A double-blind, placebo-controlled, randomised trial to assess the effect of liraglutide on ectopic fat accumulation in South Asian type 2 diabetes patients

Impact of Visceral and Hepatic Fat on Cardiometabolic Health

PURPOSE OF REVIEW

Body fat distribution plays a significant role in the cardiometabolic consequences of obesity. We review the impact of visceral and hepatic fat and highlight important interventions.

RECENT FINDINGS

Several epidemiologic studies have established a clear association between visceral fat and cardiovascular disease. The association between hepatic fat and cardiovascular disease is less clear with discordant results. Novel evidence demonstrates sodium glucose co-transporter-2 (SGLT2) inhibitors facilitate modest weight loss and reductions in ectopic fat depots in patient with type 2 diabetes. Glucagon-like peptide-1 (GLP-1) receptor agonists have been associated with decreased visceral/hepatic fat and reductions in MACE in populations with type 2 diabetes and with overweight/obesity. Clear associations between visceral fat and cardiometabolic outcomes have been established, whereas the impact of hepatic fat remains less clear. Lifestyle modification and pharmacologic interventions remain the initial therapies, while surgical intervention is associated with improved long-term outcomes. Emerging therapies have demonstrated a profound impact on body fat distribution and cardiometabolic risk.

MR Assessed Changes of Renal Sinus Fat in Response to Glucose Regulation in West European and South Asian Patients With Type 2 Diabetes

BACKGROUND

Ethnic differences in the progression and outcome of diabetic kidney disease (DKD) remain to be elucidated. MRI-quantified renal sinus fat volume could be a potential biomarker to help investigate the changes of DKD risk in response to glucose regulation.

PURPOSE

To evaluate whether the effect of glucose-lowering treatment on renal sinus fat volume differed in West Europeans (WE) compared to South Asians (SA), and whether ethnic-related difference exists regarding the effect of liraglutide on renal sinus fat.

STUDY TYPE

Retrospective.

POPULATION

Ninety-three patients with type 2 diabetes mellitus, including 47 WE (27 males) aged 59.3 ± 6.5 years, and 46 SA (19 males) aged 54.4 ± 9.8 years.

FIELD STRENGTH/SEQUENCE

3.0 T dual-echo fast gradient-echo pulse sequence using two-point Dixon technique with a phase-correction algorithm.

ASSESSMENT

Changes of renal sinus fat volume were measured by a radiologist (LL) with 4-years' experience, and were compared between the two ethnic groups, together with glycemic level, metabolic risk factors and renal function. The effects of liraglutide were assessed.

STATISTICAL TESTS

Normality of the data was visually evaluated by histograms and Q-Q plots. Within-group and between-group differences were analyzed using paired t-tests and analysis of covariance. Associations were analyzed by person's correlation and multiple linear regression models.

RESULTS

Renal sinus fat decreased in SA patients (Δ% = -7.6% ± 14.8%), but increased in WE patients (Δ% = 5.0% ± 13.1%), with a significant difference between the two ethnic groups. In the WE group, the increase of sinus fat volume was significant in the placebo subgroup (Δ% = 6.8% ± 12.5%), in contrast to the nonsignificant increase in the liraglutide subgroup (Δ% = 3.0% ± 13.8%, P = 0.444).

DATA CONCLUSION

Renal sinus fat accumulation responds differently to glucose regulation, showing a reduction in SA patients in contrast to a persistent accumulation in WE patients. A trend of less accumulation of sinus fat in WE patients receiving liraglutide has been observed.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 4.

Growth differentiation factor 15 is not modified after weight loss induced by liraglutide in South Asians and Europids with type 2 diabetes mellitus

Glucagon-like peptide-1 receptor (GLP-1R) agonists induce weight loss in patients with type 2 diabetes mellitus (T2DM), but the underlying mechanism is unclear. Recently, the mechanism by which metformin induces weight loss could be explained by an increase in growth differentiation factor 15 (GDF15), which suppresses appetite. Therefore, we aimed to investigate whether the GLP-1R agonist liraglutide modifies plasma GDF15 levels in patients with T2DM. GDF15 levels were measured in plasma samples obtained from Dutch Europids and Dutch South Asians with T2DM before and after 26 weeks of treatment with daily liraglutide (n = 44) or placebo (n = 50) added to standard care. At baseline, circulating GDF15 levels did not differ between South Asians and Europids with T2DM. Treatment with liraglutide, compared to placebo, decreased body weight, but did not modify plasma GDF15 levels in all patients, or when data were split by ethnicity. Also, the change in plasma GDF15 levels after treatment with liraglutide did not correlate with changes in body weight or HbA1c levels. In addition, the dose of metformin used did not correlate with baseline plasma GDF15 levels. Compared to placebo, liraglutide treatment for 26 weeks does not modify plasma GDF15 levels in Dutch Europid or South Asian patients with T2DM. Thus, the weight loss induced by liraglutide is likely explained by other mechanisms beyond the GDF15 pathway. HIGHLIGHTS: What is the central question of this study? Growth differentiation factor 15 (GDF15) suppresses appetite and is increased by metformin: does the GLP-1R agonist liraglutide modify plasma GDF15 levels in patients with type 2 diabetes mellitus (T2DM)? What is the main finding and its importance? Plasma GDF15 levels did not differ between South Asians and Europids with T2DM and were not modified by 26 weeks of liraglutide in either ethnicity. Moreover, there was no correlation between the changes in plasma GDF15 levels and dosage of metformin administered, changes in body weight or HbA1c levels. The appetite-suppressing effect of liraglutide is likely exerted via pathways other than GDF15.

Excessive accumulation of epicardial adipose tissue promotes microvascular obstruction formation after myocardial ischemia/reperfusion through modulating macrophages polarization

BACKGROUND

Owing to its unique location and multifaceted metabolic functions, epicardial adipose tissue (EAT) is gradually emerging as a new metabolic target for coronary artery disease risk stratification. Microvascular obstruction (MVO) has been recognized as an independent risk factor for unfavorable prognosis in acute myocardial infarction patients. However, the concrete role of EAT in the pathogenesis of MVO formation in individuals with ST-segment elevation myocardial infarction (STEMI) remains unclear. The objective of the study is to evaluate the correlation between EAT accumulation and MVO formation measured by cardiac magnetic resonance (CMR) in STEMI patients and clarify the underlying mechanisms involved in this relationship.

METHODS

Firstly, we utilized CMR technique to explore the association of EAT distribution and quantity with MVO formation in patients with STEMI. Then we utilized a mouse model with EAT depletion to explore how EAT affected MVO formation under the circumstances of myocardial ischemia/reperfusion (I/R) injury. We further investigated the immunomodulatory effect of EAT on macrophages through co-culture experiments. Finally, we searched for new therapeutic strategies targeting EAT to prevent MVO formation.

RESULTS

The increase of left atrioventricular EAT mass index was independently associated with MVO formation. We also found that increased circulating levels of DPP4 and high DPP4 activity seemed to be associated with EAT increase. EAT accumulation acted as a pro-inflammatory mediator boosting the transition of macrophages towards inflammatory phenotype in myocardial I/R injury through secreting inflammatory EVs. Furthermore, our study declared the potential therapeutic effects of GLP-1 receptor agonist and GLP-1/GLP-2 receptor dual agonist for MVO prevention were at least partially ascribed to its impact on EAT modulation.

CONCLUSIONS

Our work for the first time demonstrated that excessive accumulation of EAT promoted MVO formation by promoting the polarization state of cardiac macrophages towards an inflammatory phenotype. Furthermore, this study identified a very promising therapeutic strategy, GLP-1/GLP-2 receptor dual agonist, targeting EAT for MVO prevention following myocardial I/R injury.

Influence of glucagon-like peptide-1 receptor agonists on fat accumulation in patients with diabetes mellitus and non-alcoholic fatty liver disease or obesity: A systematic review and meta-analysis of randomized control trials

AIM

This systematic review and meta-analysis aimed to comprehensively evaluate the impact of glucagon-like peptide 1 receptor agonists (GLP-1RAs) on visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in individuals with diabetes mellitus and non-alcoholic fatty liver disease (NAFLD) or obesity.

METHODS

A search of PubMed, Embase, and Web of Science until October 2023 identified 13 Randomized Controlled Trials (RCTs) meeting the inclusion criteria. Bias risk was assessed using the Cochrane risk-of-bias instrument. Statistical analysis utilized standard mean differences (SMD) in Review Manager 5.4. Heterogeneity and publication bias were assessed. This study used the protocol registered with the Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY2023110020).

