Endocrine and liver interaction: the role of endocrine pathways in NASH

Proteomic and metabolomic analysis of GH deficiency-induced NAFLD in hypopituitarism: insights into oxidative stress

Objective

Individuals with hypopituitarism (HPs) have an increased risk of developing non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) due to growth hormone deficiency (GHD). We aimed to investigate the possible mechanisms underlying the relationship between GHD and NAFLD using proteomic and metabolomic insights.

Methods

Serum metabolic alternations were assessed in male HPs using untargeted metabolomics. A rat model of HP was established through hypophysectomy, followed by recombinant human growth hormone (rhGH) intervention. The mechanisms underlying GHD-mediated NAFLD were elucidated through the application of label-free proteomics and phosphorylation proteomics.

Results

Metabolomic analysis revealed that biomarkers of mitochondrial dysfunction and oxidative stress, such as alanine, lactate, and creatine, were significantly elevated in HPs compared to age-matched controls. In rats, hypophysectomy led to marked hepatic steatosis, lipid peroxidation, and reduced glutathione (GSH), which were subsequently modulated by rhGH replacement. Proteomic analysis identified cytochrome P450s, mitochondrial translation elongation, and PPARA activating genes as the major distinguishing pathways in hypophysectomized rats. The processes of fatty acid transport, synthesis, oxidation, and NADP metabolism were tightly described. An enhanced regulation of peroxisome β-oxidation and ω-oxidation, together with a decreased NADPH regeneration, may exacerbate oxidative stress. Phosphoproteome data showed downregulation of JAK2-STAT5B and upregulation of mTOR signaling pathway.

Conclusions

This study identified proteo-metabolomic signatures associated with the development of NAFLD in pituitary GHD. Evidence was found of oxidative stress imbalance resulting from abnormal fatty acid oxidation and NADPH regeneration, highlighting the role of GH deficiency in the development of NAFLD.

Thyroid function, adipokines and mitokines in metabolic dysfunction-associated steatohepatitis: A multi-centre biopsy-based observational study

BACKGROUND AND AIMS

Thyroid axis is currently under investigation as a therapeutic target in metabolic dysfunction-associated steatotic liver disease (MASLD). Thyroid function was examined herein in the full spectrum of disease.

METHODS

Subjects were recruited and had liver biopsies in two Gastroenterology-Hepatology Clinics (Greece and Australia) and one Bariatric-Metabolic Surgery Clinic (Italy). The main working sample was n = 677 subjects with MASLD after excluding subjects with abnormal free thyroxine levels. Participants were classified according to thyroid-stimulating hormone (TSH) standard criteria: Subclinical hyperthyroidism (<0.4 uIU/mL); Euthyroidism with relatively low (0.4 to <2.5 uIU/mL); euthyroidism with relatively high (2.5-4.0 uIU/mL); subclinical hypothyroidism (>4 uIU/mL).

RESULTS

TSH as a continuous variable was positively associated with significant fibrosis (F ≥ 2), metabolic dysfunction-associated steatohepatitis (MASH) and at-risk MASH. Subclinical hypothyroidism was associated with fibrosis F ≥ 2 (odds ratio [OR] = 3.47, 95% confident interval [CI] [1.50, 8.05], p = .02), MASH (OR = 3.44, 95% CI [1.48, 7.98] p = .001) and at-risk MASH (OR = 3.88, 95% CI [1.76, 8.55], p = .001), before and after controlling for adiposity, central obesity, and insulin resistance. When leptin, adiponectin, or growth differentiation factor-15 were examined as moderators, significance was lost. Sex-specific analysis revealed a strong association between TSH and the presence of significant fibrosis among women, eliminated only when adipokines/mitokines were adjusted for. Restricted cubic spline analysis revealed associations between TSH and liver outcomes (p-values < .01) with inflection points for fibrosis F ≥ 2 being 2.49, for MASH being 2.67 and for at-risk MASH being 6.96.

CONCLUSIONS

These observations provide support for studies on the administration of thyroid hormone in MASLD therapeutics for subclinical hypothyroidism and liver-specific thyroid receptor agonists for subjects across the TSH continuum.

