Relationships with Markers of Insulin Resistance

The gut microbiome is hypothesized to play a crucial role in the development of obesity and insulin resistance (IR); the pathways linking the microbiome to IR in pediatrics have yet to be precisely characterized. We aimed to determine the relationship between the gut microbiome composition and metabolic functions and IR in children with obesity. In a cross-sectional study, fecal samples from children with obesity (10-16 years old) were collected for taxonomical and functional analysis of the fecal microbiome using shotgun metagenomics. The homeostatic model assessment for insulin resistance (HOMA-IR) was determined using fasting glucose and insulin. Associations between HOMA-IR and α-diversity measures as well as metabolic pathways were evaluated using Spearman correlations; relationships between HOMA-IR and β-diversity were assessed by permutational multivariate analysis of variance. Twenty-one children (nine males; median: age = 12.0 years; BMI z-score = 2.9; HOMA-IR = 3.6) completed the study. HOMA-IR was significantly associated with measures of α-diversity but not with β-diversity. Children with higher HOMA-IR exhibited lower overall species richness, Firmicutes species richness, and overall Proteobacteria species Shannon diversity. Furthermore, HOMA-IR was inversely correlated with the abundance of pathways related to the biosynthesis of lipopolysaccharides, amino acids, and short-chain fatty acids, whereas positive correlations between HOMA-IR and the peptidoglycan biosynthesis pathways were observed. In conclusion, insulin resistance was associated with decreased microbial α-diversity measures and abundance of genes related to the metabolic pathways. Our study provides a framework for understanding the microbial alterations in pediatric obesity.

The impact of obesity on left ventricular hypertrophy and diastolic dysfunction in children and adolescents

Childhood obesity continues to escalate worldwide and may affect left ventricular (LV) geometry and function. The aim of this study was to investigate the impact of obesity on prevalence of left ventricular hypertrophy (LVH) and diastolic dysfunction in children. In this analysis of prospectively collected cross-sectional data of children between 5 and 16 years of age from randomly selected schools in Peru, parameters of LV geometry and function were compared according to presence or absence of obesity (body mass index z-score > 2). LVH was based on left ventricular mass index (LVMI) adjusted for age and sex and defined by a z-score of > 2. LV diastolic function was assessed using mitral inflow early-to-late diastolic flow (E/A) ratio, peak early diastolic tissue velocities of the lateral mitral annulus (E′), early diastolic transmitral flow velocity to tissue Doppler mitral annular early diastolic velocity (E/E′) ratio, and left atrial volume index (LAVI). Among 1023 children, 681 children (mean age 12.2 ± 3.1 years, 341 male (50.1%)) were available for the present analysis, of which 150 (22.0%) were obese. LVH was found in 21 (14.0%) obese and in 19 (3.6%) non-obese children (p_adjusted < 0.001). LVMI was greater in obese than that in non-obese children (36.1 ± 8.6 versus 28.7 ± 6.9 g/m^2.7, p < 0.001). The mean mitral E/E′ ratio and LAVI were significantly higher in obese than those in non-obese individuals (E/E′: 5.2 ± 1.1 versus 4.9 ± 0.8, p_adjusted = 0.043; LAVI 11.0 ± 3.2 versus 9.6 ± 2.9, p_adjusted = 0.001), whereas E′ and E/A ratio were comparable. Childhood obesity was associated with left ventricular hypertrophy and determinants of diastolic dysfunction.

ClinicalTrials.gov Identifier: NCT02353663.

Correlation of P-wave dispersion with insulin sensitivity in obese adolescents

BACKGROUND

P-wave dispersion is a new and simple electrocardiographic marker that has been reported to be associated with inhomogeneous and discontinuous propagation of sinus impulses. In the present study, we evaluated P-wave dispersion in obese adolescents and investigated the relationship between P-wave dispersion, cardiovascular risk factors, and echocardiographic parameters.

METHODS

We carried out a case-control study comparing 150 obese adolescents and 50 healthy controls. Maximum and minimum P-wave durations were measured using a 12-lead surface electrocardiogram, and P-wave dispersion was calculated as the difference between these two measures. Echocardiographic examination was also performed for each subject. Multivariate linear regression analysis with stepwise variable selection was used to evaluate parameters associated with increased P-wave dispersion in obese subjects.

RESULTS

Maximum P-wave duration and P-wave dispersion were significantly higher in obese adolescents than control subjects (143±19 ms versus 117±20 ms and 49±15 ms versus 29±9 ms, p<0.0001 for both). P-wave dispersion was positively correlated with body mass index, waist and hip circumferences, systolic and diastolic blood pressures, total cholesterol, serum levels of low-density lipoprotein cholesterol, triglycerides, glucose, and insulin, homoeostasis model assessment for insulin resistance score, left ventricular mass, and left atrial dimension. P-wave dispersion was negatively correlated with high-density lipoprotein cholesterol levels. By multiple stepwise regression analysis, left atrial dimension (β: 0.252, p=0.008) and homoeostasis model assessment for insulin resistance (β: 0.205; p=0.009) were independently associated with increased P-wave dispersion in obese adolescents.

CONCLUSIONS

Insulin resistance is a significant, independent predictor of P-wave dispersion in obese adolescents.

Atrial chamber remodelling in healthy pre-adolescent athletes engaged in endurance sports: A study with a longitudinal design. The CHILD study

AIMS

Previous studies investigated the exercise-induced adaptation of left (LA) and right atrium (RA) in adults, but little is known about respective changes in the growing heart of children. We aimed to longitudinally investigate the effects of endurance training on biatrial remodelling in preadolescent athletes.

METHODS AND RESULTS

Ninety-four children (57 endurance athletes, 37 sedentary controls; mean age 10.8±0.2 and 10.2±0.2years, respectively) were evaluated at baseline and after 5months by ECG and by two-dimensional, three-dimensional (3D) and speckle-tracking echocardiography. Athletes were trained at least 10h/week. The resting heart rate was lower in athletes (p=0.046) and decreased further after training (p<0.0001). Neither athletes nor controls had ECG evidence for LA or RA enlargement. At baseline, indexed LA volumes did not differ between groups (p=0.14) but indexed RA dimensions were larger in athletes (p=0.007). After 5months, indexed LA volumes increased in athletes but not in controls (p<0.0001, p=0.29; respectively) while indexed RA volumes increased in both groups (p<0.0001, p=0.018; respectively). At the same time, slight differences in biatrial reservoir and contractile function were found either in athletes, as demonstrated by speckle-tracking echocardiography, but 3D-derived LA and RA ejection fraction remained stable in both groups.

CONCLUSION

Endurance training influences the growing heart of preadolescent athletes with an additive increase in biatrial size, suggesting that morphological adaptations can occur also in the early phases of the sports career. Training-induced remodelling was associated with a preserved biatrial function, supporting the hypothesis of a physiological remodelling.