Dyslipidemia in nonalcoholic fatty liver disease

Hyperhomocysteinemia is linked to MASLD

BACKGROUND AND AIMS

Homocysteine (Hcy) levels are elevated in different conditions, including cardiovascular diseases (CVD), diabetes, and metabolic-associated steatotic liver disease (MASLD). In this observational retrospective study, we analyzed Hcy levels in a population of 901 outpatients, considering its putative etiological role in MASLD.

METHODS

A total of 901 outpatients underwent physical and biochemical evaluations. Abdominal and carotid ultrasound were performed to assess liver steatosis, carotid intima-media thickness (IMT) and presence of atherosclerotic plaque.

RESULTS

Hyperhomocysteinemia (HHcy) was identified in 140 subjects (16 %). Patients with HHcy showed glucose metabolism impairment (p < 0.001), altered lipid profile (p < 0.001), low Vitamin D levels (p < 0.0001), increased cardiovascular risk (p < 0.001). We then investigated the relationship between Hcy and MASLD (OR=3.6, p < 0.0001), finding that the relationship remained significant also when accounting for confounding variables (age, sex) (OR=3.2, p < 0.0001). Hcy values were significantly higher (p < 0.0001) in patients with MASLD (n = 78, 29.4 ± 10.1μmol/l) compared to those without MASLD (20.4 ± 4.8 1μmol/l). Furthermore, in MASLD patients we found a direct correlation between Hcy level and waist circumference (r = 0.3, p < 0.001) and an inverse correlation with both HDL-c (r=-0.4, p < 0.001) and Vitamin D levels (r=-0.24, p < 0.05).

CONCLUSIONS

Our data suggest an intriguing scenario whereby HHcy is present in patients with MASLD and is associated to lower vitamin D and altered glucose and lipid profile. Thus, considering Hcy levels may help clinicians with the management of patients with increased MASLD risk.

Sulfated Polysaccharides from Sea Cucumber Cooking Liquid Prevents Obesity by Modulating Gut Microbiome, Transcriptome, and Metabolite Profiles in Mice Fed a High-Fat Diet

We aimed to explore the anti-obesity mechanism from the microbiome, metabolome, and transcriptome viewpoints, focusing on the sulfated polysaccharides found in the cooking liquid of Apostichopus japonicus (CLSPAJ) to explore the potential mediators of the anti-obesity effects in mice fed a high-fat diet (HFD). The mice treated with CLSPAJ showed a decrease in obesity and blood lipid levels. Gut microbiome dysbiosis caused by the HFD was reversed after CLSPAJ supplementation, along with increased levels of indole-3-ethanol, N-2-succinyl-L-glutamic acid 5-semialdehyde, and urocanic acid. These increases were positively related to the increased Akkermansia, Lactobacillus, Roseburia, and Phascolarctobacterium. Transcriptome analysis showed that B cell receptor signaling and cytochrome P450 xenobiotic metabolism were the main contributors to the improvement in obesity. Metabolome-transcriptome analysis revealed that CLSPAJ reversal of obesity was mainly due to amino acid metabolism. These findings suggest that CLSPAJ could be a valuable prebiotic preparation for preventing obesity-related diseases.

Association between obesity phenotypes and non-alcoholic fatty liver: a large population- based study

BACKGROUND

The aim of this study was to examine the association between different metabolic obesity phenotypes and the non-alcoholic fatty liver disease (NAFLD).

METHODS

This cross-sectional analysis utilized data from the baseline phase of the Ravansar non-communicable diseases (RaNCD) cohort study, which involved 8,360 adults. Participants with a Fatty Liver Index (FLI) score of ≥ 60 was classified as having NAFLD. The FLI score was calculated using liver non-invasive markers and anthropometric measurements. Participants were categorized into four phenotypes based on the presence or absence of metabolic syndrome and obesity. Logistic regression analysis was used to evaluate the association of NAFLD and obesity phenotypes.

RESULTS

According to the FLI index, the prevalence of NAFLD was 39.56%. Participants with FLI scores of ≥ 60 had higher energy intake compared to those in the FLI < 60 group (P = 0.033). In subjects with metabolically unhealthy phenotypes, the level of physical activity was lower compared to those with metabolically healthy phenotypes. The risk of NAFLD in males with the metabolically healthy-obese phenotype increased by 8.92 times (95% CI: 2.20, 15.30), those with the metabolically unhealthy-non-obese phenotype increased by 7.23 times (95% CI: 5.82, 8.99), and those with the metabolically unhealthy-obese phenotype increased by 32.97 times (95% CI: 15.70, 69.22) compared to the metabolically healthy-non-obese phenotype. Similarly, these results were observed in females.

CONCLUSION

This study demonstrated that the risk of NAFLD is higher in individuals with metabolically healthy/obese, metabolically unhealthy/non-obese, and metabolically unhealthy/obese phenotypes compared to those with non-obese/metabolically healthy phenotypes.

