Association of cardiorespiratory fitness, body mass index, and waist circumference to nonalcoholic fatty liver disease

Centrally Distributed Adiposity as a Modifiable Risk Factor for Fecal Incontinence: United States Population-based Analysis

BACKGROUND AND AIMS

Fecal incontinence (FI) is highly prevalent with substantial impacts on quality of life and health care utilization. The impact of obesity on FI remains unclear, with differing conclusions using body mass index (BMI) as a risk factor. We aimed to determine the association between obesity and FI, and whether this relationship is dependent on the distribution of adiposity (waist circumference-to-height ratio [WHtR]).

METHODS

This was a population-based analysis of the National Health and Nutrition Examination Survey, including participants who responded to the bowel health survey in 2005 to 2010. FI was defined by the accidental bowel leakage of solid stool, liquid, or mucus at least once in the past month. Stepwise multivariable logistic regression models were constructed to assess risk factors for FI.

RESULTS

A total of 7606 participants were included, with an overall FI prevalence of 9.2%. When stratified by quartiles of body measurements, FI was increasingly prevalent from the 1st to the 4th quartile for both WHtR (range, 5.3%-12.5%) and BMI (range, 7.1%-10.5%). WHtR was associated with FI and was a stronger predictor than BMI in all quartiles of body measurement. On multivariable analysis, WHtR remained a significant predictor of FI comparing the 4th with the 1st quartile of body measurements (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.11-2.80; P = .017), whereas BMI was not. A WHtR cutoff of >0.592 optimized the Youden index in prediction of FI in the overall sample.

CONCLUSION

WHtR was independently associated with increased odds of FI in this nationally representative sample of United States adults, whereas BMI was not consistently correlated. This suggests bowel continence may depend more on how body mass is distributed.

Correlation between ZJU index and hepatic steatosis and liver fibrosis in American adults with NAFLD

Background

ZJU index, a novel calculation combining blood glucose, body mass index (BMI), lipids and liver functions, is closely related with non-alcoholic fatty liver disease (NAFLD). However, the correlation between ZJU index and hepatic steatosis and liver fibrosis has not been reported in the studies. This study aims to examine the correlation between these variables.

Methods

Data from the 2017-2020 NHANES were collected for a cross-sectional study, to explore the linear relationship between ZJU, liver stiffness measurements (LSM) and controlled attenuation parameters (CAP) with multivariate linear regression models. Restricted cubic spline (RCS) regression and threshold effect analyses were utilized to describe the nonlinear relationship. The correlation in subgroups was analyzed based on race, gender, drinking, age, BMI, diabetes and moderate activities.

Results

In this population-based study, a total of 2,122 adults aged 18-80 years old with NAFLD were included. According to the multivariate linear regression analysis, ZJU had a significant positive correlation with liver fibrosis (LSM, β = 0.182, 95%CI = 0.154-0.211, p < 0.001) and hepatic steatosis (CAP, β = 2.35, 95%CI = 2.14-2.56, p < 0.001), which was stronger in males. According to the RCS analysis, an inverted L-shaped relationship between ZJU and CAP (inflection point at 60.56) and a J-shaped relationship between ZJU index and LSM (inflection point at 51.27) were observed.

Conclusion

ZJU had a positive correlation with CAP and LSM in American adults with NAFLD. The findings suggest that ZJU may be a valuable biomarker for assessing the severity of liver fibrosis and hepatic steatosis in individuals with NAFLD.

Targeting the GLP-2 receptor in the management of obesity

Recent advancements in understanding glucagon-like peptide 2 (GLP-2) biology and pharmacology have sparked interest in targeting the GLP-2 receptor (GLP-2R) in the treatment of obesity. GLP-2 is a proglucagon-derived 33-amino acid peptide co-secreted from enteroendocrine L cells along with glucagon-like peptide 1 (GLP-1) and has a range of actions via the GLP-2R, which is particularly expressed in the gastrointestinal tract, the liver, adipose tissue, and the central nervous system (CNS). In humans, GLP-2 evidently induces intestinotrophic effects (i.e., induction of intestinal mucosal proliferation and improved gut barrier function) and promotes mesenteric blood flow. However, GLP-2 does not seem to have appetite or food intake-reducing effects in humans, but its gut barrier-promoting effect may be of interest in the context of obesity. Obesity is associated with reduced gut barrier function, increasing the translocation of proinflammatory gut content to the circulation. This phenomenon constitutes a strong driver of obesity-associated systemic low-grade inflammation, which in turn plays a major role in the development of most obesity-associated complications. Thus, the intestinotrophic and gut barrier-improving effect of GLP-2, which in obese rodent models shows strong anti-inflammatory potential, may, in combination with food intake-reducing strategies, e.g., GLP-1 receptor (GLP-1) agonism, be able to rectify core pathophysiological mechanism of obesity. Here, we provide an overview of GLP-2 physiology in the context of obesity pathophysiology and review the pharmacological potential of GLP-2R activation in the management of obesity and related comorbidities.

Genetic correlations between liver fat content, metabolic health, and adiposity distribution in the Fels Longitudinal Study

BACKGROUND AND AIMS

Hepatic steatosis is known to be heritable, but its genetic basis is mostly uncharacterized. Steatosis is associated with metabolic and adiposity features; recent studies hypothesize that shared genetic effects between these traits could account for some of the unexplained heritability. This study aimed to quantify these genetic associations in a family-based sample of non-Hispanic white adults.

METHODS AND RESULTS

704 participants (18-95 years, 55.8% female) from the Fels Longitudinal Study with an MRI assessment of liver fat were included. Quantitative genetic analyses estimated the age- and sex-adjusted heritability of individual traits and the genetic correlations within trait pairs. Mean liver fat was 5.95% (SE = 0.23) and steatosis (liver fat >5.56%) was present in 29.8% of participants. Heritability (h2± SE) of steatosis was 0.72 ± 0.17 (p = 6.80e-6). All other traits including liver enzymes, fasting glucose, HOMA-IR, visceral and subcutaneous adipose tissue (VAT, SAT), body mass index, body fat percent, waist circumference, lipids and blood pressure were also heritable. Significant genetic correlations were found between liver fat and all traits except aspartate aminotransferase (AST), and among most trait pairs. Highest genetic correlations were between liver fat and HOMA-IR (0.85 ± 0.08, p = 1.73e-8), fasting glucose and ALT (0.89 ± 0.26, p = 6.68e-5), and HOMA-IR with: waist circumference (0.81 ± 0.12, p = 3.76e-6), body fat percent (0.78 ± 0.12 p = 2.42e-5) and VAT (0.73 ± 0.07, p = 6.37e-8).

CONCLUSIONS

Common genes may exist between liver fat accumulation, metabolic features and adiposity phenotypes.

Navigating the Link Between Non-alcoholic Fatty Liver Disease/Non-alcoholic Steatohepatitis and Cardiometabolic Syndrome

The global prevalence of non-alcoholic fatty liver disease (NAFLD) is nearly 25% and is increasing rapidly. The spectrum of liver damage in NAFLD ranges from simple steatosis to non-alcoholic steatohepatitis, characterised by the presence of lobular inflammation and hepatocyte ballooning degeneration, with or without fibrosis, which can further develop into cirrhosis and hepatocellular carcinoma. Not only is NAFLD a progressive liver disease, but numerous pieces of evidence also point to extrahepatic consequences. Accumulating evidence suggests that patients with NAFLD are also at increased risk of cardiovascular disease (CVD); in fact, CVDs are the most common cause of mortality in patients with NAFLD. Obesity, type 2 diabetes and higher levels of LDL are common risk factors in both NAFLD and CVD; however, how NAFLD affects the development and progression of CVD remains elusive. In this review, we comprehensively summarise current data on the key extrahepatic manifestations of NAFLD, emphasising the possible link between NAFLD and CVD, including the role of proprotein convertase substilisin/kenin type 9, extracellular vesicles, microbiota, and genetic factors.

Divergence in aerobic capacity influences hepatic and systemic metabolic adaptations to bile acid sequestrant and short-term high-fat/sucrose feeding in rats

High versus low aerobic capacity significantly impacts the risk for metabolic diseases. Rats selectively bred for high or low intrinsic aerobic capacity differently modify hepatic bile acid metabolism in response to high-fat diets (HFDs). Here we tested if a bile acid sequestrant would alter hepatic and whole body metabolism differently in rats with high and low aerobic capacity fed a 1-wk HFD. Male rats (8 mo of age) that were artificially selected to be high (HCR) and low-capacity runners (LCR) with divergent intrinsic aerobic capacities were transitioned from a low-fat diet (LFD, 10% fat) to an HFD (45% fat) with or without a bile acid sequestrant (BA-Seq, 2% cholestyramine resin) for 7 days while maintained in an indirect calorimetry system. HFD + BA-Seq increased fecal excretion of lipids and bile acids and prevented weight and fat mass gain in both strains. Interestingly, HCR rats had increased adaptability to enhance fecal bile acid and lipid loss, resulting in more significant energy loss than their LCR counterpart. In addition, BA-Seq induced a greater expression of hepatic CYP7A1 gene expression, the rate-limiting enzyme of bile acid synthesis in HCR rats both on HFD and HFD + BA-Seq diets. HCR displayed a more significant reduction of RQ in response to HFD than LCR, but HFD + BA-Seq lowered RQ in both groups compared with HFD alone, demonstrating a pronounced impact on metabolic flexibility. In conclusion, BA-Seq provides uniform metabolic benefits for metabolic flexibility and adiposity, but rats with higher aerobic capacity display adaptability for hepatic bile acid metabolism.NEW & NOTEWORTHY The administration of bile acid sequestrant (BA-Seq) has uniform metabolic benefits in terms of metabolic flexibility and adiposity in rats with high and low aerobic capacity. However, rats with higher aerobic capacity demonstrate greater adaptability in hepatic bile acid metabolism, resulting in increased fecal bile acid and lipid loss, as well as enhanced fecal energy loss.

