Visceral adipose tissue and residual cardiovascular risk: a pathological link and new therapeutic options

Association of metabolic score for visceral fat with all-cause mortality, cardiovascular mortality, and cancer mortality: A prospective cohort study

AIM

Our study aimed to evaluate the association between the metabolic score for visceral fat (METS-VF) and mortality.

METHODS

We conducted a cohort study comprising 11,120 participants. We employed weighted multivariable Cox regression analysis to assess the relationship between METS-VF and mortality. Restricted cubic spline analyses were used to investigate potential non-linear associations. Receiver operating characteristic curves were used to evaluate the predictive value of METS-VF and other obesity-related indicators for mortality. Subgroup analysis and sensitivity analysis were performed to confirm the robustness of the results. Mendelian randomization analysis was utilized to assess potential causality.

RESULTS

Over a median follow-up duration of 83 months, a total of 1014 all-cause deaths, 301 cardiovascular deaths, and 262 cancer deaths occurred. For every 0.2-unit increase in METS-VF, the hazard ratios(HRs) of all-cause mortality, cardiovascular mortality, and cancer mortality were 1.13 [95% confidence interval (CI): 1.06, 1.20], 1.18 (95% CI: 1.06, 1.31), and 1.13 (95% CI: 1.03, 1.25), respectively. In addition, restricted cubic spline analyses revealed no significant non-linear associations between METS-VF and all-cause mortality, cardiovascular mortality, and cancer mortality. In multivariate Cox regression models, hazard ratios of all-cause mortality, cardiovascular mortality and cancer mortality were higher in the highest METS-VF group compared to the reference group. Subgroup and sensitivity analyses confirmed that our results were robust. Receiver operating characteristic curves indicated that METS-VF predicted mortality better than other obesity-related indicators. Mendelian randomization analysis confirmed significant causal relationships.

CONCLUSIONS

METS-VF was positively associated with all-cause mortality, cardiovascular mortality, and cancer mortality. These findings suggest that METS-VF could serve as a straightforward, reliable, and cost-effective marker for identifying individuals at high risk of mortality.

The challenges of assessing adiposity in a clinical setting

To tackle the burden of obesity-induced cardiometabolic disease, the scientific community relies on accurate and reproducible adiposity measurements in the clinic. These measurements guide our understanding of underlying biological mechanisms and clinical outcomes of human trials. However, measuring adiposity and adipose tissue distribution in a clinical setting can be challenging, and different measurement methods pose important limitations. BMI is a simple and high-throughput measurement, but it is associated relatively poorly with clinical outcomes when compared with waist-to-hip and sagittal abdominal diameter measurements. Body composition measurements by dual energy X-ray absorptiometry or MRI scans would be ideal due to their high accuracy, but are not high-throughput. Another important consideration is that adiposity measurements vary between men and women, between adults and children, and between people of different ethnic backgrounds. In this Perspective article, we discuss how these critical challenges can affect our interpretation of research data in the field of obesity and the design and implementation of clinical guidelines.

Relationship between Body Adiposity Indices and Reversal of Metabolically Unhealthy Obesity 6 Months after Roux-en-Y Gastric Bypass