High Starch Induces Hematological Variations, Metabolic Changes, Oxidative Stress, Inflammatory Responses, and Histopathological Lesions in Largemouth Bass (Micropterus salmoides)

This study evaluated effects of high starch (20%) on hematological variations, glucose and lipid metabolism, antioxidant ability, inflammatory responses, and histopathological lesions in largemouth bass. Results showed hepatic crude lipid and triacylglycerol (TAG) contents were notably increased in fish fed high starch. High starch could increase counts of neutrophils, lymphocytes, monocytes, eosinophils, and basophils and serum contents of TAG, TBA, BUN, and LEP (p < 0.05). There were increasing trends in levels of GLUT2, glycolysis, gluconeogenesis, and LDH in fish fed high starch through the AKT/PI3K signal pathway. Meanwhile, high starch not only triggered TAG and cholesterol synthesis, but mediated cholesterol accumulation by reducing ABCG5, ABCG8, and NPC1L1. Significant increases in lipid droplets and vacuolization were also shown in hepatocytes of D3-D7 groups fed high starch. In addition, high starch could decrease levels of mitochondrial Trx2, TrxR2, and Prx3, while increasing ROS contents. Moreover, high starch could notably increase amounts of inflammatory factors (IL-1β, TNF-α, etc.) by activating NLRP3 inflammasome key molecules (GSDME, caspase 1, etc.). In conclusion, high starch could not only induce metabolic disorders via gluconeogenesis and accumulation of glycogen, TAG, and cholesterol, but could disturb redox homeostasis and cause inflammatory responses by activating the NLRP3 inflammasome in largemouth bass.

Allium sativum: A potential natural compound for NAFLD prevention and treatment

Introduction

Non-alcoholic fatty liver disease (NAFLD) results from an excessive accumulation of fat particles that causes liver inflammation, which ultimately causes liver damage. There is still considerable uncertainty about the effects of any nutritional supplements compared to no additional intervention. This review aimed to evaluate the efficacy of Allium sativum (A. sativum), known as garlic, in preventing and treating NAFLD.

Methods

A systematic search based on a search strategy consisting of two components of "NAFLD" and "Allium sativum" in databases including PubMed, Web of Science (WoS), and SCOPUS was conducted on papers evaluating the effects of A. sativum on NAFLD treatment and prevention. We obtained studies from inception until 20 September 2022, followed by study selection and data extraction based on our eligibility criteria. Consequently, qualitative and quantitative synthesis was conducted.

Results

Our qualitative analysis reveals that A. sativum consumption is linked to the prevention of NAFLD, especially in males, although qualitative data in this study regarding the therapeutic properties of NAFLD was controversial. Our meta-analysis showed that NAFLD patients treated with A. sativum have significantly declined aminotransferase levels. That is to say, our meta-analysis revealed a lower alanine transaminase (ALT) (SMD = -0.580, 95%CI = -0.822 to -0.338), and aspartate transaminase (AST(SMD = -0.526, 95%CI = -0.767 to -0.284) in NAFLD patients treated with A. sativum compared to the placebo group. Also, pooling data from case-control studies showed that A. sativum consumption decreases the odds of being diagnosed with NAFLD by 46% (OR = 0.538, 95%CI = 0.451-0.625).

Conclusion

A. sativum consumption is not merely associated with NAFLD prevention but also results in a considerable decline in blood aminotransferase levels in patients diagnosed with NAFLD. To put it simply, A. sativum is linked to a decline in AST and ALT, which are considered reliable biomarkers of NAFLD response to treatment. Nevertheless, A. sativum is insufficient to improve NAFLD independent of other dietary amendments and lifestyle modifications.

Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a global public health problem. NAFLD is bidirectionally correlated with metabolic syndrome, which includes obesity, type 2 diabetes, hypertension, and dyslipidemia as major components. The presence of metabolic syndrome is associated with a higher prevalence of NAFLD, and vice versa. Also, the presence of metabolic syndrome in patients with NAFLD has been linked to a higher risk of cardiovascular diseases, liver-related complications, extrahepatic malignancies, and mortality, and possibly vice versa. Multidisciplinary care pathways including lifestyle modifications, control of metabolic risk, and potentially beneficial treatments are important to improve the clinical outcomes of patients with NAFLD.

Utility of traditional and non-traditional lipid indicators in the diagnosis of nonalcoholic fatty liver disease in a Japanese population

BACKGROUND

Traditional and non-traditional (TNNT) lipid indicators are known to be closely related to nonalcoholic fatty liver disease (NAFLD). This study's objective was to compare the degree of associations and diagnostic values of TNNT lipid indicators with NAFLD.

METHODS

Participants were 14,251 Japanese adults who undergoing health checkups, and we measured and calculated 11 lipid indicators, including traditional lipid indicators such as high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG), as well as non-traditional lipid indicators such as TC/HDL-C ratio, LDL-C/HDL-C ratio, TG/HDL-C ratio, non-HDL-C, remnant cholesterol (RC), RC/HDL-C ratio and non-HDL-C/HDL-C ratio. The associations between these lipid indicators and NAFLD were assessed using multivariate logistic regression, and the performance of these lipid indicators in identifying NAFLD was analyzed by receiver operating characteristic (ROC) curves.

RESULTS

After rigorous adjustment for potential confounders, multivariate logistic regression showed that all TNNT lipid indicators were independently associated with NAFLD, among which the RC/HDL-C ratio and RC had the strongest association with NAFLD. ROC analysis showed that non-traditional lipid indicators were superior to traditional lipid indicators in identifying NAFLD, especially in young adults and females. It is worth mentioning that the RC/HDL-C ratio was the best lipid indicator for identifying NAFLD with an area under the curve (AUC) of 0.82 and an optimal cut-off value of 0.43; in addition, TG/HDL-C ratio also had a high recognition performance for NAFLD.

CONCLUSION

Overall, in the Japanese population, non-traditional lipid indicators had a higher diagnostic value for NAFLD compared to traditional lipid indicators, and lipid indicators alone had a lower diagnostic value for NAFLD than the ratio of two lipid indicators, with RC/HDL-C and TG/HDL-C being the best lipid indicators for identifying NAFLD.

Association between serum uric acid-to-creatinine ratio and non-alcoholic fatty liver disease: a cross-sectional study in Chinese non-obese people with a normal range of low-density lipoprotein cholesterol

Objective

Evidence regarding the relationship between serum uric acid-to-creatinine (SUA/Scr) ratio and non-alcoholic fatty liver disease (NAFLD) in Chinese non-obese people is still limited. Therefore, the present study was undertaken to analyze the association between the SUA/Scr ratio and NAFLD.

