Role of the Metabolic Profile in Mediating the Relationship Between Body Mass Index and Left Ventricular Mass in Adolescents: Analysis of a Prospective Cohort Study

Associations between long-term averages of metabolic parameters in adulthood and cardiac structure and function in later life

The effects of long-term levels of body mass index (BMI), blood pressure (BP), plasma lipids and fasting blood glucose (FBG) on the cardiac structure and function in later life in general population are to evaluate. We included adult participants without heart failure from Framingham Heart Study. The respective averages over a span of 30-36 years of seven parameters were pooled into linear regression models simultaneously to evaluate their associations with subsequent left atrial internal dimension (LAID), left ventricular mass index (LVMi), internal dimension (LVID), ejection fraction (LVEF), global longitudinal strain (GLS) and mitral inflow velocity to early diastolic mitral annular velocity (E/é). In 1838 participants (56.0% female, mean age 66.1 years), per 1-standard deviation (SD) increment of mean BMI correlated with larger LAID and LVID (β 0.05~0.17, standard error [SE] 0.01 for all), greater LVMi (β [SE], 1.49 [0.46]), worse E/é (β [SE], 0.28 [0.05]). Per 1-SD increment of mean systolic BP correlated with greater LVMi (β [SE], 4.70 [0.69]), LVEF (β [SE], 0.73 [0.24]), E/é (β [SE], 0.52 [0.08]), whereas increase of mean diastolic BP correlated with smaller LVMi (β [SE], -1.61 [0.62]), LVEF (β [SE], -0.46 [0.22]), E/é (β [SE], -0.30 [0.07]). Per 1-SD increment of mean high density lipoprotein cholesterol (HDL-c) correlated with smaller LVID (β [SE], -0.03 [0.01]) and better systolic function (LVEF, β [SE], 0.63 [0.19]; GLS, β [SE], -0.20 [0.10]). The variabilities of BMI, BP and HDL-c also correlated with certain cardiac measurements. In long-term, BMI affected the size and mass of heart chambers, systolic and diastolic BP differently influenced left ventricular mass and function, higher HDL-c linked to better systolic function. Clinical trial registration: URL: https://clinicaltrials.gov . Identifier: NCT00005121.

Preserved Ratio Impaired Spirometry, Metabolomics, and the Risk of Type 2 Diabetes

CONTEXT

Whether baseline preserved ratio impaired spirometry (PRISm) is associated with the risk of developing type 2 diabetes (T2D) and if this association could be mediated by circulating metabolites remains to be elucidated.

OBJECTIVE

To measure the prospective association of PRISm with T2D and potential metabolic mediators thereof.

METHODS

This study used data from the UK Biobank and included 72 683 individuals without diabetes at baseline. PRISm was defined as the predicted forced expiratory volume in 1 second (FEV1) <80% and the FEV1/forced vital capacity ratio ≥0.70. Cox proportional hazards modeling was performed to assess the longitudinal relation between baseline PRISm and incident T2D. Mediation analysis was used to explore the mediation effects of circulating metabolites in the path from PRISm to T2D.

RESULTS

During a median follow-up of 12.06 years, 2513 participants developed T2D. Individuals who had PRISm (N = 8394) were 47% (95% CI, 33%-63%) more likely to develop T2D compared with those who had normal spirometry (N = 64 289). A total of 121 metabolites showed statistically significant mediation effects in the path from PRISm to T2D (false discovery rate <0.05). Glycoprotein acetyls, cholesteryl esters in large high-density lipoprotein (HDL), degree of unsaturation, cholesterol in large HDL, and cholesteryl esters in very large HDL were the top 5 metabolic markers, with mediation proportions (95% CI) being 11.91% (8.76%-16.58%), 11.04% (7.34%-15.55%), 10.36% (7.34%-14.71%), 9.87% (6.78%-14.09%), and 9.51% (6.33%-14.05%), respectively. A total of 11 principal components that explained 95% variance of the metabolic signatures accounted for 25.47% (20.83%-32.19%) of the relation between PRISm and T2D.

CONCLUSIONS

Our study revealed the association of PRISm with T2D risk and the potential roles of circulating metabolites in mediating this association.

