21st Century Advances in Multimodality Imaging of Obesity for Care of the Cardiovascular Patient

Effect of liraglutide on thigh muscle fat and muscle composition in adults with overweight or obesity: Results from a randomized clinical trial

BACKGROUND

Excess muscle fat is observed in obesity and associated with greater burden of cardiovascular risk factors and higher risk of mortality. Liraglutide reduces total body weight and visceral fat but its effect on muscle fat and adverse muscle composition is unknown.

METHODS

This is a pre-specified secondary analysis of a randomized, double-blind, placebo-controlled trial that examined the effects of liraglutide plus a lifestyle intervention on visceral adipose tissue and ectopic fat among adults without diabetes with body mass index ≥30 kg/m2 or ≥27 kg/m2 and metabolic syndrome. Participants were randomly assigned to a once-daily subcutaneous injection of liraglutide (target dose 3.0 mg) or matching placebo for 40 weeks. Body fat distribution and muscle composition was assessed by magnetic resonance imaging at baseline and 40-week follow-up. Muscle composition was described by the combination of thigh muscle fat and muscle volume. Treatment difference (95% confidence intervals [CI]) was calculated by least-square means adjusted for baseline thigh muscle fat. The association between changes in thigh muscle fat and changes in body weight were assessed using Spearman correlation coefficients. The effect of liraglutide versus placebo on adverse muscle composition, denoted by high thigh muscle fat and low thigh muscle volume, was explored.

RESULTS

Among the 128 participants with follow-up imaging (92.2% women, 36.7% Black), median muscle fat at baseline was 7.8%. The mean percent change in thigh muscle fat over median follow-up of 36 weeks was -2.87% among participants randomized to liraglutide (n = 73) and 0.05% in the placebo group (absolute change: -0.23% vs. 0.01%). The estimated treatment difference adjusted for baseline thigh muscle fat was -0.24% (95% CI, -0.41 to -0.06, P-value 0.009). Longitudinal change in thigh muscle fat was significantly associated with change in body weight in the placebo group but not the liraglutide group. The proportion of participants with adverse muscle composition decreased from 11.0% to 8.2% over follow-up with liraglutide, but there was no change with placebo.

CONCLUSIONS

In a cohort of predominantly women with overweight or obesity in the absence of diabetes, once-daily subcutaneous liraglutide was associated with a reduction in thigh muscle fat and adverse muscle composition compared with placebo. The contribution of muscle fat improvement to the cardiometabolic benefits of liraglutide requires further study.

Multimodality Imaging in Metabolic Syndrome: State-of-the-Art Review

Metabolic syndrome comprises a set of risk factors that include abdominal obesity, impaired glucose tolerance, hypertriglyceridemia, low high-density lipoprotein levels, and high blood pressure, at least three of which must be fulfilled for diagnosis. Metabolic syndrome has been linked to an increased risk of cardiovascular disease and type 2 diabetes mellitus. Multimodality imaging plays an important role in metabolic syndrome, including diagnosis, risk stratification, and assessment of complications. CT and MRI are the primary tools for quantification of excess fat, including subcutaneous and visceral adipose tissue, as well as fat around organs, which are associated with increased cardiovascular risk. PET has been shown to detect signs of insulin resistance and may detect ectopic sites of brown fat. Cardiovascular disease is an important complication of metabolic syndrome, resulting in subclinical or symptomatic coronary artery disease, alterations in cardiac structure and function with potential progression to heart failure, and systemic vascular disease. CT angiography provides comprehensive evaluation of the coronary and systemic arteries, while cardiac MRI assesses cardiac structure, function, myocardial ischemia, and infarction. Liver damage results from a spectrum of nonalcoholic fatty liver disease ranging from steatosis to fibrosis and possible cirrhosis. US, CT, and MRI are useful in assessing steatosis and can be performed to detect and grade hepatic fibrosis, particularly using elastography techniques. Metabolic syndrome also has deleterious effects on the pancreas, kidney, gastrointestinal tract, and ovaries, including increased risk for several malignancies. Metabolic syndrome is associated with cerebral infarcts, best evaluated with MRI, and has been linked with cognitive decline. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Pickhardt in this issue.

Association of organ damage with predicted fat mass in a community-dwelling elderly: the Northern Shanghai study

BACKGROUND

Body fat mass (FM) is associated with multiple organ damage. However, data regarding the relationship between various organ damage and FM are rare in the elderly. Therefore, we aim to perform an analysis on the relationship between organ damage and FM in a geriatric cohort.