Methods

This study was a cross-sectional study that non-selectively and consecutively collected 182,320 non-obese individuals with a normal range of low-density lipoprotein cholesterol in a Chinese hospital from January 2010 to December 2014. A binary logistic regression model was used to evaluate the independent association between the SUA/Scr ratio and NAFLD. A generalized additive model (GAM) and smooth curve fitting (penalized spline method) was conducted to explore the exact shape of the curve between them. A series of sensitivity analyses were used to ensure the robustness of the results. Moreover, subgroup analyses were conducted. In addition, the diagnostic value of the SUA/Scr ratio for NAFLD was evaluated based on the area under the receiver-operating characteristic curve (AUROC). It was stated that the data had been uploaded to the DATADRYAD website.

Results

The average participants' age was 40.96 ± 14.05 years old, and 90,305 (49.5%) were male. The prevalence of NAFLD was 13.7%, and the mean SUA/Scr was 3.62 ± 0.92. After adjusting covariates, the results showed that SUA/Scr ratio was positively associated with NAFLD (OR = 1.424, 95%CI: 1.396, 1.454). There was also a non-linear relationship between SUA/Scr ratio and NAFLD in participants with normal kidney function, and the inflection point of the SUA/Scr ratio was 4.425. The effect sizes (OR) on the left and right sides of the inflection point were 1.551 (1.504, 1.599) and 1.234 (1.179, 1.291), respectively. And the sensitive analysis demonstrated the robustness of the results. Subgroup analysis showed a stronger association between SUA/Scr ratio and NAFLD in females and the population with age < 50 years, FPG ≤ 6.1 mmol/L, BMI < 24 kg/m², and HDL-c ≥ 1 mmol/L. In contrast, the weaker association was probed in males and the population with age ≥ 50 years, BMI ≥ 24 kg/m², FPG > 6.1 mmol/L, and HDL-c < 1 mmol/L. The SUA/Scr ratio had an AUC of 0.6624 (95% CI 0.6589, 0.6660) for diagnosing NAFLD. Based on the best cut-off value of 3.776, the negative predictive value of the SUA/Scr ratio for identifying NAFLD was 91.0%.

Conclusion

This study demonstrates an independent positive association between SUA/Scr ratio and NAFLD in Chinese non-obese people with a normal range of low-density lipoprotein cholesterol. There is also a non-linear relationship between the SUA/Scr ratio and NAFLD in participants with normal kidney function, and the SUA/Scr ratio is strongly related to NAFLD when SUA/Scr ratio is less than 4.425. The SUA/Scr ratio has a certain reference value for determining NAFLD. When the SUA/Scr ratio is lower than 3.776, identifying NAFLD patients with low risk is a great reference.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02500-w.

Risk Factors and Prediction Models for Nonalcoholic Fatty Liver Disease Based on Random Forest

Objective

To establish a risk prediction model of nonalcoholic fatty liver disease (NAFLD) and provide management strategies for preventing this disease.

Methods

A total of 200 inpatients and physical examinees were collected from the Department of Gastroenterology and Endocrinology and Physical Examination Center. The data of physical examination, laboratory examination, and abdominal ultrasound examination were collected. All subjects were randomly divided into a training set (70%) and a verification set (30%). A random forest (RF) prediction model is constructed to predict the occurrence risk of NAFLD. The receiver operating characteristic (ROC) curve is used to verify the prediction effect of the prediction models.

Results

The number of NAFLD patients was 44 out of 200 enrolled patients, and the cumulative incidence rate was 22%. The prediction models showed that BMI, TG, HDL-C, LDL-C, ALT, SUA, and MTTP mutations were independent influencing factors of NAFLD, all of which has statistical significance (P < 0.05). The area under curve (AUC) of logistic regression and the RF model was 0.940 (95% CI: 0.870~0.987) and 0.945 (95% CI: 0.899~0.994), respectively.

Conclusion

This study established a prediction model of NAFLD occurrence risk based on the RF, which has a good prediction value.

Management of Dyslipidemia in Patients with Non-Alcoholic Fatty Liver Disease

PURPOSE OF REVIEW

Patients with non-alcoholic fatty liver disease (NAFLD), often considered as the hepatic manifestation of the metabolic syndrome, represent a population at high cardiovascular risk and frequently suffer from atherogenic dyslipidemia. This article reviews the pathogenic interrelationship between NAFLD and dyslipidemia, elucidates underlying pathophysiological mechanisms and focuses on management approaches for dyslipidemic patients with NAFLD.

RECENT FINDINGS

Atherogenic dyslipidemia in patients with NAFLD results from hepatic and peripheral insulin resistance along with associated alterations of hepatic glucose and lipoprotein metabolism, gut dysbiosis, and genetic factors. Since atherogenic dyslipidemia and NAFLD share a bi-directional relationship and are both major driving forces of atherosclerotic cardiovascular disease (ASCVD) development, early detection and adequate treatment are warranted. Thus, integrative screening and management programs are urgently needed. A stepwise approach for dyslipidemic patients with NAFLD includes (i) characterization of dyslipidemia phenotype, (ii) individual risk stratification, (iii) definition of treatment targets, (iv) lifestyle modification, and (v) pharmacotherapy if indicated.