Obesity as a Neuroendocrine Disorder

Obesity is one of the most prevalent diseases in the world. Based on hundreds of clinical and basic investigations, its etiopathogenesis goes beyond the simple imbalance between energy intake and expenditure. The center of the regulation of appetite and satiety lies in the nuclei of the hypothalamus where peripheral signals derived from adipose tissue (e.g., leptin), the gastrointestinal tract, the pancreas, and other brain structures, arrive. These signals are part of the homeostatic control system (eating to survive). Additionally, a hedonic or reward system (eating for pleasure) is integrated into the regulation of appetite. This reward system consists of a dopaminergic circuit that affects eating-related behaviors influencing food preferences, food desires, gratification when eating, and impulse control to avoid compulsions. These systems are not separate. Indeed, many of the hormones that participate in the homeostatic system also participate in the regulation of the hedonic system. In addition, factors such as genetic and epigenetic changes, certain environmental and sociocultural elements, the microbiota, and neuronal proinflammatory effects of high-energy diets also contribute to the development of obesity. Therefore, obesity can be considered a complex neuroendocrine disease, and all of the aforementioned components should be considered for the management of obesity.

Changes in Hepatic Fat Content by CT 1 Year After Sleeve Gastrectomy in Adolescents and Young Adults With Obesity

CONTEXT

Obesity is associated with nonalcoholic fatty liver disease (NAFLD). Sleeve gastrectomy (SG) is an effective means of weight loss and improvement of NAFLD in adults; however, data regarding the efficacy of SG in the early stages of pediatric NAFLD are sparse.

OBJECTIVE

To assess the impact of SG on hepatic fat content 1 year after SG in youth with obesity compared with nonsurgical controls with obesity (NS).

DESIGN

A 12-month prospective study in 52 participants (mean age, 18.2 ± .36 years) with obesity, comprising 25 subjects who underwent SG (84% female; median body mass index [BMI], 44.6 [42.1-47.9] kg/m2) and 27 who were NS (70% female; median BMI, 42.2 [38.7-47.0] kg/m2).

MAIN OUTCOME MEASURES

Hepatic fat content by computed tomography (liver/spleen ratio), abdominal fat by magnetic resonance imaging.

RESULTS

Mean 12-month decrease in BMI was greater in SG vs NS (-12.5 ± .8 vs -.2 ± .5 kg/m2, P < .0001). There was a within-group increase in the liver-to-spleen (L/S) ratio in SG (.13 ± .05, P = .014) but not NS with a trend for a difference between groups (P = .055). All SG participants with an L/S ratio <1.0 (threshold for the diagnosis of NAFLD) before surgery had a ratio of >1.0 a year after surgery, consistent with resolution of NAFLD. Within SG, the 12-month change in L/S ratio was negatively associated with 12-month change in visceral fat (ρ = -.51 P = .016).

CONCLUSIONS

Hepatic fat content as assessed by noncontrast computed tomography improved after SG over 1 year in youth with obesity with resolution of NAFLD in all subjects. This was associated with decreases in visceral adiposity.

Associations of Skeletal Muscle Mass, Muscle Fat Infiltration, Mitochondrial Energetics, and Cardiorespiratory Fitness with Liver Fat Among Older Adults

Background

Muscle mass loss may be associated with liver fat accumulation, yet scientific consensus is lacking and evidence in older adults is scant. It is unclear which muscle characteristics might contribute to this association in older adults.

Methods

We associated comprehensive muscle-related phenotypes including muscle mass normalized to body weight (D 3 -creatine dilution), muscle fat infiltration (MRI), carbohydrate-supported muscle mitochondrial maximal oxidative phosphorylation (respirometry), and cardiorespiratory fitness (VO 2 peak) with liver fat among older adults. Linear regression models adjusted for age, gender, technician (respirometry only), daily minutes of moderate to vigorous physical activity, and prediabetes/diabetes status tested main effects and interactions of each independent variable with waist circumference (high: women-≥88 cm, men-≥102 cm) and gender.

Results

Among older adults aged 75 (IQR 73, 79 years; 59.8% women), muscle mass and liver fat were not associated overall but were positively associated among participants with a high waist circumference (β: 25.2; 95%CI 11.7, 40.4; p =.0002; N=362). Muscle fat infiltration and liver fat were positively associated (β: 15.2; 95%CI 6.8, 24.3; p =.0003; N=378). Carbohydrate-supported maximum oxidative phosphorylation and VO 2 peak (adjusted β: -12.9; 95%CI -20.3, -4.8; p =0.003; N=361) were inversely associated with liver fat; adjustment attenuated the estimate for maximum oxidative phosphorylation although the point estimate remained negative (β: -4.0; 95%CI -11.6, 4.2; p =0.32; N=321).

Conclusions

Skeletal muscle-related characteristics are metabolically relevant factors linked to liver fat in older adults. Future research should confirm our results to determine whether trials targeting mechanisms common to liver and muscle fat accumulation are warranted.

Associations of objectively measured physical activity, sedentary time and cardiorespiratory fitness with adipose tissue insulin resistance and ectopic fat

BACKGROUND/OBJECTIVES

Inadequate movement, excess adiposity, and insulin resistance augment cardiometabolic risk. This study examined the associations of objectively measured moderate-to-vigorous intensity physical activity (MVPA), sedentary time and cardiorespiratory fitness (CRF), with adipose tissue insulin resistance and ectopic fat.

METHODS

Data were combined from two previous experimental studies with community volunteers (n = 141, male = 60%, median (interquartile range) age = 37 (19) years, body mass index (BMI) = 26.1 (6.3) kg·m-2). Adipose tissue insulin resistance was assessed using the adipose tissue insulin resistance index (Adipo-IR); whilst magnetic resonance imaging (MRI) was used to measure liver, visceral (VAT) and subcutaneous abdominal adipose tissue (ScAT). Sedentary time and MVPA were measured via an ActiGraph GT3X+ accelerometer. Generalized linear models examined the association of CRF, MVPA, and sedentary time with Adipo-IR and fat depots. Interaction terms explored the moderating influence of age, sex, BMI and CRF.

RESULTS

After controlling for BMI and cardiometabolic variables, sedentary time was positively associated with Adipo-IR (β = 0.68 AU [95%CI = 0.27 to 1.10], P < 0.001). The association between sedentary time and Adipo-IR was moderated by age, CRF and BMI; such that it was stronger in individuals who were older, had lower CRF and had a higher BMI. Sedentary time was also positively associated with VAT (β = 0.05 L [95%CI = 0.01 to 0.08], P = 0.005) with the relationship being stronger in females than males. CRF was inversely associated with VAT (β = -0.02 L [95%CI = -0.04 to -0.01], P = 0.003) and ScAT (β = -0.10 L [95%CI = -0.13 to -0.06], P < 0.001); with sex and BMI moderating the strength of associations with VAT and ScAT, respectively.

CONCLUSIONS

Sedentary time is positively associated with adipose tissue insulin resistance which regulates lipogenesis and lipolysis. CRF is independently related to central fat storage which is a key risk factor for cardiometabolic disease.

Comparison between metabolic-associated fatty liver disease and nonalcoholic fatty liver disease: From nomenclature to clinical outcomes

As a result of the obesity epidemic, Nonalcoholic fatty liver disease (NAFLD) and its complications have increased among millions of people. Consequently, a group of experts recommended changing the term NAFLD to an inclusive terminology more reflective of the underlying pathogenesis; metabolic-associated fatty liver disease (MAFLD). This new term of MAFLD has its own disease epidemiology and clinical outcomes prompting efforts in studying its differences from NAFLD. This article discusses the rationale behind the nomenclature change, the main differences, and its clinical implications.

Novel Therapeutics in Nonalcoholic Fatty Liver Disease: A Focus on Adult Stem Cells

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder that is associated with abnormal accumulation of fat in the liver, which can lead to a wide variety of pathological liver defects and associated insulin resistance (IR), obesity, hypertension, dyslipidemia, diabetes, and cardiovascular disease. The molecular mechanisms that cause the initiation and progression of NAFLD are not fully understood. Increased lipolysis and de novo hepatic lipid synthesis lead to oxidative stress induced by reactive oxygen species and inflammation. Both these two entities could be interrelated and be an important mechanistic pathway, which can lead to tissue injury and hepatic cell death. Mechanisms for worsening of NAFLD include mitochondrial abnormalities, downregulation of glutathione (GSH), decreased activity of GSH-dependent antioxidants, accumulation of activated macrophages, hepatic inflammation, systemic inflammation, IR, and poorly controlled type 2 diabetes mellitus. Although no specific therapy has been approved for NAFLD, we review the latest medical therapeutics with emphasis on stem cell-based possibilities based on the presumed pathophysiology of NAFLD.