Ischaemic events in hypertrophic cardiomyopathy patients with and without atrial fibrillation: a systematic review and meta-analysis

Hypertrophic cardiomyopathy predisposes to acute cerebrovascular events including ischaemic stroke, transient ischaemic attack and systemic thromboembolism. Atrial fibrillation confers even higher risk. We aim to report the incidence of these complications and to investigate the impact of atrial fibrillation on the ischaemic risk in patients with hypertrophic cardiomyopathy. A literature search was performed on PubMed, Scopus, Embase/Ovid and Cochrane library from inception to 20th March 2021. We compared the incidence of ischaemic strokes, transient ischaemic attack, non-specified thromboembolism events and systemic thromboembolism in hypertrophic cardiomyopathy patients with or without atrial fibrillation. Non-specified thromboembolism events in our paper referred to thromboembolic events whereby types were not specified in the studies. Meta-analysis was performed using StataSE 16 software, and heterogeneity was assessed using I² test. A total of 713 studies were identified. Thirty-five articles with 42,570 patients were included. The pooled incidence of stroke/ transient ischaemic attack was 7.45% (95% confidence interval [CI] 5.80-9.52, p < 0.001) across 24 studies with a total of 37,643 hypertrophic cardiomyopathy patients. Atrial fibrillation significantly increased the risk of total stroke/ transient ischaemic attack (Risk Ratio 3.26, 95% CI 1.75-6.08, p < 0.001, I² = 76.0). The incidence of stroke/ transient ischaemic attack was 9.30% (95% CI 6.64-12.87, p = 0.316) in the apical hypertrophic cardiomyopathy subgroup. Concomitant atrial fibrillation in hypertrophic cardiomyopathy increases the risk of thromboembolic events including ischaemic stroke and transient ischaemic attack. The apical subgroup shows a similar risk of acute cerebrovascular events as the overall hypertrophic cardiomyopathy population.

Case report: Diagnosis of apical hypertrophic cardiomyopathy that escaped clinical and echocardiographic investigations for twenty years: Reasons and clinical implications

Background

Apical hypertrophic cardiomyopathy (ApHCM) is a rare form of hypertrophic cardiomyopathy which predominantly affects the apex of the left ventricle. The diagnosis can be challenging due to several factors, ranging from no typical clinical and electrocardiogram (EKG) findings to potential difficulties in executing and interpreting the echocardiographic examination.

Case presentation

We report the case of an 84-year-old woman who came to our echo-lab to undergo a routine echocardiogram. She had a history of permanent atrial fibrillation, paced rhythm and previous episodes of heart failure (HF), allegedly explained by a diagnosis of hypertensive heart disease that had been confirmed many times over the previous 20 years. The clinical examination and the EKG were unremarkable. The echocardiographic images were poor quality. But a senior cardiologist, expert in imaging and echocardiography, noted the lack of delineation of the endocardial border of the left ventricular (LV) apex region. Contrast echocardiography was performed and severe apical hypertrophy discovered.

Conclusion

ApHCM can be a challenging diagnosis. Contrast echocardiography must always be applied in cases of poor delineation of the LV apical endocardial border at baseline echocardiography. Timely detection and appropriate lifestyle intervention might slow the development of LV hypertrophy, and possibly minimize and delay heart failure (HF) related symptoms and arrhythmias. The prognosis remains relatively benign during long term follow-up.

Role of the Metabolic Profile in Mediating the Relationship Between Body Mass Index and Left Ventricular Mass in Adolescents: Analysis of a Prospective Cohort Study

Background We aimed to quantify the role of the plasma metabolic profile in explaining the effect of adiposity on cardiac structure. Methods and Results Body mass index (BMI) was measured at age 11 in the Avon Longitudinal Study of Parents and Children. Left ventricular mass indexed to height^2.7 (LVMI) was assessed by echocardiography at age 17. The metabolic profile was quantified via ¹H-nuclear magnetic resonance spectroscopy at age 15. Multivariable confounder (maternal age, parity, highest qualification, maternal smoking, prepregnancy BMI, prepregnancy height, household social class, adolescent birthweight, adolescent smoking, fruit and vegetable consumption, and physical activity)-adjusted linear regression estimated the association of BMI with LVMI and mediation by metabolic traits. We considered 156 metabolomic traits individually and jointly as principal components explaining 95% of the variance in the nuclear magnetic resonance platform and assessed whether the principal components for the metabolic traits added to the proportion of the association explained by putative cardiovascular risk factors (systolic and diastolic blood pressures, insulin, triglycerides, low-density lipoprotein cholesterol, and glucose). A 1 kg/m² higher BMI was associated with a 0.70 g/m^2.7 (95% CI, 0.53-0.88 g/m^2.7) and 0.66 g/m^2.7 (95% CI, 0.53-0.79 g/m^2.7) higher LVMI in males (n=437) and females (n=536), respectively. Putative risk factors explained 3% (95% CI, 2%-5%) of this association in males, increasing to 10% (95% CI, 8%-13%) when including metabolic principal components. In females, the standard risk factors explained 3% (95% CI, 2%-5%) of the association and did not increase when including the metabolic principal components. Conclusions The addition of the nuclear magnetic resonance-measured metabolic traits appears to mediate more of the association of BMI on LVMI than the putative risk factors alone in adolescent males, but not females.