Liver Steatosis: A Marker of Metabolic Risk in Children

Obesity is one of the greatest health challenges affecting children of all ages and ethnicities. Almost 19% of children and adolescents worldwide are overweight or obese, with an upward trend in the last decades. These reports imply an increased risk of fat accumulation in hepatic cells leading to a series of histological hepatic damages gathered under the acronym NAFLD (Non-Alcoholic Fatty Liver Disease). Due to the complex dynamics underlying this condition, it has been recently renamed as 'Metabolic Dysfunction Associated Fatty Liver Disease (MAFLD)', supporting the hypothesis that hepatic steatosis is a key component of the large group of clinical and laboratory abnormalities of Metabolic Syndrome (MetS). This review aims to share the latest scientific knowledge on MAFLD in children in an attempt to offer novel insights into the complex dynamics underlying this condition, focusing on the novel molecular aspects. Although there is still no treatment with a proven efficacy for this condition, starting from the molecular basis of the disease, MAFLD's therapeutic landscape is rapidly expanding, and different medications seem to act as modifiers of liver steatosis, inflammation, and fibrosis.

Comparison of several blood lipid-related indexes in the screening of non-alcoholic fatty liver disease in women: a cross-sectional study in the Pearl River Delta region of southern China

Background

Lipid metabolism disorders play a critical role in the progression of non-alcoholic fatty liver disease (NAFLD). However, the number of studies on the relationships among blood lipid-related indexes and NAFLD is limited, and few studies have emphasized the comparison of blood lipid-related indexes in the same population to identify the optimal index for NAFLD screening. This study aimed to investigate the relationships among several blood lipid-related indexes and NAFLD, and to find the index with the best screening value for NAFLD.

Methods

Based on a general health examination at community health service agencies in the Pearl River Delta region of China in 2015, 3239 women were recruited in this cross-sectional study. The relationships among blood lipid-related indexes and NAFLD were assessed separately by constructing multivariate logistic regression models. Receiver operating characteristic analysis was used to evaluate and compare the screening abilities of the indexes for NAFLD. All data analyses were conducted in SPSS and MedCalc software.

Results

Whether in the crude model or each model adjusted for possible confounding factors, the risk of NAFLD significantly rose with increasing cardiometabolic index (CMI), triglyceride glucose index (TyG), triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C) ratio (TG/HDL-C), total cholesterol (TC) to HDL-C ratio (TC/HDL-C) and low-density lipoprotein (LDL-C) to HDL-C ratio (LDL-C/HDL-C). Moreover, the area under the curve (AUC) of CMI was 0.744, which was better than that of TyG (0.725), TG/HDL-C (0.715), TC/HDL-C (0.650), and LDL-C/HDL-C (0.644) (P < 0.001). In addition, the optimal cut-off points were 0.62 for CMI, 8.55 for TyG, 1.15 for TG/HDL-C, 4.17 for TC/HDL-C, and 2.22 for LDL-C/HDL-C.

Conclusions

CMI is easy to obtain, is a recommended index in the screening of NAFLD in women and may be useful for detecting populations that are at high risk of NAFLD.

The Changing Epidemiology of Liver Disease Among US Children and Adolescents From 1999 to 2016

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) and infection with hepatitis B virus (HBV) or hepatitis C virus (HCV) are major causes of liver disease in adults. However, data for children and adolescents are limited. Our study aimed to characterize the prevalence, trend, and risk factors of infection of HBV and HCV and possible NAFLD for this population.

METHODS

We analyzed 6,647 children and adolescents (aged 6-21 years) from the 1999-2016 National Health and Nutrition Examination Survey.

RESULTS

Among individuals aged 6-21 years, HBV prevalence decreased after 2011, from 0.72% in 1999-2004 and 0.85% in 2005-2010 to 0.27% in 2011-2016 (P < 0.001), whereas HCV prevalence increased to 0.26% in 2011-2016 after an initial decline from 0.15% in 1999-2004 to 0.02% in 2005-2010 (P = 0.01). Possible NAFLD prevalence also increased by approximately 40% in individuals aged 12-21 years, from 8.54% in 1999-2004 to 10.1% in 2005-2010 and then 11.8% in 2011-2016 (P = 0.033), with most possible NAFLD individuals being male, being obese, or having higher glucose, fasting insulin, hemoglobin A1c, homeostatic model assessment of insulin resistance, liver enzymes, lipids, and uric acid (all P < 0.01). On multivariate logistic regression, hypertension (odds ratio 4.79, 95% confidence interval 1.44-15.9) and dyslipidemia (odds ratio 11.6, 95% confidence interval 5.65-23.9) increased risk for possible NAFLD but not income:poverty ratio, hours spent on computer use, or added sugars.

DISCUSSION

Although HBV prevalence has decreased in recent years among US children and adolescents, HCV and possible NAFLD have increased. Public health efforts must seek further understanding of the driving factors of this increase so that age-appropriate interventions can be developed and implemented.

Association of lipid profile with decompensation, liver dysfunction, and mortality in patients with liver cirrhosis

BACKGROUND AND AIMS

Lipid metabolism is often disrupted in liver cirrhosis. The present study aimed to evaluate the impact of lipid profile on decompensation events, severity of liver dysfunction, and death in patients with liver cirrhosis.

METHODS

In a cross-sectional study, 778 patients with lipid profile data were enrolled, and then were divided into 240 and 538 patients with and without liver cirrhosis, respectively. In a cohort study, 314 cirrhotic patients with lipid profile data, who were prospectively followed, were enrolled. Lipid profile included total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein-cholesterol (LDL-c), triglycerides (TG), and lipoprotein(a).