METHODS

3331 participants were included in this analysis. Based on age, body height, body weight, waist circumference, and race, we calculated FM with the established formula. Organ damage, including arterial stiffening, lower extremity atherosclerosis, left ventricular hypertrophy (LVH), micro-albuminuria, and chronic kidney disease (CKD), were measured and calculated with standard methods.

RESULTS

All organ damage parameters were significantly related to FM (all p < 0.001). In univariate logistics regression, the highest quartile of FM was tied to the increased risk of arterial stiffening, lower extremity atherosclerosis, LVH, micro-albuminuria, and CKD (all p < 0.05). After adjustment, participants with higher quantiles of FM had a significantly increased odd ratio (OR) for arterial stiffening [OR = 1.51, 95% confidence interval (CI): 1.15-1.99, p = 0.002] and LVH (OR = 1.99, 95% CI: 1.48-2.67, p < 0.001). Moreover, FM was linearly associated with arterial stiffening and LVH in total population and gender subgroups. Independent of confounders, FM was significantly correlated with arterial stiffening, lower extremity atherosclerosis, LVH and CKD in female, while was only related to LVH in male.

CONCLUSIONS

Among various organ damage, elevated FM is significantly and independently associated with arterial stiffening and LVH in the elderly. Compared with men, women with increased FM are more likely to have multiple organ damage.

Sex-Specific Changes in Body Composition Following Metabolic and Bariatric Surgery Are Associated with the Remission of Metabolic Syndrome

PURPOSE

Metabolic and bariatric surgery (MBS) is the most effective treatment for metabolic syndrome (MetS). However, the mechanism of MetS remission after MBS remains unclear. We aimed to explore the relationship between sex differences, body composition, and the remission of MetS after MBS.

MATERIALS AND METHODS

Cross-sectional study of 80 patients with obesity and MetS who underwent MBS with case-control design. The International Diabetes Federation criteria were used to define MetS. Body composition was measured using dual-energy X-ray absorptiometry before and 1 year after the operation. In addition to calculating changes in MetS and its prevalence, we performed a multiple logistic regression to determine predictors of MetS remission.

RESULTS

There were significant differences in body composition between males and females after MBS. Both males and females had significant improvements in the overall prevalence of MetS, decreasing from 100 to 21.74% (P <0.001) and from 100 to 35.29% (P <0.001), respectively. A higher percentage of visceral adipose tissue (VAT) reduction tends to be associated with a higher chance of MetS remission in men. In females, the MetS nonremission subgroup had a higher %Trunk lean body mass (LBM), and %Android LBM reduction than the remission subgroup, but the multiple logistic regression analysis result was not statistically significant.

CONCLUSION

After MBS, reduced VAT might be related to MetS reversibility in males, while reduced LBM may result in MetS nonremission in females.

Obesity in adult acute myeloid leukemia is not associated with inferior response or survival even when dose capping anthracyclines: An ECOG-ACRIN analysis

BACKGROUND

Obesity (body mass index [BMI] ≥30 kg/m2 ) is an important epidemiological risk factor for developing acute myeloid leukemia (AML). Therefore, the authors studied the association of obesity with clinical and genetic phenotype and its impact on outcome in adults with AML.

METHODS

The authors analyzed BMI in 1088 adults who were receiving intensive remission induction and consolidation therapy in two prospective, randomized therapeutic clinical trials of the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network: E1900 (ClinicalTrials.gov identifier NCT00049517; patients younger than 60 years) and E3999 (ClinicalTrials.gov identifier NCT00046930; patients aged 60 years or older).

RESULTS

Obesity was prevalent at diagnosis (33%) and, compared with nonobesity, was associated with intermediate-risk cytogenetics group (p = .008), poorer performance status (p = .01), and a trend toward older age (p = .06). Obesity was not associated with somatic mutations among a selected 18-gene panel that was tested in a subset of younger patients. Obesity was not associated with clinical outcome (including complete remission, early death, or overall survival), and the authors did not identify any patient subgroup that had inferior outcomes based on BMI. Obese patients were significantly more likely to receive <90% of the intended daunorubicin dose despite protocol specification, particularly in the E1900 high-dose (90 mg/m2 ) daunorubicin arm (p = .002); however, this did not correlate with inferior overall survival on multivariate analysis (hazard ratio, 1.39; 95% confidence interval, 0.90-2.13; p = .14).