Therapeutic Physical Exercise Programs in the Context of NASH Cirrhosis and Liver Transplantation: A Systematic Review

In recent years, various physical exercise interventions have been developed with a view to reducing comorbidity and morbidity rates among patients with chronic diseases. Regular physical exercise has been shown to reduce hypertension and mortality in patients with type 2 diabetes. Diabetes and obesity are often associated with the development of nonalcoholic fatty liver disease, which can lead to liver fibrosis and then (in some cases) nonalcoholic steatohepatitis cirrhosis. We searched the literature for publications on personalized physical exercise programs in cirrhotic patients before and after liver transplantation. Eleven studies in cirrhotic patients and one study in liver transplant recipients were included in the systematic review, the results of which were reported in compliance with the preferred reporting items for systematic reviews and meta-analyses guidelines. The personalized physical exercise programs lasted for 6 to 16 weeks. Our review evidenced improvements in peak oxygen consumption and six-minute walk test performance and a reduction in the hepatic venous pressure gradient. In cirrhotic patients, personalized physical exercise programs improve quality of life, are not associated with adverse effects, and (for transplant recipients) might reduce the 90-day hospital readmission rate. However, none of the literature data evidenced reductions in the mortality rates before and after transplantation. Further prospective studies are needed to evaluate the benefit of long-term physical exercise programs in cirrhotic patients before and after liver transplantation.

Comprehensive Review of Cardiovascular Disease Risk in Nonalcoholic Fatty Liver Disease

Nonalcoholic Fatty Liver Disease (NAFLD) is a growing global phenomenon, and its damaging effects in terms of cardiovascular disease (CVD) risk are becoming more apparent. NAFLD is estimated to affect around one quarter of the world population and is often comorbid with other metabolic disorders including diabetes mellitus, hypertension, coronary artery disease, and metabolic syndrome. In this review, we examine the current evidence describing the many ways that NAFLD itself increases CVD risk. We also discuss the emerging and complex biochemical relationship between NAFLD and its common comorbid conditions, and how they coalesce to increase CVD risk. With NAFLD's rising prevalence and deleterious effects on the cardiovascular system, a complete understanding of the disease must be undertaken, as well as effective strategies to prevent and treat its common comorbid conditions.

The value of combining the simple anthropometric obesity parameters, Body Mass Index (BMI) and a Body Shape Index (ABSI), to assess the risk of non-alcoholic fatty liver disease

Background

Body mass index (BMI) and A Body Shape Index (ABSI) are current independent risk factors for non-alcoholic fatty liver disease (NAFLD). The aim of this study was to explore the value of combining these two most common obesity indexes in identifying NAFLD.

Methods

The subjects in this study were 14,251 individuals from the NAfld in the Gifu Area, Longitudinal Analysis (NAGALA) cohort who underwent routine health examination. We integrated BMI with WC and with ABSI to construct 6 combined obesity indicators—obesity phenotypes, the combined anthropometric risk index (ARI) for BMI and ABSI, optimal proportional combination O_BMI+WC and O_BMI+ABSI, and multiplicative combination BMI*WC and BMI*ABSI. Several multivariable logistic regression models were established to evaluate the relationship between BMI, WC, ABSI, and the above six combined indicators and NAFLD; receiver operating characteristic (ROC) curves were drawn to compare the ability of each obesity indicator to identify NAFLD.

Results

A total of 2,507 (17.59%) subjects were diagnosed with NAFLD. BMI, WC, ABSI, and all other combined obesity indicators were significantly and positively associated with NAFLD in the current study, with BMI*WC having the strongest correlation with NAFLD in female subjects (OR per SD increase: 3.13) and BMI*ABSI having the strongest correlation in male subjects (OR per SD increase: 2.97). ROC analysis showed that ARI and O_BMI+ABSI had the best diagnostic performance in both sexes, followed by BMI*WC (area under the curve: female 0.8912; male 0.8270). After further age stratification, it was found that ARI and multiplicative indicators (BMI*WC, BMI*ABSI) and optimal proportional combination indicators (O_BMI+WC, O_BMI+ABSI) significantly improved the NAFLD risk identification ability of the basic anthropometric parameters in middle-aged females and young and middle-aged males.

Conclusion

In the general population, BMI combined with ABSI best identified obesity-related NAFLD risk and was significantly better than BMI or WC, or ABSI. We find that ARI and the multiplicative combined indicators BMI*WC and BMI*ABSI further improved risk prediction and may be proposed for possible use in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01717-8.

Relationship between liver fat content and lifestyle factors in adults with metabolic syndrome

The aim of this study was to investigate the associations between liver fat content (LFC), sedentary behaviour (SB), physical activity (PA), fitness, diet, body composition, and cardiometabolic risk factors in adults with metabolic syndrome. A total of 44 sedentary adults (mean age 58 [SD 7] years; 25 women) with overweight or obesity participated. LFC was assessed with magnetic resonance spectroscopy and imaging, SB and PA with hip-worn accelerometers (26 [SD 3] days), fitness by maximal bicycle ergometry, body composition by air displacement plethysmography and nutrient intake by 4-day food diaries. LFC was not independently associated with SB, PA or fitness. Adjusted for sex and age, LFC was associated with body fat%, body mass index, waist circumference, triglycerides, alanine aminotransferase, and with insulin resistance markers. There was and inverse association between LFC and daily protein intake, which persisted after further adjusment with body fat%. LFC is positively associated with body adiposity and cardiometabolic risk factors, and inversely with daily protein intake. SB, habitual PA or fitness are not independent modulators of LFC. However, as PA is an essential component of healthy lifestyle, it may contribute to liver health indirectly through its effects on body composition in adults with metabolic syndrome.

Body weight and physical fitness in women with ischaemic heart disease: does physical fitness contribute to our understanding of the obesity paradox in women?

AIMS

Body mass index (BMI) defined obesity is paradoxically associated with lower all-cause mortality in patients with known cardiovascular disease. This study aims to determine the role of physical fitness in the obesity paradox in women with ischaemic heart disease (IHD).

METHODS AND RESULTS

Women undergoing invasive coronary angiography with signs/symptoms of IHD in the Women's Ischemia Syndrome Evaluation (WISE) prospective cohort (enrolled 1997-2001) were analysed. This study investigated the longer-term risk of major adverse cardiovascular events (MACE) and all-cause mortality associated with BMI and physical fitness measured by Duke Activity Status Index (DASI). Overweight was defined as BMl ≥25 to 30 kg/m2, obese as BMI ≥30 kg/m2, unfit as DASI scores <25, equivalent to ≤7 metabolic equivalents. Among 899 women, 18.6% were normal BMI-fit, 11.4% overweight-fit, 10.4% obese-fit, 15.3% normal BMI-unfit, 23.8% overweight-unfit, and 30.4% obese-unfit. In adjusted models compared to normal BMI-fit, normal BMI-unfit women had higher MACE risk [hazard ratio (HR) 1.65, 95% confidence interval (CI) 1.17-2.32; P = 0.004]; whereas obese-fit and overweight-fit women had lower risk of mortality (HR 0.60, 95% CI 0.40-0.89; P = 0.012 and HR 0.62, 95% CI 0.41-0.92; P = 0.018, respectively).

CONCLUSION

To address the paradox of body weight and outcomes in women, we report for the first time that among women with signs/symptoms of IHD overweight-fit and obese-fit were at lower risk of long-term all-cause mortality; whereas normal BMI-unfit were at higher risk of MACE. Physical fitness may contribute to the obesity paradox in women, warranting future studies to better understand associations between body weight, body composition, and physical fitness to improve cardiovascular outcomes in women.

Rats with high aerobic capacity display enhanced transcriptional adaptability and upregulation of bile acid metabolism in response to an acute high-fat diet

Rats selectively bred for the high intrinsic aerobic capacity runner (HCR) or low aerobic capacity runner (LCR) show pronounced differences in susceptibility for high-fat/high sucrose (HFHS) diet-induced hepatic steatosis and insulin resistance, replicating the protective effect of high aerobic capacity in humans. We have previously shown multiple systemic differences in energy and substrate metabolism that impacts steatosis between HCR and LCR rats. This study aimed to investigate hepatic-specific mechanisms of action via changes in gene transcription. Livers of HCR rats had a greater number of genes that significantly changed in response to 3-day HFHS compared with LCR rats (171 vs. 75 genes: >1.5-fold, p < 0.05). HCR and LCR rats displayed numerous baseline differences in gene expression while on a low-fat control diet (CON). A 3-day HFHS diet resulted in greater expression of genes involved in the conversion of excess acetyl-CoA to cholesterol and bile acid (BA) synthesis compared with the CON diet in HCR, but not LCR rats. These results were associated with higher fecal BA loss and lower serum BA concentrations in HCR rats. Exercise studies in rats and mice also revealed higher hepatic expression of cholesterol and BA synthesis genes. Overall, these results suggest that high aerobic capacity and exercise are associated with upregulated BA synthesis paired with greater fecal excretion of cholesterol and BA, an effect that may play a role in protection against hepatic steatosis in rodents.