RESULTS

In the cross-sectional study, cirrhotic patients with decompensation events had significantly lower levels of TC and lipoprotein(a) than those without; and cirrhotic patients with Child-Pugh class B and C had significantly lower levels of TC, HDL-c, LDL-c, and lipoprotein(a) than those with Child-Pugh class A. In the cohort study, there was an inverse association of survival with TC, HDL-c, and lipoprotein(a) levels; after adjusting for MELD score, TC (Hazard Ratio [HR] = 1.703, P = 0.034) and HDL-c (HR = 2.036, P = 0.005), but not lipoprotein(a) (HR = 1.377, P = 0.191), remained a significant predictor of death; when TC, HDL-c, lipoprotein(a), and MELD score were included in the multivariate Cox regression analysis, HDL-c (HR = 1.844, P = 0.024) was the only independent predictor of death.

CONCLUSIONS

Decreased levels in specific components of lipid profile indicate more decompensation events, worse liver function, and reduced survival in liver cirrhosis. MELD score combined with HDL-c should be promising for the assessment of outcomes of cirrhotic patients.

Perspectives on Precision Medicine Approaches to NAFLD Diagnosis and Management

Precision medicine defines the attempt to identify the most effective approaches for specific subsets of patients based on their genetic background, clinical features, and environmental factors. Nonalcoholic fatty liver disease (NAFLD) encompasses the alcohol-like spectrum of liver disorders (steatosis, steatohepatitis with/without fibrosis, and cirrhosis and hepatocellular carcinoma) in the nonalcoholic patient. Recently, disease renaming to MAFLD [metabolic (dysfunction)-associated fatty liver disease] and positive criteria for diagnosis have been proposed. This review article is specifically devoted to envisaging some clues that may be useful to implementing a precision medicine-oriented approach in research and clinical practice. To this end, we focus on how sex and reproductive status, genetics, intestinal microbiota diversity, endocrine and metabolic status, as well as physical activity may interact in determining NAFLD/MAFLD heterogeneity. All these factors should be considered in the individual patient with the aim of implementing an individualized therapeutic plan. The impact of considering NAFLD heterogeneity on the development of targeted therapies for NAFLD subgroups is also extensively discussed.

LDL/HDL cholesterol ratio is associated with new-onset NAFLD in Chinese non-obese people with normal lipids: a 5-year longitudinal cohort study

Background

Low-density lipoprotein to high density lipoprotein (LDL/HDL) cholesterol ratio has been reported to predict the risk of many metabolic diseases. However, the association between the LDL/HDL cholesterol ratio and nonalcoholic fatty liver disease (NAFLD) has not been established.

Methods

A longitudinal cohort design was adopted in this study; 9767 non-obese subjects without NAFLD were included and analyzed. The subjects were grouped according to the quintile of LDL/HDL cholesterol ratio. The cumulative incidence of NAFLD and the independent effect of the LDL/HDL cholesterol ratio on NAFLD during 5 years of follow-up were calculated using the Kaplan-Meier method and Cox proportional-hazards regression model.

Results

During the 5-year follow-up period, 841 subjects were diagnosed with new-onset NAFLD, and the 1-, 2-, 3-, 4-, and 5-year cumulative incidence rates of NAFLD were 1.16, 4.65, 8.33, 12.43, and 25.14%, respectively. In the multivariable-adjusted Cox proportional-hazards regression model, the LDL/HDL cholesterol ratio was significantly associated with the risk for NAFLD (HR: 1.66, 95% CI: 1.38–1.99, P trend< 0.001), especially among young people (HR: 3.96, 95% CI: 1.50–10.46, P interaction< 0.05). Additionally, receiver operating characteristic curve analysis showed that the LDL/HDL cholesterol ratio was better than HDL cholesterol and LDL cholesterol in predicting new-onset NAFLD.

Conclusions

LDL/HDL cholesterol ratio is an independent predictor of NAFLD in Chinese non-obese people with normal lipids, and its predictive value is higher than that of other lipoproteins. In clinical practice, the LDL/HDL cholesterol ratio can be used to identify people at high risk of NAFLD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01457-1.

Study of Cellular Senescence and Vitamin D Deficiency in Nonalcoholic Fatty Liver Disease and The Potential Protective Effect of Vitamin D Supplementation

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a pathological process characterized by excessive hepatic fatty deposition with possible involvement of vitamin D deficiency and cellular senescence. The aim of this study is to investigate the pathophysiologic role of vitamin D deficiency and cellular senescence in NAFLD development. Moreover, it aims to investigate the potential protective role of vitamin D supplementation.

METHODS

This is an experimental Case/Control study. Forty-five male albino rats were enrolled in this study. Animals were divided into four groups: negative and positive control groups (10 for each group), a model of NAFLD (11) and vitamin D-treated NAFLD groups (14). At the end of the experiment, all rats were subjected to the following investigation; biochemical estimation of serum 25 hydroxycholecalciferol, senescence marker protein-30 (SMP-30), lipid profile and calculation of homeostatic model of insulin resistance (HOMA-IR).

RESULTS

NAFLD group shows a significant increase in glucose, insulin levels, and HOMA- IR compared with both normal controls. This finding indicates the intimate association between insulin resistance and NAFLD pathogenesis. Moreover, it was found that NAFLD group shows a significant decrease in SMP-30 level compared with normal controls. While vitamin D-treated NAFLD group shows significant increased SMP-30 and decrease in HOMA-IR in comparison with nontreated NAFLD group.

CONCLUSION

Vitamin D deficiency and increased cellular senescence are key features of NAFLD. Vitamin D supplementation could play a protective role, which needs further investigation including clinical human study.

