Assessing the causal role of body mass index on cardiovascular health in young adults: Mendelian randomization and recall-by-genotype analyses

Association of Anthropometric Indices With Midlife Cardiovascular Risk in Young Individuals Without Obesity and Traditional Risk Factors

BACKGROUND

The aim of this study was to assess how early-adulthood body mass index (BMI) and waist circumference (WC) relate to long-term cardiovascular structure, function, and prognosis in individuals without obesity and with low cardiovascular risk factor (CVRF) burden.

METHODS AND RESULTS

A total of 2024 participants aged 18 to 30 from the CARDIA (Coronary Artery Risk Development in Young Adults) study, without obesity and with low CVRFs defined as the absence of cardiovascular disease (CVD), diabetes, hypertension, current smoking, and dyslipidemia were included. A CVRF-optimal subgroup was also defined, with blood pressure<120/80 mm Hg, fasting glucose <100 mg/dL, total cholesterol <200, low-density lipoprotein cholesterol <130, and women with high-density lipoprotein cholesterol ≥50 mg/dL. Coronary artery calcification, carotid intima-media thickness, left ventricular mass, left ventricular ejection fraction, longitudinal peak systolic strain, and diastolic function were assessed in midlife. Cox regression was used to calculate hazard ratios of BMI and WC for all-cause death and CVD events. Logistic regression was used to estimate odds ratios for subclinical CVD. Over 33.9 years (median follow-up), 5.2% (n=105) died, and 2.6% (n=52) had CVD events. Each 1-SD BMI increase was associated with 27% (95% CI, 1.10-1.47), 24% (1.08-1.43), 42% (1.20-1.68), 28% (1.05-1.57), 51% (1.20-1.90), and 49% (1.10-2.02) higher odds of coronary artery calcification presence, increased carotid intima-media thickness, left ventricular hypertrophy, reduced left ventricular ejection fraction, low longitudinal peak systolic strain, and diastolic dysfunction, respectively, in the CVRF-low group. Generally, similar associations were found for WC and in the CVRF-optimal subgroup. No significant associations between BMI and WC with CVD and death were found.

CONCLUSIONS

Elevations in BMI and WC among young low-risk individuals, even within the nonobesity range, are associated with midlife cardiovascular health.

KAT8 beyond Acetylation: A Survey of Its Epigenetic Regulation, Genetic Variability, and Implications for Human Health

Lysine acetyltransferase 8, also known as KAT8, is an enzyme involved in epigenetic regulation, primarily recognized for its ability to modulate histone acetylation. This review presents an overview of KAT8, emphasizing its biological functions, which impact many cellular processes and range from chromatin remodeling to genetic and epigenetic regulation. In many model systems, KAT8's acetylation of histone H4 lysine 16 (H4K16) is critical for chromatin structure modification, which influences gene expression, cell proliferation, differentiation, and apoptosis. Furthermore, this review summarizes the observed genetic variability within the KAT8 gene, underscoring the implications of various single nucleotide polymorphisms (SNPs) that affect its functional efficacy and are linked to diverse phenotypic outcomes, ranging from metabolic traits to neurological disorders. Advanced insights into the structural biology of KAT8 reveal its interaction with multiprotein assemblies, such as the male-specific lethal (MSL) and non-specific lethal (NSL) complexes, which regulate a wide range of transcriptional activities and developmental functions. Additionally, this review focuses on KAT8's roles in cellular homeostasis, stem cell identity, DNA damage repair, and immune response, highlighting its potential as a therapeutic target. The implications of KAT8 in health and disease, as evidenced by recent studies, affirm its importance in cellular physiology and human pathology.

Hemodynamic and Metabolic Responses to Moderate and Vigorous Cycle Ergometry in Men Who Have Had Transtibial Amputation

Adults who have had an amputation face barriers to having an active lifestyle which attenuates cardiorespiratory fitness. Prior studies in amputees typically involve treadmill walking or arm ergometry, yet physiological responses to bilateral leg cycling are less understood. This study assessed the hemodynamic and metabolic responses to moderate and vigorous cycle ergometry in men who have had a transtibial amputation (TTA). Five men who had had a unilateral TTA (age = 39 ± 15 yr) and six controls (CONs) without an amputation (age = 31 ± 11 yr) performed two 20 min bouts of cycling differing in intensity. Cardiac output (CO), stroke volume (SV), and oxygen consumption (VO2) were measured during moderate intensity continuous exercise (MICE) and high intensity interval exercise (HIIE) using thoracic impedance and indirect calorimetry. In response to MICE and HIIE, the HR and VO2 levels were similar (p > 0.05) between groups. Stroke volume and CO were higher (p < 0.05) in the CONs, which was attributed to their higher body mass. In men with TTAs, HIIE elicited a peak HR = 88%HRmax and substantial blood lactate accumulation, representing vigorous exercise intensity. No adverse events were exhibited in the men with TTAs. The men with TTAs show similar responses to MICE and HIIE versus the CONs.

Genome-wide analysis reveals extensive genetic overlap between childhood phenotypes and later-life type 2 diabetes

Observational studies have indicated a potential influence of childhood phenotypes on the later development of type 2 diabetes (T2D). However, the underlying biological mechanisms remain unclear. In this study, we conducted a comprehensive genome-wide analysis to investigate the shared genetic architecture and genetic loci between nine childhood phenotypes (N = 4202-620,26) and later-life T2D (N = 80,154) using genetic correlation, mendelian randomization (MR), and conjunctional false discovery rate (conjFDR) statistical frameworks. Our findings demonstrated substantial genetic correlations and pleiotropic enrichment between childhood obesity, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), and later-life T2D. Childhood obesity exhibited a significant association with increased later-life T2D risk through 10 mediators, 6 of which were adulthood obesity-related phenotypes. Additionally, we identified 69, 83, 3, 5, 10, 5, 3, and 7 loci shared between childhood obesity, BMI, SBP, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein A-I (ApoA-I), apolipoprotein B (ApoB), and T2D at conjFDR <0.05, with the majority of these loci being novel discoveries. Overall, our study reveals extensive genetic overlap between childhood obesity-related phenotypes and T2D with concordant effect directions, shedding new light on variants and phenotypes with lifelong effects.

Longitudinal effects of FTO gene polymorphism on body composition, cardiorespiratory fitness, physical activity, inflammatory markers, and cardiovascular risk in children and adolescents. "The UP & DOWN study"

The role of polymorphism rs9939609 of the FTO gene has been related with fat mass and cardiovascular risk in adults, but it remains unclear in children and adolescents. Hence, the main aim of this study was to determine the FTO polymorphism effects on body composition, cardiorespiratory fitness (CRF), physical activity (PA), inflammatory markers, and cardiovascular risk both in cross-sectional analysis and after two-years of follow-up in children and adolescents. A total of 2129 participants were included in this study. The rs9939609 polymorphism was genotyped. Body composition measurements, CRF, and moderate-to-vigorous PA (MVPA) were determined at baseline and after two-year of follow-up. Moreover, plasma leptin and adiponectin were also determined as inflammatory markers. Furthermore, an index of cardiovascular disease risk factors (CVDRF-I) was calculated. Codominant (TT vs. TA vs. AA) and dominant (AA+AT vs. TT) models were applied for statistical analysis. The results showed a main effect of the FTO genotype on body composition measures in both first and third year (p < 0.05), with lower adiposity in TT compared with AA or AA+AT group. These differences were maintained after accounting for pubertal maturity, sex, age, VO2 max, and MVPA. Moreover, lower leptin level was observed in TT compared to AA+AT group in the third year. An interaction in Gene*Time*Sex was found in height and neck circumference in dominant model (p = 0.047; p = 0.020, respectively). No differences were found in CRF, MVPA nor CVDRF-I between groups. Hence, homozygous TT allele could be a protective factor against weight gain from early childhood.

The burden of untreated insomnia disorder in a sample of 1 million adults: a cohort study

BACKGROUND

Insomnia disorder is a highly prevalent, significant public health concern associated with substantial and growing health burden. There are limited real-world data assessing the burden of insomnia disorder on daytime functioning and its association with comorbidities. The objective of this study was to leverage large-scale, real-world data to assess the burden of untreated insomnia disorder in terms of daytime impairment and clinical outcomes.

METHODS

This United States medical claims database study compares patients diagnosed with insomnia disorder but not receiving treatment ('untreated insomnia' cohort) to patients without an insomnia disorder diagnosis and without treatment ('non-insomnia' cohort). International Classification of Disease, Tenth Revision codes were used as a proxy to represent the three symptom domains (Sleepiness, Alert/Cognition, Mood) of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ), a newly developed and validated tool used in clinical studies to assess daytime functioning in insomnia disorder. Chronic Fatigue (R53.83) and Other Fatigue (R53.83), Somnolence (R40.0) and Disorientation (R41.0) were selected as categories representing one or more IDSIQ domains. Clinical outcomes included cardiovascular events, psychiatric disorders, cognitive impairment and metabolic disorders.