The factors determining the reversal of metabolically unhealthy obesity (MUO) to metabolically healthy obesity (MHO) after Roux-en-Y gastric bypass (RYGB) are not completely elucidated. The present study aims to evaluate body adiposity and distribution, through different indices, according to metabolic phenotypes before and 6 months after RYGB, and the relationship between these indices and transition from MUO to MHO. This study reports a prospective longitudinal study on adults with obesity who were evaluated before (T0) and 6 months (T1) after RYGB. Bodyweight, height, waist circumference (WC), BMI, waist-to-height ratio (WHR), total cholesterol (TC), HDL-c, LDL-c, triglycerides, insulin, glucose, HbA1c and HOMA-IR were evaluated. The visceral adiposity index (VAI), the conicity index (CI), the lipid accumulation product (LAP), CUN-BAE and body shape index (ABSI) were calculated. MUO was classified based on insulin resistance. MUO at T0 with transition to MHO at T1 formed the MHO-t group MHO and MUO at both T0 and T1 formed the MHO-m and MUO-m groups, respectively. At T0, 37.3% of the 62 individuals were classified as MHO and 62.7% as MUO. Individuals in the MUO-T0 group had higher blood glucose, HbA1c, HOMA-IR, insulin, TC and LDL-c compared to those in the MHO-T0 group. Both groups showed significant improvement in biochemical and body variables at T1. After RYGB, 89.2% of MUO-T0 became MHO (MHO-t). The MUO-m group presented higher HOMA-IR, insulin and VAI, compared to the MHO-m and MHO-t groups. CI and ABSI at T0 correlated with HOMA-IR at T1 in the MHO-t and MHO-m groups. CI and ABSI, indicators of visceral fat, are promising for predicting post-RYGB metabolic improvement. Additional studies are needed to confirm the sustainability of MUO reversion and its relationship with these indices.

A detailed analysis of body composition in relation to cardiopulmonary exercise test indices

A cardiopulmonary exercise test (CPET) is a test assessing an individual's physiological response during exercise. Results may be affected by body composition, which is best evaluated through imaging techniques like magnetic resonance imaging (MRI). The aim of this study was to assess relationships between body composition and indices obtained from CPET. A total of 234 participants (112 female), all aged 50 years, underwent CPETs and whole-body MRI scans (> 1 million voxels). Voxel-wise statistical analysis of tissue volume and fat content was carried out with a method called Imiomics and related to the CPET indices peak oxygen consumption (V̇O2peak), V̇O2peak scaled by body weight (V̇O2kg) and by total lean mass (V̇O2lean), ventilatory efficiency (V̇E/V̇CO2-slope), work efficiency (ΔV̇O2/ΔWR) and peak exercise respiratory exchange ratio (RERpeak). V̇O2peak showed the highest positive correlation with volume of skeletal muscle. V̇O2kg negatively correlated with tissue volume in subcutaneous fat, particularly gluteal fat. RERpeak negatively correlated with tissue volume in skeletal muscle, subcutaneous fat, visceral fat and liver. Some associations differed between sexes: in females ΔV̇O2/ΔWR correlated positively with tissue volume of subcutaneous fat and V̇E/V̇CO2-slope with tissue volume of visceral fat, and, in males, V̇O2peak correlated positively to lung volume. In conclusion, voxel-based Imiomics provided detailed insights into how CPET indices were related to the tissue volume and fat content of different body structures.

Impact of diet intervention on visceral adipose tissue and hepatic fat in patients with obesity or type 2 diabetes: a randomized trial

This study aimed to assess the effects of a diet intervention on visceral and hepatic fat in patients with obesity or type 2 diabetes (T2D). Participants with obesity or T2D were randomized to a diet intervention or their usual diet. The intervention comprised a "3G rice" regimen combined with a low-salt, high-fiber diet. The primary outcomes were changes in visceral adipose tissue (VAT) area and hepatic fat over 12 weeks assessed by magnetic resonance imaging. Eighty-six patients were randomized. Their mean age was 47.5 ± 11.0 years, and 82.3% were female. Eighty-one (94.2%) had obesity, and 16 (18.6%) had T2D. Baseline metrics were body weight 76.3 ± 16.1 kg, BMI 29.6 ± 4.6, VAT 12 629 ± 5819 mm2, and hepatic fat 7.9% ± 7.2%. At the 12-week follow-up, the diet group had greater VAT and hepatic fat reductions than controls (- 1468 ± 1468 vs. - 179 ± 1576 mm2, P = 0.001; and - 2.6% ± 3.4% vs. 0.4% ± 2.2%, P < 0.001). Adjusted differences remained significant for VAT (- 1093 mm2, P < 0.001) and hepatic fat (- 2.5%, P < 0.001). In conclusion, the 12-week diet intervention decreased VAT, hepatic fat, body weight, and BMI compared to a usual diet.