Pomegranate juice intake enhances the effects of aerobic training on insulin resistance and liver enzymes in type 2 diabetic men: a single-blind controlled trial

BACKGROUND

Lifestyle interventions are the first-line treatment for Type 2 diabetes mellitus (T2DM), highly prevalent in the community. This study aimed to examine the 8-week separate and combined effects of aerobic training (AT) and pomegranate juice intake (PJI) on insulin resistance and serum levels of liver enzymes, liver enzymes, and insulin resistance in men with T2DM.

METHODS

This study evaluated the alterations of anthropometric indices, insulin resistance, and liver enzymes in 40 middle-aged men (40-50) with T2DM. Participants were randomly assigned into four groups: AT+PJI (n = 10); AT (n = 10); PJI (n = 10), and control (C) (n = 10). The AT program consisted of 60-75% of maximum heart rate (HR_max), 40-60 min/day, and 3 days/wk. Participants in the PJI group consumed 240 ml of pomegranate juice (sugar or additive-free) daily for 8 weeks.

RESULTS

AT+PJI, PJI, and AT groups decreased anthropometric indices, HOMA-IR, and liver enzymes after 8 weeks. In contrast, the C group significantly increased the mentioned variables after the intervention. The result showed that AT+PJI significantly lowered liver enzymes, anthropometric indices, and HOMA-IR than AT or PJI alone. Also, the results of this study showed no significant difference between AT and PJI groups. However, in these groups, significant improvements in these variables were observed compared to the control group.

CONCLUSION

Due to the effect of combined AT+PJI in improving T2DM risk factors, it could be recommended for T2DM patients to prevent increased liver enzymes and insulin resistance.

Prevalence and characteristics of MAFLD in Chinese adults aged 40 years or older: A community-based study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) was recently proposed to be renamed metabolic dysfunction-associated fatty liver disease (MAFLD) with the diagnostic criteria revised. We investigated the similarities and differences in the prevalence and clinical characteristics of MAFLD and NAFLD in Chinese adults.

METHODS

A cross-sectional study of 9980 Chinese individuals aged 40 years or older was performed between 2011 and 2012 using randomized, stratified cluster sampling in Shanghai, China. A detailed questionnaire and the results of abdominal ultrasonography, a standardized 2-h 75-g oral glucose tolerance test and blood biochemical examinations were collected.

RESULTS

A total of 9927 subjects were included in this study. The prevalence of MAFLD (40.3%) was significantly higher than that of NAFLD (36.9%) (P < 0.05). MAFLD was highly prevalent in type 2 diabetes mellitus (T2DM) (53.8%), impaired fasting glucose (35.7%) and impaired glucose tolerance (40.9%). High risk of advanced fibrosis based on fibrosis-4 was highly prevalent (14.7%) in lean MAFLD with T2DM. Among 9927 subjects, 3481 (35.1%) fulfilled the diagnostic criteria for MAFLD and NAFLD (MAFLD+NAFLD+), 521 (5.2%) MAFLD+NAFLD-, and 181 (1.8%) MAFLD-NAFLD+. The MAFLD+NAFLD- group had more significant metabolic disorders than those in the MAFLD+NAFLD+ group (all P < 0.05). Among MAFLD-NAFLD+ subjects, 82.9% had metabolic disorders.

CONCLUSIONS

The new definition of MAFLD may better reflect the pathogenesis related to metabolism. Future research should focus on studying the natural history, pathogenesis and treatment effectivity of the overlap and non-overlap of NAFLD and MAFLD subjects.

Overweight, Obesity, and CVD Risk: a Focus on Visceral/Ectopic Fat

PURPOSE OF REVIEW

Despite its prevalence and well-documented impact on population health, obesity has not emerged as a strong independent risk factor for cardiovascular disease after control for intermediate risk factors. The purpose of this brief narrative review is to highlight results from imaging studies that have not only documented the remarkable heterogeneity of body fat topography but also the importance of visceral adiposity as a key body fat depot associated with cardiovascular disease risk and type 2 diabetes.

RECENT FINDINGS

Simple tools are also discussed in order to refine cardiometabolic risk assessment in persons with overweight/obesity. It is proposed that four lifestyle vital signs should be considered in clinical practice to improve discrimination of health risk in individuals with overweight/obesity: waist circumference as a simple marker of abdominal adiposity, cardiorespiratory fitness, overall diet quality, and level of reported physical activity. Heterogeneity of obesity is proposed as an example of a condition that would benefit from a precision lifestyle medicine approach.

Stratification by obesity class, rather than age, can identify a higher percent of children at risk for non-alcoholic fatty liver disease and metabolic dysfunction

BACKGROUND

An increasing number of clinical practice guidelines recommend screening children with obesity for non-alcoholic fatty liver disease (NAFLD). However, there is limited evidence regarding what parameters should be used to initiate the screening.

OBJECTIVE

The objective of this study was to determine whether obesity class rather than age group can identify a higher percent of children at risk of NAFLD as assessed by abnormal alanine aminotransferase (ALT).

METHODS

This is a cross-sectional study in a regional referral clinic for evaluation of obesity. Children were stratified by age group or by obesity class, and data obtained at first visit were analysed.

RESULTS

Of the 784 children, 482 were ≥10, 209 were 6 to 9 and 93 were 2 to 5 years of age. Abnormal ALT was observed in 32.1%, 46.9% and 61.0% of children with class I, II or III obesity, respectively (p < 0.001), while the risk of abnormal ALT did not differ in very young (2-5), young (6-9), or children older than 10 years. A multivariable analysis showed that class II and class III obesity were associated with 2.1-fold (1.27-3.72) and 4-fold (2.41-6.96) greater odds of abnormal ALT compared with class I obesity. African-American children had lower risk of abnormal ALT (0.27), whereas Hispanic children had higher risk (2.37). Obesity class was a better predictor of abnormal ALT than age, especially in girls. Furthermore, 66.7% of boys (p = 0.009) and 69% of girls (p < 0.001) with abnormal ALT exhibited additional signs of metabolic dysfunction.

CONCLUSION

Obesity class is more strongly associated with abnormal ALT than age.

Potential Mechanisms for How Long-Term Physical Activity May Reduce Insulin Resistance

Insulin became available for the treatment of patients with diabetes 100 years ago, and soon thereafter it became evident that the biological response to its actions differed markedly between individuals. This prompted extensive research into insulin action and resistance (IR), resulting in the universally agreed fact that IR is a core finding in patients with type 2 diabetes mellitus (T2DM). T2DM is the most prevalent form of diabetes, reaching epidemic proportions worldwide. Physical activity (PA) has the potential of improving IR and is, therefore, a cornerstone in the prevention and treatment of T2DM. Whereas most research has focused on the acute effects of PA, less is known about the effects of long-term PA on IR. Here, we describe a model of potential mechanisms behind reduced IR after long-term PA to guide further mechanistic investigations and to tailor PA interventions in the therapy of T2DM. The development of such interventions requires knowledge of normal glucose metabolism, and we briefly summarize an integrated physiological perspective on IR. We then describe the effects of long-term PA on signaling molecules involved in cellular responses to insulin, tissue-specific functions, and whole-body IR.

Higher Healthy Lifestyle Score is associated with lower presence of non-alcoholic fatty liver disease in middle-aged and older Chinese adults: a community-based cross-sectional study

OBJECTIVE

Previous studies have reported inverse associations between certain healthy lifestyle factors and non-alcoholic fatty liver disease (NAFLD), but limited evidence showed the synergistic effect of those lifestyles. This study examined the relationship of a combination of lifestyles, expressed as Healthy Lifestyle Score (HLS), with NAFLD.

DESIGN

A community-based cross-sectional study. Questionnaires and body assessments were used to collect data on the six-item HLS (ranging from 0 to 6, where higher scores indicate better health). The HLS consists of non-smoking (no active or passive smoking), normal BMI (18·5-23·9 kg/m2), physical activity (moderate or vigorous physical activity ≥ 150 min/week), healthy diet pattern, good sleep (no insomnia or <6 months) and no anxiety (Self-rating Anxiety Scale < 50), one point each. NAFLD was diagnosed by ultrasonography.

SETTING

Guangzhou, China.

PARTICIPANTS

Two thousand nine hundred and eighty-one participants aged 40-75 years.

RESULTS

The overall prevalence of NAFLD was 50·8 %. After adjusting for potential covariates, HLS was associated with lower presence of NAFLD. The OR of NAFLD for subjects with higher HLS (3, 4, 5-6 v. 0-1 points) were 0·68 (95 % CI 0·51, 0·91), 0·58 (95 % CI 0·43, 0·78) and 0·35 (95 % CI 0·25, 0·51), respectively (P-values < 0·05). Among the six items, BMI and physical activity were the strongest contributors. Sensitivity analyses showed that the association was more significant after weighting the HLS. The beneficial association remained after excluding any one of the six components or replacing BMI with waist circumference.

CONCLUSIONS

Higher HLS was associated with lower presence of NAFLD, suggesting that a healthy lifestyle pattern might be beneficial to liver health.