Temporal Development of Dyslipidemia and Nonalcoholic Fatty Liver Disease (NAFLD) in Syrian Hamsters Fed a High-Fat, High-Fructose, High-Cholesterol Diet

The use of translationally relevant animal models is essential, also within the field of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Compared to frequently used mouse and rat models, the hamster may provide a higher degree of physiological similarity to humans in terms of lipid profile and lipoprotein metabolism. However, the effects in hamsters after long-term exposure to a NASH diet are not known. Male Syrian hamsters were fed either a high-fat, high-fructose, high-cholesterol diet (NASH diet) or control diets for up to 12 months. Plasma parameters were assessed at two weeks, one, four, eight and 12 months and liver histopathology and biochemistry was characterized after four, eight and 12 months on the experimental diets. After two weeks, hamsters on NASH diet had developed marked dyslipidemia, which persisted for the remainder of the study. Hepatic steatosis was present in NASH-fed hamsters after four months, and hepatic stellate cell activation and fibrosis was observed within four to eight months, respectively, in agreement with progression towards NASH. In summary, we demonstrate that hamsters rapidly develop dyslipidemia when fed a high-fat, high-fructose, high-cholesterol diet. Moreover, within four to eight months, the NASH-diet induced hepatic changes with resemblance to human NAFLD.

The association between triglycerides and ectopic fat obesity: An inverted U-shaped curve

Background

Ectopic fat obesity and triglycerides are risk factors for diabetes and multiple cardiovascular diseases. However, there have been limited studies on the association between triglycerides and ectopic fat obesity. The purpose of this study was to explore the association between triglycerides and ectopic fat obesity.

Methods and results

In this cross-sectional study, we retrospectively analyzed 15464 adult participants recruited by Murakami Memorial Hospital (8430 men and 7034 women, average age of 43.71 ± 8.90). All patients were divided into two groups according to the threshold used to diagnose hypertriglyceridemia. The logistic regression model was used to analyze the association between triglycerides and the risk of ectopic fat obesity, and the generalized additive model was used to identify the nonlinear association. In this study population, the prevalence of ectopic fat obesity was 17.73%. After adjusting other covariables, triglycerides were positively correlated with the risk of ectopic fat obesity (OR: 1.54, 95% CI:1.41–1.69, P<0.0001). Through smooth curve fitting, we found that there was an inverted U-shaped curve association between triglycerides and ectopic fat obesity. This association remained unchanged even if the adjusted covariables were removed from the model, and the inflection point of the curve was 3.98. When triglyceride levels were ≤3.98, triglycerides were positively correlated with the risk of ectopic fat obesity (OR:1.784, 95% CI:1.611–1.975, P<0.0001). When triglyceride levels were >3.98 (right side of the inflection point), there was a negative correlation (OR:0.519, 95% CI:0.333–0.810, P = 0.0039).

Conclusions

Our research showed that there is a significant association between triglycerides and ectopic fat obesity. This relation is not a simple linear relationship but instead an inverted U-shaped curve association.

Metabolic Syndrome and Abnormal Peri-Organ or Intra-Organ Fat (APIFat) Deposition in Chronic Obstructive Pulmonary Disease: An Overview

Chronic obstructive pulmonary disease (COPD) is a common disorder with an increasing prevalence, characterised by persistent respiratory symptoms and airflow limitation. Systemic inflammation is involved in the pathogenesis of COPD and can also predispose to metabolic disorders (e.g., metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD)). Such comorbidities can negatively affect COPD outcomes, cardiovascular risk, and quality of life. Apart from NAFLD, abnormal peri-organ or intra-organ fat (APIFat) could be considered as markers for cardiometabolic diseases and even for COPD. The present narrative review considers the associations of COPD with MetS, NAFLD, and other APIFat, including epicardial, perirenal, peripancreatic, and intramuscular adipose tissue. Further research is needed to define these relationships and identify any potential clinical implications.

Associations of HDL Subspecies Defined by ApoC3 with Non-Alcoholic Fatty Liver Disease: The Multi-Ethnic Study of Atherosclerosis

Previously, we reported that inverse associations of high-density lipoprotein (HDL) with cardiovascular disease and diabetes were only observed for HDL that lacked the pro-inflammatory protein apolipoprotein C3 (apoC3). To provide further insight into the cardiometabolic properties of HDL subspecies defined by the presence or absence of apoC3, we aimed to examine these subspecies with liver fat content and non-alcoholic fatty liver disease (NAFLD). We investigated cross-sectional associations between ELISA-measured plasma levels of apoA1 in HDL that contained or lacked apoC3 and computed tomography-determined liver fat content and NAFLD (<51 HU) at baseline (2000–2002) among 5007 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) without heavy alcohol consumption (>14 drinks/week in men and >7 drinks/week in women). In multivariable-adjusted regression models, apoA1 in HDL that contained or lacked apoC3 was differentially associated with liver fat content (P_{heterogeneity} = 0.048). While apoA1 in HDL that lacked apoC3 was inversely associated with liver fat content (P_trend < 0.0001), apoA1 in HDL that contained apoC3 was not statistically significantly associated with liver fat content (P_trend = 0.57). Higher apoA1 in HDL that lacked apoC3 was related to a lower prevalence of NAFLD (OR per SD: 0.80; 95% CI: 0.72, 0.89), whereas no association was found for apoA1 in HDL that contained apoC3 (OR per SD: 0.95; 95% CI: 0.85, 1.05; P_{heterogeneity} = 0.09). Higher apoA1 in HDL that lacked apoC3 was associated with less liver fat content and a lower prevalence of NAFLD. This finding extends the inverse association of HDL lacking apoC3 from cardiovascular disease to NAFLD. Lack of biopsy-proven hepatic steatosis and fibrosis data requires the replication of our study in further studies.