RESULTS

Approximately 1 million patients were included (untreated insomnia: n = 139,959; non-insomnia: n = 836,975). Compared with the 'non-insomnia' cohort, the 'untreated insomnia' cohort was more likely to experience daytime impairments, with mean differences in occurrences per 100 patient-years for: (a) fatigue, at 27.35 (95% confidence interval [CI] 26.81, 27.77, p < 0.01); (b) dizziness, at 4.66 (95% CI 4.40, 4.90, p < 0.01); (c) somnolence, at 4.18 (95% CI 3.94, 4.43, p < 0.01); and (d) disorientation, at 0.92 (95% CI 0.77, 1.06, p < 0.01). During the 1-year look-back period, patients in the 'untreated insomnia' cohort were also more likely to have been diagnosed with arterial hypertension (40.9% vs. 26.3%), psychiatric comorbidities (40.1% vs. 13.2%), anxiety (29.2% vs. 8.5%), depression (26.1% vs. 8.1%) or obesity (21.3% vs. 11.1%) compared with those in the 'non-insomnia' cohort.

CONCLUSIONS

This large-scale study confirms the substantial burden of insomnia disorder on patients in a real-world setting, with significant daytime impairment and numerous comorbidities. This reinforces the need for timely insomnia disorder diagnosis and treatments that improve both sleep, as well as daytime functioning.

From target discovery to clinical drug development with human genetics

The substantial investments in human genetics and genomics made over the past three decades were anticipated to result in many innovative therapies. Here we investigate the extent to which these expectations have been met, excluding cancer treatments. In our search, we identified 40 germline genetic observations that led directly to new targets and subsequently to novel approved therapies for 36 rare and 4 common conditions. The median time between genetic target discovery and drug approval was 25 years. Most of the genetically driven therapies for rare diseases compensate for disease-causing loss-of-function mutations. The therapies approved for common conditions are all inhibitors designed to pharmacologically mimic the natural, disease-protective effects of rare loss-of-function variants. Large biobank-based genetic studies have the power to identify and validate a large number of new drug targets. Genetics can also assist in the clinical development phase of drugs-for example, by selecting individuals who are most likely to respond to investigational therapies. This approach to drug development requires investments into large, diverse cohorts of deeply phenotyped individuals with appropriate consent for genetically assisted trials. A robust framework that facilitates responsible, sustainable benefit sharing will be required to capture the full potential of human genetics and genomics and bring effective and safe innovative therapies to patients quickly.

Whole-Body Magnetic Resonance Imaging Assessment of the Contributions of Adipose and Nonadipose Tissues to Cardiovascular Remodeling in Adolescents

Background Greater body mass index is associated with cardiovascular remodeling in adolescents. However, body mass index cannot differentiate between adipose and nonadipose tissues. We examined how visceral and subcutaneous adipose tissue are linked with markers of early cardiovascular remodeling, independently from nonadipose tissue. Methods and Results Whole-body magnetic resonance imaging was done in 82 adolescents (39 overweight/obese; 36 female; median age, 16.3 [interquartile range, 14.4-18.1] years) to measure body composition and cardiovascular remodeling markers. Left ventricular diastolic function was assessed by echocardiography. Waist, waist:height ratio, and body mass index z scores were calculated. Residualized nonadipose tissue, subcutaneous adipose tissue, and visceral adipose tissue variables, uncorrelated with each other, were constructed using partial regression modeling to allow comparison of their individual contributions in a 3-compartment body composition model. Cardiovascular variables mostly related to nonadipose rather than adipose tissue. Nonadipose tissue was correlated positively with left ventricular mass (r=0.81), end-diastolic volume (r=0.70), stroke volume (r=0.64), left ventricular mass:end-diastolic volume (r=0.37), and systolic blood pressure (r=0.35), and negatively with heart rate (r=-0.33) (all P<0.01). Subcutaneous adipose tissue was associated with worse left ventricular diastolic function (r=-0.42 to -0.48, P=0.0007-0.02) and higher heart rates (r=0.34, P=0.007) but linked with better systemic vascular resistance (r=-0.35, P=0.006). There were no significant relationships with visceral adipose tissue and no associations of any compartment with pulse wave velocity. Conclusions Simple anthropometry does not reflect independent effects of nonadipose tissue and subcutaneous adipose tissue on the adolescent cardiovascular system. This could result in normal cardiovascular adaptations to growth being misinterpreted as pathological sequelae of excess adiposity in studies reliant on such measures.

Temporal relationships between BMI and obesity-related predictors of cardiometabolic and breast cancer risk in a longitudinal cohort

Prospective inter-relationships among biomarkers were unexplored, which may provide mechanistic insights into diseases. We investigated the longitudinal associations of BMI change with trajectories of biomarkers related to cardiometabolic or breast cancer risk. A longitudinal study was conducted among 444 healthy women between 2019 to 2021. Cross‑lagged path analysis was used to examine the temporal relationships among BMI, cardiometabolic risk score (CRS), and obesity‑related proteins score (OPS) of breast cancer. Linear mixed-effect models were applied to investigate associations of time-varying BMI with biomarker-based risk score trajectories. Baseline BMI was associated with subsequent change of breast cancer predictors (P = 0.03), and baseline CRS were positively associated with OPS change (P < 0.001) but not vice versa. After fully adjustment of confounders, we found a 0.058 (95%CI = 0.009-0.107, P = 0.020) units increase of CRS and a 1.021 (95%CI = 0.041-1.995, P = 0.040) units increase of OPS as BMI increased 1 kg/m² per year in postmenopausal women. OPS increased 0.784 (95%CI = 0.053-1.512, P = 0.035) units as CRS increased 1 unit per year. However, among premenopausal women, BMI only significantly affected CRS (β = 0.057, 95%CI = 0.007 to 0.107, P = 0.025). No significant change of OPS with time-varying CRS was found. Higher increase rates of BMI were associated with worse trajectories of biomarker-based risk of cardiometabolic and breast cancer. The longitudinal impact of CRS on OPS is unidirectional. Recommendations such as weight control for the reduction of cardiometabolic risk factors may benefit breast cancer prevention, especially in postmenopausal women.

A multivariate genome-wide association study of psycho-cardiometabolic multimorbidity

Coronary artery disease (CAD), type 2 diabetes (T2D) and depression are among the leading causes of chronic morbidity and mortality worldwide. Epidemiological studies indicate a substantial degree of multimorbidity, which may be explained by shared genetic influences. However, research exploring the presence of pleiotropic variants and genes common to CAD, T2D and depression is lacking. The present study aimed to identify genetic variants with effects on cross-trait liability to psycho-cardiometabolic diseases. We used genomic structural equation modelling to perform a multivariate genome-wide association study of multimorbidity (Neffective = 562,507), using summary statistics from univariate genome-wide association studies for CAD, T2D and major depression. CAD was moderately genetically correlated with T2D (rg = 0.39, P = 2e-34) and weakly correlated with depression (rg = 0.13, P = 3e-6). Depression was weakly correlated with T2D (rg = 0.15, P = 4e-15). The latent multimorbidity factor explained the largest proportion of variance in T2D (45%), followed by CAD (35%) and depression (5%). We identified 11 independent SNPs associated with multimorbidity and 18 putative multimorbidity-associated genes. We observed enrichment in immune and inflammatory pathways. A greater polygenic risk score for multimorbidity in the UK Biobank (N = 306,734) was associated with the co-occurrence of CAD, T2D and depression (OR per standard deviation = 1.91, 95% CI = 1.74-2.10, relative to the healthy group), validating this latent multimorbidity factor. Mendelian randomization analyses suggested potentially causal effects of BMI, body fat percentage, LDL cholesterol, total cholesterol, fasting insulin, income, insomnia, and childhood maltreatment. These findings advance our understanding of multimorbidity suggesting common genetic pathways.

Prevalence and risk factors of prehypertension/hypertension among freshman students from the Vietnam National University: a cross-sectional study

BACKGROUND

Prehypertension (PHT) and hypertension (HTN) in young adults are essential risk factors for other cardiovascular diseases (CVD) in later years of life. However, there is a lack of knowledge about the burden and risk factors of PHT/HTN for Vietnamese youth. The aim of this study was to investigate the prevalence of PHT/HTN and risk factors among university students in Hanoi, Vietnam.

METHODS

This study was designed as a cross-sectional investigation with 840 students (394 males and 446 females) randomly sampled from freshmen of Vietnam National University, Hanoi (VNU). Socio-demographic, anthropometric, and lifestyle data were collected using questionnaire forms and physical measurements. HTN was defined as blood pressure (BP) ≥ 140/90 mmHg and/or current treatment with antihypertensive medications. PHT was defined as a systolic BP from 120 to 139 mmHg and/or a diastolic BP from 80 to 89 mmHg. Body mass index (BMI) was classified according to the WHO diagnostic criteria for Asian adults: normal weight (BMI 18.5-22.9 kg/m2), underweight (BMI < 18.5 kg/m2), overweight (BMI 23-24.9 kg/m2), and obese (BMI ≥ 25 kg/m2). Bivariable and multivariable log-binomial regression analyses were conducted to explore the association of PHT/HTN with different risk factors.