RESULTS

GLP-1RA treatment significantly reduced VAT (SMD -0.55, 95 % CI [-0.90, -0.19]), SAT (SMD -0.59, 95 % CI [-0.99, -0.19]), body weight (SMD -1.07, 95 % CI [-1.67, -0.47]), and body mass index (BMI) (SMD -1.10, 95 % CI [-1.74, -0.47]) compared to controls. Heterogeneity was observed for VAT (I2 = 79 %, P < 0.01), SAT (I2 = 73 %, P < 0.01), body weight (I2 = 82 %, P < 0.01), and BMI (I2 = 82 %, P < 0.01). No publication bias was detected for VAT (P = 0.57) and SAT (P = 0.18). GLP-1RA treatment improved fasting blood glucose (FBG), postprandial glucose (PPG), hemoglobin A1c (HbA1c), Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), and fibrosis-4 (FIB-4).

CONCLUSIONS

This meta-analysis highlights GLP-1RAs' potential to reduce fat accumulation, body weight, and BMI and improve glycemic control in individuals with diabetes mellitus and NAFLD or obesity. These findings supported using GLP-1RAs as promising therapeutic agents to address abnormal adipose tissue distribution and metabolic dysfunction.

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.

Epicardial Adipose Tissue: A Precise Biomarker for Cardiovascular Risk, Metabolic Diseases, and Target for Therapeutic Interventions

Epicardial adipose tissue (EAT) is located between the heart muscle and visceral pericardium, where it has direct contact with coronary blood vessels. Elevated thickness of this tissue can induce local inflammation affecting the myocardium and the underlying coronary arteries, contributing to various cardiovascular diseases such as coronary artery disease, atrial fibrillation, or heart failure with preserved ejection fraction. Recent studies have identified EAT thickness as a simple and reliable biomarker for certain cardiovascular outcomes. Examples include the presence of atherosclerosis, incident cardiovascular disease (CVD) in individuals with type 2 diabetes mellitus (T2DM), and the prevalence of atrial fibrillation. Furthermore, EAT measurements can help to identify patients with a higher risk of developing metabolic syndrome. Since the EAT thickness can be easily measured using echocardiography, such examinations could serve as a useful and cost-effective preventive tool for assessing cardiovascular health. This review also summarizes therapeutical interventions aimed at reducing EAT. Reducing EAT thickness has been shown to be possible through pharmacological, surgical, or lifestyle-change interventions. Pharmaceutical therapies, including thiazolidinediones, glucagon-like peptide 1-receptor agonists, sodium-glucose cotransporter 2 inhibitors, dipeptidyl peptidase-4 inhibitors, and statins, have been shown to influence EAT thickness. Additionally, EAT thickness can also be managed more invasively through bariatric surgery, or noninvasively through lifestyle changes to diet and exercise routines.

Role of epicardial adipose tissue in diabetic cardiomyopathy through the lens of cardiovascular magnetic resonance imaging - a narrative review

Accumulating evidence suggests that ectopic/visceral adiposity may play a key role in the pathogenesis of nonischaemic cardiovascular diseases associated with type 2 diabetes. Epicardial adipose tissue (EAT) is a complex visceral fat depot, covering 80% of the cardiac surface with anatomical and functional contiguity to the myocardium and coronary arteries. EAT interacts with the biology of the underlying myocardium by secreting a wide range of adipokines. Magnetic resonance imaging (MRI) is the reference modality for structural and functional imaging of the heart. The technique is now also emerging as the reference imaging modality for EAT quantification. With this narrative review, we (a) surveyed contemporary clinical studies that utilized cardiovascular MRI to characterize EAT (studies published 2010-2023); (b) listed the clinical trials monitoring the response to treatment in EAT size as well as myocardial functional and structural parameters and (c) discussed the potential pathophysiological role of EAT in the development of diabetic cardiomyopathy. We concluded that increased EAT quantity and its inflammatory phenotype correlate with early signs of left ventricle dysfunction and may have a role in the pathogenesis of cardiac disease in diabetes with and without coronary artery disease.

Ethnic Disparities in Lipid Metabolism and Clinical Outcomes between Dutch South Asians and Dutch White Caucasians with Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) poses a higher risk for complications in South Asian individuals compared to other ethnic groups. To shed light on potential mediating factors, we investigated lipidomic changes in plasma of Dutch South Asians (DSA) and Dutch white Caucasians (DwC) with and without T2DM and explore their associations with clinical features. Using a targeted quantitative lipidomics platform, monitoring over 1000 lipids across 17 classes, along with 1H NMR based lipoprotein analysis, we studied 51 healthy participants (21 DSA, 30 DwC) and 92 T2DM patients (47 DSA, 45 DwC) from the MAGNetic resonance Assessment of VICTOza efficacy in the Regression of cardiovascular dysfunction in type 2 dIAbetes mellitus (MAGNA VICTORIA) study. This comprehensive mapping of the circulating lipidome allowed us to identify relevant lipid modules through unbiased weighted correlation network analysis, as well as disease and ethnicity related key mediatory lipids. Significant differences in lipidomic profiles, encompassing various lipid classes and species, were observed between T2DM patients and healthy controls in both the DSA and DwC populations. Our analyses revealed that healthy DSA, but not DwC, controls already exhibited a lipid profile prone to develop T2DM. Particularly, in DSA-T2DM patients, specific lipid changes correlated with clinical features, particularly diacylglycerols (DGs), showing significant associations with glycemic control and renal function. Our findings highlight an ethnic distinction in lipid modules influencing clinical outcomes in renal health. We discover distinctive ethnic disparities of the circulating lipidome and identify ethnicity-specific lipid markers. Jointly, our discoveries show great potential as personalized biomarkers for the assessment of glycemic control and renal function in DSA-T2DM individuals.

Epicardial adipose tissue, metabolic disorders, and cardiovascular diseases: recent advances classified by research methodologies

Epicardial adipose tissue (EAT) is located between the myocardium and visceral pericardium. The unique anatomy and physiology of the EAT determines its great potential in locally influencing adjacent tissues such as the myocardium and coronary arteries. Classified by research methodologies, this study reviews the latest research progress on the role of EAT in cardiovascular diseases (CVDs), particularly in patients with metabolic disorders. Studies based on imaging techniques demonstrated that increased EAT amount in patients with metabolic disorders is associated with higher risk of CVDs and increased mortality. Then, in-depth profiling studies indicate that remodeled EAT may serve as a local mediator of the deleterious effects of cardiometabolic conditions and plays a crucial role in CVDs. Further, in vitro coculture studies provided preliminary evidence that the paracrine effect of remodeled EAT on adjacent cardiomyocytes can promote the occurrence and progression of CVDs. Considering the important role of EAT in CVDs, targeting EAT might be a potential strategy to reduce cardiovascular risks. Several interventions have been proved effective in reducing EAT amount. Our review provides valuable insights of the relationship between EAT, metabolic disorders, and CVDs, as well as an overview of the methodological constructs of EAT-related studies.

Comparative efficacy of glucose-lowering drugs on liver steatosis as assessed by means of magnetic resonance imaging in patients with type 2 diabetes mellitus: systematic review and network meta-analysis

PURPOSE

To assess the comparative efficacy of glucose-lowering drugs on liver steatosis as assessed by means of magnetic resonance imaging (MRI) in patients with T2D.

METHODS

We searched several databases and grey literature sources. Eligible trials had at least 12 weeks of intervention, included patients with T2D, and assessed the efficacy of glucose-lowering drugs as monotherapies. The primary outcome of interest was absolute reduction in liver fat content (LFC), assessed by means of MRI. Secondary efficacy outcomes were reduction in visceral and subcutaneous adipose tissue. We performed random effects frequentist network meta-analyses to estimate mean differences (MDs) with 95% confidence intervals (CIs). We ranked treatments based on P-scores.

RESULTS

We included 29 trials with 1906 patients. Sodium-glucose cotransporter-2 (SGLT-2) inhibitors (P-score 0.84) and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) (0.71) were the most efficacious in terms of liver fat content reduction. Among individual agents, empagliflozin was the most efficacious (0.86) and superior to pioglitazone (MD -5.7, 95% CI -11.2 to -0.3) (very low confidence). GLP-1 RAs had also the most favorable effects on visceral and subcutaneous adipose tissue.

CONCLUSIONS

GLP-1 RAs and SGLT-2 inhibitors seem to be the most efficacious glucose-lowering drugs for liver steatosis in patients with T2D. Assessment of their efficacy on NAFLD in patients irrespective of presence of T2D is encouraged.

Comparison of the efficacy and safety of 10 glucagon-like peptide-1 receptor agonists as add-on to metformin in patients with type 2 diabetes: a systematic review

Purpose

This study aimed to perform a network meta-analysis to objectively evaluate the efficacy and safety of 10 Glucagon-like peptide-1 receptor agonists (GLP-1RAs) in combination with metformin that is approved for use worldwide in patients with type 2 diabetes and to provide evidence-based support and reference for the selection of clinical treatment.