CONCLUSIONS

Obesity is associated with unique clinical and disease-related phenotypic features in AML and may influence physician treatment decisions regarding daunorubicin dosing. However, the current study demonstrates that obesity is not a factor in survival, and strict adherence to body surface area-based dosing is not necessary because dose adjustments do not affect outcomes.

Obesity and the risk of cardiometabolic diseases

The prevalence of obesity has reached pandemic proportions, and now approximately 25% of adults in Westernized countries have obesity. Recognized as a major health concern, obesity is associated with multiple comorbidities, particularly cardiometabolic disorders. In this Review, we present obesity as an evolutionarily novel condition, summarize the epidemiological evidence on its detrimental cardiometabolic consequences and discuss the major mechanisms involved in the association between obesity and the risk of cardiometabolic diseases. We also examine the role of potential moderators of this association, with evidence for and against the so-called 'metabolically healthy obesity phenotype', the 'fatness but fitness' paradox or the 'obesity paradox'. Although maintenance of optimal cardiometabolic status should be a primary goal in individuals with obesity, losing body weight and, particularly, excess visceral adiposity seems to be necessary to minimize the risk of cardiometabolic diseases.

Heterogeneous Comorbidity in Individuals With Different Phenotypes of Obesity

Introduction The prevalence of obesity is steadily increasing worldwide. Obesity is one of the most potent risk factors for various diseases and is simultaneously a heterogeneous condition. Different types of obesity could be identified according to body mass index (BMI), waist circumference, and visceral fat level; these conditions may present individually or in combination and pose a risk of developing certain comorbidities. However, the current obesity classification systems do not allow for accurate diagnosis and prediction of the comorbidity risk of patients, which is crucial for their clinical management. This points to the importance of studying obesity phenotyping in the context of body composition. Our study aimed to determine the contribution of obesity phenotypes in forming various comorbidities. Materials and methods This case-control study was conducted at the Clinical and Diagnostic Center of the Aviastroitelny District, Kazan. Patients were selected based on BMI per inclusion and exclusion criteria. A total of 151 patients with a median age of 43 [34.5-50] years were included in the study. The participants were distributed into six groups according to BMI and a combination of abdominal obesity (AO) and excess visceral fat. Results The participants were distributed in the following phenogroups: The first group - normal BMI without AO and excess visceral fat (n=47; 31.1%); the second group - overweight without AO and excess visceral fat (n=26; 17.2%); the third group - normal BMI with AO and without excess visceral fat (n=11; 7.3%); fourth group - overweight with AO and without excess visceral fat (n=34; 22.5%); fifth group - general obesity with AO and without excess visceral fat (n=20; 13.2%); sixth group - general obesity with AO and excess visceral fat (n=13; 8.6%). The five most frequently observed conditions in the general cohort were dyslipidemia (71.5%; n=108), disorders of the gastrointestinal tract (53.0%; n=80), cardiovascular disease (46.4%; n=70), musculoskeletal diseases (40.4%; n=61) and impaired carbohydrate metabolism (25.2%; n=38). The median number of pathological combinations in the general cohort was 5 [IQR: 3-7]. As the group number increased, the median number of comorbidities also increased. While BMI was significantly associated only with arterial hypertension, the level of visceral fat was associated with most comorbidities (obstructive sleep apnea syndrome, non-alcoholic fatty liver disease, chronic pancreatitis, hypertriglyceridemia, and prediabetes), followed by abdominal obesity (gastroesophageal reflux disease, hypertriglyceridemia, arterial hypertension, hypercholesterolemia). Conclusions In working-age people, group 1 and 4 phenotypes were more frequent than others. Abdominal obesity and visceral fat were associated with the most comorbid conditions. However, the individual types of these comorbidities were not the same.