Management of non-alcoholic fatty liver disease in patients with sarcopenia

INTRODUCTION

Sarcopenia usually occurs with aging, sedentary lifestyle, unhealthy dietary habits, and chronic disorders pathophysiologically and bi-directionally linked to obesity and nonalcoholic fatty liver disease (NAFLD). Because of the global increase in aging and obesity populations, patients with concomitant sarcopenia and NAFLD are common, accompanied by various disorders relevant to obesity and sarcopenia, with across-the-board impact on socio-economic and public health life worldwide. Therefore, developing effective and practical management of these patients has become a pressing clinical issue.

AREAS COVERED

The authors searched literature from PubMed and Ovid MEDLINE up until Feb 2020. Emerging data on the management of sarcopenia and nonalcoholic fatty liver disease were examined and discussed.

EXPERT OPINION

Although NAFLD in patients with sarcopenia has become a critical problem worldwide, we still don't know much about the management of such patients. Based on theoretical speculations, we can recommend lifestyle intervention, including diet control with adequate protein intake, exercise intervention, and weight reduction as the mainstay of management at the first stage. More studies are needed in the future to identify the most suitable treatment and solve this important problem.

Prospective evaluation of the prevalence of non-alcoholic fatty liver disease and steatohepatitis in a large middle-aged US cohort

BACKGROUND & AIMS

Large prospective studies to establish the prevalence of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH), are lacking. We prospectively assessed the prevalence and severity of NAFLD/NASH in a cohort of asymptomatic middle-aged Americans attending a colonoscopy class at a gastroenterology clinic.

METHODS

Screening for NAFLD was performed using magnetic resonance (MR)-based LiverMultiScan® proton density fat fraction (LMS-PDFF). MR exams also included corrected T1 and elastography for liver stiffness measurement (LSM). FibroScan® was also used to measure LSM. Participants with predetermined abnormal imaging parameters were offered a liver biopsy. Biopsies were read in a blinded fashion with results based on the consensus by 2 expert pathologists. The prevalence of NAFLD was determined by PDFF ≥5% or by histological diagnosis of NAFLD (if biopsy data were available). The prevalence of NASH was defined by biopsy.

RESULTS

Of 835 participants, 664 met the inclusion and exclusion criteria. The mean age was 56 ± 6.4 years, 50% were male, the mean BMI was 30.48 ± 5.46 kg/m², and 52% were obese. The prevalence of NAFLD was 38% (95% CI 34-41%) and the prevalence of NASH was 14% (95% CI 12-17%). While no patient had cirrhosis on biopsy, significant fibrosis (F ≥2) was present in 5.9% (95% CI 4-8%) and bridging fibrosis in 1.6% (95% CI 1-3%). In a multivariable analysis, factors associated with the presence of NASH were race, obesity, and diabetes.

CONCLUSION

Using state-of-the-art liver imaging modalities and reference biopsy, this study establishes an overall prevalence of NAFLD of 38% and NASH by biopsy of 14% in this cohort of asymptomatic middle-aged US adults.

LAY SUMMARY

There are no prospective studies to determine how common is nonalcoholic steatohepatitis (NASH), the severe form of non-alcoholic fatty liver disease (NAFLD). In a large number of asymptomatic middle-aged Americans, we used a combination of state-of-the-art liver imaging methods and liver biopsy to prospectively determine the prevalence of NAFLD and NASH. NAFLD was diagnosed in 38%, NASH in 14%, and significant liver fibrosis in 6% of asymptomatic middle-aged Americans.

Patient initiation and maintenance of GLP-1 RAs for treatment of obesity

Introduction: Healthcare providers (HCPs) see many patients with obesity-related complications and are therefore well placed to help treat obesity itself. However, limited collated information exists to help HCPs with the practical use of anti-obesity medications (AOMs). We focus on the initiation and maintenance of a glucagon-like peptide-1 receptor agonist (GLP-1 RA) for weight management, liraglutide 3.0 mg. Literature search was conducted between 25-28 November 2019 on PubMed and ClinicalTrials.gov.Areas covered: Clinical trial and real-world data describing weight-loss efficacy, cardiometabolic risk factors, incidence of adverse events (AEs), and persistence are presented to assist HCPs with patient discussions. Practical considerations to overcome barriers to optimal use are provided, equipping HCPs with the information required to aid with adherence to and persistence with AOMs. The use of other GLP-1- RA therapies in obesity is discussed in light of the recent US Food and Drug Administration approval of semaglutide 2.4 mg for weight management.Expert opinion: Liraglutide 3.0 mg provides benefits regarding weight loss and improvements in cardiometabolic risk factors. Promising areas of future research in the field of obesity include dual receptor agonists and the combination of glucagon-like peptide-1 receptor agonists with other molecules.

Dose-response association of the ZJU index and fatty liver disease risk: A large cohort in China

AIM

The aim of this study is to investigate the sex-specific association between the ZJU index and risk of fatty liver disease in a large Chinese cohort.

METHODS

A total of 28 729 adults without fatty liver disease at baseline and who completed at least one follow-up of annual examinations between 2009 and 2016 were included in this study. The Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for fatty liver disease risk associated with the ZJU index.

RESULTS

During a median follow-up of 3.01 years, 7373 developed fatty liver disease. There were significant associations between the ZJU index and fatty liver disease for women and men with increasing HRs as the quartiles increase across Q2-Q4, corresponding HRs (95% CIs) in M3 were 2.28 (1.98-2.64), 3.52 (3.07-4.04), and 4.87 (4.24-5.59) for women and 2.44 (2.17-2.75), 4.18 (3.73-4.68), and 6.23 (5.56-6.98) for men. The association between the ZJU index and fatty liver disease risk remained significant in all the subgroups except that of T2DM and abdominal obesity subgroups for men. However, the association became nonsignificant when comparing Q3 and Q2 of the ZJU index with reference in the subgroups of T2DM for men, and nonsignificant when comparing Q3 of the ZJU index with reference in the subgroups of participants with T2DM and abdominal obesity for women.

CONCLUSION

The ZJU index was significantly associated with the risk of fatty liver disease in Chinese population. It will be better to keep body mass index, alanine aminotransferase, aspartate aminotransferase, triglyceride, and fasting plasma glucose at a normal level for preventing fatty liver disease.

Lean Americans With Nonalcoholic Fatty Liver Disease Have Lower Rates of Cirrhosis and Comorbid Diseases

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is typically associated with obesity. Little is known about the prevalence of cirrhosis in patients with NAFLD and a normal body mass index (BMI).

METHODS

We determined prevalence of cirrhosis, cardiovascular disease (CVD), and metabolic abnormalities among participants in all BMI categories in the TARGET-NASH study. A total of 3386 patients with NAFLD were enrolled from August 2016 through March 2019. The odds ratios of cirrhosis, CVD, and metabolic abnormalities were estimated by age and race, adjusting for sex and center type.

RESULTS

Based on standard BMI cutoff values, 12.8% of study subjects were lean, 27.1% were overweight, 26.5% had class 1 obesity, and 33.7% had class 2 or 3 obesity. Asians accounted for 48.7% of lean participants, and proportions decreased as BMI categories increased (P < .0001). Lower proportions of lean participants had cirrhosis (22.6% vs 40.2% of non-lean participants), CVD history (9.0% vs 14.8% of nonlean participants), diabetes (32.6% vs 53.5% of non-lean participants), hypertension (47.8% vs 67.4% of non-lean participants), or dyslipidemia (54.0% vs 64.1% of non-lean participants). Asian participants had a lower prevalence of cirrhosis, history of CVD, cardiovascular events, and diabetes compared with non-Asians, independent of BMI category. After we adjusted for age, sex, and center type and site, the odds of NAFLD-associated cirrhosis in Asians who were lean was almost half the odds of NAFLD-associated cirrhosis in non-Asians who were lean (odds ratio, 0.47; 95% CI, 0.29-0.77).

CONCLUSIONS

More than 10% participants in a cohort of persons with NAFLD in the United States are lean; Asians account for almost half of the lean persons with NAFLD. Lean participants had a lower prevalence of cirrhosis, CVD, and metabolic abnormalities than non-lean persons with NAFLD. Asian participants had a significantly lower prevalence of cirrhosis, CVD, and metabolic abnormalities than non-Asians in all BMI categories. ClinicalTrials.gov, Number: NCT02815891.

Adipose Insulin Resistance and Decreased Adiponectin Are Correlated With Metabolic Abnormalities in Nonobese Men

CONTEXT

Adipose tissue dysfunction is characterized by decreased adiponectin (AN) levels and impaired adipose tissue insulin sensitivity (ATIS) and is associated with metabolic disorders. While Asians readily develop metabolic disease without obesity, it remains unclear how decreased AN level and impaired ATIS affect metabolic abnormalities in nonobese Asians.

DESIGN AND SETTING

To investigate the relationships between decreased AN level, impaired ATIS, and metabolic abnormalities, we studied 94 Japanese men whose body mass index was less than 25 kg/m2. We divided the subjects into 4 groups based on their median AN level and ATIS, the latter calculated as the degree of insulin-mediated suppression of free fatty acids during hyperinsulinemic euglycemic clamp, and compared the metabolic parameters in the 4 groups.

RESULTS

The High-ATIS/High-AN group (n = 29) showed similar anthropometric data to the High-ATIS/Low-AN group (n = 18). In contrast, both the Low-ATIS/High-AN (n = 18) and Low-ATIS/Low-AN (n = 29) groups showed significantly lower muscle insulin sensitivity than the High-ATIS groups. The intrahepatic lipid level in the Low-ATIS/Low-AN group was significantly higher than that in the High-ATIS groups. In addition, the Low-ATIS/Low-AN group had a significantly higher fasting serum triglyceride level and significantly lower high-density lipoprotein cholesterol level than the other 3 groups.