Methods

Three databases (PubMed, Embase, and Cochrane Library) were searched from their respective inception until September 30, 2022. Only randomized controlled trials comparing the efficacy and safety of GLP-1RAs for treating type 2 diabetes (T2D) were included. The 10 GLP-1RAs are exenatide (including exenatide twice daily and once weekly), liraglutide, lixisenatide, dulaglutide, PEX168, semaglutide (subcutaneous and oral semaglutide), tirzepatide and albiglutide.

Results

34 RCTs with 10 GLP-1RAs and 12993 patients were included in the Network Meta-Analysis (NMA). According to the NMA, tirzepatide 15 mg, semaglutide 1.0 mg, PEX168-200μg, oral semaglutide 14 and dulaglutide 1.5 mg reduced HbA1c by -2.23%, -1.57%, -1.12%, -1.10%, -1.09% and body weight by -11.33 kg, -5.99 kg, +0.40 kg, -3.95 kg, -1.87 kg, respectively. There was no significant difference in the rate of adverse events for tirzepatide 15 mg, oral-semaglutide 14 mg, and semaglutide 1.0 mg. PEX168-200μg, tirzepatide 15mg, and oral semaglutide 14mg had Surface Under the Cumulative Ranking (SUCRA) values greater than placebo, and only tirzepatide 15mg and oral semaglutide 14mg were significantly different from placebo in the rate of serious adverse events. All GLP-1RA did not lead to increased incidence of hypoglycemia. Albiglutide 30mg and semaglutide 1.0mg significantly differed from placebo in Adverse Event (AE) withdrawal. Finally, the sensitivity analysis and publication bias analysis results indicate that the study results are reliable.

Conclusion

This study's results showed that GLP-1RAs were effective in lowering HbA1c and reducing body weight without increased incidence of hypoglycemic reactions. In addition, this study may provide reference and evidence-based medical evidence for clinicians to select GLP-1RAs in patients with T2D and high body mass index (BMI). Based on the NMA results, tirzepatide 15mg and semaglutide 1.0mg may be preferred.

The effects of GLP-1 receptor agonists on visceral fat and liver ectopic fat in an adult population with or without diabetes and nonalcoholic fatty liver disease: A systematic review and meta-analysis

AIM

To uncover the effect of GLP-1 receptor agonists (GLP-1 RAs) on the visceral- and hepatic fat content of adults.

METHODS

PubMed, EMBASE, Cochrane Library, and Web of Science were searched from inception until November 2022. Randomized controlled trials (RCTs) of GLP-1Ras was extracted, including reports of effects on visceral adipose tissue and hepatic fat content in individuals with type 2 diabetes, non-type 2 diabetes, NAFLD (non-alcoholic fatty liver disease), and non-NAFLD. Meta-analyses used random-effects models.

RESULTS

1736 individuals in the 30 qualified RCTs were included, comprising 1363 people with type 2 diabetes and 318 with NFLD. GLP-1 RAs reduced visceral adipose tissue (standard mean difference [SMD] = -0.59, 95% CI [-0.83, -0.36], P<0.00001) and hepatic fat content (weighted mean difference [WMD] = -3.09, 95% CI [-4.16, -2.02], P<0.00001) compared to other control treatment. Subgroup analysis showed that GLP-1Ras dramatically decreased visceral fat in patients with type 2 diabetes (SMD = -0.49, 95% CI [-0.69, -0.29] P<0.00001), NAFLD (SMD = -0.99, 95% CI [-1.64, -0.34] P = 0.003), non-type 2 diabetes (SMD = -1.38, 95% CI [-2.44, -0.32] P = 0.01), and non-NAFLD (SMD = -0.53, 95% CI [-0.78, -0.28] P<0.0001). GLP-1Ras reduced the liver fat level of type 2 diabetes (WMD = -3.15, 95% CI [-4.14, -2.15] P<0.00001), NAFLD (WMD = -3.83, 95% CI [-6.30, -1.37] P = 0.002), and type 2 diabetes with NAFLD (WMD = -4.27, 95% CI [-6.80, -1.74] P = 0.0009), while showed no impact on the hepatic fat content in non-Type 2 diabetes (WMD = -12.48, 95% CI [-45.19, 20.24] P = 0.45).

CONCLUSIONS

LP-1 RAs significantly reduce visceral- and liver fat content in adults.

Targeting epicardial adipose tissue: A potential therapeutic strategy for heart failure with preserved ejection fraction with type 2 diabetes mellitus

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with various comorbidities, multiple cardiac and extracardiac pathophysiologic abnormalities, and diverse phenotypic presentations. Since HFpEF is a heterogeneous disease with different phenotypes, individualized treatment is required. HFpEF with type 2 diabetes mellitus (T2DM) represents a specific phenotype of HFpEF, with about 45%-50% of HFpEF patients suffering from T2DM. Systemic inflammation associated with dysregulated glucose metabolism is a critical pathological mechanism of HFpEF with T2DM, which is intimately related to the expansion and dysfunction (inflammation and hypermetabolic activity) of epicardial adipose tissue (EAT). EAT is well established as a very active endocrine organ that can regulate the pathophysiological processes of HFpEF with T2DM through the paracrine and endocrine mechanisms. Therefore, suppressing abnormal EAT expansion may be a promising therapeutic strategy for HFpEF with T2DM. Although there is no treatment specifically for EAT, lifestyle management, bariatric surgery, and some pharmaceutical interventions (anti-cytokine drugs, statins, proprotein convertase subtilisin/kexin type 9 inhibitors, metformin, glucagon-like peptide-1 receptor agonists, and especially sodium-glucose cotransporter-2 inhibitors) have been shown to attenuate the inflammatory response or expansion of EAT. Importantly, these treatments may be beneficial in improving the clinical symptoms or prognosis of patients with HFpEF. Accordingly, well-designed randomized controlled trials are needed to validate the efficacy of current therapies. In addition, more novel and effective therapies targeting EAT are needed in the future.

Differences in Inflammatory Pathways Between Dutch South Asians vs Dutch Europids With Type 2 Diabetes

CONTEXT

South Asian individuals are more prone to develop type 2 diabetes (T2D) coinciding with earlier complications than Europids. While inflammation plays a central role in the development and progression of T2D, this factor is still underexplored in South Asians.

OBJECTIVE

This work aimed to study whether circulating messenger RNA (mRNA) transcripts of immune genes are different between South Asian compared with Europid patients with T2D.

METHODS

A secondary analysis was conducted of 2 randomized controlled trials of Dutch South Asian (n = 45; age: 55 ± 10 years, body mass index [BMI]: 29 ± 4 kg/m2) and Dutch Europid (n = 44; age: 60 ± 7 years, BMI: 32 ± 4 kg/m2) patients with T2D. Main outcome measures included mRNA transcripts of 182 immune genes (microfluidic quantitative polymerase chain reaction; Fluidigm Inc) in fasted whole-blood, ingenuity pathway analyses (Qiagen).

RESULTS

South Asians, compared to Europids, had higher mRNA levels of B-cell markers (CD19, CD79A, CD79B, CR2, CXCR5, IGHD, MS4A1, PAX5; all fold change > 1.3, false discovery rate [FDR] < 0.008) and interferon (IFN)-signaling genes (CD274, GBP1, GBP2, GBP5, FCGR1A/B/CP, IFI16, IFIT3, IFITM1, IFITM3, TAP1; all FC > 1.2, FDR < 0.05). In South Asians, the IFN signaling pathway was the top canonical pathway (z score 2.6; P < .001) and this was accompanied by higher plasma IFN-γ levels (FC = 1.5, FDR = 0.01). Notably, the ethnic difference in gene expression was larger for women (20/182 [11%]) than men (2/182 [1%]).

CONCLUSION

South Asian patients with T2D show a more activated IFN-signaling pathway compared to Europid patients with T2D, which is more pronounced in women than men. We speculate that a more activated IFN-signaling pathway may contribute to the more rapid progression of T2D in South Asian compared with Europid individuals.

Safety and efficacy of liraglutide on reducing visceral and ectopic fat in adults with or without type 2 diabetes mellitus: A systematic review and meta-analysis

AIM

To assess the efficacy and safety of liraglutide to reduce visceral and ectopic fat in adults with or without type 2 diabetes mellitus (T2DM).

METHODS

Four databases were searched up to 6 May 2022 for randomized clinical trials assessing the effect of liraglutide on visceral and ectopic fat. The mean and standard deviation of the values of visceral fat, ectopic fat and body mass index were calculated. Subgroup analyses were performed based on the type of disease (T2DM or non-T2DM), duration of intervention, dosage of liraglutide and whether life interventions were added to liraglutide therapy. We extracted and integrated the safety assessments reported in each article.

