Original article: The prognostic value of including non-alcoholic fatty liver disease in the definition of metabolic syndrome

The new definition of metabolic syndrome including hyperuricemia improves its prognostic value: results from NHANES database

BACKGROUND

Metabolic syndrome (MetS) is a significant global health issue that is strongly associated with an increased risk of cardiovascular disease (CVD). While MetS was initially proposed to identify more high-risk individuals and facilitate early management, hyperuricemia has not yet been included in its definition, despite its strong association with MetS. This study aims to explore the prognostic value of incorporating hyperuricemia into the definition of MetS.

METHODS

Data derived from the National Health and Nutrition Examination Survey (NHANES) conducted between 1999 and 2018 were analyzed. The old version of MetS (MetSold) aligned with NCEP-ATP III criteria, whereas the new version of MetS (MetSnew) included hyperuricemia as a sixth criterion. Baseline characteristics were compared between participants with and without MetS, and outcomes were assessed by multivariate analyses.

RESULTS

Among the 36,363 participants analyzed, 12,594 (34.6%) and 14,137 (38.9%) met MetSold and MetSnew criteriarespectively. Compared to MetSold, MetSnew identified additional 1534(4.24%) participants at metabolic risk. Both MetSold and MetSnew were significantly associated with long-term all-cause and CVD mortality (all P < 0.001). Furthermore, the additional participants identified by MetSnew exhibited a similar risk of all-cause and CVD mortality as those meeting MetSold criteria. MetSnew demonstrated enhanced identification and reclassification abilities compared to MetSold, as evidenced by improvement in C-index, NRI and IDI.

CONCLUSIONS

The inclusion of hyperuricemia in the MetS criteria could identify a larger proportion of individuals at metabolic risk, thereby facilitating early management to prevent long-term adverse events.

Long-term all-cause mortality of metabolic-dysfunction associated steatotic liver disease based on body weight phenotypes following acute myocardial infarction: A retrospective cohort study

OBJECTIVE

Metabolic dysfunction-associated steatotic liver disease (MASLD) and obesity increases risk of cardiovascular disease. This cohort study examines the prognostic value of MASLD, across body weight categories, in a secondary preventative acute myocardial infarction (AMI) cohort.

METHODS

Patients with AMI were stratified into four phenotypes-obesity MASLD, non-obesity MASLD, obesity non-MASLD, non-obesity non-MASLD. The primary outcome was all-cause mortality. Cox regression analysis was performed to investigate determinants of long-term all-cause mortality.

RESULTS

Of 5702 patients, majority were in the non-obesity non-MASLD group (66.7%), followed by obesity MASLD (16.1%), non-obesity MASLD (11.2%) and non-obesity MASLD (6.0%). Across the four phenotypes, obesity MASLD had the highest cardiometabolic burden, followed by non-obesity MASLD. Non-obesity MASLD had the highest risk of heart failure (p = 0.034), cardiogenic shock (p < 0.001), and all-cause long-term mortality (p = 0.019). The non-obesity MASLD (HR 1.400, 95%CI 1.077-1.820, p = 0.012) and obesity MASLD phenotypes (HR 1.222, 95%CI 1.005-1.485, p = 0.044) were independently associated with long-term all-cause mortality.

CONCLUSIONS

Obesity and non-obesity MASLD phenotypes were predictors of all-cause mortality following AMI, with an even larger magnitude of mortality risk in the non-obesity MASLD group. The recognition of MASLD and its body weight phenotypes will be beneficial in the prognostication following AMI.