NAFLD is related to Post-prandial Triglyceride-enrichment of HDL Particles in Association with Endothelial and HDL Dysfunction

NAFLD is closely related with the metabolic syndrome (MetS) and increased risk of cardiovascular disease. Liver fat associates with post-prandial hypertriglyceridemia, potentially contributing to triglyceride-enrichment of high-density lipoproteins (HDL-TG), and subsequent HDL dysfunction. We assessed liver fat by MR spectroscopy, and its association with HDL physiochemical properties, and endothelial function, measured as flow-mediated dilation (FMD), before and following three consecutive meals, in 36 men with type 2 diabetes mellitus (T2DM), with the MetS, and controls. Plasma triglycerides increased significantly following the meals (P < .001). Fasting HDL-TG was highest in T2DM, relative to MetS and controls (P = .002), and increased post-prandially in all groups (P < .001). HDL function was negatively associated with HDL-TG following three meals (r = -.32, P<.05). Liver fat associated with HDL-TG after three meals (r = .65, P < .001). HDL-TG was independently associated with FMD following three consecutive meals (r = -.477, P = .003). We conclude liver fat is associated with post-prandial HDL-TG enrichment which was closely related with endothelial and HDL dysfunction.

Abdominal Obesity, Adipokines and Non-communicable Diseases

Abdominal obesity may be defined as excess deposits of fat in the abdominal region. It is a common health condition seen in South Asians and is positively related to non-communicable diseases (NCDs). It is independent of body mass index and measured by raised waist circumference for men≥90 cm and women≥80 cm. The reason for its prevalence being common in Indians finds its root from pregnancy, during fetal period and has emerged as a concept of 'Thin Fat Indian'. Malnutrition in such a critical period of growth has consequences in the form of reduced basal metabolic rate (BMR), reduced blood flow to growing tissues, reduced functional ability of vital organs, endocrine changes and reduced capacity of primary adipose tissue. However, excess of visceral fat facilitates high dosage of adipokines in the portal vein to liver and other body tissues having serious implications seen in the form NCDs like diabetes, hypertension, heart diseases, non-alcoholic fatty liver diseases, kidney disorders, cancer and other health problems. Abdominal obesity should be addressed before it has progressed further to defined health issues by exercise and diet, so that people can live a quality life.

Association between fasting plasma glucose and nonalcoholic fatty liver disease in a nonobese Chinese population with normal blood lipid levels: a prospective cohort study

Background

Fasting plasma glucose (FPG) is an easily quantifiable and inexpensive metabolic marker, which is often used to assess cardiovascular disease and diabetes. However, there have been limited studies on the association between FPG and nonalcoholic fatty liver disease (NAFLD) risk in nonobese people, especially in Chinese individuals. The purpose of this study was to investigate the association between FPG and NAFLD in nonobese Chinese people with normal blood lipid levels.

Methods

In this prospective cohort study, 9767 nonobese participants with normal blood lipid levels without NAFLD were recruited and prospectively followed for 5 years. The Cox proportional hazard model was used to evaluate the risk factors of NAFLD. Moreover, a Cox model with cubic spline functions and smooth curve fitting (the cubic spline smoothing) were used to identify the nonlinear association between FPG and NAFLD.

Results

During the 5-year follow-up, 841 (8.61%) participants were diagnosed with NAFLD. The good functional results (without NAFLD) estimated by the Kaplan-Meier method for 1 year, 2 years, 3 years, 4 years, and 5 years were 98.84, 95.35, 91.67%, 87.57 and 74.86%, respectively. Additionally, through the Cox proportional hazard model, after adjusting for other covariates, there was an independent positive correlation between FPG and increased NAFLD risk (HR:1.21, 95% CI:1.15–1.28, P < 0.0001), and the NAFLD risk was incrementally higher with the rising FPG quartile. The nonlinear association between FPG and NAFLD was visualized by cubic spline smoothing technique. It was calculated that the inflection point of FPG was 5.54. When FPG ≤ 5.54, there was a positive correlation between FPG and the risk of NAFLD (HR:2.20, 95% CI:1.78–2.73, P < 0.0001). When FPG > 5.54, the risk of NAFLD increased by 50% (HR:1.10, 95% CI:1.02–1.18, P = 0.0159) compared with the left side of the inflection point and gradually leveled off.

Conclusions

In a nonobese Chinese population with normal lipid levels, there is an independent nonlinear association between FPG and NAFLD, and the increase in FPG may indicate an increased risk of NAFLD. Additionally, this independent association is more obvious in the short stature population.

HDL-apoA-I kinetics in response to 16 wk of exercise training in men with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is characterized by low-circulating concentration of high-density lipoprotein cholesterol (HDL-C) and raised triacylglycerol (TAG). Exercise reduces hepatic fat content, improves insulin resistance and increases clearance of very-low-density lipoprotein-1 (VLDL₁). However, the effect of exercise on TAG and HDL-C metabolism is unknown. We randomized male participants to 16 wk of supervised, moderate-intensity aerobic exercise (n = 15), or conventional lifestyle advice (n = 12). Apolipoprotein A-I (apoA-I) and VLDL-TAG and apolipoprotein B (apoB) kinetics were investigated using stable isotopes (1-[¹³C]-leucine and 1,1,2,3,3-²H₅ glycerol) pre- and postintervention. Participants underwent MRI/spectroscopy to assess changes in visceral fat. Results are means ± SD. At baseline, there were no differences between exercise and control groups for age (52.4 ± 7.5 vs. 52.8 ± 10.3 yr), body mass index (BMI: 31.6 ± 3.2 vs. 31.7 ± 3.6 kg/m²), and waist circumference (109.3 ± 7.5 vs. 110.0 ± 13.6 cm). Percentage of liver fat was 23.8 (interquartile range 9.8-32.5%). Exercise reduced body weight (101.3 ± 10.2 to 97.9 ± 12.2 kg; P < 0.001) and hepatic fat content [from 19.6%, interquartile range (IQR) 14.6-36.1% to 8.9% (4.4-17.8%); P = 0.001] and increased the fraction HDL-C concentration (measured following ultracentrifugation) and apoA-I pool size with no change in the control group. However, plasma and VLDL₁-TAG concentrations and HDL-apoA-I fractional catabolic rate (FCR) and production rate (PR) did not change significantly with exercise. Both at baseline (all participants) and after exercise there was an inverse correlation between apoA-I pool size and VLDL-TAG and -apoB pool size. The modest effect of exercise on HDL metabolism may be explained by the lack of effect on plasma and VLDL₁-TAG.