The association between parental cardiovascular health status and the risk of obesity in their offspring: Tehran Lipid and Glucose Study

BACKGROUND AND AIMS

Little is known about the association of parental cardiovascular risk factors with the risk of obesity in offspring. We aimed to investigate whether parental ideal cardiovascular health (ICVH) status was associated with the risk of general and central obesity in their young/adult offspring.

METHODS AND RESULTS

Of individuals who participated in the 2012-15 phase of the Tehran Lipid and Glucose Study, 2395 pairs of parent-unmarried offspring aged ≥6 years were selected in this cross-sectional study. General and central obesity were defined based on Iranian BMI percentile reference data for offspring aged ≤18 years. For subjects aged ≥19 years, central obesity was defined based on the introduced cut-off points for Iranian adults. We employed the American Heart Association's 2020 impact goal criteria of ICVH. The mean ± SD age of fathers and mothers were respectively 55.4 ± 9.79 and 48.4 ± 9.88. About 55% of offspring were older than 19 years. Higher adherence to ICVH score in mothers was associated with lower risk of overweight/obesity in female offspring (OR for Q1-Q4: 1, 0.56, 0.57, 0.37, P < 0.05 for all quartiles). Among ICVH components, only ideal BMI status in fathers was observed to be associated with a lower risk of overweight/obesity in their male offspring. The risk of abdominal obesity decreased in female offspring with increasing total ICVH score in mothers.

CONCLUSION

Higher adherence of parents to ICVH and its components was positively associated with a lower risk of general and abdominal obesity in their offspring. Our findings demonstrate that maternal-offspring relationship was stronger than paternal-offspring association.

Molecular Mechanisms behind Obesity and Their Potential Exploitation in Current and Future Therapy

Obesity is a chronic disease caused primarily by the imbalance between the amount of calories supplied to the body and energy expenditure. Not only does it deteriorate the quality of life, but most importantly it increases the risk of cardiovascular diseases and the development of type 2 diabetes mellitus, leading to reduced life expectancy. In this review, we would like to present the molecular pathomechanisms underlying obesity, which constitute the target points for the action of anti-obesity medications. These include the central nervous system, brain-gut-microbiome axis, gastrointestinal motility, and energy expenditure. A significant part of this article is dedicated to incretin-based drugs such as GLP-1 receptor agonists (e.g., liraglutide and semaglutide), as well as the brand new dual GLP-1 and GIP receptor agonist tirzepatide, all of which have become "block-buster" drugs due to their effectiveness in reducing body weight and beneficial effects on the patient's metabolic profile. Finally, this review article highlights newly designed molecules with the potential for future obesity management that are the subject of ongoing clinical trials.

The effect of incretin-based drugs on the riks of acute pancreatitis: a review

Objectives

In recent years, new hypoglycaemic drugs that affect the incretin system have become increasingly popular in the treatment of type 2 diabetes mellitus (T2DM): glucagon-like receptor 1 agonists (GLP1RAs), dipeptidyl peptidase 4 inhibitors (DPP4is) and the recently developed dual glucagon-like receptor 1 agonist and glucose-dependent insulinotropic polypeptide (tirzepatide). Their main role of these drugs is to normalise blood glucose levels. In addition, GLP1RAs are approved for the treatment of excessive body weight. The efficacy of drugs affecting the incretin system is well described in the literature, however, there are still only few reports about their safety. This review aims to summarize the results of current research and meta-analyses on risk of acute pancreatitis (AP) during incretin-affecting drugs treatment.

Methods

A narrative review was performed using present literature in an attempt to identify the relationship between AP and incretin-affecting drugs. The following keywords were used: acute pancreatitis, glucagon-like receptor 1 agonists, dipeptidyl peptidase 4 inhibitors and tirzepatide.

Results

It was demonstrated that the use of DPP4is is safe for the majority of patients with T2DM, whereas a risk of AP should be noted in case of GLP1RAs therapy. To date, most studies found no significant association between tirzepatide therapy and the increased risk of AP.