CONCLUSIONS

In nonobese Japanese men with high ATIS, the AN level was not associated with metabolic characteristics. On the other hand, subjects with low ATIS showed reduced muscle insulin sensitivity, and those with a decreased AN level demonstrated multiple metabolic abnormalities, represented by fatty liver and dyslipidemia.

The abdominal waist circumference and 4-year outcomes following peripheral bypass grafting

BACKGROUND

Current literature evaluating the relationship between obesity, utilizing measures other than the Body Mass Index (BMI), and postoperative outcomes following vascular surgery are sparse. This study aimed to investigate any association between abdominal waist circumference (AWC) and waist-hip ratio (WHR) in relation to postoperative morbidity and mortality following peripheral artery bypass graft (PABG) surgery.

METHODS

AWC and hip circumference (HC) were measured from pre-intervention magnetic resonance (MR) and computed tomography (CT) scans of patients undergoing elective and nonelective PABG. The AWC and WHR were assessed in relation to: the need for higher level care (i.e. level 2/3), the duration of higher level care, postoperative limb ischemia, postoperative hospital stay, graft patency on discharge and 30 day readmission, using logistic and linear regression analysis. Mortality was assessed using cox-regression analysis with calculation of hazard ratios at 30 days and 4 years.

RESULTS

In total, 177 patient images performed between January 2014 to January 2017 were analyzed. There were no significant intra-observer and interobserver differences in measurements of AWC and HC. Pre-intervention AWC was predictive of the need for higher level care following non-elective PABG (adjusted OR 1.1 [95% CI: 1.0-1.1, P=0.026]). An inverse relationship between AWC and mortality at 4 years was also observed (adjusted HR=0.9, 95% CI: 0.9-1.0, P=0.028). However, pre-intervention WHR failed to predict mortality and morbidity.

CONCLUSIONS

AWC may potentially be a suitable risk stratification tool in patients undergoing non-elective PABG. The association of AWC with long-term mortality outcomes require further investigation so that suitable cut-off values may be determined.

Composite BMI and Waist-to-Height Ratio Index for Risk Assessment of Non-alcoholic Fatty Liver Disease in Adult Populations

Background: As obesity becomes more prevalent, non-alcoholic fatty liver disease (NAFLD) is also becoming a major worldwide health problem and the most common cause of chronic liver disease. A new obesity classification method based on a composite index which includes both the body mass index (BMI) and the waist-to-height ratio (WHtR) was recently proposed. However, the usefulness of this approach to assess the risk of NAFLD is unclear. Methods: This is a cross-sectional study of 1,276 adult individuals in Dalian, China. The Mann Whitney U test, χ2 test and t-test were used to compare differences between groups. Binary logistic regression analysis was used to identify independent risk factors. Based on BMI and WHtR tertiles, individuals were divided into five new groups. Spearman correlation and receiver operating characteristic curve (ROC) analyses were performed to compare the NAFLD risk factors among groups based on BMI alone, WHtR alone, or the combination of both indexes. Results: BMI, waistline circumference (WC), WHtR, alanine aminotransferase (ALT), weight, triglycerides (TG), γ-glutamyl transpeptidase (GGT), serum uric acid (SUA), red blood cell (RBC) counts, hemoglobin levels (HGB), fasting blood glucose (FBG) and aspartate aminotransferase (AST) levels were identified as high risk factors for NAFLD (all AUC > 0.7). Logistic regression analysis suggested that BMI and WHtR were independent predictors of the appearance of NAFLD (the ORs for BMI and WHtR were 1.595 and 4.060E-11, respectively; all P < 0.001). The combination of BMI and WHtR tertiles significantly improved the correlation coefficient and Area under the receiver operating characteristic curve (AUC) for NAFLD risk factors in subjects classified as overweight or obese when compared with either BMI or WHtR alone. Conclusions: BMI, WC, WHtR, ALT, weight, TG, GGT, SUA, RBC, HGB, FBG, AST were high risk factors for NAFLD. The composite BMI and WHtR index improved body fat classification and the ability to detect individuals with NAFLD risk, offering a more precise method for the early identification of high- and low-risk NAFLD patients.

Aerobic Exercise in the Management of Metabolic Dysfunction Associated Fatty Liver Disease

Sedentarism is the pandemic of modern times. It is associated with several medical conditions including obesity, type 2 diabetes mellitus, cardiovascular diseases and also liver disease, particularly metabolic dysfunction associated fatty liver disease (MAFLD). In an era when MAFLD is the most prevalent chronic liver disease worldwide, whilst no pharmacological therapy has been approved for it, exercise has proved to be effective in improving liver steatosis. Interestingly, exercise decreases liver fat even in the absence of weight loss. The challenge for the clinician is to motivate the obese patient with MAFLD, and associated co-morbidities, who has crystallized a sedentary behavior, at times when every need is at the distance of a click on the Internet, and the entire world can be visited behind a screen. In this review, the aggregate evidence on the mechanisms and effects of exercise in the management of MAFLD is summarized, with simple recommendations for everyday clinical practice.

Body composition, phenotype and central obesity indices in Egyptian women with non-alcoholic fatty liver disease

OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. The aim of this study is to investigate body composition and phenotype of Egyptian women with non-alcoholic fatty liver disease (NAFLD) and compare with those without and determine the optimal cut-off values of central obesity indices for predicting NAFLD.

METHODS

The study included 100 women with NAFLD and 100 age and sex matched healthy controls without NAFLD. All women were subjected to ultrasonography examination. Anthropometric measurements included weight, height, waist circumference (WC), hip circumference (HC) and skinfolds thickness were assessed for all participants. Body fat % was evaluated by Tanita body composition analyzer. Body mass index (BMI), WC / height ratio (WHtR), WC / HC ratio (WHR) and visceral adiposity index (VAI) were calculated. Receiver-operating characteristic (ROC) curve was used to determine the optimal cut-off values.

RESULTS

Data showed significant higher levels of WHtR, WHR, BMI, sum of skinfolds, body fat %, serum fasting blood lipids and glucose in NAFLD women compared to group of patients without NAFLD. The area under curve (AUC) was 0.920 for VIA, 0.883 for WHtR and 0.647 for WHR. The optimal cutoff value of VAI was 3.66, of WHtR was 0.66 and WHR was 0.84. All values showed high sensitivity and specificity values.

CONCLUSION

NAFLD women were obese, had excess subcutaneous fat and body fat ratio. Central obesity indices are closely associated with the presence of NAFLD in Egyptian women and might be responsible for its development. Visceral adiposity index had superior diagnostic performance.

Patient initiation and maintenance of GLP-1 RAs for treatment of obesity: a narrative review and practical considerations for primary care providers

Obesity is a chronic, relapsing metabolic disease, linked to a number of health risks and serious complications. Although highly prevalent in adults in the United States, it is underdiagnosed and untreated. Primary care providers (PCPs) are uniquely poised to diagnose and treat patients with obesity, using a selection of treatment strategies including lifestyle modifications and pharmacotherapies. As a physiological regulator of appetite and energy intake, the glucagon-like peptide-1 receptor agonist (GLP-1 RA) liraglutide 3.0 mg is approved for chronic weight management in individuals with overweight (pre-obesity) or obesity. In this review, we provide an overview of the clinical data supporting the use of liraglutide 3.0 mg, as well as practical advice for PCPs on the initiation and maintenance of treatment over the long term. This also covers the management of side effects and how to manage patient expectations over time.

Non-alcoholic fatty liver disease to metabolic dysfunction-associated fatty liver disease: Conceptual changes for clinicians, researchers and patients

Non-alcoholic fatty liver disease (NAFLD) is now the most common etiology of chronic liver disease threatening global public health. However, the name "NAFLD" is no longer appropriate with the change of time. Recently, a new term, "metabolic dysfunction-associated fatty liver disease" has been proposed by an international panel of experts, which implies profound conceptual changes in terms of its metabolism-related etiology and disease heterogeneity. In this article we discuss the specific conceptual changes that clinicians, researchers and patients must absorb.