RESULTS

The overall prevalence of prehypertension and hypertension was 33.5% [95% CI: 30.3-36.8%] (54.1% in men and 15.3% in women) and 1.4% [95% CI: 0.7-2.5%] (2.5% in men and 0.5% in women), respectively. Regarding CVD major risk factors, 119 (14.2%) were identified as overweight/obese, 461 (54.9%) were physical inactivity, 29.4% of men and 8.1% of women reported consuming alcohol. The multivariable analysis indicated the male sex (adjusted prevalence ratio [aPR] = 3.07; 95% CI: 2.32-4.06), alcohol consumption (aPR = 1.28; 95% CI: 1.03-1.59) and obesity (aPR = 1.35; 95% CI: 1.08-1.68) as the independent risk factors for PHT/HTN.

CONCLUSIONS

The results revealed the high burden of prehypertension and hypertension among university freshmen in VNU. Male sex, alcohol consumption, and obesity were identified as important risk factors for PHT/HTN. Our study suggests an early screening program for PHT/HTN and campaigns to promote a healthy lifestyle for young adults in Vietnam.

A Study to Evaluate the Effect of a Combined Approach of Yoga and Diet in High-risk Cardiovascular Subjects

Background

Cardiovascular disease (CVD) is a group of disorders of the heart and blood vessels, including coronary heart disease, cerebrovascular disease, rheumatic heart disease, peripheral artery disease, congenital heart disease, deep vein thrombosis, and pulmonary embolism.

Aim

The aim of this study was to assess cardiovascular risk factors and evaluate the effectiveness of combined approach of yoga and diet in reducing cardiovascular risk factors among high-risk subjects.

Materials and Methods

This interventional study was conducted at RUHS College of Medical Sciences and Associated Hospitals, Jaipur, on the high-risk population of either sex in the age group of 40-70 years. QRISK3 web calculator was used as the method of measurement for outcome of interest. The combined approach of yoga intervention includes yogic asanas and pranayamas and dietary modification.

Results

This study compared physiological parameters (blood pressure) and biochemical parameters (fasting blood sugar, glycosylated hemoglobin, lipid profile) at baseline, three months and six months after yoga and diet intervention in participants who were at high-risk of cardiovascular disease development in future and were found to be having significantly decreased systolic blood pressure (P=0.000), fasting blood glucose (P=0.000), glycosylated hemoglobin (HbA1C) (P=0.011), total cholesterol-high density lipoprotein ratio (P=0.000), low density lipoprotein (P=0.009), triglyceride (P=0.034), and QRISK3 Score (P=0.000) after combined approach of yoga and diet.

Conclusions

This study concluded that the short-term combined approach of yoga-based life-style intervention and diet reduced cardiovascular risk factors in subjects at high-risk of developing cardiovascular disease.

Obesity and cardiovascular disease: mechanistic insights and management strategies. A joint position paper by the World Heart Federation and World Obesity Federation

The ongoing obesity epidemic represents a global public health crisis that contributes to poor health outcomes, reduced quality of life, and >2.8 million deaths each year. Obesity is relapsing, progressive, and heterogeneous. It is considered a chronic disease by the World Obesity Federation (WOF) and a chronic condition by the World Heart Federation (WHF). People living with overweight/obesity are at greater risk for cardiovascular (CV) morbidity and mortality. Increased adiposity (body fat), particularly visceral/abdominal fat, is linked to CV risk and CV disease (CVD) via multiple direct and indirect pathophysiological mechanisms. The development of CVD is driven, in part, by obesity-related metabolic, endocrinologic, immunologic, structural, humoral, haemodynamic, and functional alterations. The complex multifaceted nature of these mechanisms can be challenging to understand and address in clinical practice. People living with obesity and CVD often have concurrent chronic physical or psychological disorders (multimorbidity) requiring multidisciplinary care pathways and polypharmacy. Evidence indicates that intentional weight loss (particularly when substantial) lowers CVD risk among people with overweight/obesity. Long-term weight loss and maintenance require ongoing commitment from both the individual and those responsible for their care. This position paper, developed by the WOF and the WHF, aims to improve understanding of the direct and indirect links between overweight/obesity and CVD, the key controversies in this area and evidence relating to cardiometabolic outcomes with available weight management options. Finally, an action plan for clinicians provides recommendations to help in identifying and addressing the risks of obesity-related CVD (recognizing resource and support variances between countries).

Relationship between blood pressure and BMI in young adult population: a national-level assessment in Bangladesh

Young adulthood is a crucial period for major physiological transitions. Environmental changes associated with these transitions can influence health behaviour and health (e.g. poor diet, high body weight and elevated blood pressure (EBP)). Excess body weight can lead to EBP; however, little is known about this relationship among young adults in developing countries. Focusing on Bangladesh, this study assessed the association between BMI and blood pressure (BP) metrics (systolic BP (SBP), diastolic BP (DBP) and BP class (optimal, normal/high normal and elevated)). Sex-specific analyses of these relationships were performed to assess any difference across sexes. Furthermore, associations of overweight/obesity with BP metrics were investigated. Young adults aged 18-24 years (n 2181) were included from nationally representative cross-sectional Bangladesh Demographic and Health Survey 2017-2018. Multivariable linear and multinomial logistic regression models examined the relationships between BMI, overweight/obesity and BP metrics. Findings reveal that higher BMI was associated with higher SBP (0·83; 95 % CI 0·67, 0·99), DBP (0·66; 95 % CI 0·54, 0·74) and higher odds of having EBP (adjusted OR 1·24; 95 % CI 1·17, 1·31). These relationships were stronger among males than females. Moreover, overweight/obese individuals had higher SBP, DBP and higher odds of having EBP than individuals with normal BMI. Strategies to reduce body weight and to improve healthy lifestyle, and awareness and monitoring of BP may help to address these serious health problems, particularly at an early age.

Adiposity and NMR-measured lipid and metabolic biomarkers among 30,000 Mexican adults

BACKGROUND

Adiposity is a major cause of morbidity and mortality in part due to effects on blood lipids. Nuclear magnetic resonance (NMR) spectroscopy provides direct information on >130 biomarkers mostly related to blood lipid particles.

METHODS

Among 28,934 Mexican adults without chronic disease and not taking lipid-lowering therapy, we examine the cross-sectional relevance of body-mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), and hip circumference (HC) to NMR-measured metabolic biomarkers. Confounder-adjusted associations between each adiposity measure and NMR biomarkers are estimated before and after mutual adjustment for other adiposity measures.

RESULTS

Markers of general (ie, BMI), abdominal (ie, WC and WHR) and gluteo-femoral (ie, HC) adiposity all display similar and strong associations across the NMR-platform of biomarkers, particularly for biomarkers that increase cardiometabolic risk. Higher adiposity associates with higher levels of Apolipoprotein-B (about 0.35, 0.30, 0.35, and 0.25 SD higher Apolipoprotein-B per 2-SD higher BMI, WHR, WC, and HC, respectively), higher levels of very low-density lipoprotein particles (and the cholesterol, triglycerides, and phospholipids within these lipoproteins), higher levels of all fatty acids (particularly mono-unsaturated fatty acids) and multiple changes in other metabolic biomarkers including higher levels of branched-chain amino acids and the inflammation biomarker glycoprotein acetyls. Associations for general and abdominal adiposity are fairly independent of each other but, given general and abdominal adiposity, higher gluteo-femoral adiposity is associated with a strongly favourable cardiometabolic lipid profile.

CONCLUSIONS

Our results provide insight to the lipidic and metabolomic signatures of different adiposity markers in a previously understudied population where adiposity is common but lipid-lowering therapy is not.

Conventional and Bidirectional Genetic Evidence on Resting Heart Rate and Cardiometabolic Traits

CONTEXT

Observational studies have suggested that higher resting heart rate (RHR) may be associated with increased cardiometabolic risk. However, causal associations are not fully understood.

OBJECTIVE

We aimed to examine the direction, strength, and causality of the associations of RHR with cardiometabolic traits.

METHODS

We assessed the strength of associations between measured RHR and cardiometabolic traits in 506 211 and 372 452 participants from China Kadoorie Biobank (CKB) and UK Biobank (UKB). Mendelian randomization (MR) analyses were used to make causal inferences in 99 228 and 371 508 participants from CKB and UKB, respectively.