Transcriptomic and lipid profiling analysis reveals a functional interplay between testosterone and growth hormone in hypothyroid liver

Preclinical and clinical studies suggest that hypothyroidism might cause hepatic endocrine and metabolic disturbances with features that mimic deficiencies of testosterone and/or GH. The absence of physiological interactions between testosterone and GH can be linked to male differentiated liver diseases. Testosterone plays relevant physiological effects on somatotropic-liver axis and liver composition and the liver is a primary organ of interactions between testosterone and GH. However, testosterone exerts many effects on liver through complex and poorly understood mechanisms. Testosterone impacts liver functions by binding to the Androgen Receptor, and, indirectly, through its conversion to estradiol, and cooperation with GH. However, the role of testosterone, and its interaction with GH, in the hypothyroid liver, remains unclear. In the present work, the effects of testosterone, and how they impact on GH-regulated whole transcriptome and lipid composition in the liver, were studied in the context of adult hypothyroid-orchiectomized rats. Testosterone replacement positively modulated somatotropic-liver axis and impacted liver transcriptome involved in lipid and glucose metabolism. In addition, testosterone enhanced the effects of GH on the transcriptome linked to lipid biosynthesis, oxidation-reduction, and metabolism of unsaturated and long-chain fatty acids (FA). However, testosterone decreased the hepatic content of cholesterol esters and triacylglycerols and increased fatty acids whereas GH increased neutral lipids and decreased polar lipids. Biological network analysis of the effects of testosterone on GH-regulated transcriptome confirmed a close connection with crucial proteins involved in steroid and fatty acid metabolism. Taken together, this comprehensive analysis of gene expression and lipid profiling in hypothyroid male liver reveals a functional interplay between testosterone and pulsed GH administration.

Lack of thyroid hormone receptor beta is not detrimental for non-alcoholic steatohepatitis progression

Agonists for thyroid hormone receptor β (TRβ) show promise in preclinical studies and clinical trials to improve non-alcoholic fatty liver disease. A recent study on human livers, however, revealed reduced TRβ expression in non-alcoholic steatohepatitis (NASH), indicating a developing thyroid hormone resistance, which could constitute a major obstacle for those agonists. Using a rapid NASH paradigm combining choline-deficient high-fat diet and thermoneutrality, we confirm that TRβ declines during disease progression in mice similar to humans. Contrary to expectations, mice lacking TRβ showed less liver fibrosis, and NASH marker genes were not elevated. Conversely, increasing TRβ expression in wild-type NASH mice using liver-targeted gene therapy did not improve histology, gene expression, or metabolic parameters, indicating that TRβ receptor levels are of minor relevance for NASH development and progression in our model, and suggest that liver-rather than isoform-specificity might be more relevant for NASH treatment with thyroid hormone receptor agonists.

Thyroid hormone action and liver disease, a complex interplay

Thyroid hormone action is involved in virtually all physiological processes. It is well known that the liver and thyroid are intimately linked, with thyroid hormone playing important roles in de novo lipogenesis, beta-oxidation (fatty acid oxidation), cholesterol metabolism, and carbohydrate metabolism. Clinical and mechanistic research studies have shown that thyroid hormone can be involved in chronic liver diseases, including alcohol-associated or NAFLD and HCC. Thyroid hormone action and synthetic thyroid hormone analogs can exert beneficial actions in terms of lowering lipids, preventing chronic liver disease and as liver anticancer agents. More recently, preclinical and clinical studies have indicated that some analogs of thyroid hormone could also play a role in the treatment of liver disease. These synthetic molecules, thyromimetics, can modulate lipid metabolism, particularly in NAFLD/NASH. In this review, we first summarize the thyroid hormone signaling axis in the context of liver biology, then we describe the changes in thyroid hormone signaling in liver disease and how liver diseases affect the thyroid hormone homeostasis, and finally we discuss the use of thyroid hormone-analog for the treatment of liver disease.

The Impact of the COVID-19 Pandemic on Outcomes in Acute Pancreatitis: A Propensity Score Matched Study Comparing before and during the Pandemic

We aimed to evaluate the outcomes and survival of patients with acute pancreatitis who shared the same clinical form, age, and sex before the pandemic, during the pandemic, and among those with confirmed COVID-19 infection upon hospital admission. This consideration used the sparse data in the existing literature on the influence of the pandemic and COVID-19 infection on patients with acute pancreatitis. To accomplish this, we conducted a multicentric, retrospective case-control study using propensity score matching with a 2:1 match of 28 patients with SARS-CoV-2 infection and acute pancreatitis, with 56 patients with acute pancreatitis pre-pandemic, and 56 patients with acute pancreatitis during the pandemic. The study outcome demonstrated a six-fold relative risk of death in patients with acute pancreatitis and SARS-CoV-2 infection compared to those with acute pancreatitis before the pandemic. Furthermore, restrictive measures implemented during the pandemic period led to a partial delay in the care of patients with acute pancreatitis, which likely resulted in an impairment of their immune state. This, in certain circumstances, resulted in a restriction of surgical treatment indications, leading to a three-fold relative risk of death in patients with acute pancreatitis during the pandemic compared to those with acute pancreatitis before the pandemic.