Divergence in aerobic capacity impacts bile acid metabolism in young women

Liver adaptations may be critical for regular exercise and high aerobic capacity to protect against metabolic disease, but mechanisms remain unknown. Bile acids (BAs) synthesized in the liver are bioactive and can putatively modify energy metabolism. Regular exercise influences BA metabolism in rodents, but effects in humans are unknown. This study tested whether female subjects screened for high aerobic capacity (Hi-Fit, n = 19) [peak oxygen consumption (V̇o2peak) ≥45 mL·kg-1·min-1] have increased hepatic BA synthesis and different circulating BA composition compared with those matched for age and body mass with low aerobic capacity (Lo-Fit, n = 19) (V̇o2peak ≤35 mL·kg-1·min-1). Diet patterns, activity level, stool, and blood were collected at baseline before participants received a 1-wk standardized, eucaloric diet. After the 1-wk standardized diet, stool and blood were again collected and an oral glucose tolerance test (OGTT) was performed to assess insulin sensitivity and postprandial BA response. Contrary to our hypothesis, serum 7α-hydroxy-4-cholesten-3-one (C4), a surrogate of BA synthesis, was not different between groups, whereas Hi-Fit women had lower fecal BA concentrations compared with Lo-Fit women. However, Lo-Fit women had a higher and more sustained rise in circulating conjugated BAs during the OGTT. Hi-Fit women showed a significant post-OGTT elevation of the secondary BA, lithocholic acid (a potent TGR5 agonist), in contrast to Lo-Fit women where no response was observed. A 1-wk control diet eliminated most differences in circulating BA species between groups. Overall, the results emphasize the importance of using a standardized diet when evaluating BAs and indicate that regular exercise and aerobic capacity modulate BA metabolism under postprandial conditions.NEW & NOTEWORTHY Women with contrasting exercise and aerobic capacity levels show clear differences in bile acid (BA) metabolism. Women with low aerobic capacity (Lo-Fit) have increased circulating conjugated BAs post oral glucose tolerance test (OGTT), whereas women with high aerobic capacity (Hi-Fit) display a transient increase. Hi-Fit women show an increase in the secondary BA, lithocholic acid, during the OGTT not seen in Lo-Fit women. Differences in circulating BA species between Hi- and Lo-Fit women possibly contribute to differences in insulin sensitivity and energy regulation via different signaling mechanisms.

Regular moderate aerobic exercise improves high-fat diet-induced nonalcoholic fatty liver disease via monoacylglycerol O-acyltransferase 1 pathway suppression

PURPOSE

Monoacylglycerol O-acyltransferase 1 (MGAT1) is reported to play a key role in the development of diet-induced nonalcoholic fatty liver disease (NAFLD). Thus, this study investigated the effect of exercise on suppression of the MGAT1 pathway in NAFLD tissue of high-fat diet (HFD)-induced obese rats.

METHODS

Male Sprague-Dawley rats were fed an HFD containing 45% fat for 6 weeks. Upon confirmation that NAFLD had been induced in the obese animals, they were divided into HFD-fed groups provided with exercise (HFD + EXE) or without exercise (HFD) and a group given dietary adjustment (DA) only, for a further 6 weeks of intervention treatment. The 6-week regular moderate aerobic exercise consisted of an accommodation phase with increasing exercise. Lipid accumulation in the liver tissue was determined by Oil Red O staining. The MGAT1 and liver lipogenic gene mRNA levels were measured by qPCR, and their protein levels by western blot assay.

RESULTS

Oil Red O staining showed that NAFLD was successfully induced by HFD-fed. The gene expression of MGAT1 was significantly lower in HFD + EXE than HFD. However, there was no significant difference between HFD + EXE and DA. The protein expression of MGAT1 was significantly lower in HFD + EXE than both HFD and DA. Messenger RNA and protein expression of other lipogenic genes were not different among groups. These data indicate that exercise suppresses MGAT1 pathway regardless of HFD feeding; in part, this effect could be greater than DA.

CONCLUSION

Our data suggest that exercise can improve NAFLD, which is probably due to suppression of MGAT1 pathway.

Exercise and metabolic health: beyond skeletal muscle

Regular exercise is a formidable regulator of insulin sensitivity and overall systemic metabolism through both acute events driven by each exercise bout and through chronic adaptations. As a result, regular exercise significantly reduces the risks for chronic metabolic disease states, including type 2 diabetes and non-alcoholic fatty liver disease. Many of the metabolic health benefits of exercise depend on skeletal muscle adaptations; however, there is plenty of evidence that exercise exerts many of its metabolic benefit through the liver, adipose tissue, vasculature and pancreas. This review will highlight how exercise reduces metabolic disease risk by activating metabolic changes in non-skeletal-muscle tissues. We provide an overview of exercise-induced adaptations within each tissue and discuss emerging work on the exercise-induced integration of inter-tissue communication by a variety of signalling molecules, hormones and cytokines collectively named 'exerkines'. Overall, the evidence clearly indicates that exercise is a robust modulator of metabolism and a powerful protective agent against metabolic disease, and this is likely to be because it robustly improves metabolic function in multiple organs. Graphical abstract.

Decreased Physical Working Capacity in Adolescents With Nonalcoholic Fatty Liver Disease Associates With Reduced Iron Availability

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is common and related to obesity and insulin resistance. Iron metabolism is impaired in obese individuals and iron deficiency has been associated with physical inactivity. We investigated whether iron bioavailability is reduced in patients with NAFLD and contributes to reduced cardiorespiratory fitness.

METHODS

We collected information on weight-adjusted, submaximal physical work capacity (PWC), ultrasound-determined hepatic steatosis, iron indices, and hematologic and metabolic parameters from 390 female and 458 male participants of the Raine Study-a longitudinal study of disease development in 2868 children in Western Australia. X² and linear regression analyses were used to compare characteristics of study participants according to NAFLD status at age 17 years.

RESULTS

Fourteen percent of the cohort had NAFLD. PWC was significantly reduced in adolescents with NAFLD compared to adolescents without NAFLD (reduction of 0.17 W/kg, P = .0003, adjusted for sex and body mass index [BMI]). Iron bioavailability (assessed by mean corpuscular volume [MCV], mean corpuscular haemoglobin [MCH], transferrin saturation, and serum levels of iron) was inversely correlated with BMI in adolescents with NAFLD (P ≤ .01 for all, adjusted for sex) but not in adolescents without NAFLD (P > .30). MCV and MCH correlated with PWC (MCV, P = .002 for female and P = .0003 male participants; MCH, P = .004 for female and P = .01 for male participants), irrespective of NAFLD status. Reduced PWC was associated with lower transferrin saturation in adolescents with NAFLD (reduction of 0.012 W/kg per unit decrease in transferrin saturation, P = .007) but not in adolescents without NAFLD (reduction of 0.001 W/kg, P = .40), adjusted for sex. This association was independent of MCV or MCH.

CONCLUSIONS

In a well-defined cohort of adolescents, we found NAFLD to be associated with decreased cardiorespiratory fitness, independent of BMI. The relationship between transferrin saturation and PWC in adolescents with NAFLD indicates that functional iron deficiency might contribute to reductions in cardiorespiratory fitness.

Exercise Improves Outcomes of Surgery on Fatty Liver in Mice: A Novel Effect Mediated by the AMPK Pathway

OBJECTIVE

To investigate whether exercise improves outcomes of surgery on fatty liver, and whether pharmacological approaches can substitute exercising programs.

SUMMARY OF BACKGROUND DATA

Steatosis is the hepatic manifestation of the metabolic syndrome, and decreases the liver's ability to handle inflammatory stress or to regenerate after tissue loss. Exercise activates adenosine monophosphate-activated kinase (AMPK) and mitigates steatosis; however, its impact on ischemia-reperfusion injury and regeneration is unknown.

METHODS

We used a mouse model of simple, diet-induced steatosis and assessed the impact of exercise on metabolic parameters, ischemia-reperfusion injury and regeneration after hepatectomy. The same parameters were evaluated after treatment of mice with the AMPK activator 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). Mice on a control diet served as age-matched controls.

RESULTS

A 4-week-exercising program reversed steatosis, lowered insulin levels, and improved glucose tolerance. Exercise markedly enhanced the ischemic tolerance and the regenerative capacity of fatty liver. Replacing exercise with AICAR was sufficient to replicate the above benefits. Both exercise and AICAR improved survival after extended hepatectomy in mice challenged with a Western diet, indicating protection from resection-induced liver failure.

CONCLUSIONS

Exercise efficiently counteracts the metabolic, ischemic, and regenerative deficits of fatty liver. AICAR acts as an exercise mimetic in settings of fatty liver disease, an important finding given the compliance issues associated with exercise. Exercising, or its substitution through AICAR, may provide a feasible strategy to negate the hepatic consequences of energy-rich diet, and has the potential to extend the application of liver surgery if confirmed in humans.

Combined effect of canagliflozin and exercise training on high-fat diet-fed mice

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) have been reported to improve obesity, diabetes, and nonalcoholic fatty liver disease (NAFLD) in addition to exercise training, whereas the combined effects remain to be elucidated fully. We investigated the effect of the combination of the SGLT2i canagliflozin (CAN) and exercise training in high-fat diet-induced obese mice. High-fat diet-fed mice were housed in normal cages (sedentary; Sed) or wheel cages (WCR) with or without CAN (0.03% of diet) for 4 wk. The effects on obesity, glucose metabolism, and hepatic steatosis were evaluated in four groups (Control/Sed, Control/WCR, CAN/Sed, and CAN/WCR). Numerically additive improvements were found in body weight, body fat mass, blood glucose, glucose intolerance, insulin resistance, and the fatty liver of the CAN/WCR group, whereas CAN increased food intake and reduced running distance. Exercise training alone, CAN alone, or both did not change the weight of skeletal muscle, but microarray analysis showed that each resulted in a characteristic change of gene expression in gastrocnemius muscle. In particular, in the CAN/WCR group, there was acceleration of the angiogenesis pathway and suppression of the adipogenesis pathway compared with the CAN/Sed group. In conclusion, the combination of an SGLT2i and exercise training improves obesity, insulin resistance, and NAFLD in an additive manner. Changes of gene expression in skeletal muscle may contribute, at least in part, to the improvement of obesity and insulin sensitivity.