RESULTS

Sixteen randomized clinical trials with, in total, 845 participants were included in the meta-analysis. Liraglutide could significantly decrease visceral fat [standard mean difference (SMD) = -0.72, 95% confidence interval (CI; -1.12, -0.33)], liver fat [SMD = -0.78, 95% CI (-1.24, -0.32)] and body mass index [weighted mean difference = -1.44, 95% CI (-1.95, -0.92)] in adult patients with or without T2DM when compared with the control group. However, reduction of epicardial fat by liraglutide [SMD = -0.74, 95% CI (-1.82, 0.34)] was not statistically significant. Subgroup analysis revealed that an adequate dosage (≥1.8 mg/day) and appropriate duration of treatment (ranging from 16 to 40 weeks) were the decisive factors for liraglutide to reduce visceral fat effectively. Mild gastrointestinal reactions were the main adverse event of liraglutide.

CONCLUSIONS

Liraglutide significantly and safely reduces visceral and ectopic liver fat irrespective of T2DM status, and reduces visceral fat provided adequate dosage and duration of therapy are ensured.

Efficacy of cardiometabolic drugs in reduction of epicardial adipose tissue: a systematic review and meta-analysis

BACKGROUND

Epicardial adipose tissue (EAT) plays an important role in cardiometabolic risk. EAT is a modifiable risk factor and could be a potential therapeutic target for drugs that already show cardiovascular benefits. The aim of this study is to evaluate the effect of cardiometabolic drugs on EAT reduction.

METHODS

A detailed search related to the effect on EAT reduction due to cardiometabolic drugs, such as glucagon-like peptide-1 receptor agonist (GLP-1 RA), sodium-glucose cotransporter-2 inhibitors (SGLT2-i), and statins was conducted according to PRISMA guidelines. Eighteen studies enrolling 1064 patients were included in the qualitative and quantitative analyses.

RESULTS

All three analyzed drug classes, in particular GLP-1 RA, show a significant effect on EAT reduction (GLP-1 RA standardize mean difference (SMD) = - 1.005; p < 0.001; SGLT2-i SMD = - 0.552; p < 0.001, and statin SMD = - 0.195; p < 0.001). The sensitivity analysis showed that cardiometabolic drugs strongly benefit EAT thickness reduction, measured by ultrasound (overall SMD of - 0.663; 95%CI - 0.79, - 0.52; p < 0.001). Meta-regression analysis revealed younger age and higher BMI as significant effect modifiers of the association between cardiometabolic drugs and EAT reduction for both composite effect and effect on EAT thickness, (age Z: 3.99; p < 0.001 and Z: 1.97; p = 0.001, respectively; BMI Z: - 4.40; p < 0.001 and Z: - 2.85; p = 0.004, respectively).

CONCLUSIONS

Cardiometabolic drugs show a significant beneficial effect on EAT reduction. GLP-1 RA was more effective than SGLT2-i, while statins had a rather mild effect. We believe that the most effective treatment with these drugs should target younger patients with high BMI.

Benefits of GLP-1 Mimetics on Epicardial Adiposity

The epicardial adipose tissue, which is referred to as fats surrounding the myocardium, is an active organ able to induce cardiovascular problems in pathophysiologic conditions through several pathways, such as inflammation, fibrosis, fat infiltration, and electrophysiologic problems. So, control of its volume and thickness, especially in patients with diabetes, is highly important. Incretin-based pharmacologic agents are newly developed antidiabetics that could provide further cardiovascular benefits through control and modulating epicardial adiposity. They can reduce cardiovascular risks by rapidly reducing epicardial adipose tissues, improving cardiac efficiency. We are at the first steps of a long way, but current evidence demonstrates the sum of possible mechanisms. In this study, we evaluate epicardial adiposity in physiologic and pathologic states and the impact of incretin-based drugs.

Effect of glucagon-like peptide-1 receptor agonists on glycemic control, and weight reduction in adults: A multivariate meta-analysis

AIMS

To explore the effect of glucagon-like peptide-1 receptor agonist (GLP-1 RAs) on glycemic control and weight reduction in adults.

METHODS

Databases were searched from August 2021 to March 2022. Data were analyzed using mean difference (MD) values with 95% confidence intervals (CIs). Both random-and fixed-effect models were employed. Heterogeneity was explored using pre-specified subgroup analyses and meta-regression. Structural equation modeling fitting was used for the multivariate meta-analysis.

RESULTS

A total of 31 double-blind randomized controlled trials with 22,948 participants were included in the meta-analysis. The MD and 95% CI of the pooled GLP1-RA-induced change in the glycated hemoglobin level was -0.78% (-0.97%, -0.60%) in the random-effects model and -0.45% (-0.47%, -0.44%) in the fixed-effect model, with a high heterogeneity (I2 = 97%). The pooled body weight reduction was -4.05 kg (-5.02 kg, -3.09 kg) in the random-effects model and -2.04 kg (-2.16 kg, -1.92 kg) in the fixed-effect model (I2 = 98%). The standardized pooled correlation coefficient between HbA1c levels and body weight was -0.42. A negative correlation between glycemic control and weight reduction was obtained.

CONCLUSION

Long-acting GLP-1 RAs significantly reduced the glycated hemoglobin level and body weight in adults.

Comparative analysis of the efficacies of probiotic supplementation and glucose-lowering drugs for the treatment of type 2 diabetes: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to evaluate the effects of probiotics and glucose-lowering drugs (thiazolidinedione [TZD], glucagon-like pep-tide-1 receptor agonists [GLP-1 RA], dipeptidyl peptidase IV inhibitors, and sodium glucose co-transporter 2 inhibitors [SGLT-2i]) in patients with type 2 diabetes from randomized con-trolled trials (RCTs). The PubMed, Web of science, Embase, and Cochrane Library databases were searched on the treatment effects of probiotics and glucose-lowering drugs on glycemia, lipids, and blood pressure metabolism published between Jan 2015 and April 2021. We performed meta-analyses using the random-effects model. We included 25 RCTs (2,843 participants). Overall, GLP-1RA, SGLT-2i, and TZD significantly reduce fasting blood sugar (FBS) and glycated hemoglobin (HbA1c), whereas GLP-1 RA increased the risk of hypoglycaemia. Multispecies probiotics decrease FBS, total cholesterol (TC), and systolic and diastolic blood pressure (SBP, DBP). Moreover, subgroup analyses indicated that participants aged >55 years, BMI ≥30 kg/m2, longer duration of intervention, and subjects from Eastern countries, showed significantly higher reduction in FBS and HbA1c, TC, TG and SBP. This meta-analysis revealed that including multiple probiotic rather than glucose-lowering drugs might be more beneficial regarding T2D prevention who suffering from simultaneously hyperglycemia, hypercholesterolemia, and hypertension.

The effects of glucagon-like peptide-1 receptor agonists on adipose tissues in patients with type 2 diabetes: A meta-analysis of randomised controlled trials

Aims

Glucagon‑like peptide 1 receptor agonist (GLP-1RA) treatment can improve adipose distribution. We performed this meta-analysis to investigate whether GLP-1RAs preferentially reduce visceral adipose tissue (VAT) over subcutaneous adipose tissue (SAT) in patients with type 2 diabetes.

Materials and methods

We searched MEDLINE and the Cochrane Library for randomised controlled trials explicitly reporting changes in VAT and SAT. A random-effects model was performed to estimate the weighted mean difference (MD) for VAT and SAT. Heterogeneity among the studies was assessed using I2 statistics, and publication bias was assessed using Egger’s tests. Meta-regression was performed to identify the correlation between changes in adipose tissues and changes in body weight and glycated haemoglobin level.

Results

Ten trials with 924 patients were enrolled in the meta-analysis. GLP-1RA treatment led to similar absolute area (cm2) reductions in VAT (MD -21.13 cm2, 95% CI [-29.82, -12.44]) and SAT (MD -22.89 cm2, 95% CI [-29.83, -15.95]). No significant publication bias was detected, and this result was stable in the sensitivity and subgroup analyses. Moreover, GLP-1RA treatment resulted in a greater reduction in VAT and SAT in the subgroup with a greater reduction in body weight. The absolute area reduction in VAT was significantly correlated with the reduction in body weight (r = 6.324, p = 0.035).

Conclusions

GLP-1RA treatment leads to significant and similar absolute reductions in VAT and SAT, and the reduction in adipose tissues may be correlated with the reduction in body weight.

Effect of glucagon-like peptide-1 (GLP-1) analogues on epicardial adipose tissue: A meta-analysis

BACKGROUND AND AIMS

Glucagon-like peptide-1 (GLP-1) analogues reduce body fat and cardiovascular events in patients with type 2 diabetes. Accumulation of epicardial adipose tissue (EAT) is associated with increased cardio-metabolic risks and coronary events in type 2 diabetes.

METHODS

A systematic review and meta-analysis were performed from Glucagon-like peptide-1 analogues therapy on type 2 diabetes patients, reporting data from changes in EAT, after searching the PubMed/MEDLINE, Embase, Science Direct, Scopus, Google Scholar, and Cochrane databases.