RESULTS

We identified significant directionally concordant observational associations between RHR and higher total cholesterol, triglycerides (TG), low-density lipoprotein, C-reactive protein (CRP), glucose, body mass index, waist-hip ratio (WHR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) after the Bonferroni correction. MR analyses showed that 10 beat/min higher genetically predicted RHR was trans-ethnically associated with a higher DBP (beta 2.059 [95% CI 1.544, 2.574] mmHg in CKB; 2.037 [1.845, 2.229] mmHg in UKB), higher CRP (0.180 [0.057, 0.303] log mg/L in CKB; 0.154 [0.134, 0.174] log mg/L in UKB), higher TG (0.052 [-0.009, 0.113] log mmol/L in CKB; 0.020 [0.010, 0.030] log mmol/L in UKB) and higher WHR (0.218 [-0.033, 0.469] % in CKB; 0.225 [0.111, 0.339] % in UKB). In the opposite direction, higher genetically predicted SBP, TG, glucose, and WHR, and lower high-density lipoprotein, were associated with elevated RHR.

CONCLUSION

Our large-scale analyses provide causal evidence for associations between RHR and cardiometabolic traits, highlighting the importance of monitoring heat rate as a means of alleviating the adverse effects of metabolic disorders.

Cardiac remodeling and subclinical left ventricular dysfunction in adults with uncomplicated obesity: a cardiovascular magnetic resonance study

BACKGROUND

Obesity often exists alongside comorbidities and increases the risk of heart failure and cardiovascular mortality. However, the specific effects of obesity on cardiac structure and function have not been clarified. This study set out to evaluate left ventricular (LV) geometric and functional changes using cardiovascular magnetic resonance imaging (CMR) in adults with uncomplicated obesity.

METHODS

Forty-eight patients with uncomplicated obesity [body mass index (BMI) mean ± SD: 29.8±2.1 kg/m²] and 25 healthy controls were included in this study. CMR was used to assess LV geometry, global systolic function, and strains, and to quantify epicardial adipose tissue (EAT). Body composition was measured by dual X-ray absorptiometry.

RESULTS

Compared with healthy controls, patients with obesity had increased LV size, mass, and myocardial thickness, and impaired myocardial contractility, with lower global radial, circumferential, and longitudinal peak strains (PS), and circumferential and longitudinal peak diastolic strain rates (PDSR; all P<0.05). Multivariable linear regression showed that BMI was independently associated with LV maximum myocardial thickness (LVMMT) (β=0.197, P=0.016). Visceral adipose tissue (VAT) was independently associated with LV global longitudinal PS (β=-2.684, P=0.001), and both longitudinal (β=-0.192, P=0.002) and circumferential (β=-0.165, P=0.014) PDSR. Homeostasis model assessment of insulin resistance (HOMA-IR) was mildly correlated with BMI (r=0.327) and body fat percentage (BF%) (r=0.295) in patients with obesity (all P<0.05). HOMA-IR was independently associated with LV global circumferential PS (β=-0.276, P=0.04) and PDSR (β=-0.036, P=0.026).

CONCLUSIONS

Extensive LV geometric remodeling and marked changes in cardiac strains were observed in adults with obesity. Tissue tracking with CMR can reveal subclinical impaired ventricular function with preserved LV ejection fraction in such patients. BMI was independently related to LV remodeling in obesity. HOMA-IR and VAT are potentially superior to BMI as predictors of subclinical dysfunction, assessed by strain, in obesity.

TRIAL REGISTRY

This study has been registered with the Chinese Clinical Trial Registry (ID: ChiCTR1900026476; Effect of lifestyle intervention on metabolism of obese patients based on smart phone software).

Harnessing tissue-specific genetic variation to dissect putative causal pathways between body mass index and cardiometabolic phenotypes

Body mass index (BMI) is a complex disease risk factor known to be influenced by genes acting via both metabolic pathways and appetite regulation. In this study, we aimed to gain insight into the phenotypic consequences of BMI-associated genetic variants, which may be mediated by their expression in different tissues. First, we harnessed meta-analyzed gene expression datasets derived from subcutaneous adipose (n = 1257) and brain (n = 1194) tissue to identify 86 and 140 loci, respectively, which provided evidence of genetic colocalization with BMI. These two sets of tissue-partitioned loci had differential effects with respect to waist-to-hip ratio, suggesting that the way they influence fat distribution might vary despite their having very similar average magnitudes of effect on BMI itself (adipose = 0.0148 and brain = 0.0149 standard deviation change in BMI per effect allele). For instance, BMI-associated variants colocalized with TBX15 expression in adipose tissue (posterior probability [PPA] = 0.97), but not when we used TBX15 expression data derived from brain tissue (PPA = 0.04) This gene putatively influences BMI via its role in skeletal development. Conversely, there were loci where BMI-associated variants provided evidence of colocalization with gene expression in brain tissue (e.g., NEGR1, PPA = 0.93), but not when we used data derived from adipose tissue, suggesting that these genes might be more likely to influence BMI via energy balance. Leveraging these tissue-partitioned variant sets through a multivariable Mendelian randomization framework provided strong evidence that the brain-tissue-derived variants are predominantly responsible for driving the genetically predicted effects of BMI on cardiovascular-disease endpoints (e.g., coronary artery disease: odds ratio = 1.05, 95% confidence interval = 1.04-1.07, p = 4.67 × 10^-14). In contrast, our analyses suggested that the adipose tissue variants might predominantly be responsible for the underlying relationship between BMI and measures of cardiac function, such as left ventricular stroke volume (beta = 0.21, 95% confidence interval = 0.09-0.32, p = 6.43 × 10^-4).

Association of childhood obesity phenotypes with early adulthood Carotid Intima-Media Thickness (CIMT): Tehran lipid and glucose study

BACKGROUND AND AIMS

Over the past few years, obesity and metabolic syndrome prevalence among children and adolescence have an increasing trend. This study aims to investigate the association of obesity phenotypes during childhood and adolescence with early adulthood carotid intima-media thickness (CIMT).

METHODS AND RESULTS

Participants were divided into four obesity phenotypes: Metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO). Participants were followed for 18 years. Multivariate-adjusted Risk Ratios (RRs) were calculated for high CIMT (≥95% percentile) incidence. In this cohort study 1220 children and adolescents with the average age of 10.9 ± 4.0 years were included. CIMT values had a significantly increasing trend from MHNW to MUO group (p for trend<0.001). Individuals with normal weight status, even with an unhealthy metabolic profile did not have higher risk of high CIMT. Similarly, Children with obesity but healthy metabolic status was not at higher risk. On the other hand, MUO phenotype during childhood was associated with increased risk of high CIMT in early adulthood (RR = 2.13, 95%CI (1.02-4.48)). This association became insignificant for all obesity phenotypes after adjusting for adulthood BMI.

CONCLUSION

Adulthood CIMT has an increasing trend based on childhood and adolescence obesity phenotypes from MHNW to MUO. Children with MUO phenotype was the only ones that had an increased risk of high CIMT incidence in early adulthood.

A genome-wide association study of childhood adiposity and blood lipids

Background: The rising prevalence of childhood obesity and dyslipidaemia is a major public health concern due to its association with morbidity and mortality in later life. Methods: In this study, we have conducted genome-wide association studies (GWAS) for eight measures of adiposity and lipids in a cohort of young individuals (mean age 9.9) from the Avon Longitudinal Study of Parents and Children (ALSPAC). These measures were body mass index (BMI), systolic and diastolic blood pressure, high- density and low-density lipoprotein cholesterol, triglycerides, apolipoprotein A-I and apolipoprotein B. We next undertook functional enrichment, pathway analyses and linkage disequilibrium (LD) score regression to evaluate genetic correlations with later-life cardiometabolic diseases. Results: Using GWAS we identified 14 unique loci associated with at least one risk factor in this cohort of age 10 individuals (P<5x10-8), with lipoprotein lipid-associated loci being enriched for liver tissue-derived gene expression and lipid synthesis pathways. LD score regression provided evidence of various genetic correlations, such as childhood systolic blood pressure being genetically correlated with later-life coronary artery disease (rG=0.26, 95% CI=0.07 to 0.46, P=0.009) and hypertension (rG=0.37, 95% CI=0.19 to 0.55, P=6.57x10-5), as well as childhood BMI with type 2 diabetes (rG=0.35, 95% CI=0.18 to 0.51, P=3.28x10-5). Conclusions: Our findings suggest that there are genetic variants inherited at birth which begin to exert their effects on cardiometabolic risk factors as early as age 10 in the life course. However, further research is required to assess whether the genetic correlations we have identified are due to direct or indirect effects of childhood adiposity and lipid traits.

A Systematic Review of the Long-Term Trajectory of Hemodynamics and Body Composition in Childhood Obesity

Obesity has long been cited as a significant risk factor for high blood pressure, with long-term exposure linked with an increased incidence of carotid artery atherosclerosis. However, as obesity is becoming more common in young-aged children, it is important to recognize combinational factors like lifestyle, socioeconomic, and genetic factors as a cause. Increasing weight during childhood, on the other hand, is a clinically significant challenge for many physicians. It is critical to identify these risk factors since early prevention (primordial prevention) or treatment (primary prevention) to reverse the potential risks is much more likely to be effective. The objective of this review was to explore the relationship between lifestyle, anthropometric, and genetic factors and cardiometabolic risk factors. We are hopeful that our findings may aid in the primary prevention of hypertension in children and the prevention of any related cardiovascular complications that may arise later in life as a result of obesity. The synthesis of this systematic review includes a total of 15 studies using defined criteria, published up to October 2021. In addition, a total of 2,397 articles were found through an initial electronic database search and included a total of 38,182 participants. Studies explored included one or more of the following cardiovascular risk factors: body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides (TG). The findings of this study support the notion that childhood obesity may be a risk factor for a variety of adult cardiovascular disease risk factors. Several behavioral, genetic, and anthropometric factors are linked to the development of obesity during early ages, overall creating challenges in cardiovascular health during adulthood. As a result, addressing the risk factors for childhood hypertension would be advantageous for the primary prevention of its sequelae in adulthood.