Conclusion

The majority of studies have shown that DPP4is, GLP1RAs and tirzepatide are effective and safe in most T2DM patients. However, the follow-up time for patients treated with tirzepatide is short, therefore more studies are required to confirm the safety of this drug.

Bioactive Compounds Formulated in Phytosomes Administered as Complementary Therapy for Metabolic Disorders

Metabolic disorders (MDs), including dyslipidemia, non-alcoholic fatty liver disease, diabetes mellitus, obesity and cardiovascular diseases are a significant threat to human health, despite the many therapies developed for their treatment. Different classes of bioactive compounds, such as polyphenols, flavonoids, alkaloids, and triterpenes have shown therapeutic potential in ameliorating various disorders. Most of these compounds present low bioavailability when administered orally, being rapidly metabolized in the digestive tract and liver which makes their metabolites less effective. Moreover, some of the bioactive compounds cannot fully exert their beneficial properties due to the low solubility and complex chemical structure which impede the passive diffusion through the intestinal cell membranes. To overcome these limitations, an innovative delivery system of phytosomes was developed. This review aims to highlight the scientific evidence proving the enhanced therapeutic benefits of the bioactive compounds formulated in phytosomes compared to the free compounds. The existing knowledge concerning the phytosomes' preparation, their characterization and bioavailability as well as the commercially available phytosomes with therapeutic potential to alleviate MDs are concisely depicted. This review brings arguments to encourage the use of phytosome formulation to diminish risk factors inducing MDs, or to treat the already installed diseases as complementary therapy to allopathic medication.

The pathophysiology of visceral adipose tissues in cardiometabolic diseases

Central pattern of fat distribution, especially fat accumulation within the intraabdominal cavity increases risks for cardiometabolic diseases. Portal hypothesis combined with a pathological remodeling in visceral fat is considered the major etiological factor explaining the independent contribution of visceral obesity to cardiometabolic diseases. Excessive remodeling in visceral fat during development of obesity leads to dysfunctions in the depot, characterized by hypertrophy and death of adipocytes, hypoxia, inflammation, and fibrosis. Dysfunctional visceral fat secretes elevated levels of fatty acids, glycerol, and proinflammatory and profibrotic cytokines into the portal vein directly impacting the liver, the central regulator of systemic metabolism. These metabolic and endocrine products induce ectopic fat accumulation, insulin resistance, inflammation, and fibrosis in the liver, which in turn causes or exacerbates systemic metabolic derangements. Elucidation of underlying mechanisms that lead to the pathological remodeling and higher degree of dysfunctions in visceral adipose tissue is therefore, critical for the development of therapeutics to prevent deleterious sequelae in obesity. We review depot differences in metabolic and endocrine properties and expendabilities as well as underlying mechanisms that contribute to the pathophysiological aspects of visceral adiposity in cardiometabolic diseases. We also discuss impacts of different weight loss interventions on visceral adiposity and cardiometabolic diseases.

Are we ready for an adipocentric approach in people living with type 2 diabetes and chronic kidney disease?

We are entering a new era in the management of adiposity-based chronic disease (ABCD) with type 2 diabetes (T2D) and related chronic kidney disease (CKD). ABCD, T2D and CKD can affect almost every major organ system and have a particularly strong impact on the incidence of cardiovascular disease (CVD) and heart failure. ABCD and the associated insulin resistance are at the root of many cardiovascular, renal and metabolic (CKM) disorders, thus an integrated therapeutic framework using weight loss (WL) as a disease-modifying intervention could simplify the therapeutic approach at different stages across the lifespan. The breakthrough of highly effective WL drugs makes achieving a WL of >10% possible, which is required for a potential T2D disease remission as well as for prevention of microvascular disease, CKD, CVD events and overall mortality. The aim of this review is to discuss the link between adiposity and CKM conditions as well as placing weight management at the centre of the holistic CKM syndrome approach with a focus on CKD. We propose the clinical translation of the available evidence into a transformative Dysfunctional Adipose Tissue Approach (DATA) for people living with ABCD, T2D and CKD. This model is based on the interplay of four essential elements (i.e. adipocentric approach and target organ protection, dysfunctional adiposity, glucose homeostasis, and lifestyle intervention and de-prescription) together with a multidisciplinary person-centred care. DATA could facilitate decision-making for all clinicians involved in the management of these individuals, and if we do this in a multidisciplinary way, we are prepared to meet the adipocentric challenge.