RESULTS

It has been found a limited number of studies, a total of 4 studies (n = 160 patients with GLP-1 analogues therapy) were included in the final analysis. Pooled analysis revealed that GLP-1 analogues reduce EAT (MD: 1.83 mm [-2.50; -1.10]; P < 0.01). Compared with the patients before the treatment, the patients after the treatment had a smaller HbA1c (MD -1.10%[-1.80; -0.30]; p = 0.0143) and body mass index was reduced (MD -2.20 kg/m²[-3.70; -0.60]; p = 0.0058), GLP-1 therapy reduced low-density lipoprotein levels (MD-13.53 mg/dL [-21.74; -5.31]; p = 0.001) and reduced triglycerides levels significantly (MD -18.32 -28.20 mg/dL; -8.50); p = 0.0003).

CONCLUSIONS

This meta-analysis suggests that the amount of EAT is significantly reduced in T2D patients with Glucagon-like peptide-1 analogues.

Epicardial adipose tissue in obesity-related cardiac dysfunction

Obesity is associated with the development of heart failure and is a major risk factor for heart failure with preserved ejection fraction (HFpEF). Epicardial adipose tissue (EAT) is a unique visceral fat in close proximity to the heart and is of particular interest to the study of cardiac disease. Small poorly differentiated adipocytes with altered lipid:water content are associated with a proinflammatory secretome and may contribute to the pathophysiology observed in HFpEF. Multimodality imaging approaches can be used to quantify EAT volume and characterise EAT composition. Current research studies remain unclear as to the magnitude of effect that EAT plays on myocardial dysfunction and further work using multimodality imaging techniques is ongoing. Pharmacological interventions, including glucagon-like peptide 1 receptor agonists and sodium-dependent glucose linked transporter 2 inhibitors have shown promise in attenuating the deleterious metabolic and inflammatory changes seen in EAT. Clinical studies are ongoing to explore whether these therapies exert their beneficial effects by modifying this unique adipose deposit.

Effect of Glucagon-like Peptide-1 Receptor Agonists on Fat Distribution in Patients with Type 2 Diabetes: A Systematic Review and Meta-analysis

Aims/Introduction

Glucagon‐like peptide‐1 receptor agonists (GLP‐1Ras) are widely used to treat type 2 diabetes. They not only reduce glucose, but also have a positive effect on weight loss. However, few studies have reported the effect of GLP‐1Ras on fat distribution.

Materials and Methods

PubMed, Cochrane, Embase and ClinicalTrials.gov were searched for randomized controlled trials on GLP‐1Ras and type 2 diabetes, published from inception to June 2021. Our main outcomes were the reductions of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Other anthropometric outcomes were also assessed. We used the Cochrane Collaboration tools to assess the risk of bias in the included studies. The quality of the evidence was assessed using the Grades of Recommendation, Assessment, Development and Evaluation profiler version 3.6. Review Manager 5.4.1 and Stata 16.0 were used for data analysis.

Results

A total of 10 studies involving 541 patients were included. Compared with the control groups, the GLP‐1Ras groups showed reductions in VAT (standard mean difference −0.54, 95% confidence interval [CI] −0.92, −0.17, I² = 79%, P = 0.005) and SAT (standard mean difference −0.44, 95% CI −0.60, −0.27, I² = 44%, P < 0.00001). In addition, bodyweight (weighted mean difference −3.59, 95% CI −4.30, −2.88, I² = 0%, P < 0.00001), waist circumference (weighted mean difference −3.09, 95% CI −4.66, −1.52, I² = 70%, P = 0.0001) and body mass index (weighted mean difference −1.11, 95% CI −1.35, −0.86, I² = 47%, P < 0.00001) were significantly decreased. According to the Grades of Recommendation, Assessment, Development and Evaluation approach, the level of evidence was low or moderate.

Conclusion

This study highlights that GLP‐1Ras, especially liraglutide and exenatide, might play an active role in fat distribution in patients with type 2 diabetes. After treatment with GLP‐1Ras, both VAT and SAT decreased, and the decrease of VAT was numerically greater than that of SAT.

Dysregulated Epicardial Adipose Tissue as a Risk Factor and Potential Therapeutic Target of Heart Failure with Preserved Ejection Fraction in Diabetes

Cardiovascular (CV) disease and heart failure (HF) are the leading cause of mortality in type 2 diabetes (T2DM), a metabolic disease which represents a fast-growing health challenge worldwide. Specifically, T2DM induces a cluster of systemic metabolic and non-metabolic signaling which may promote myocardium derangements such as inflammation, fibrosis, and myocyte stiffness, which represent the hallmarks of heart failure with preserved ejection fraction (HFpEF). On the other hand, several observational studies have reported that patients with T2DM have an abnormally enlarged and biologically transformed epicardial adipose tissue (EAT) compared with non-diabetic controls. This expanded EAT not only causes a mechanical constriction of the diastolic filling but is also a source of pro-inflammatory mediators capable of causing inflammation, microcirculatory dysfunction and fibrosis of the underlying myocardium, thus impairing the relaxability of the left ventricle and increasing its filling pressure. In addition to representing a potential CV risk factor, emerging evidence shows that EAT may guide the therapeutic decision in diabetic patients as drugs such as metformin, glucagon-like peptide‑1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 inhibitors (SGLT2-Is), have been associated with attenuation of EAT enlargement.

Liraglutide reduces cardiac adipose tissue in type 2 diabetes: A secondary analysis of the LIRAFLAME randomized placebo-controlled trial

AIM

To test the hypothesis that treatment with liraglutide can reduce cardiac adipose tissue.

MATERIALS AND METHODS

LIRAFLAME is a randomized placebo-controlled, double-blind, parallel clinical study. Participants with type 2 diabetes were randomized to treatment with liraglutide 1.8 mg/d or placebo for 26 weeks. Computed tomography was performed at baseline and at end of treatment to evaluate the cardiac adipose tissue volume, quantified automatically. We report the results of a secondary endpoint evaluating changes in cardiac adipose tissue.

RESULTS

A total of 102 participants were randomly assigned to liraglutide (n = 51) or placebo (n = 51). At baseline, the mean (SD) cardiac adipose tissue volume was comparable between the liraglutide and the placebo group (232.6 [112.8] vs. 227.0 [103.2] mL; P = 0.80). The mean change in body weight was -3.7 (-4.8, -2.6) kg in the liraglutide and -0.18 (-0.76, 0.40) kg in the placebo group. From baseline to end of treatment the mean cardiac adipose tissue change was -11.5 (95% confidence interval -17.6, -5.4) mL in the liraglutide (P < 0.001) and -0.01 (-5.3, 5.3) mL in the placebo (P = 1.00) groups. The reduction in cardiac adipose tissue was significantly greater in the liraglutide compared to the placebo group (mean difference -11.4 [-19.4, -3.3] mL; P = 0.006), but significance was lost after adjustment for changes in body mass index (P = 0.46).

CONCLUSION

Treatment with liraglutide for 26 weeks was associated with a reduction in cardiac adipose tissue compared to placebo. The reduction was not independent of weight loss, suggesting that this is not a drug-specific effect.

Renal sinus fat volume in type 2 diabetes mellitus is associated with glycated hemoglobin and metabolic risk factors

AIMS

We aimed to compare renal sinus fat volume assessed by MRI between patients with type 2 diabetes and healthy volunteers, and investigate the association between renal sinus fat and metabolic traits.

METHODS

In this cross-sectional study, renal sinus fat and parenchyma volumes measured on abdominal MRI were compared between patients and controls using analysis of covariance. Associations of renal parameters with clinical characteristics were analyzed using linear regression analysis.

RESULTS

A total of 146 participants were enrolled, consisting of 95 type 2 diabetes patients (57.2±8.8years, 49.5% male) and 51 controls (54.0±9.2years, 43.1% male). Patients with diabetes demonstrated larger sinus fat volumes (15.4±7.5cm³ vs. 10.3±7.1cm³, p<0.001) and sinus fat-parenchyma ratio than controls. In the total population, renal sinus fat was positively associated with HbA1c, abdominal VAT, cholesterol and triglycerides, after adjustment for age, sex, ethnicity and type 2 diabetes. In type 2 diabetes patients, increased sinus fat volume was significantly associated with urinary albumin-to-creatinine ratio.

CONCLUSION

Renal sinus fat volume is positively associated with several metabolic risk factors including HbA1c level and urinary albumin-to-creatinine ratio in type 2 diabetes patients, indicating a potential role of renal sinus fat in the development of diabetic nephropathy. Future studies are needed to investigate whether sinus fat volume can serve as an early biomarker for diabetic nephropathy.

Effects of liraglutide on visceral and ectopic fat in adults with overweight and obesity at high cardiovascular risk: a randomised, double-blind, placebo-controlled, clinical trial

BACKGROUND

Visceral and ectopic fat are key drivers of adverse cardiometabolic outcomes in obesity. We aimed to evaluate the effects of injectable liraglutide 3·0 mg daily on body fat distribution in adults with overweight or obesity without type 2 diabetes at high cardiovascular disease risk.