Metabolic syndrome

The metabolic syndrome (MetS) is a multiplex modifiable risk factor for cardiovascular disease, type 2 diabetes mellitus and other health outcomes, and is a major challenge to clinical practice and public health. The rising global prevalence of MetS, driven by urbanization, sedentary lifestyles and dietary changes, underlines the urgency of addressing this syndrome. We explore the complex underlying mechanisms, including genetic predisposition, insulin resistance, accumulation of dysfunctional adipose tissue and ectopic lipids in abdominal obesity, systemic inflammation and dyslipidaemia, and how they contribute to the clinical manifestations of MetS. Diagnostic approaches vary but commonly focus on abdominal obesity (assessed using waist circumference), hyperglycaemia, dyslipidaemia and hypertension, highlighting the need for population-specific and phenotype-specific diagnostic strategies. Management of MetS prioritizes lifestyle modifications, such as healthy dietary patterns, physical activity and management of excess visceral and ectopic adiposity, as foundational interventions. We also discuss emerging therapies, including new pharmacological treatments and surgical options, providing a forward-looking perspective on MetS research and care. This Primer aims to inform clinicians, researchers and policymakers about MetS complexities, advocating for a cohesive, patient-centred management and prevention strategy. Emphasizing the multifactorial nature of MetS, this Primer calls for integrated public health efforts, personalized care and innovative research to address this escalating health issue.

NAFLD and MAFLD independently increase the risk of major adverse cardiovascular events (MACE): a 20-year longitudinal follow-up study from regional Australia

BACKGROUND AND AIMS

The association between fatty liver disease (FLD) and cardiovascular disease (CVD) in an Australian context has yet to be defined. The primary aim of this study was to investigate the association between FLD and 3-point major adverse cardiovascular events (MACE).

METHODS

This was a longitudinal follow-up study of a randomly sampled adult cohort from regional Australia between 2001 and 2003. Baseline covariates included demographic details, anthropometry, health and lifestyle data, and laboratory tests. Non-alcoholic fatty liver disease (NAFLD) and metabolic-(dysfunction) associated fatty liver disease (MAFLD) were diagnosed in participants with fatty liver index (FLI) ≥ 60 and meeting other standard criteria. ICD-10 codes were used to define clinical outcomes linked to hospitalisations. Three-point MACE defined as non-fatal myocardial infarction (MI) and cerebrovascular accident (CVA) and CVD death.

RESULTS

In total, 1324 and 1444 participants met inclusion criteria for NAFLD and MAFLD analysis, respectively. Over 23,577 and 25,469 person-years follow-up, NAFLD and MAFLD were independent predictors for 3-point MACE, adjusting for demographic covariates and known cardiometabolic risk factors, whilst considering non-CVD death as a competing event (NAFLD: sub-hazard ratio [sHR] 1.56, 95% confidence interval [CI 1.12-2.19]; MAFLD: sHR 1.51, 95% CI 1.11-2.06). The results held true on several sensitivity analyses.

CONCLUSIONS

Both forms of FLD increase the risk for CVD independent of traditional cardiometabolic risk factors.

Heavy arch: from inflammatory bowel diseases to metabolic disorders

BACKGROUND

Metabolic disorders and inflammatory bowel diseases (IBD) have captured the globe during Westernisation of lifestyle and related dietary habits over the last decades. Both disease entities are characterised by complex and heterogeneous clinical spectra linked to distinct symptoms and organ systems which, on a first glimpse, do not have many commonalities in clinical practice. However, experimental studies indicate a common backbone of inflammatory mechanisms in metabolic diseases and gut inflammation, and emerging clinical evidence suggests an intricate interplay between metabolic disorders and IBD.

OBJECTIVE

We depict parallels of IBD and metabolic diseases, easily overlooked in clinical routine.

DESIGN

We provide an overview of the recent literature and discuss implications of metabolic morbidity in patients with IBD for researchers, clinicians and healthcare providers.

CONCLUSION

The Western lifestyle and diet and related gut microbial perturbation serve as a fuel for metabolic inflammation in and beyond the gut. Metabolic disorders and the metabolic syndrome increasingly affect patients with IBD, with an expected negative impact for both disease entities and risk for complications. This concept implies that tackling the obesity pandemic exerts beneficial effects beyond metabolic health.