The Prognostic Significance of Body Mass Index and Metabolic Parameter Variabilities in Predialysis CKD: A Nationwide Observational Cohort Study

BACKGROUND

The association between variabilities in body mass index (BMI) or metabolic parameters and prognosis of patients with CKD has rarely been studied.

METHODS

In this retrospective observational study on the basis of South Korea's national health screening database, we identified individuals who received ≥3 health screenings, including those with persistent predialysis CKD (eGFR <60 ml/min per 1.73 m² or dipstick albuminuria ≥1). The study exposure was variability in BMI or metabolic parameters until baseline assessment, calculated as the variation independent of the mean and stratified into quartiles (with Q4 the highest quartile and Q1 the lowest). We used Cox regression adjusted for various clinical characteristics to analyze risks of all-cause mortality and incident myocardial infarction, stroke, and KRT.

RESULTS

The study included 84,636 patients with predialysis CKD. Comparing Q4 versus Q1, higher BMI variability was significantly associated with higher risks of all-cause mortality (hazard ratio [HR], 1.66; 95% confidence interval [95% CI], 1.53 to 1.81), P [for trend] <0.001), KRT (HR, 1.20; 95% CI, 1.09 to 1.33; P<0.001), myocardial infarction (HR, 1.19; 95% CI, 1.05 to 1.36, P=0.003), and stroke (HR, 1.19; 95% CI, 1.07 to 1.33, P=0.01). The results were similar in the subgroups divided according to positive or negative trends in BMI during the exposure assessment period. Variabilities in certain metabolic syndrome components (e.g., fasting blood glucose) also were significantly associated with prognosis of patients with predialysis CKD. Those with a higher number of metabolic syndrome components with high variability had a worse prognosis.

CONCLUSIONS

Higher variabilities in BMI and certain metabolic syndrome components are significantly associated with a worse prognosis in patients with predialysis CKD.

The role of age at menarche and age at menopause in Alzheimer's disease: evidence from a bidirectional mendelian randomization study

The association between endogenous estrogen exposure and Alzheimer's disease (AD) remains inconclusive in previous observational studies, and few Mendelian randomization (MR) studies have focused on their causality thus far. We performed a bidirectional MR study to clarify the causality and causal direction of age at menarche and age at menopause, which are indicators of endogenous estrogen exposure, on AD risk. We obtained all genetic datasets for the MR analyses using publicly available summary statistics based on individuals of European ancestry from the IEU GWAS database. The MR analyses indicated no significant causal relationship between the genetically determined age at menarche (outlier-adjusted inverse variance weighted odds ratio [IVWOR] = 0.926; 95% confidence interval [CI], 0.803-1.066) or age at menopause (outlier-adjusted IVWOR = 0.981; 95% CI, 0.941-1.022) and AD risk. Similarly, AD did not show any causal association with age at menarche or age at menopause. The sensitivity analyses yielded similar results. In contrast, an inverse association was detected between age at menarche and body mass index (BMI, outlier-adjusted IVW β = -0.043; 95% CI, -0.077 to -0.009). Our bidirectional MR study provides no evidence for a causal relationship between the genetically determined age at menarche or age at menopause and AD susceptibility, or vice versa. However, earlier menarche might be associated with higher adult BMI.

Role of Perivascular Adipose Tissue and Exercise on Arterial Function with Obesity

Adipose tissue and arterial dysfunction are common in the obese state. Perivascular adipose tissue (PVAT) plays an important role in mediating arterial health, and with obesity, the PVAT dysfunction negatively affects arterial health. Exercise training exerts direct and beneficial effects on PVAT, providing an additional and novel pathway by which exercise can improve arterial health in diseased populations.

Balancing scientific interests and the rights of participants in designing a recall by genotype study

Recall by genotype (RbG) studies aim to better understand the phenotypes that correspond to genetic variants of interest, by recruiting carriers of such variants for further phenotyping. RbG approaches pose major ethical and legal challenges related to the disclosure of possibly unwanted genetic information. The Cooperative Health Research in South Tyrol (CHRIS) study is a longitudinal cohort study based in South Tyrol, Italy. Demand has grown for CHRIS study participants to be enrolled in RbG studies, thus making the design of a suitable ethical framework a pressing need. We here report upon the design of a pilot RbG study conducted with CHRIS study participants. By reviewing the literature and by consulting relevant stakeholders (CHRIS participants, clinical geneticists, ethics board, GPs), we identified key ethical issues in RbG approaches (e.g. complexity of the context, communication of genetic results, measures to further protect participants). The design of the pilot was based on a feasibility assessment, the selection of a suitable test case within the ProtectMove Research Unit on reduced penetrance of hereditary movement disorders, and the development of appropriate recruitment and communication strategies. An empirical study was embedded in the pilot study with the aim of understanding participants' views on RbG. Our experience with the pilot study in CHRIS allowed us to contribute to the development of best practices and policies for RbG studies by drawing recommendations: addressing the possibility of RbG in the original consent, implementing tailored communication strategies, engaging stakeholders, designing embedded empirical studies, and sharing research experiences and methodology.

The impact of visceral and general obesity on vascular and left ventricular function and geometry: a cross-sectional magnetic resonance imaging study of the UK Biobank

Aims 

We aimed to evaluate the associations of body fat distribution with cardiovascular function and geometry in the middle-aged general population.

Methods and results 

Four thousand five hundred and ninety participants of the UK Biobank (54% female, mean age 61.1 ± 7.2 years) underwent cardiac magnetic resonance for assessment of left ventricular (LV) parameters [end-diastolic volume (EDV), ejection fraction (EF), cardiac output (CO), and index (CI)] and magnetic resonance imaging for body composition analysis [subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT)]. Body fat percentage (BF%) was assessed by bioelectrical impedance. Linear regressions were performed to assess the impact of visceral (VAT) and general (SAT and BF%) obesity on cardiac function and geometry. Visceral obesity was associated with a smaller EDV [VAT: β −1.74 (−1.15 to −2.33)], lower EF [VAT: β −0.24 (−0.12 to −0.35), SAT: β 0.02 (−0.04 to 0.08), and BF%: β 0.02 (−0.02 to 0.06)] and the strongest negative association with CI [VAT: β −0.05 (−0.06 to −0.04), SAT: β −0.02 (−0.03 to −0.01), and BF% β −0.01 (−0.013 to −0.007)]. In contrast, general obesity was associated with a larger EDV [SAT: β 1.01 (0.72–1.30), BF%: β 0.37 (0.23–0.51)] and a higher CO [SAT: β 0.06 (0.05–0.07), BF%: β 0.02 (0.01–0.03)]. In the gender-specific analysis, only men had a significant association between VAT and EF [β −0.35 (−0.19 to −0.51)].

Conclusion 

Visceral obesity was associated with a smaller LV EDV and subclinical lower LV systolic function in men, suggesting that visceral obesity might play a more important role compared to general obesity in LV remodelling.

Blood pressure variability and night-time dipping assessed by 24-hour ambulatory monitoring: Cross-sectional association with cardiac structure in adolescents

Greater blood pressure (BP) is associated with greater left ventricular mass indexed to height2.7 (LVMi2.7) in adolescents. This study examined whether greater BP variability and reduced night-time dipping are associated with cardiac remodeling in a general population of adolescents. A cross-sectional analysis was undertaken in 587 UK adolescents (mean age 17.7 years; 43.1% male). BP was measured in a research clinic and using 24-hour ambulatory monitoring. We examined associations (for both systolic and diastolic BP) of: 1) clinic and 24-hour mean BP; 2) measures of 24-hour BP variability: standard deviation weighted for day/night (SDdn), variability independent of the mean (VIM) and average real variability (ARV); and 3) night-time dipping with cardiac structures. Cardiac structures were assessed by echocardiography: 1) LVMi2.7; 2) relative wall thickness (RWT); 3) left atrial diameter indexed to height (LADi) and 4) left ventricular internal diameter in diastole (LVIDD). Higher systolic BP was associated with greater LVMi2.7. Systolic and diastolic BP were associated with greater RWT. Associations were inconsistent for LADi and LVIDD. There was evidence for associations between both greater SDdn and ARV and higher RWT (per 1 SD higher diastolic ARV, mean difference in RWT was 0.13 SDs, 95% CI 0.045 to 0.21); these associations with RWT remained after adjustment for mean BP. There was no consistent evidence of associations between night-time dipping and cardiac structure. Measurement of BP variability, even in adolescents with blood pressure in the physiologic range, might benefit risk of cardiovascular remodeling assessment.