METHODS

In this randomised, double-blind, placebo-controlled, phase 4, single centre trial, we enrolled community-dwelling adults, recruited from the University of Texas Southwestern Medical Center, with BMI of at least 30 kg/m² or BMI of at least 27 kg/m² with metabolic syndrome but without diabetes and randomly assigned them, in a 1:1 ratio, to 40 weeks of treatment with once-daily subcutaneous liraglutide 3·0 mg or placebo, in addition to a 500 kcal deficient diet and guideline-recommended physical activity counselling. The primary endpoint was percentage reduction in visceral adipose tissue (VAT) measured with MRI. All randomly assigned participants with a follow-up imaging assessment were included in efficacy analyses and all participants who received at least one dose of study drug were included in the safety analyses. The trial is registered on ClinicalTrials.gov: NCT03038620.

FINDINGS

Between July 20, 2017 and Feb 21, 2020 from 235 participants assessed for eligibility, 185 participants were randomly assigned (n=92 liraglutide, n=93 placebo) and 128 (n=73 liraglutide, n=55 placebo) were included in the final analysis (92% female participants, 37% Black participants, 24% Hispanic participants, mean age 50·2 years (SD 9·4), mean BMI 37·7 kg/m²). Mean change in VAT over median 36·2 weeks was -12·49% (SD 9·3%) with liraglutide compared with -1·63% (SD 12·3%) with placebo, estimated treatment difference -10·86% (95% CI -6·97 to -14·75, p<0·0001). Effects seemed consistent across subgroups of age, sex, race-ethnicity, BMI, and baseline prediabetes. The most frequently reported adverse events were gastrointestinal-related (43 [47%] of 92 with liraglutide and 12 [13%] of 93 with placebo) and upper respiratory tract infections (10 [11%] of 92 with liraglutide and 14 [15%] of 93 with placebo).

INTERPRETATION

In adults with overweight or obesity at high cardiovascular disease risk, once-daily liraglutide 3·0 mg plus lifestyle intervention significantly lowered visceral adipose tissue over 40 weeks of treatment. Visceral fat reduction may be one mechanism to explain the benefits seen on cardiovascular outcomes in previous trials with liraglutide among patients with type 2 diabetes.

FUNDING

NovoNordisk.

Management of Obesity in Cardiovascular Practice: JACC Focus Seminar

Obesity contributes to reduced life expectancy because of its link with type 2 diabetes and cardiovascular disease. Yet, targeting this poorly diagnosed, ill-defined, and underaddressed modifiable risk factor remains a challenge. In this review, we emphasize that the tendency among health care professionals to amalgam all forms of obesity altogether as a single entity may contribute to such difficulties and discrepancies. Obesity is a heterogeneous condition both in terms of causes and health consequences. Attention should be given to 2 prevalent subgroups of individuals: 1) patients who are overweight or moderately obese with excess visceral adipose tissue; and 2) patients with severe obesity, the latter group having distinct additional health issues related to their large body fat mass. The challenge of tackling high-cardiovascular-risk forms of obesity through a combination of personalized clinical approaches and population-based solutions is compounded by the current obesogenic environment and economy.

Can We Decrease Epicardial and Pericardial Fat in Patients With Diabetes?

Diabetes mellitus (DM) is a chronic and complex metabolic disorder and also an important cause of cardiovascular (CV) disease (CVD). Patients with type 2 DM (T2DM) and obesity show a greater propensity for visceral fat deposition (and excessive fat deposits elsewhere) and the link between adiposity and CVD risk is greater for visceral than for subcutaneous (SC) adipose tissue (AT). There is growing evidence that epicardial AT (EAT) and pericardial AT (PAT) play a role in the development of DM-related atherosclerosis, atrial fibrillation (AF), myocardial dysfunction, and heart failure (HF). In this review, we will highlight the importance of PAT and EAT in patients with DM. We also consider therapeutic interventions that could have a beneficial effect in terms of reducing the amount of AT and thus CV risk. EAT is biologically active and a likely determinant of CV morbidity and mortality in patients with DM, given its anatomical characteristics and proinflammatory secretory pattern. Consequently, modification of EAT/PAT may become a therapeutic target to reduce the CV burden. In patients with DM, a low calorie diet, exercise, antidiabetics and statins may change the quantity of EAT, PAT or both, alter the secretory pattern of EAT, improve the metabolic profile, and reduce inflammation. However, well-designed studies are needed to clearly define CV benefits and a therapeutic approach to EAT/PAT in patients with DM.

Efficacy of liraglutide on glycemic endpoints in people of Western European and South Asian descent with T2DM using multiple daily insulin injections: results of the MAGNA VICTORIA studies

AIMS

Data on the effect of liraglutide on glycemic endpoints in people with T2DM using multiple daily insulin injections (MDI) are scarce, especially in the context of ethnicity.

METHODS

This is a secondary analysis of the placebo-controlled randomized clinical "MAGNA VICTORIA" trials in Western European (WE) and South Asian (SA) people with T2DM. Participants had inadequate glycemic control despite using metformin and/or sulfonylurea derivatives and/or insulin. Participants were assigned to liraglutide (1.8 mg) or placebo for 6 months, in addition to standard care. The primary endpoint number of participants reaching target HbA1c was compared for liraglutide versus placebo in the complete dataset and MDI-treated participants using Chi-square test. Liraglutide's efficacy in WE and SA was compared using a generalized linear model.

RESULTS

Forty-five subjects were randomized to liraglutide and 51 to placebo. In each group, one participant did not complete the study. Liraglutide-treated patients reached target HbA1c more frequently: 23/45 (51%) vs 11/51 (22%), relative probability 2.4 (1.3-4.3), p = 0.002. Subgroup analysis in 43 MDI participants showed that the proportion reaching target HbA1c using liraglutide was significantly higher than in placebo: 9/22 (41%) vs 1/21 (5%), p = 0.005. There was no difference between WE and SA in terms of liraglutide efficacy (p = 0.18).

CONCLUSIONS

Liraglutide treatment resulted in increased chance of reaching target HbA1c as compared to placebo. Liraglutide efficacy was sustained in participants using MDI regimens and those of SA descent. Liraglutide should be considered for T2DM people with inadequate glycemic control despite MDI.

Incretin Hormones in Obesity and Related Cardiometabolic Disorders: The Clinical Perspective

The prevalence of obesity continues to grow rapidly worldwide, posing many public health challenges of the 21st century. Obese subjects are at major risk for serious diet-related noncommunicable diseases, including type 2 diabetes mellitus, cardiovascular disease, and non-alcoholic fatty liver disease. Understanding the mechanisms underlying obesity pathogenesis is needed for the development of effective treatment strategies. Dysregulation of incretin secretion and actions has been observed in obesity and related metabolic disorders; therefore, incretin-based therapies have been developed to provide new therapeutic options. Incretin mimetics present glucose-lowering properties, together with a reduction of appetite and food intake, resulting in weight loss. In this review, we describe the physiology of two known incretins—glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), and their role in obesity and related cardiometabolic disorders. We also focus on the available and incoming incretin-based medications that can be used in the treatment of the above-mentioned conditions.

Targeting epicardial adipose tissue with exercise, diet, bariatric surgery or pharmaceutical interventions: A systematic review and meta-analysis

Epicardial adipose tissue (EAT) and pericardial adipose tissue (PAT) are metabolically active fat depots implicated in cardiovascular disease, and EAT has potential as a novel cardiac risk factor, suitable as a target for interventions. The objective of this systematic review and meta-analysis was to investigate the evidence whether EAT and PAT volume can be reduced by weight-loss interventions (exercise, diet, bariatric surgery or pharmaceutical interventions). A systematic literature search identified 34 studies that were included in the qualitative synthesis (exercise, n = 10, diet, n = 5, bariatric surgery, n = 9 and pharmaceutical interventions, n = 10). Of the 34 studies, 10 reported sufficient data to be included in the meta-analysis. The meta-analysis was only conducted for changes in EAT volume, since only few controlled studies reported changes in PAT (n = 3) or total cardiac adipose tissue volume (n = 1). A significant pooled effect size (ES) for reduction in EAT volume was observed following weight-loss interventions as compared with control interventions (ES = -0.89, 95% CI: -1.23 to -0.55, P < 0.001). When comparing the effect of exercise training versus control on EAT volume reduction, there was a significant pooled ES favouring exercise training (ES: -1.11, 95% CI: -1.57 to -0.65, P < 0.001). Similarly, the ES of pharmaceutical versus control interventions on EAT volume reduction was significant, favouring pharmaceutical interventions (ES: -0.79, 95% CI: -1.37 to -0.21, P < 0.0072). In conclusion, this systematic review and meta-analysis provides evidence that exercise, diet, bariatric surgery and pharmaceutical interventions can reduce cardiac adipose tissue volume.