Relevance of obesity-related organ damage and metabolic syndrome classification in cardiovascular and renal risk stratification in patients with essential hypertension

Introduction

Hypertension is a relevant cardiovascular comorbidity. Adipose tissue represents a metabolically active tissue involved in the regulation of blood pressure and metabolic alterations. In recent decades, several classifications for the metabolic syndrome (MS) have been proposed. Recently, a new syndrome called the "Cardiovascular-kidney-metabolic" (CKM) syndrome was identified, to determine patients at high cardiovascular and metabolic risk. The aim of the study was to compare different classifications in a large population of hypertensive patients.

Materials and methods

Between September 2022 and August 2023, we consecutively enrolled 772 hypertensive patients (407 men; 365 women; mean age 52.2 ± 15.1 years), evaluating anthropometric, biochemical, and instrumental parameters (transthoracic echocardiogram, carotid echo-Doppler, 24-h ambulatory blood pressure monitoring, fundus oculi).

Results

Using different classifications we found MS prevalence: Adult Treatment Panel III (ATP-III) 28.8%, International Diabetes Federation (IDF) 31.5%, CKM 40.7%. CKM Classes 3 and 4 showed higher body mass index and waist circumference compared with other groups. Compared with ATP-III and IDF, CKM Class 4 showed higher 24-h systolic blood pressure, lower percentage of controlled hypertension, increased interventricular septum and posterior wall, reduced ejection fraction, and greater prevalence of hypertensive arterial retinal damage.

Discussion

Visceral obesity and MS are frequent conditions with healthy impact, becoming an important trigger for the development of cardiovascular and metabolic complications. The different MS classifications allow the early identification of patients at high risk of cardiometabolic complications. The new CKM syndrome proves useful to identify individuals at high risk for CKM morbidity and mortality.

Subclinical Hypothyroidism in Patients with Obesity and Metabolic Syndrome: A Narrative Review

The literature on the connection between obesity, metabolic syndrome, and subclinical hypothyroidism is critically analyzed in this narrative review. These conditions are frequently observed among adult populations and various studies and meta-analyses have assessed their association. The prevalence of subclinical hypothyroidism in obese individuals is higher than in non-obese subjects and this trend is more pronounced in unhealthy obesity phenotypes. However, the diagnosis and treatment of subclinical hypothyroidism can be difficult in obese patients. Exaggerated body fat is linked to thyroid hypoechogenicity as evident through ultrasonography and euthyroid obese people have greater TSH, FT3, and FT3/FT4 ratios than non-obese individuals in a euthyroid condition. Moreover, a reduced expression of the TSH receptor and altered function of deiodinases has been found in the adipose tissue of obese patients. Current data do not support the necessity of a pharmacological correction of the isolated hyperthyrotropinemia in euthyroid obese patients because treatment with thyroid hormone does not significantly improve weight loss and the increase in serum TSH can be reversible after hypocaloric diet or bariatric surgery. On the other hand, obesity is linked to elevated leptin levels. Inflammation can raise the risk of Hashimoto thyroiditis, which increases the likelihood that obese patients will experience overt or subclinical hypothyroidism. Both metabolic syndrome and subclinical hypothyroidism are associated with atherosclerosis, liver and kidney disease. Hence, the association of these two illnesses may potentiate the adverse effects noted in each of them. Subclinical hypothyroidism should be identified in patients with obesity and treated with appropriate doses of L-thyroxine according to the lean body mass and body weight. Randomized controlled trials are necessary to verify whether treatment of thyroid deficiency could counteract the expected risks.