Loss-of-function mutations in the melanocortin 4 receptor in a UK birth cohort

Mutations in the melanocortin 4 receptor gene (MC4R) are associated with obesity but little is known about the prevalence and impact of such mutations throughout human growth and development. We examined the MC4R coding sequence in 5,724 participants from the Avon Longitudinal Study of Parents and Children, functionally characterized all nonsynonymous MC4R variants and examined their association with anthropometric phenotypes from childhood to early adulthood. The frequency of heterozygous loss-of-function (LoF) mutations in MC4R was ~1 in 337 (0.30%), considerably higher than previous estimates. At age 18 years, mean differences in body weight, body mass index and fat mass between carriers and noncarriers of LoF mutations were 17.76 kg (95% CI 9.41, 26.10), 4.84 kg m-2 (95% CI 2.19, 7.49) and 14.78 kg (95% CI 8.56, 20.99), respectively. MC4R LoF mutations may be more common than previously reported and carriers of such variants may enter adult life with a substantial burden of excess adiposity.

Joint Modeling of Individual Trajectories, Within-Individual Variability, and a Later Outcome: Systolic Blood Pressure Through Childhood and Left Ventricular Mass in Early Adulthood

Within-individual variability of repeatedly measured exposures might predict later outcomes (e.g., blood pressure (BP) variability (BPV) is an independent cardiovascular risk factor above and beyond mean BP). Because 2-stage methods, known to introduce bias, are typically used to investigate such associations, we introduce a joint modeling approach, examining associations of mean BP and BPV across childhood with left ventricular mass (indexed to height; LVMI) in early adulthood with data (collected 1990-2011) from the UK Avon Longitudinal Study of Parents and Children cohort. Using multilevel models, we allowed BPV to vary between individuals (a "random effect") as well as to depend on covariates (allowing for heteroskedasticity). We further distinguished within-clinic variability ("measurement error") from visit-to-visit BPV. BPV was predicted to be greater at older ages, at higher body weights, and in female participants and was positively correlated with mean BP. BPV had a weak positive association with LVMI (10% increase in within-individual BP variance was predicted to increase LVMI by 0.21%, 95% credible interval: -0.23, 0.69), but this association became negative (-0.78%, 95% credible interval: -2.54, 0.22) once the effect of mean BP on LVMI was adjusted for. This joint modeling approach offers a flexible method of relating repeatedly measured exposures to later outcomes.

Vascular diameter and intima-media thickness to diameter ratio values of the carotid artery in 642 healthy children

In children, arterial alterations occur with increased intima-media thickness as well as vascular diameter enlargement. Both conditions correlate with higher cardiovascular risk in adults, and both the array and proportion of these alterations are important hemodynamic parameters. In terms of functional adaptation processes, they influence several arterial wall properties as for example the shear and tensile stress of the vessel. There are no reference values for the vascular diameter and intima-media thickness/diameter ratio of the carotid artery in children. Therefore, this study aimed to assess vascular diameter, intima-media thickness/diameter ratio and related tensile stress values in children and to further investigate the influence of sex, age, body mass index, and blood pressure. The parameters were measured with high-resolution semi-automated ultrasound. Sex- and age-dependent values were calculated with the LMS method for a cross-sectional sample of 642 healthy, non-obese children aged 8-17 years. The mean vascular diameter was 5.45 ± 0.46 mm; the median intima-media thickness/diameter ratio was 0.085 (0.079-0.092); the median tensile stress was 105.4 (95.2-116.4) kPa. The vascular diameter and the tensile stress were higher, and the intima-media thickness/diameter ratio was lower in boys than in girls. In comparison to the normal weight study population the excludedobese children had a significantly higher diameter, a lower intima-media thickness/diameter ratio, and a higher tensile stress. In multiple regression analyses of diameter, intima-media thickness/diameter ratio, and tensile stress, all parameters were influenced by sex and body mass index. Furthermore, systolic and diastolic blood pressure significantly influenced the vascular diameter, and systolic blood pressure significantly influenced the intima-media thickness/diameter ratio. Conclusion: This study is the first to report values for the diameter, the intima-media thickness/diameter ratio of the carotid artery, and the related tensile stress allowing a more differentiated view of cardiovascular adaptations as it combines structural and functional vascular parameters. What is known: • Intima-media thickness and vascular diameter are related to a higher cardiovascular risk in adults • The intima-media thickness/diameter ratio gives information about hemodynamic and functional vessel adaptation What is new: • Values for vascular diameter, intima-media thickness/diameter ratio, and tensile stress of the carotid artery in children are presented in this study • Intima-media thickness as a surrogate marker for arterial health in children should be complemented by intima-media thickness/diameter ratio measurement.

Determinants of Intima-Media Thickness in the Young: The ALSPAC Study

OBJECTIVES

This study characterized the determinants of carotid intima-media thickness (cIMT) in a large (n > 4,000) longitudinal cohort of healthy young people age 9 to 21 years.

BACKGROUND

Greater cIMT is commonly used in the young as a marker of subclinical atherosclerosis, but its evolution at this age is still poorly understood.

METHODS

Associations between cardiovascular risk factors and cIMT were investigated in both longitudinal (ages 9 to 17 years) and cross-sectional (ages 17 and 21 years) analyses, with the latter also related to other measures of carotid structure and stress. Additional use of ultra-high frequency ultrasound in the radial artery at age 21 years allowed investigation of the distinct layers (i.e., intima or media) that may underlie observed differences.

RESULTS

Fat-free mass (FFM) and systolic blood pressure were the only modifiable risk factors positively associated with cIMT (e.g., mean difference in cIMT per 1-SD increase in FFM at age 17: 0.007 mm: 95% confidence interval [CI]: 0.004 to 0.010; p < 0.001), whereas fat mass was negatively associated with cIMT (difference: -0.0032; 95% CI: 0.004 to -0.001; p = 0.001). Similar results were obtained when investigating cumulative exposure to these factors throughout adolescence. An increase in cIMT maintained circumferential wall stress in the face of increased mean arterial pressure when increases in body mass were attributable to increased FFM, but not fat mass. Risk factor-associated differences in the radial artery occurred in the media alone, and there was little evidence of a relationship between intimal thickness and any risk factor.

CONCLUSIONS

Subtle changes in cIMT in the young may predominantly involve the media and represent physiological adaptations as opposed to subclinical atherosclerosis. Other vascular measures may be more appropriate for the identification of arterial disease before adulthood.

Anthropometric and Biochemical Parameters in Relation to Dietary Habits as Early Indicator of Cardiovascular Impairment in Young Adult Cohort

Adjusted dietary assessment questionnaire was used to determine dietary habits of medical students which were related to biochemical and anthropometric markers of studied cohort. Thirty-seven young and healthy volunteers aged 19–28 years old entered the protocol and were divided according to sex and according to residence. Subjects were given questionnaires for tracking food/beverage consumption. Venous blood samples were taken after overnight fast (n = 32). Nutrient status and energy consumption were determined and analyzed. Study population had normal weight and body mass index (BMI). Biochemical characteristics were within normal reference range, while some participants had lipid profile disbalance. Men had significantly higher BMI than women. Average BMI was significantly higher in participants with elevated cholesterol levels compared to participants with normal cholesterol levels. Majority of participants consumed less than five meals per day with no major differences between students according to residence and sex. Men had significantly higher protein intake and consumed at least four meals daily compared to woman who had three or less meals daily with no differences in intake according to residence. Students with normal lipid profile consumed more carbohydrates than students with increased cholesterol. Results suggest that students with bad dietary habits have potentially higher risk for future cardiovascular problems, even before the onset of adverse effects.

The role of insulin resistance in the relation of visceral, abdominal subcutaneous and total body fat to cardiovascular function

BACKGROUND AND AIMS

The separate cardiovascular effects of type 2 diabetes and adiposity remain to be examined. This study aimed to investigate the role of insulin resistance in the relations of visceral (VAT), abdominal subcutaneous (aSAT) adipose tissue and total body fat (TBF) to cardiovascular remodeling.

METHODS AND RESULTS

In this cross-sectional analysis of the population-based Netherlands Epidemiology of Obesity study, 914 middle-aged individuals (46% men) were included. Participants underwent magnetic resonance imaging. Standardized linear regression coefficients (95%CI) were calculated, adjusted for potential confounding factors. All fat depots and insulin resistance (HOMA-IR), separate from VAT and TBF, were associated with lower mitral early and late peak filling rate ratios (E/A): -0.04 (-0.09;0.01) per SD (54 cm²) VAT; -0.05 (-0.10;0.00) per SD (94 cm²) aSAT; -0.09 (-0.16;-0.02) per SD (8%) TBF; -0.11 (-0.17;-0.05) per 10-fold increase in HOMA-IR, whereas VAT and TBF were differently associated with left ventricular (LV) end-diastolic volume: -8.9 (-11.7;-6.1) mL per SD VAT; +5.4 (1.1;9.7) mL per SD TBF. After adding HOMA-IR to the model to evaluate the mediating role of insulin resistance, change in E/A was -0.02 (-0.07;0.04) per SD VAT; -0.03 (-0.08;0.02) per SD aSAT; -0.06 (-0.13;0.01) per SD TBF, and change in LV end-diastolic volume was -7.0 (-9.7;-4.3) mL per SD VAT. In women, adiposity but not HOMA-IR was related to higher aortic arch pulse wave velocity.