Therapeutic approaches for non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) have been reported as a novel worldwide epidemic, very often associated with obesity, metabolic syndrome, and type 2 diabetes. Both conditions have also been shown to be associated with a number of endocrine pathologies. Despite the epidemic, the complex pathophysiology and major complications, ranging from metabolic disturbances (diabetes and more) to cardiovascular disease, people with NASH are left with very few management options. The best and most approved therapeutic option is lifestyle intervention. Although pharmacotherapies based on pathophysiological background are in development, response rates appear modest, mainly for fibrosis treatment, which is the reason for lack of approved drug therapy. Previous drugs analyzed, such as pioglitazone and vitamin E, show weak efficacy. From different phase II trials, antidiabetic (injectable) drugs seem to be promising, both in mono- or bitherapy. Also, derivatives of peroxisome proliferator-activated receptors may have an interesting future, as well. For that reason, more focus should be given on prevention of this novel disease entity. In view of this booming epidemic, with a background of obesity and type 2 diabetes, and the important medical consequences, early recognition, prevention and intervention of NAFLD/NASH seems appropriate. In this review, we will focus on the different current and future therapeutic intervention options, taking into consideration the complex pathophysiology of this disease.

Roles of Epicardial Adipose Tissue in the Pathogenesis of Coronary Atherosclerosis - An Update on Recent Findings

Adipose tissue serves not only as an energy store or a mechanical cushion, but also as an endocrine organ. Recent evidence revealed that perivascular adipose tissue is involved in vascular homeostasis and pathophysiology of adjacent arteries by producing various adipokines. Epicardial adipose tissue (EAT) is located between the surface of the heart and the visceral layer of the pericardium and surrounds the coronary arteries. Many clinical studies suggest that an increase in EAT volume is associated with coronary artery disease. It has been reported that exercise and some antidiabetic drugs can reduce EAT volume. In this review, we outline recent findings on the roles of EAT in the pathogenesis of coronary atherosclerosis.

The Effect of Glycemic Control on Renal Triglyceride Content Assessed by Proton Spectroscopy in Patients With Type 2 Diabetes Mellitus: A Single-Center Parallel-Group Trial

OBJECTIVE

Ectopic lipid accumulation in the kidney (fatty kidney) is a potential driver of diabetic kidney disease, and tight glycemic control can reduce risk of diabetic nephropathy. We assessed whether glycemic control influences renal triglyceride content (RTGC). Furthermore, we compared glucagon-like peptide-1 receptor agonist liraglutide versus standard glucose-lowering therapy.

DESIGN AND METHODS

In this single-center parallel-group trial, patients with type 2 diabetes mellitus were randomized to liraglutide or placebo added to standard care (metformin/sulfonylurea derivative/insulin). Changes in RTGC after 26 weeks of glycemic control measured by proton spectroscopy and difference in RTGC between treatment groups were analyzed.

RESULTS

Fifty patients with type 2 diabetes mellitus were included in the baseline analysis (mean age, 56.5 ± 9.1 years; range, 33-73 years; 46% males). Seventeen patients had baseline and follow-up measurements. Mean glycated hemoglobin was 7.8 ± 0.8%, which changed to 7.3 ± 0.9% after 26 weeks of glycemic control irrespective of treatment group (P = .046). Log-transformed RTGC was -0.68 ± 0.30% and changed to -0.83 ± 0.32% after 26 weeks of glycemic control irrespective of treatment group (P = .049). A 26-week-to-̶baseline RTGC ratio (95% confidence interval) was significantly different between liraglutide (-0.30 [-0.50, -0.09]) and placebo added to standard care (-0.003 [-0.34, 0.34]) (P = .04).

CONCLUSION

In this exploratory study, we found that 26 weeks of glycemic control resulted in lower RTGC, in particular for liraglutide; however, larger clinical studies are needed to assess whether these changes reflect a true effect of glycemic control on fatty kidney.

Association of glucose uptake of visceral fat and acute myocardial infarction: a pilot 18F-FDG PET/CT study

Background

Inflamed visceral adipose tissue (VAT) facilitates chronic inflammation in atherosclerotic lesions thereby leading to increased risk of coronary artery disease (CAD). In this study, we evaluated the glucose uptake of VAT and the carotid artery with ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET/CT) and their association with CAD, including acute myocardial infarction (AMI).

Methods

A total of 90 participants were enrolled (32 with AMI, 33 with chronic stable angina; CSA, and 25 control participants) and undertook ¹⁸F-FDG PET/CT. VAT glucose uptake was measured by using maximum standardized uptake value (SUVmax) of VAT region. The target-to-background ratio (TBR) of carotid artery was defined as the SUVmax of carotid artery divided by the SUVmax of jugular vein. The SUVmax of spleen, bone-marrow (BM), and high-sensitivity C-reactive protein (hsCRP) were used for the assessment of systemic inflammatory activity.

Results

VAT SUVmax was highest in participants with AMI, intermediate in participants with CSA, and lowest in control participants. Carotid artery TBR and systemic inflammatory surrogate markers including spleen SUVmax, BM SUVmax, and hsCRP were also higher in the AMI group than in the CSA or control group. Furthermore, VAT SUVmax showed significant positive correlation with carotid artery TBR, spleen SUVmax, BM SUVmax, and hsCRP. In multivariate linear regression and logistic regression analyses, VAT SUVmax was independently associated with carotid artery TBR and AMI.

Conclusions

Glucose uptake of VAT assessed by ¹⁸F-FDG PET/CT was associated with the severity of CAD and synchronized with the carotid artery inflammation in participants with CAD.

Associations between abdominal obesity indices and diabetic complications: Chinese visceral adiposity index and neck circumference

Background and aims

Obesity, especially abdominal obesity, has been considered a risk factor for diabetic complications. Many abdominal obesity indices have been established, including neck circumference (NC), waist-to-hip ratio (WHR), lipid accumulation product (LAP), visceral adiposity index (VAI) and the Chinese visceral adiposity index (CVAI). However, studies investigating the associations between these indices and diabetic complications are limited. The objective of this study was to investigate the associations of the abdominal obesity indices with cardiovascular and cerebrovascular disease (CVD), diabetic kidney disease (DKD) and diabetic retinopathy (DR).

Methods

A total of 4658 diabetic participants were enrolled from seven communities in Shanghai, China, in 2018. Participants completed questionnaires and underwent blood pressure, glucose, lipid profile, and urine albumin/creatinine ratio measurements; fundus photographs; and anthropometric parameters, including height, weight, waist circumference (WC), NC and hip circumference (HC).

Results

In men, a one standard deviation (SD) increase in CVAI level was significantly associated with a greater prevalence of CVD (OR 1.35; 95% CI 1.13, 1.62) and DKD (OR 1.38; 95% CI 1.12, 1.70) (both P < 0.05). In women, a one SD increase in CVAI level was significantly associated with a greater prevalence of CVD (OR 1.32; 95% CI 1.04, 1.69) and DKD (OR 2.50; 95% CI 1.81, 3.47) (both P < 0.05). A one SD increase in NC was significantly associated with a greater prevalence of CCA plaque in both men (OR 1.26; 95% CI 1.10, 1.44) and women (OR 1.20; 95% CI 1.07, 1.35). These associations were all adjusted for potential confounding factors.

Conclusions

CVAI was most strongly associated with the prevalence of CVD and DKD among the abdominal obesity indices, and NC was unique associated with the prevalence of CCA plaque in Chinese adults with diabetes.

Trial registration ChiCTR1800017573, www.chictr.org.cn. Registered 04 August 2018.

Metabolic and Molecular Imaging of the Diabetic Cardiomyopathy

The term diabetic cardiomyopathy is defined as the presence of abnormalities in myocardial structure and function that occur in the absence of, or in addition to, well-established cardiovascular risk factors. A key contributor to this abnormal structural-functional relation is the complex interplay of myocardial metabolic remodeling, defined as the loss the flexibility in myocardial substrate metabolism and its downstream detrimental effects, such as mitochondrial dysfunction, inflammation, and fibrosis. In parallel with the growth in understanding of these biological underpinnings has been developmental advances in imaging tools such as positron emission tomography and magnetic resonance imaging and spectroscopy that permit the detection and in many cases quantification, of the processes that typifies the myocardial metabolic remodeling in diabetic cardiomyopathy. The imaging readouts can be obtained in both preclinical models of diabetes mellitus and patients with diabetes mellitus facilitating the bi-directional movement of information between bench and bedside. Moreover, imaging biomarkers provided by these tools are now being used to enhance discovery and development of therapies designed to reduce the myocardial effects of diabetes mellitus through metabolic modulation. In this review, the use of these imaging tools in the patient with diabetes mellitus from a mechanistic, therapeutic effect, and clinical management perspective will be discussed.