Epicardial fat links obesity to cardiovascular diseases

Patients with obesity have been historically associated with higher risk to develop cardiovascular diseases (CVD). However, regional, visceral, organ specific adiposity seems to play a stronger role in the development of those cardiovascular diseases than obesity by itself. Epicardial adipose tissue is the visceral fat depot of the heart with peculiar anatomy, regional differences, genetic profile and functions. Due to its unobstructed contiguity with heart and intense pro inflammatory and pro arrhythmogenic activities, epicardial fat is directly involved in major obesity-related CVD complications, such as coronary artery disease (CAD), atrial fibrillation (AF) and heart failure (HF). Current and developing imaging techniques can measure epicardial fat thickness, volume, density and inflammatory status for the prediction and stratification of the cardiovascular risk in both symptomatic and asymptomatic obese individuals. Pharmacological modulation of the epicardial fat with glucagon like peptide-1 receptor (GLP1R) analogs, sodium glucose transporter-2 inhibitors, and potentially dual (glucose-dependent insulinotropic polypeptide -GLP1R) agonists, can reduce epicardial fat mass, resume its original cardio-protective functions and therefore reduce the cardiovascular risk. Epicardial fat assessment is poised to change the traditional paradigm that links obesity to the heart.

Relationship of anthropometric measurements and percent body fat mass to cardiovascular disease risk factors in adults with cerebral palsy

INTRODUCTION

Adults with cerebral palsy (CP) face high morbidity from cardiovascular disease (CVD). Of concern, classic screening parameters are inconsistent in identifying CVD risk in this population. Dual-energy x-ray absorptiometry (DEXA), which provides direct measurements of fat mass (FM), may be an alternative screening method.

OBJECTIVE

To evaluate whether FM measurement with DEXA is feasible in screening adults with CP and compare FM and anthropometric measures to CVD risk factors.

DESIGN

Cross-sectional study.

SETTING

Outpatient rehabilitation hospital.

PARTICIPANTS

Forty-seven adults with CP.

MAIN OUTCOME MEASURES

Weight, height, waist circumference (WC), and hip circumference (HC) were measured; waist-to-hip ratio (WHR) and body mass index (BMI) were calculated. Blood pressure (BP), FM by DEXA, hemoglobin A1c (HbA1c), and lipid measurements were obtained. Logistic regression models investigated odds ratios (ORs) and 95% confidence intervals (CIs) between anthropometric measurements/FM and CVD risk factors; correlations were assessed using Pearson correlation coefficients.

RESULTS

Elevated BP or hypertension diagnosis was present in 47.8%; HbA1c ≥5.7% in 22.2%; and high-density lipoprotein (HDL) level below optimal for 33.3%. DEXA FM was obtained in 29 of 47 participants, as surgical metal and positioning limited many studies. Excess FM was noted in 75.9% versus 41.3% overweight/obese by BMI. WC correlated with HbA1c (r = 0.46, p = .002), HDL (r = -0.36, p = .018), and triglyceride (TG) levels (r = 0.30, p = .045); however at-risk WC values were associated only with odds of elevated HbA1c (OR 8.53, 95% CI 1.46-50.05; p = .018). HC correlated with HbA1c levels (r = 0.38, p = .011) and systolic BPs (r = 0.35, p = .019); similarly, ORs for elevated HC were weakly associated with elevated HbA1c and BPs (OR 1.08, 95% CI 1.01-1.16; p = .024 and OR 1.07, 95% CI 1.01-1.14; p = .024, respectively). WHR correlated with TGs; however few TG levels were elevated. FM measures were not associated with at-risk lab values or BPs.

CONCLUSIONS

DEXA FM measurements may not be feasible for CVD screening in many adults with CP. Although CVD risk factors are frequently present, anthropometric measurements commonly used for general population screening may not translate well to adults with CP.

Obesity and Cancer: A Current Overview of Epidemiology, Pathogenesis, Outcomes, and Management

BACKGROUND

Obesity or excess body fat is a major global health challenge that has not only been associated with diabetes mellitus and cardiovascular disease but is also a major risk factor for the development of and mortality related to a subgroup of cancer. This review focuses on epidemiology, the relationship between obesity and the risk associated with the development and recurrence of cancer and the management of obesity.

METHODS

A literature search using PubMed and Google Scholar was performed and the keywords 'obesity' and cancer' were used. The search was limited to research papers published in English prior to September 2022 and focused on studies that investigated epidemiology, the pathogenesis of cancer, cancer incidence and the risk of recurrence, and the management of obesity.