CONCLUSION

Insulin resistance was associated with reduced diastolic function, separately from VAT and TBF, and partly mediated the associations between adiposity depots and lower diastolic function.

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.

The contribution of tissue-grouped BMI-associated gene sets to cardiometabolic-disease risk: a Mendelian randomization study

Background

Body mass index (BMI)-associated loci are used to explore the effects of obesity using Mendelian randomization (MR), but the contribution of individual tissues to risks remains unknown. We aimed to identify tissue-grouped pathways of BMI-associated loci and relate these to cardiometabolic disease using MR analyses.

Methods

Using Genotype-Tissue Expression (GTEx) data, we performed overrepresentation tests to identify tissue-grouped gene sets based on mRNA-expression profiles from 634 previously published BMI-associated loci. We conducted two-sample MR with inverse-variance-weighted methods, to examine associations between tissue-grouped BMI-associated genetic instruments and type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD), with use of summary-level data from published genome-wide association studies (T2DM: 74 124 cases, 824 006 controls; CAD: 60 801 cases, 123 504 controls). Additionally, we performed MR analyses on T2DM and CAD using randomly sampled sets of 100 or 200 BMI-associated genetic variants.

Results

We identified 17 partly overlapping tissue-grouped gene sets, of which 12 were brain areas, where BMI-associated genes were differentially expressed. In tissue-grouped MR analyses, all gene sets were similarly associated with increased risks of T2DM and CAD. MR analyses with randomly sampled genetic variants on T2DM and CAD resulted in a distribution of effect estimates similar to tissue-grouped gene sets.

Conclusions

Overrepresentation tests revealed differential expression of BMI-associated genes in 17 different tissues. However, with our biology-based approach using tissue-grouped MR analyses, we did not identify different risks of T2DM or CAD for the BMI-associated gene sets, which was reflected by similar effect estimates obtained by randomly sampled gene sets.

BMI Is Causally Associated With Pulmonary Artery Pressure But Not Hemodynamic Evidence of Pulmonary Vascular Remodeling

BACKGROUND

There is an unclear relationship of obesity to the pathogenesis and severity of pulmonary arterial hypertension (PAH) and pulmonary venous hypertension (PVH).

RESEARCH QUESTION

Is BMI casually associated with pulmonary artery pressure (PAP) and/or markers of pulmonary vascular remodeling?

STUDY DESIGN AND METHODS

The study design was a two-sample inverse-variance weighted Mendelian randomization. We constructed two BMI genetic risk scores from genome-wide association study summary data and deployed them in nonoverlapping cohorts of subjects referred for right heart catheterization (RHC) or echocardiography. A BMI highly polygenic risk score (hpGRS) optimally powered to detect shared genetic architecture of obesity with other traits was tested for association with RHC parameters including markers of pulmonary vascular remodeling. A BMI strict genetic risk score (sGRS) composed of high-confidence genetic variants was used for Mendelian randomization analyses to assess if higher BMI causes higher PAP.

RESULTS

Among all subjects, both directly measured BMI and hpGRS were positively associated with pulmonary arterial pressures but not markers of pulmonary vascular remodeling. Categorical analyses revealed BMI and hpGRS were associated with PVH but not PAH. Mendelian randomization of the sGRS supported that higher BMI is causal of higher systolic pulmonary artery pressure (sPAP). Sensitivity analyses showed sPAP-BMI sGRS relationship was preserved when either individuals with PAH or PVH were excluded. In the echocardiographic cohort, BMI and hpGRS were positively associated with estimated PAP and markers of left heart remodeling.

INTERPRETATION

BMI is a modifier of pulmonary hypertension severity in both PAH and PVH but is only involved in the pathogenesis of PVH.

Association of body mass index with serum alanine aminotransferase in Chinese adolescents: a school-based cross-sectional study

BACKGROUND

Numerous studies have consistently demonstrated that high body mass index (BMI) is related to elevated serum alanine aminotransferase (ALT) among adults, but little is known about the association regarding adolescents, especially in China. In this study, we aimed to investigate the association between BMI and ALT activity among Chinese adolescents.

METHODS

A school-based cross-sectional study was performed among nine high schools in Shenzhen, China between February 2017 and June 2018. A generalized linear-regression model adjusting for age and gender was conducted, and bivariate correlation analysis between ALT and BMI was also performed.

RESULTS

A total of 7,271 adolescents aged from 9 years to 17 years were enrolled. Height, weight, BMI, and ALT were higher among boys than among girls (all P < 0.001). The mean (standard deviation) of serum ALT levels was 14.26 (14.77) U/L. In the entire BMI range, the BMI-ALT correlation was stronger for boys (Spearman's r = 0.396, P < 0.001) and adolescents of 14 years-17 years (r = 0.356, P < 0.001) than for girls (r = 0.203, P < 0.001) and adolescents of 9 years-13 years (r = 0.221, P < 0.001), respectively. Serum ALT increased rapidly and followed a linear pattern from the point of BMI ≥20.5 kg/m², and each increase of 1 kg/m² in BMI range above 20.5 kg/m² was averagely correlated with an increase of 2.71 U/L in ALT levels (P < 0.001).

CONCLUSIONS

We found a significant BMI-ALT relationship. BMI at 20.5 kg/m² may be a cut-off for evaluating serum ALT. BMIs ≥27.1 kg/m² for boys and ≥24.9 kg/m² for girls were linked to an elevated ALT activity for Shenzhen adolescents.

Contrasting Associations of Body Mass Index and Hemoglobin A1c on the Excess Risk of Acute Myocardial Infarction and Heart Failure in Type 2 Diabetes Mellitus

Background Body mass index (BMI) may be a stronger risk factor for heart failure than for coronary heart disease in type 2 diabetes mellitus, but prior studies have not been powered to investigate the relative and absolute risks for acute myocardial infarction and heart failure in type 2 diabetes mellitus by BMI and glycemic level combined as compared with age- and sex-matched general population comparators. Methods and Results We identified 181 045 patients from The Swedish National Diabetes Registry, registered during 1998 to 2012 and 1538 434 general population comparators without diabetes mellitus, matched for age, sex, and county, all without prior major cardiovascular disease. Cases and comparators were followed with respect to the outcomes through linkage to the Swedish Inpatient Registry. Over a median follow-up time of 5.7 years, there were 28 855 acute myocardial infarction and 33 060 heart failure cases among patients and comparators. Excess risk (above that of comparators in whom no data on hemoglobin A1c and BMI was available), incidence rates and hazard ratios for heart failure were substantially higher among the obese patients compared with those with low BMI, where very obese patients (BMI ≥40 kg/m2) who also had poor glycemic control, suffered a 7-fold risk of heart failure versus comparators (reference level). By contrast, for acute myocardial infarction, the highest absolute and relative risks were found among patients with poor glycemic control, with no additional risk conferred by increasing BMI. Conclusions BMI is a strong independent risk factor for heart failure but not for acute myocardial infarction among patients with type 2 diabetes mellitus.

Postprandial Vascular Dysfunction Is Associated With Raised Blood Pressure and Adverse Left Ventricular Remodeling in Adolescent Adiposity

BACKGROUND

Left ventricular hypertrophy (LVH) is a major risk factor for cardiovascular disease, including heart failure. Although linked to obesity and hypertension, its pathogenesis is multifactorial. Blunted postprandial sympathetic regulation of gut blood flow has been observed in overweight animals and suggested as a promotor of hypertension and LVH. We hypothesized that blunted postprandial superior mesenteric blood flow responses would be more common in overweight humans and associated with increased blood pressure and LVH.

METHODS

Left ventricular dimensions and hemodynamic responses to a standardized high-calorie liquid meal were measured in healthy adolescents (n=82; 39 overweight/obese) by magnetic resonance imaging. Covariates such as body mass index, blood pressure, Tanner score, and an index of insulin resistance were included in multiple regression models to examine the independent associations of mesenteric flow response with blood pressure status and LVH.

RESULTS

Food ingestion increased cardiac output (Δmean, 0.45 [SD, 0.62] L·min^-1; P=3.8×10^-8) and superior mesenteric artery flow (Δmean, 0.76 [SD, 0.35] L·min^-1; P=4.2×10^-31). A blunted mesenteric flow response was associated with increased left ventricular mass (B=-12.7 g·m^-2.7 per L·min^-1·m^-0.92; P=6×10^-5) and concentric LVH (log likelihood, -9.9; P=0.001), independently of known determinants of LVH, including body mass index. It was also associated with elevated systolic blood pressure (B=-18.0 mm Hg per L·min^-1·m^-0.92; P=0.001), but this link did not explain the association with left ventricular mass.