Exercise Combats Hepatic Steatosis: Potential Mechanisms and Clinical Implications

Hepatic steatosis, the excess storage of intrahepatic lipids, is a rampant clinical problem associated with the obesity epidemic. Hepatic steatosis is linked to increased risk for insulin resistance, type 2 diabetes, and cardiovascular and advanced liver disease. Accumulating evidence shows that physical activity, exercise, and aerobic capacity have profound effects on regulating intrahepatic lipids and mediating susceptibility for hepatic steatosis. Moreover, exercise can effectively reduce hepatic steatosis independent of changes in body mass. In this perspective, we highlight 1) the relationship between obesity and metabolic pathways putatively driving hepatic steatosis compared with changes induced by exercise; 2) the impact of physical activity, exercise, and aerobic capacity compared with caloric restriction on regulating intrahepatic lipids and steatosis risk; 3) the effects of exercise training (modalities, volume, intensity) for treatment of hepatic steatosis, and 4) evidence for a sustained protection against steatosis induced by exercise. Overall, evidence clearly indicates that exercise powerfully regulates intrahepatic storage of fat and risk for steatosis.

Effects of high-intensity interval and moderate-intensity continuous aerobic exercise on diabetic obese patients with nonalcoholic fatty liver disease: A comparative randomized controlled trial

BACKGROUND

Some studies assessed the effect of aerobic exercise on diabetic obese patients with hepatic disease, while very limited studies compared high-intensity interval (HII) versus moderate-intensity continuous (MIC) on diabetic obese patients with non-alcoholic fatty liver disease (NAFLD).

OBJECTIVES

This study was designed to assess the effects of HII versus MIC on intrahepatic triglycerides (IHTG) and visceral lipids in diabetic obese patients with NAFLD.

DESIGN

Randomized controlled trial.

METHODS

Forty-seven diabetic obese individuals with NAFLD were enrolled in this study. The individuals were randomly divided into 16 in HII group, 15 in MIC group, and 16 in the controls. HII group received HII exercise, MIC group received 8-week MIC exercise while the control group did not receive any exercise intervention. IHTG and visceral lipids were assessed pre- and post-intervention.

RESULTS

Baseline and clinical characteristics showed nonsignificant difference among the 3 groups (P > .05). Both HII and MIC groups showed a significant reduction in hepatic fat and visceral lipids (P < .05), while the controls showed nonsignificant difference (P > .05) after completing the study intervention. Postintervention analysis showed nonsignificant changes between the HII and MIC groups (P > .05).

CONCLUSIONS

Exercise training wither HII or MIC aerobic exercise reduces IHGT and visceral lipids in diabetic obese patients with NAFLD. No differences were observed between the effects of both exercise programs on diabetic obese patients with NAFLD.

High Protein Diet and Metabolic Plasticity in Non-Alcoholic Fatty Liver Disease: Myths and Truths

Non-alcoholic fatty liver disease (NAFLD) is characterized by lipid accumulation within the liver affecting 1 in 4 people worldwide. As the new silent killer of the twenty-first century, NAFLD impacts on both the request and the availability of new liver donors. The liver is the first line of defense against endogenous and exogenous metabolites and toxins. It also retains the ability to switch between different metabolic pathways according to food type and availability. This ability becomes a disadvantage in obesogenic societies where most people choose a diet based on fats and carbohydrates while ignoring vitamins and fiber. The chronic exposure to fats and carbohydrates induces dramatic changes in the liver zonation and triggers the development of insulin resistance. Common believes on NAFLD and different diets are based either on epidemiological studies, or meta-analysis, which are not controlled evidences; in most of the cases, they are biased on test-subject type and their lifestyles. The highest success in reverting NAFLD can be attributed to diets based on high protein instead of carbohydrates. In this review, we discuss the impact of NAFLD on body metabolic plasticity. We also present a detailed analysis of the most recent studies that evaluate high-protein diets in NAFLD with a special focus on the liver and the skeletal muscle protein metabolisms.

Different predictors of steatosis and fibrosis severity among lean, overweight and obese patients with nonalcoholic fatty liver disease

BACKGROUNDS

Non-obese nonalcoholic fatty liver disease (NAFLD) is paradoxically associated with improved metabolic and pathological features at diagnosis but worse prognosis relative to obese NAFLD.

AIM

To compare predictors of disease severity in NAFLD with different body mass index (BMI) categories.

METHODS

All 1509 consecutive NAFLD patients were classified as lean (20.2%), overweight (23.1%) and obese (56.7%). Liver fat content (LFC) and fibrosis were estimated with magnetic resonance imaging-based proton density fat fraction and shear wave elastography respectively.

RESULTS

Lipid profiles and uric acid (UA) were significantly increased in parallel with BMI categories (pairwise comparison P < 0.001), but insulin resistance (IR) was significantly different between the non-obese and obese groups. For LFC ≥ 10%, increased waist circumference (WC) was an independent predictor in all groups, while UA elevation (P = 0.02) was predictive in the overweight patients, but BMI ≥ 28 kg/m² (P = 0.029) and IR (P = 0.026) were significant in the obese patients. For fibrosis, alanine aminotransferase (ALT) > 40 U/L (P = 0.031), increased WC (P = 0.012) and BMI ≥ 28 kg/m² (P < 0.001) plus ALT > 40 U/L (P = 0.007) were predictors in the lean, overweight and obese patients, respectively.

CONCLUSIONS

WC was strongly predictive of disease severity in all NAFLD, while UA and BMI plus IR were additional predictors in the overweight and obese NAFLD respectively. Individualized screening strategies should be established for NAFLD according to different BMIs.

Effects of different exercise modalities on novel hepatic steatosis indices in overweight women with type 2 diabetes

BACKGROUND/AIMS

Fatty liver is a clinical and pathologic condition in individuals with type 2 diabetes (T2D). The purpose of this study is to examine the effects of different exercise modalities on non-alcoholic fatty liver indices (fatty liver index [FLI], lipid accumulation product [LAP], hepatic steatosis index [HSI], and Framingham Steatosis Index [FSI]) in women with T2D.

METHODS

Fifty-two women with T2D and a mean age of 55.07±5.92 yrs, body mass index (BMI) 28.94±4.09 kg/m2 , and hemoglobin A1c (HbA1c) 9.41±0.82% were randomized to a sprint interval training (SIT) (n=17), combined aerobic and resistance (A+R) training (n=17), or control group (n=18) for 10 weeks. Two-way repeated analysis of variance (ANOVA) was used to find differences between groups and the effects of time and Time×Group interactions after 10 weeks on non-alcoholic fatty liver indices. After this, ANOVA models were constructed to determine the effects of group allocation and change in non-alcoholic fatty liver indices.

RESULTS

There were significant time interactions for FLI (P<0.001), HSI (P<0.001), and LAP (P<0.001). Also, there were significant Time×Group interactions for fasting blood glucose (P=0.034), and HbA1c (P=0.006).

CONCLUSION

Results highlight that exercise training, independent of mode of training, is an effective strategy to improve some indices related to hepatic steatosis and blood glucose profiles in women with T2D.

Comprehensive lifestyle intervention vs soy protein-based meal regimen in non-alcoholic steatohepatitis

BACKGROUND

Non-alcoholic steatohepatitis (NASH) has become one of the leading causes of liver disease in the western world. In obese patients weight reduction is recommended. Up to now there are no specific guidelines for weight loss in order to reduce hepatic fat content.

AIM

To investigate the effects of a 24-wk guided lifestyle intervention program compared to a meal replacement regimen based on soy protein.

METHODS

Twenty-six subjects with NASH participated in a randomized single-center study. They were randomly assigned to either meal replacement group (MR-G) with soy-yogurt-honey preparation or to guided lifestyle change group (LC-G) with endurance activity and nutrition counselling. Serum alanine transaminase (ALT), aspartate transaminase (AST), lipid parameters, and adipokines were measured. Liver fat content and lipid composition were determined by magnetic resonance imaging and magnetic resonance spectroscopy. Body fat mass and lean body mass were assessed using Bod Pod^® device. Pre- and post-intervention monitoring of parameters was performed. Statistical analyses were conducted with SPSS software, results were expressed as median (interquartile range).

RESULTS

Twenty-two subjects (MR-G, n = 11 and LC-G, n = 11) completed the study (9 women, 13 men; age 52.1 (15.0) years, body mass index (BMI) 32.3 (3.3) kg/m²). In both groups a significant weight loss was achieved (MR-G: -6.4 (3.6) kg, P < 0.01; LC-G: -9.1 (10.4) kg, P < 0.01). BMI dropped in both groups (MR-G: -2.3 (1.5) kg/m², P = 0.003; LC-G: -3.0 (3.4) kg/m², P = 0.006). Internal fat and hepatic lipid content were markedly reduced in both groups in comparable amount. There was a strong correlation between reduction in liver fat and decrease in ALT. Likewise, both groups showed an improvement in glycemic control and lipid profile. Changes in adipokines, particularly in adiponectin and leptin were closely related to intrahepatic lipid changes.

CONCLUSION

Comprehensive lifestyle intervention and meal replacement regimen have comparable effects on body and liver fat, as well as decrease in markers of hepatic inflammation among NASH patients.