RESULTS

About 4-8% of all cancers are attributed to obesity. Obesity is a risk factor for several major cancers, including post-menopausal breast, colorectal, endometrial, kidney, esophageal, pancreatic, liver, and gallbladder cancer. Excess body fat results in an approximately 17% increased risk of cancer-specific mortality. The relationship between obesity and the risk associated with the development of cancer and its recurrence is not fully understood and involves altered fatty acid metabolism, extracellular matrix remodeling, the secretion of adipokines and anabolic and sex hormones, immune dysregulation, and chronic inflammation. Obesity may also increase treatment-related adverse effects and influence treatment decisions regarding specific types of cancer therapy. Structured exercise in combination with dietary support and behavior therapy are effective interventions. Treatment with glucagon-like peptide-1 analogues and bariatric surgery result in more rapid weight loss and can be considered in selected cancer survivors.

CONCLUSIONS

Obesity increases cancer risk and mortality. Weight-reducing strategies in obesity-associated cancers are important interventions as a key component of cancer care. Future studies are warranted to further elucidate the complex relationship between obesity and cancer with the identification of targets for effective interventions.

Gliflozins: From Antidiabetic Drugs to Cornerstone in Heart Failure Therapy-A Boost to Their Utilization and Multidisciplinary Approach in the Management of Heart Failure

Heart failure (HF) is a complex, multifactorial, progressive clinical condition affecting 64.3 million people worldwide, with a strong impact in terms of morbidity, mortality and public health costs. In the last 50 years, along with a better understanding of HF physiopathology and in agreement with the four main models of HF, many therapeutic options have been developed. Recently, the European Society of Cardiology (ESC) HF guidelines enthusiastically introduced inhibitors of the sodium-glucose cotransporter (SGLT2i) as first line therapy for HF with reduced ejection fraction (HFrEF) in order to reduce hospitalizations and mortality. Despite drugs developed as hypoglycemic agents, data from the EMPA-REG OUTCOME trial encouraged the evaluation of the possible cardiovascular effects, showing SGLT2i beneficial effects on loading conditions, neurohormonal axes, heart cells' biochemistry and vascular stiffness, determining an improvement of each HF model. We want to give a boost to their use by increasing the knowledge of SGLT2-I and understanding the probable mechanisms of this new class of drugs, highlighting strengths and weaknesses, and providing a brief comment on major trials that made Gliflozins a cornerstone in HF therapy. Finally, aspects that may hinder SGLT2-i widespread utilization among different types of specialists, despite the guidelines' indications, will be discussed.

Disruption of adipocyte HIF-1α improves atherosclerosis through the inhibition of ceramide generation

Atherosclerosis is a chronic multifactorial cardiovascular disease. Western diets have been reported to affect atherosclerosis through regulating adipose function. In high cholesterol diet-fed ApoE^–/– mice, adipocyte HIF-1α deficiency or direct inhibition of HIF-1α by the selective pharmacological HIF-1α inhibitor PX-478 alleviates high cholesterol diet-induced atherosclerosis by reducing adipose ceramide generation, which lowers cholesterol levels and reduces inflammatory responses, resulting in improved dyslipidemia and atherogenesis. Smpd3, the gene encoding neutral sphingomyelinase, is identified as a new target gene directly regulated by HIF-1α that is involved in ceramide generation. Injection of lentivirus-SMPD3 in epididymal adipose tissue reverses the decrease in ceramides in adipocytes and eliminates the improvements on atherosclerosis in the adipocyte HIF-1α-deficient mice. Therefore, HIF-1α inhibition may constitute a novel approach to slow atherosclerotic progression.

Diabetes Status Modifies the Association Between Different Measures of Obesity and Heart Failure Risk Among Older Adults: A Pooled Analysis of Community-Based NHLBI Cohorts

BACKGROUND

Obesity and diabetes are associated with a higher risk of heart failure (HF). The interrelationships between different measures of adiposity-overall obesity, central obesity, fat mass (FM)-and diabetes status for HF risk are not well-established.

METHODS

Participant-level data from the ARIC study (Atherosclerosis Risk in Communities; visit 5) and the CHS (Cardiovascular Health Study; visit 1) cohorts were obtained from the National Heart, Lung, and Blood Institute Biologic Specimen and Data Repository Information Coordinating Center, harmonized, and pooled for the present analysis, excluding individuals with prevalent HF. FM was estimated in all participants using established anthropometric prediction equations additionally validated using the bioelectrical impedance-based FM in the ARIC subgroup. Incident HF events on follow-up were captured across both cohorts using similar adjudication methods. Multivariable-adjusted Fine-Gray models were created to evaluate the associations of body mass index (BMI), waist circumference (WC), and FM with risk of HF in the overall cohort as well as among those with versus without diabetes at baseline. The population attributable risk of overall obesity (BMI≥30 kg/m²), abdominal obesity (WC>88 and 102 cm in women and men, respectively), and high FM (above sex-specific median) for incident HF was evaluated among participants with and without diabetes.