Anti-obesity therapy with peripheral CB1 blockers: from promise to safe(?) practice

Pharmacological blockers of the cannabinoid receptor type-1 (CB1) have been considered for a long time as the holy grail of obesity pharmacotherapy. These agents were hastily released in the clinical setting, due to their clear-cut therapeutic efficacy. However, the first generation of these drugs, which were able to target both the brain and peripheral tissues, had serious neuropsychiatric effects, leading authorities to ban their clinical use. New peripherally restricted CB1 blockers, characterized by low brain penetrance, have been developed over the past 10 years. In preclinical studies, these molecules seem to overcome the neuropsychiatric negative effects previously observed with brain-penetrant CB1 inhibitors, while retaining or even outperforming their efficacy. The mechanisms of action of these peripherally restricted compounds are only beginning to emerge, and a balanced discussion of the risk/benefits ratio associated to their possible clinical use is urgently needed, in order to avoid repeating past mistakes. Here, we will critically discuss the advantages and the possible hidden threats associated with the use of peripheral CB1 blockers for the pharmacotherapy of obesity and its associated metabolic complications. We will address whether this novel pharmacological approach might 'compete' with current pharmacotherapies for obesity and diabetes, while also conceptualizing future CB1-based pharmacological trends that may significantly lower the risk/benefits ratio associated with the use of these drugs.

The unfolded protein response and hepatic lipid metabolism in non alcoholic fatty liver disease

Nonalcoholic fatty liver disease is a major public health burden. Although many features of nonalcoholic fatty liver disease pathogenesis are known, the specific mechanisms and susceptibilities that determine an individual's risk of developing nonalcoholic steatohepatitis versus isolated steatosis are not well delineated. The predominant and defining histologic and imaging characteristic of nonalcoholic fatty liver disease is the accumulation of lipids. Dysregulation of lipid homeostasis in hepatocytes leads to transient generation or accumulation of toxic lipids that result in endoplasmic reticulum (ER) stress with inflammation, hepatocellular damage, and apoptosis. ER stress activates the unfolded protein response (UPR) which is classically viewed as an adaptive pathway to maintain protein folding homeostasis. Recent studies have uncovered the contribution of the UPR sensors in the regulation of hepatic steatosis and in the cellular response to lipotoxic stress. Interestingly, the UPR sensors can be directly activated by toxic lipids, independently of the accumulation of misfolded proteins, termed lipotoxic and proteotoxic stress, respectively. The dual function of the UPR sensors in protein and lipid homeostasis suggests that these two types of stress are interconnected likely due to the central role of the ER in protein folding and trafficking and lipid biosynthesis and trafficking, such that perturbations in either impact the function of the ER and activate the UPR sensors in an effort to restore homeostasis. The precise molecular similarities and differences between proteotoxic and lipotoxic ER stress are beginning to be understood. Herein, we provide an overview of the mechanisms involved in the activation and cross-talk between the UPR sensors, hepatic lipid metabolism, and lipotoxic stress, and discuss the possible therapeutic potential of targeting the UPR in nonalcoholic fatty liver disease.

Concurrent nonalcoholic fatty liver disease and type 2 diabetes: diagnostic and therapeutic considerations

Introduction: The relationship between nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) is complex and bidirectional. NAFLD increases the risk of incident diabetes and is very prevalent in T2DM patients and T2DM is an aggravating factor for NAFLD. Timely T2DM diagnosis and treatment in subjects with NAFLD and diagnosis, staging and treatment of NAFLD in those with T2DM are critical issues. Areas covered: PubMed/MEDLINE was searched for articles related to concomitant occurrence of NAFLD and T2DM between January 2013 and May 2019. Areas covered included epidemiological, diagnostic and therapeutic aspects. Expert opinion: there is a need for increased awareness on NAFLD adding liver disease as an end-organ complication of T2DM. Emphasis on use of simple non-invasive tools to triage patients with potentially severe liver disease should be made. Management of patients with NAFLD and T2DM relies on lifestyle optimization to achieve significant weight loss. Currently, there is no drug approved for treatment of NAFLD in patients with T2DM although Vitamin E and pioglitazone might be used in selected patients. Approved diabetic medications hold promise for NAFLD treatment and several liver-specific drugs are in evaluation clinical trials. A combination approach will likely represent the future of NAFLD therapeutics.

The Liver in Children With Metabolic Syndrome

Non-alcoholic fatty liver disease (NAFLD) is recognized as an emerging health risk in obese children and adolescents. NAFLD represents a wide spectrum of liver conditions, ranging from asymptomatic steatosis to steatohepatitis. The growing prevalence of fatty liver disease in children is associated with an increased risk of metabolic and cardiovascular complications. NAFLD is considered the hepatic manifestation of Metabolic Syndrome (MetS) and several lines of evidence have reported that children with NAFLD present one or more features of MetS. The pathogenetic mechanisms explaining the interrelationships between fatty liver disease and MetS are not clearly understood. Altough central obesity and insulin resistance seem to represent the core of the pathophysiology in both diseases, genetic susceptibility and enviromental triggers are emerging as crucial components promoting the development of NAFLD and MetS in children. In the present review we have identified and summarizied studies discussing current pathogenetic data of the association between NAFLD and MetS in children.