CONCLUSIONS

Postprandial mesenteric vascular dysfunction is associated with LVH and hypertension, independently of common risk factors for those conditions. These findings highlight a new, independent marker of cardiovascular risk in the young.

Higher Body Mass Index in Adolescence Predicts Cardiomyopathy Risk in Midlife

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Background:

Modifiable lifestyle factors in relation to risk for cardiomyopathy, a common and increasing cause of heart failure in the young, have not been widely studied. We sought to investigate a potential link between obesity, a recognized predictor of early heart failure, in adolescence and being diagnosed with cardiomyopathy in adulthood.

Methods:

This was a nationwide register-based prospective cohort study of 1 668 893 adolescent men (mean age, 18.3 years; SD, 0.7 years) who enlisted for compulsory military service from 1969 to 2005. At baseline, body mass index (BMI), blood pressure, and medical disorders were registered, along with test results for fitness and muscle strength. Cardiomyopathy diagnoses were identified from the National Hospital Register and Cause of Death Register during an up to 46-year follow-up and divided into categories: dilated, hypertrophic, alcohol/drug-induced, and other. Hazard ratios were calculated with Cox proportional hazards models.

Results:

During follow-up (median, 27 years; Q1–Q3, 19–35 years), 4477 cases of cardiomyopathy were identified, of which 2631 (59%) were dilated, 673 (15%) were hypertrophic, and 480 (11%) were alcohol/drug-induced. Increasing BMI was strongly associated with elevated risk of cardiomyopathy, especially dilated, starting at levels considered normal (BMI, 22.5–<25 kg/m²; hazard ratio, 1.38 [95% CI, 1.22–1.57]), adjusted for age, year, center, and baseline comorbidities, and with a >8-fold increased risk at BMI ≥35 kg/m² compared with BMI of 18.5 to <20 kg/m². For each 1-unit increase in BMI, similarly adjusted hazard ratios were 1.15 (95% CI, 1.14–1.17) for dilated cardiomyopathy, 1.09 (95% CI, 1.06–1.12) for hypertrophic cardiomyopathy, and 1.10 (1.06–1.13) for alcohol/drug-induced cardiomyopathy.

Conclusions:

Even mildly elevated body weight in late adolescence may contribute to being diagnosed with cardiomyopathy in adulthood. The already marked importance of weight control in youth is further strengthened by these findings, as well as greater evidence for obesity as a potential important cause of adverse cardiac remodeling that is independent of clinically evident ischemic heart disease.

Associations of Cognitive Function with BMI, Body Fat Mass and Visceral Fat in Young Adulthood

Background and objectives: Existing studies concerning the associations of cognitive function with adiposity in young adults are sparse. The purpose of the study was to examine the associations of adiposity with cognitive control in young adults. Materials and Methods: Participants were 213 young adults (98 women and 115 men). Cognitive control was measured using a modified task-switching paradigm. Anthropometrics were measured by standardized procedures. Body fat mass and visceral fat area were measured by bioelectrical impedance analysis. Results: The results showed that increased body mass index (BMI, p = 0.02), body fat percentage (p = 0.02), and visceral fat area (p = 0.01) were significantly correlated with larger global switch costs of accuracy in women. In men, high levels of body fat percentage (p = 0.01) and visceral fat area (p = 0.03) were significantly correlated with larger local switch costs of reaction time. Conclusions: The results indicated that elevated adiposity was associated with worse performance on measures of cognitive control in young adults.

Real-World Strategies to Treat Hypertension Associated with Pediatric Obesity

PURPOSE OF REVIEW

To review the most recent literature on current strategies for the treatment of hypertension associated with pediatric obesity.

RECENT FINDINGS

Over the last three decades, childhood and adolescent overweight and obesity prevalence in the USA has continued to rise. Unsurprisingly but rather disturbingly, this rising prevalence has been paralleled by an increase in cardiovascular disease (CVD) risk factors in childhood such as hypertension, dyslipidemia, and diabetes that become manifest earlier than previously reported. These childhood CVD risk factors are not only associated with target organ damage in childhood but also track into adulthood, increasing the risk of long-term CVD morbidity and mortality. There have been several mechanisms proposed to explain the role of obesity on the development of hypertension in childhood. However, central to the management of obesity-related hypertension is a multifaceted approach targeting lifestyle modifications and weight loss. Effective treatment often also requires a pharmacologic approach and rarely bariatric surgery.

Change in body mass index from childhood onwards and risk of adult cardiovascular disease

Childhood obesity adversely affects the structure and function of the cardiovascular system, but the relationship between excessive weight gain during childhood and adult cardiovascular disease (CVD) is not fully understood. This review summarizes evidence for associations of change in body mass index (BMI) from childhood onwards with CVD outcomes. We found that excessive gain in BMI from childhood onwards was consistently associated with the presence of CVD risk factors, with increased risks of coronary heart disease, and there were suggestions of associations with stroke, atrial fibrillation and heart failure, but a lack of evidence precludes firm conclusions. These results indicate that the risk of CVD can be traced back to child ages and highlights the importance of primordial prevention of CVD by preventing excessive weight gain in childhood.

Coronary artery disease, genetic risk and the metabolome in young individuals

Background: Genome-wide association studies have identified genetic variants associated with coronary artery disease (CAD) in adults - the leading cause of death worldwide. It often occurs later in life, but variants may impact CAD-relevant phenotypes early and throughout the life-course. Cohorts with longitudinal and genetic data on thousands of individuals are letting us explore the antecedents of this adult disease. Methods: 148 metabolites, with a focus on the lipidome, measured using nuclear magnetic resonance ( 1H-NMR) spectroscopy, and genotype data were available from 5,907 individuals at ages 7, 15, and 17 years from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort. Linear regression was used to assess the association between the metabolites and an adult-derived genetic risk score (GRS) of CAD comprising 146 variants. Individual variant-metabolite associations were also examined. Results: The CAD-GRS associated with 118 of 148 metabolites (false discovery rate [FDR] < 0.05), the strongest associations being with low-density lipoprotein (LDL) and atherogenic non-LDL subgroups. Nine of 146 variants in the GRS associated with one or more metabolites (FDR < 0.05). Seven of these are within lipid loci: rs11591147 PCSK9, rs12149545 HERPUD1-CETP, rs17091891 LPL, rs515135 APOB, rs602633 CELSR2-PSRC1, rs651821 APOA5, rs7412 APOE-APOC1. All associated with metabolites in the LDL or atherogenic non-LDL subgroups or both including aggregate cholesterol measures. The other two variants identified were rs112635299 SERPINA1 and rs2519093 ABO. Conclusions: Genetic variants that influence CAD risk in adults are associated with large perturbations in metabolite levels in individuals as young as seven. The variants identified are mostly within lipid-related loci and the metabolites they associated with are primarily linked to lipoproteins. Along with further research, this knowledge could allow for preventative measures, such as increased monitoring of at-risk individuals and perhaps treatment earlier in life, to be taken years before any symptoms of the disease arise.

Association of body mass index with mortality in cardiovascular disease: New insights into the obesity paradox from multiple perspectives

Over the past 4 decades, prevalence of obesity has increased rapidly at both the national and global level and presents a major public health challenge. Obesity is associated with increased risk of morbidity from cardiovascular diseases. Data suggesting that the presence of obesity may be protective in individuals with clinically manifest cardiovascular disease have led to discussion of an "obesity paradox", stirring controversy and leading to unclear messaging regarding the true health risks of excess weight. This review explores the relationship between obesity and fatal and non-fatal outcomes in patients with prevalent cardiovascular disease and offers novel insights into the obesity paradox.

Genotype-Based Recall Studies in Complex Cardiometabolic Traits

In genotype-based recall (GBR) studies, people (or their biological samples) who carry genotypes of special interest for a given hypothesis test are recalled from a larger cohort (or biobank) for more detailed investigations. There are several GBR study designs that offer a range of powerful options to elucidate (1) genotype-phenotype associations (by increasing the efficiency of genetic association studies, thereby allowing bespoke phenotyping in relatively small cohorts), (2) the effects of environmental exposures (within the Mendelian randomization framework), and (3) gene-treatment interactions (within the setting of GBR interventional trials). In this review, we overview the literature on GBR studies as applied to cardiometabolic health outcomes. We also review the GBR approaches used to date and outline new methods and study designs that might enhance the utility of GBR-focused studies. Specifically, we highlight how GBR methods have the potential to augment randomized controlled trials, providing an alternative application for the now increasingly accepted Mendelian randomization methods usually applied to large-scale population-based data sets. Further to this, we consider how functional and basic science approaches alongside GBR designs offer intellectually intriguing and potentially powerful ways to explore the implications of alterations to specific (and potentially druggable) biological pathways.