RESULTS

The study included 10 387 participants (52.9% ARIC; 25.1% diabetes; median age, 74 years). The correlation between predicted and bioelectrical impedance-based FM was high (R²=0.90; n=5038). During a 5-year follow-up, 447 participants developed HF (4.3%). Higher levels of each adiposity measure were significantly associated with higher HF risk (hazard ratio [95% CI] per 1 SD higher BMI=1.15 [1.05, 1.27], WC=1.22 [1.10, 1.36]; FM=1.13 [1.02, 1.25]). A significant interaction was noted between diabetes status and measures of BMI (P interaction=0.04) and WC (P interaction=0.004) for the risk of HF. In stratified analysis, higher measures of each adiposity parameter were significantly associated with higher HF risk in individuals with diabetes (hazard ratio [95% CI] per 1 SD higher BMI=1.29 [1.14-1.47]; WC=1.48 [1.29-1.70]; FM=1.25 [1.09-1.43]) but not those without diabetes, including participants with prediabetes and euglycemia. The population attributable risk percentage of overall obesity, abdominal obesity, and high FM for incident HF was higher among participants with diabetes (12.8%, 29.9%, and 13.7%, respectively) versus those without diabetes (≤1% for each).

CONCLUSIONS

Higher BMI, WC, and FM are strongly associated with greater risk of HF among older adults, particularly among those with prevalent diabetes.

Mechanistic Insights of Empagliflozin in Nondiabetic Patients With HFrEF: From the EMPA-TROPISM Study

OBJECTIVES

The goal of this study was to evaluate the effect of empagliflozin, in addition to optimal medical treatment, on epicardial adipose tissue (EAT), interstitial myocardial fibrosis, and aortic stiffness in nondiabetic patients with heart failure with reduced ejection fraction (HFrEF).

BACKGROUND

Several randomized clinical trials have established the benefits of the inhibitors of the sodium-glucose cotransporter-2 receptor (SGLT2-i) in HFrEF, independent of their hypoglycemic effects. The mechanisms of the benefits of SGLT2-i in HFrEF have not been well defined.

METHODS

This study was a secondary analysis of patients enrolled in the EMPA-TROPISM [ATRU-4] (Are the cardiac benefits of Empagliflozin independent of its hypoglycemic activity?) clinical trial. It was a double-blind, placebo-controlled randomized clinical trial investigating the effect of empagliflozin in nondiabetic patients with HFrEF. Patients underwent cardiac magnetic resonance at baseline and after 6 months. Interstitial myocardial fibrosis was calculated by using T₁ mapping (extracellular volume). Aortic stiffness was calculated by using pulsed wave velocity, and EAT was measured from the cine sequences.

RESULTS

Empagliflozin is associated with significant reductions in EAT volume (-5.14 mL; 95% CI: -8.36 to -1.92) compared with placebo (-0.75 mL; 95% CI: -3.57 to 2.06; P < 0.05); this finding was paralleled by reductions in subcutaneous adipose tissue area (-5.33 cm² [95% CI: -12.61 to 1.95] vs 9.13 cm² [95% CI: -2.72 to 20.99]; P < 0.05). Empagliflozin-treated patients reported a reduction in extracellular volume (-1.25% [±0.56 95% CI] vs 0.24% [±0.57 95% CI]; (P < 0.01)]; specifically, empagliflozin reduced both matrix volume (-7.24 mL [95% CI: -11.59 to -2.91] vs 0.70 mL [95% CI: -0.89 to 2.29]; P < 0.001) and cardiomyocyte volume (-11.08 mL [95% CI: -19.62 to -2.55] vs 0.80 mL [95% CI: -1.96 to 3.55]; P < 0.05). Pulsed wave velocity was also significantly reduced in the empagliflozin group (-0.58 cm/s [95% CI: -0.92 to -0.25] vs 0.60 cm/s [95% CI: 0.14 to 1.06]; P < 0.01). Using proteomics, empagliflozin was associated with a significant reduction in inflammatory biomarkers.