Type 2 diabetes mellitus and cardiometabolic outcomes in metabolic dysfunction-associated steatotic liver disease population

The metabolic syndrome, characterized by type 2 diabetes mellitus (T2DM), hypertension, hyperlipidemia, and obesity, collectively increases the risk of cardiovascular diseases. Nonalcoholic fatty liver disease (NAFLD) is a prominent manifestation, affecting over a third of the global population with a concerning annual increase in prevalence. Nearly 70 % of overweight individuals have NAFLD, and NAFLD-related deaths are predicted to rise, especially among young adults. The association of T2DM and NAFLD has led to the proposal of "metabolic dysfunction-associated steatotic liver disease" (MASLD) terminology, encompassing individuals with T2DM, overweight/obesity, hypertension, hypertriglyceridemia, or low HDL-cholesterol. Patients with MASLD will likely have double the risk of developing T2DM, and the combination of insulin resistance, overweight/obesity, and MASLD significantly elevates the risk of T2DM. Cardiovascular diseases remain the leading cause of mortality in the MASLD and T2DM population, with MASLD directly associated with coronary artery disease, compounded by coexisting insulin resistance and T2DM. Urgency lies in early detection of subclinical cardiovascular diseases among patients with T2DM and MASLD. Novel strategies targeting multiple pathways offer hope for effectively improving cardiometabolic health. Understanding and addressing the intertwined factors contributing to these disorders can pave the way towards better management and prevention of cardiometabolic complications.

Longitudinal Outcomes Associated With Metabolic Dysfunction-Associated Steatotic Liver Disease: A Meta-analysis of 129 Studies

BACKGROUND & AIMS

The progression of metabolic dysfunction-associated steatotic liver disease (MASLD) has been found to manifest in a series of hepatic and extrahepatic complications. A comprehensive meta-analysis of the longitudinal outcomes associated with MASLD has yet to be conducted.

METHODS

To investigate the longitudinal outcomes associated with MASLD, Medline and Embase databases were searched to identify original studies that evaluated the longitudinal risks of incident clinical outcomes among MASLD patients compared with non-MASLD individuals. DerSimonian Laird random-effects meta-analysis was performed. Pooled effect estimates were calculated, and heterogeneity among studies was evaluated.

RESULTS

One hundred twenty-nine studies were included in the meta-analysis. Meta-analysis revealed a significant increase in the risk of cardiovascular outcomes (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.27-1.60; P < .01), various metabolic outcomes such as incident hypertension (HR, 1.75; 95% CI, 1.46-2.08; P < .01), diabetes (HR, 2.56; 95% CI, 2.10-3.13; P < .01), pre-diabetes (HR, 1.69; 95% CI, 1.22-2.35; P < .01), metabolic syndrome (HR, 2.57; 95% CI, 1.13-5.85; P = .02), chronic kidney disease (HR, 1.38; 95% CI, 1.27-1.50; P < .01), as well as all cancers (HR, 1.54; 95% CI, 1.35-1.76; P < .01) among MASLD patients compared with non-MASLD individuals. By subgroup analysis, MASLD patients with advanced liver disease (HR, 3.60; 95% CI, 2.10-6.18; P < .01) were also found to be associated with a significantly greater risk (P = .02) of incident diabetes than those with less severe MASLD (HR, 1.63; 95% CI, 1.0-2.45; P = .02) when compared with non-MASLD.

CONCLUSIONS

The present study emphasizes the association between MASLD and its clinical outcomes including cardiovascular, metabolic, oncologic, and other outcomes. The multisystemic nature of MASLD found in this analysis requires treatment targets to reduce systemic events and end organ complications.

Bioactive oxylipins in type 2 diabetes mellitus patients with and without hypertriglyceridemia

Objective

Dyslipidemia, in particular elevated triglycerides (TGs) contribute to increased cardiovascular risk in type 2 diabetes mellitus (T2DM). In this pilot study we aimed to assess how increased TGs affect hepatic fat as well as polyunsaturated fatty acid (PUFA) metabolism and oxylipin formation in T2DM patients.