How Do SGLT2 (Sodium-Glucose Cotransporter 2) Inhibitors and GLP-1 (Glucagon-Like Peptide-1) Receptor Agonists Reduce Cardiovascular Outcomes?: Completed and Ongoing Mechanistic Trials

OBJECTIVE

There is substantial interest in how GLP-1RA (glucagon-like peptide-1 receptor agonists) and SGLT2 (sodium-glucose cotransporter 2) inhibitors reduce cardiovascular and renal events; yet, robust mechanistic data in humans remain sparse. We conducted a narrative review of published and ongoing mechanistic clinical trials investigating the actions of SGLT2 inhibitors and GLP-1RAs to help the community appreciate the extent of ongoing work and the variety and design of such trials. Approach and Results: To date, trials investigating the mechanisms of action of SGLT2 inhibitors have focused on pathways linked to glucose metabolism and toxicity, hemodynamic/volume, vascular and renal actions, and cardiac effects, including those on myocardial energetics. The participants studied have included those with established cardiovascular disease (including coronary artery disease and heart failure), liver disease, renal impairment, obesity, and hypertension; some of these trials have enrolled patients both with and without type 2 diabetes mellitus. GLP-1RA mechanistic trials have focused on glucose-lowering, insulin-sparing, weight reduction, and blood pressure-lowering effects, as well as possible direct vascular, cardiac, and renal effects of these agents. Very few mechanisms of action of SGLT2 inhibitors or GLP-1RAs have so far been convincingly demonstrated. One small trial (n=97) of SGLT2 inhibitors has investigated the cardiac effects of these drugs, where a small reduction in left ventricular mass was found. Data on vascular effects are limited to one trial in type 1 diabetes mellitus, which suggests some beneficial actions. SGLT2 inhibitors have been shown to reduce liver fat. We highlight the near absence of mechanistic data to explain the beneficial effects of SGLT2 inhibitors in patients without diabetes mellitus. GLP-1RAs have not been found to have major cardiovascular mechanisms of action in the limited, completed trials. Conflicting data around the impact on infarct size have been reported. No effect on left ventricular ejection fraction has been demonstrated.

CONCLUSIONS

We have tabulated the extensive ongoing mechanistic trials that will report over the coming years. We report 2 exemplar ongoing mechanistic trials in detail to give examples of the designs and techniques employed. The results of these many ongoing trials should help us understand how SGLT2 inhibitors and GLP-1RAs improve cardiovascular and renal outcomes and may also identify unexpected mechanisms suggesting novel therapeutic applications.

Epicardial adipose tissue: an emerging biomarker of cardiovascular complications in type 2 diabetes?

Type 2 diabetes (T2D) is associated with an increased risk of cardiovascular disease and heart failure, which highlights the need for improved understanding of factors contributing to the pathophysiology of these complications as they are the leading cause of mortality in T2D. Patients with T2D have high levels of epicardial adipose tissue (EAT). EAT is known to secrete inflammatory factors, lipid metabolites, and has been proposed to apply mechanical stress on the cardiac muscle that may accelerate atherosclerosis, cardiac remodeling, and heart failure. High levels of EAT in patients with T2D have been associated with atherosclerosis, diastolic dysfunction, and incident cardiovascular events, and this fat depot has been suggested as an important link coupling diabetes, obesity, and cardiovascular disease. Despite this, the predictive potential of EAT in general, and in patients with diabetes, is yet to be established, and, up until now, the clinical relevance of EAT is therefore limited. Should this link be established, importantly, studies show that this fat depot can be modified both by pharmacological and lifestyle interventions. In this review, we first introduce the role of adipose tissue in T2D and present mechanisms involved in the pathophysiology of EAT and pericardial adipose tissue (PAT) in general, and in patients with T2D. Next, we summarize the evidence that these fat depots are elevated in patients with T2D, and discuss whether they might drive the high cardiometabolic risk in patients with T2D. Finally, we discuss the clinical potential of cardiac adipose tissues, address means to target this depot, and briefly touch upon underlying mechanisms and future research questions.

Effect of Liraglutide on Cardiovascular Function and Myocardial Tissue Characteristics in Type 2 Diabetes Patients of South Asian Descent Living in the Netherlands: A Double-Blind, Randomized, Placebo-Controlled Trial

Background

The glucagon‐like peptide‐1 (GLP‐1) receptor agonist liraglutide may be beneficial in the regression of diabetic cardiomyopathy. South Asian ethnic groups in particular are at risk of developing type 2 diabetes.

Purpose

To assess the effects of liraglutide on left ventricular (LV) diastolic and systolic function in South Asian type 2 diabetes patients.

Study Type

Prospective, double‐blind, randomized, placebo‐controlled trial.

Population

Forty‐seven type 2 diabetes patients of South Asian ancestry living in the Netherlands, with or without ischemic heart disease, who were randomly assigned to 26‐week treatment with liraglutide (1.8 mg/day) or placebo.

Field Strength/Sequence

3T (balanced steady‐state free precession cine MRI, 2D and 4D velocity‐encoded MRI, ¹H‐MRS, T₁ mapping).

Assessment

Primary endpoints were changes in LV diastolic function (early deceleration peak [Edec], ratio of early and late peak filling rate [E/A], estimated LV filling pressure [E/Ea]) and LV systolic function (ejection fraction). Secondary endpoints were changes in aortic stiffness (aortic pulse wave velocity [PWV]), myocardial steatosis (myocardial triglyceride content), and diffuse fibrosis (extracellular volume [ECV]).

Statistical Tests

Data were analyzed according to intention‐to‐treat. Between‐group differences were reported as mean (95% confidence interval [CI]) and were assessed using analysis of covariance (ANCOVA).

Results

Liraglutide (n = 22) compared with placebo (n = 25) did not change Edec (+0.2 mL/s² × 10^‐3 (–0.3;0.6)), E/A (–0.09 (–0.23;0.05)), E/Ea (+0.1 (–1.2;1.3)) and ejection fraction (0% (–3;2)), but decreased stroke volume (–9 mL (–14;–5)) and increased heart rate (+10 bpm (4;15)). Aortic PWV (+0.5 m/s (–0.6;1.6)), myocardial triglyceride content (+0.21% (–0.09;0.51)), and ECV (–0.2% (–1.4;1.0)) were unaltered.

Data Conclusion

Liraglutide did not affect LV diastolic and systolic function, aortic stiffness, myocardial triglyceride content, or extracellular volume in Dutch South Asian type 2 diabetes patients with or without coronary artery disease.

Level of Evidence: 1

Technical Efficacy Stage: 4

J. Magn. Reson. Imaging 2020;51:1679–1688.

Phenotyping diabetic cardiomyopathy in Europeans and South Asians

Background

The pathogenesis and cardiovascular impact of type 2 diabetes (T2D) may be different in South Asians compared with other ethnic groups. The phenotypic characterization of diabetic cardiomyopathy remains debated and little is known regarding differences in T2D-related cardiovascular remodeling across ethnicities. We aimed to characterize the differences in left ventricular (LV) diastolic and systolic function, LV structure, myocardial tissue characteristics and aortic stiffness between T2D patients and controls and to assess the differences in T2D-related cardiovascular remodeling between South Asians and Europeans.

Methods

T2D patients and controls of South Asian and European descent underwent 3 Tesla cardiovascular magnetic resonance imaging (CMR) and cardiac proton-magnetic resonance spectroscopy (¹H-MRS). Differences in cardiovascular parameters between T2D patients and controls were examined using ANCOVA and were reported as mean (95% CI). Ethnic group comparisons in the association of T2D with cardiovascular remodeling were made by adding the interaction term between ethnicity and diabetes status to the model.

Results

A total of 131 individuals were included (54 South Asians [50.1 ± 8.7 years, 33% men, 33 patients vs. 21 controls) and 77 Europeans (58.8 ± 7.0 years, 56% men, 48 patients vs. 29 controls)]. The ratio of the transmitral early and late peak filling rate (E/A) was lower in T2D patients compared with controls, in South Asians [− 0.20 (− 0.36; − 0.03), P = 0.021] and Europeans [− 0.20 (− 0.36; − 0.04), P = 0.017], whereas global longitudinal strain and aortic pulse wave velocity were similar. South Asian T2D patients had a higher LV mass [+ 22 g (15; 30), P < 0.001] (P for interaction by ethnicity = 0.005) with a lower extracellular volume fraction [− 1.9% (− 3.4; − 0.4), P = 0.013] (P for interaction = 0.114), whilst European T2D patients had a higher myocardial triglyceride content [+ 0.59% (0.35; 0.84), P = 0.001] (P for interaction = 0.002) than their control group.

Conclusions

Diabetic cardiomyopathy was characterized by impaired LV diastolic function in South Asians and Europeans. Increased LV mass was solely observed among South Asian T2D patients, whereas differences in myocardial triglyceride content between T2D patients and controls were only present in the European cohort. The diabetic cardiomyopathy phenotype may differ between subsets of T2D patients, for example across ethnicities, and tailored strategies for T2D management may be required.