CONCLUSIONS

Empagliflozin significantly improved adiposity, interstitial myocardial fibrosis, aortic stiffness, and inflammatory markers in nondiabetic patients with HFrEF. These results shed new light on the mechanisms of action of the benefits of SGLT2-i. (Are the "Cardiac Benefits" of Empagliflozin Independent of Its Hypoglycemic Activity [ATRU-4] [EMPA-TROPISM]; NCT03485222).

Regional adiposity, cardiorespiratory fitness, and left ventricular strain: an analysis from the Dallas Heart Study

BACKGROUND

Low cardiorespiratory fitness (CRF), high body mass index, and excess visceral adiposity are each associated with impairment in left ventricular (LV) peak circumferential strain (Ecc), an intermediate phenotype that precedes the development of clinical heart failure (HF). However, the association of regional fat distribution and CRF with Ecc independent of each other and other potential confounders is not known.

METHODS

Participants from the Dallas Heart Study Phase 2 who underwent dual energy X-ray absorptiometry assessment of regional fat distribution, CRF assessment by submaximal treadmill test, and Ecc quantification by tissue-tagged cardiovascular magnetic resonance were included in the analysis. The cross-sectional associations of measures of regional adiposity, namely visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and lower-body fat (LBF) with Ecc after adjustment for CRF and other potential confounders (independent variables) were assessed using multivariable linear regression analysis.

RESULTS

The study included 1089 participants (55% female, 39% black). In the unadjusted analysis, higher VAT was associated with greater impairment in Ecc. After adjustment for baseline risk factors, CRF, parameters of LV structure and function, and other fat depots such as SAT and LBF, higher VAT remained associated with greater impairment in Ecc (β: 0.19, P = 0.002). SAT and LBF were not significantly associated with Ecc, however, CRF remained associated with Ecc in the fully adjusted model including all fat depots (β: - 0.15, P < 0.001).

CONCLUSIONS

VAT and CRF are each independently associated with impairment in Ecc, suggesting that higher VAT burden and low CRF mediate pathological cardiac remodeling through distinct mechanisms.

Cardiac Adiposity and Arrhythmias: The Role of Imaging

Increased cardiac fat depots are metabolically active tissues that have a pronounced pro-inflammatory nature. Increasing evidence supports a potential role of cardiac adiposity as a determinant of the substrate of atrial fibrillation and ventricular arrhythmias. The underlying mechanism appears to be multifactorial with local inflammation, fibrosis, adipocyte infiltration, electrical remodeling, autonomic nervous system modulation, oxidative stress and gene expression playing interrelating roles. Current imaging modalities, such as echocardiography, computed tomography and cardiac magnetic resonance, have provided valuable insight into the relationship between cardiac adiposity and arrhythmogenesis, in order to better understand the pathophysiology and improve risk prediction of the patients, over the presence of obesity and traditional risk factors. However, at present, given the insufficient data for the additive value of imaging biomarkers on commonly used risk algorithms, the use of different screening modalities currently is indicated for personalized risk stratification and prognostication in this setting.

Review: Obesity and COVID-19: A Detrimental Intersection

Obesity has been recognized as an independent risk factor for critical illness and major severity in subjects with coronavirus disease 2019 (COVID-19). The role of fat distribution, particularly visceral fat (often linked to metabolic abnormalities), is still unclear. The adipose tissue represents a direct source of cytokines responsible for the pathological modifications occurring within adipose tissue in obese subjects. Adipokines are a crucial connection between metabolism and immune system: their dysregulation in obesity contributes to chronic low-grade systemic inflammation and metabolic comorbidities. Therefore the increased amount of visceral fat can lead to a proinflammatory phenotypic shift. This review analyzes the interrelation between obesity and COVID-19 severity, as well as the cellular key players and molecular mechanisms implicated in adipose inflammation, investigating if adipose tissue can constitute a reservoir for viral spread, and contribute to immune activation and cytokines storm. Targeting the underlying molecular mechanisms might have therapeutic potential in the management of obesity-related complications in COVID-19 patients.

Association of Baseline and Longitudinal Changes in Body Composition Measures With Risk of Heart Failure and Myocardial Infarction in Type 2 Diabetes: Findings From the Look AHEAD Trial

BACKGROUND

Intentional weight loss is associated with lower risk of heart failure (HF) and atherosclerotic cardiovascular disease among patients with type 2 diabetes. However, the contribution of baseline measures and longitudinal changes in fat mass (FM), lean mass (LM), and waist circumference (WC) to the risk of HF and myocardial infarction (MI) in type 2 diabetes is not well established.