Methods

40 patients with T2DM were characterized analyzing routine lipid blood parameters, as well as medical history and clinical characteristics. Patients were divided into a hypertriglyceridemia (HTG) group (TG ≥ 1.7mmol/l) and a normal TG group with TGs within the reference range (TG < 1.7mmol/l). Profiles of PUFAs and their oxylipins in plasma were measured by gas chromatography and liquid chromatography/tandem mass spectrometry. Transient elastography (TE) was used to assess hepatic fat content measured as controlled attenuation parameter (CAP) (in dB/m) and the degree of liver fibrosis measured as stiffness (in kPa).

Results

Mean value of hepatic fat content measured as CAP as well as body mass index (BMI) were significantly higher in patients with high TGs as compared to those with normal TGs, and correlation analysis showed higher concentrations of TGs with increasing CAP and BMI scores in patients with T2DM. There were profound differences in plasma oxylipin levels between these two groups. Cytochrome P450 (CYP) and lipoxygenase (LOX) metabolites were generally more abundant in the HTG group, especially those derived from arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), γ-linolenic acid (γ-LA), and α-linolenic acid (α-LA), and a strong correlation between TG levels and plasma metabolites from different pathways was observed.

Conclusions

In adult patients with T2DM, elevated TGs were associated with increased liver fat and BMI. Furthermore, these patients also had significantly higher plasma levels of CYP- and LOX- oxylipins, which could be a novel indicator of increased inflammatory pathway activity, as well as a novel target to dampen this activity.

The heterogeneity of metabolic syndrome presentation and challenges this causes in its pharmacological management: a narrative review focusing on principal risk modifiers

INTRODUCTION

Metabolic syndrome (MetS), i.e. the cluster of cardiometabolic risk factors comprising visceral obesity, impaired glucose metabolism, arterial hypertension and atherogenic dyslipidemia, is prevalent globally and exacts a heavy toll on health care expenditures.

AREAS COVERED

The pathophenotypes of individual traits of the MetS in adults are discussed first, with strong emphasis on nonalcoholic fatty liver disease (NAFLD) and sex differences. Next, I discuss recent studies on phenotypic and outcome heterogeneity of the MetS, highlighting the role of NAFLD, sex, reproductive status, and depressive disorders. In the second half of the article, the therapeutic implications of the variable MetS types and features are analyzed, focusing on the most recent developments, and guidelines.

EXPERT OPINION

I have identified physiological, pathological, social and medical sources of phenotypical heterogeneity in the MetS and its constitutive traits. Improved understanding of these variables may be utilized in the setting of future precision medicine approaches in the field of metabolic disorders and target organ damage.

Letter: for improved prognostic value, use MAFLD

This article is linked to Fu et al paper. To view this article, visit https://doi.org/10.1111/apt.17397

Nutrients, Physical Activity, and Mitochondrial Dysfunction in the Setting of Metabolic Syndrome

Metabolic syndrome (MetS) is a cluster of metabolic risk factors for diabetes, coronary heart disease, non-alcoholic fatty liver disease, and some tumors. It includes insulin resistance, visceral adiposity, hypertension, and dyslipidemia. MetS is primarily linked to lipotoxicity, with ectopic fat deposition from fat storage exhaustion, more than obesity per se. Excessive intake of long-chain saturated fatty acid and sugar closely relates to lipotoxicity and MetS through several pathways, including toll-like receptor 4 activation, peroxisome proliferator-activated receptor-gamma regulation (PPARγ), sphingolipids remodeling, and protein kinase C activation. These mechanisms prompt mitochondrial dysfunction, which plays a key role in disrupting the metabolism of fatty acids and proteins and in developing insulin resistance. By contrast, the intake of monounsaturated, polyunsaturated, and medium-chain saturated (low-dose) fatty acids, as well as plant-based proteins and whey protein, favors an improvement in sphingolipid composition and metabolic profile. Along with dietary modification, regular exercises including aerobic, resistance, or combined training can target sphingolipid metabolism and improve mitochondrial function and MetS components. This review aimed to summarize the main dietary and biochemical aspects related to the physiopathology of MetS and its implications for mitochondrial machinery while discussing the potential role of diet and exercise in counteracting this complex clustering of metabolic dysfunctions.