METHODS

Adults from the Look AHEAD trial (Action for Health in Diabetes) without prevalent HF were included. FM and LM were predicted using validated equations and compared with dual-energy x-ray absorptiometry measurements in a subgroup. Adjusted Cox models were used to evaluate the associations of baseline and longitudinal changes in FM, LM, and WC over 1- and 4-year follow-up with risk of overall HF, HF with preserved ejection fraction (EF; EF ≥50%), HF with reduced EF (EF <50%), and MI.

RESULTS

Among 5103 participants, there were 257 incident HF events over 12.4 years of follow-up. Predicted and measured FM/LM were highly correlated (R²=0.87-0.90; n=1369). FM and LM decreased over 4-year follow-up with greater declines in the intensive lifestyle intervention arm. In adjusted analysis, baseline body composition measures were not significantly associated with HF risk. Decline in FM and WC, but not LM, over 1 year were each significantly associated with lower risk of overall HF (adjusted hazard ratio per 10% decrease in FM, 0.80 [95% CI, 0.68-0.95]; adjusted hazard ratio per 10% decrease in WC, 0.77 [95% CI, 0.62-0.95]). Decline in FM was significantly associated with lower risk of both HF subtypes. In contrast, decline in WC was significantly associated with lower risk of HF with preserved EF but not HF with reduced EF. Similar patterns of association were observed for 4-year changes in body composition and HF risk. Longitudinal changes in body composition were not significantly associated with risk of MI.

CONCLUSIONS

In adults with type 2 diabetes, a lifestyle intervention is associated with significant loss of FM and LM. Declines in FM and WC, but not LM, were each significantly associated with lower risk of HF but not MI. Furthermore, decline in WC was significantly associated with lower risk of HF with preserved EF but not HF with reduced EF. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00017953.

The impact of obesity on severe disease and mortality in people with SARS-CoV-2: A systematic review and meta-analysis

Background

Obesity accompanied by excess ectopic fat storage has been postulated as a risk factor for severe disease in people with SARS-CoV-2 through the stimulation of inflammation, functional immunologic deficit and a pro-thrombotic disseminated intravascular coagulation with associated high rates of venous thromboembolism.

Methods

Observational studies in COVID-19 patients reporting data on raised body mass index at admission and associated clinical outcomes were identified from MEDLINE, Embase, Web of Science and the Cochrane Library up to 16 May 2020. Mean differences and relative risks (RR) with 95% confidence intervals (CIs) were aggregated using random effects models.

Results

Eight retrospective cohort studies and one cohort prospective cohort study with data on of 4,920 patients with COVID-19 were eligible. Comparing BMI ≥ 25 vs <25 kg/m², the RRs (95% CIs) of severe illness and mortality were 2.35 (1.43-3.86) and 3.52 (1.32-9.42), respectively. In a pooled analysis of three studies, the RR (95% CI) of severe illness comparing BMI > 35 vs <25 kg/m² was 7.04 (2.72-18.20). High levels of statistical heterogeneity were partly explained by age; BMI ≥ 25 kg/m² was associated with an increased risk of severe illness in older age groups (≥60 years), whereas the association was weaker in younger age groups (<60 years).

Conclusions

Excess adiposity is a risk factor for severe disease and mortality in people with SARS-CoV-2 infection. This was particularly pronounced in people 60 and older. The increased risk of worse outcomes from SARS-CoV-2 infection in people with excess adiposity should be taken into account when considering individual and population risks and when deciding on which groups to target for public health messaging on prevention and detection measures. Systematic review registration: PROSPERO 2020: CRD42020179783.

Obesity and Outcomes in COVID-19: When an Epidemic and Pandemic Collide

Obesity has reached epidemic proportions in the United States and in much of the westernized world, contributing to considerable morbidity. Several of these obesity-related morbidities are associated with greater risk for death with coronavirus disease 2019 (COVID-19). Severe acute respiratory syndrome coronavirus 2 penetrates human cells through direct binding with angiotensin-converting enzyme 2 receptors on the cell surface. Angiotensin-converting enzyme 2 expression in adipose tissue is higher than that in lung tissue, which means that adipose tissue may be vulnerable to COVID-19 infection. Obese patients also have worse outcomes with COVID-19 infection, including respiratory failure, need for mechanical ventilation, and higher mortality. Clinicians need to be more aggressive when treating obese, especially severely obese, patients with COVID-19 infection.