Thyroid hormone upregulates LAMP2 expression and lysosome activity

Thyroid hormone (T₃)-induced autophagy and its biological significance have been extensively investigated in recent years. However, limited studies to date have focused on the important role of lysosomes in autophagy. In this study, we explored the effects of T₃ on lysosomal protein expression and trafficking in detail. Our findings showed that T₃ activates rapid lysosomal turnover and expression of numerous lysosomal genes, including TFEB, LAMP2, ARSB, GBA, PSAP, ATP6V0B, ATP6V0D1, ATP6V1E1, CTSB, CTSH, CTSL, and CTSS, in a thyroid hormone receptor-dependent manner. In a murine model, LAMP2 protein was specifically induced in mice with hyperthyroidism. T₃-promoted microtubule assembly was significantly disrupted by vinblastine, resulting in accumulation of the lipid droplet marker PLIN2. In the presence of the lysosomal autophagy inhibitors bafilomycin A1, chloroquine and ammonium chloride, we observed substantial accumulation of LAMP2 but not LAMP1 protein. T₃ further enhanced the protein levels of ectopically expressed LAMP1 and LAMP2. Upon knockdown of LAMP2, cavities of lysosomes and lipid droplets accumulated in the presence of T₃, although the changes in LAMP1 and PLIN2 expression were less pronounced. More specifically, the protective effect of T₃ against ER stress-induced death was abolished by knockdown of LAMP2. Our collective results indicate that T₃ not only promotes lysosomal gene expression but also LAMP protein stability and microtubule assembly, leading to enhancement of lysosomal activity in digesting any additional autophagosomal burden.

The Role of Growth Hormone and Insulin Growth Factor 1 in the Development of Non-Alcoholic Steato-Hepatitis: A Systematic Review

Diabetic and obese patients have a high prevalence of non-alcoholic fatty liver disease (NAFLD). This condition groups a spectrum of conditions varying from simple steatosis to non-alcoholic steatohepatitis (NASH), with or without fibrosis. Multiple factors are involved in the development of NAFLD. However, details about its pathogenesis and factors that promote the progression to NASH are still missing. Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) regulate metabolic, immune, and hepatic stellate cell functions. Increasing evidence suggests they may have roles in the progression from NAFLD to NASH. Following the PRISMA reporting guidelines, we conducted a systematic review to evaluate all clinical and experimental studies published in the literature correlating GH and IGF-1 to inflammation and fibrosis in NAFLD and NASH. Our results showed that GH and IGF-1 have a fundamental role in the pathogenesis of NASH, acting in slightly different ways to produce a synergic effect. Indeed, GH may mediate its protective effect in the pathogenesis of NASH by regulating lipogenesis pathways, while IGF-1 has the same effect by regulating cholesterol transport. Therefore, they could be used as therapeutic strategies in preventing NAFLD progression to NASH.

Exploring the Regulatory Role of ncRNA in NAFLD: A Particular Focus on PPARs

Liver diseases are responsible for global mortality and morbidity and are a significant cause of death worldwide. Consequently, the advancement of new liver disease targets is of great interest. Non-coding RNA (ncRNA), such as microRNA (miRNA) and long ncRNA (lncRNA), has been proven to play a significant role in the pathogenesis of virtually all acute and chronic liver disorders. Recent studies demonstrated the medical applications of miRNA in various phases of hepatic pathology. PPARs play a major role in regulating many signaling pathways involved in various metabolic disorders. Non-alcoholic fatty liver disease (NAFLD) is the most prevalent form of chronic liver disease in the world, encompassing a spectrum spanning from mild steatosis to severe non-alcoholic steatohepatitis (NASH). PPARs were found to be one of the major regulators in the progression of NAFLD. There is no recognized treatment for NAFLD, even though numerous clinical trials are now underway. NAFLD is a major risk factor for developing hepatocellular carcinoma (HCC), and its frequency increases as obesity and diabetes become more prevalent. Reprogramming anti-diabetic and anti-obesity drugs is an effective therapy option for NAFLD and NASH. Several studies have also focused on the role of ncRNAs in the pathophysiology of NAFLD. The regulatory effects of these ncRNAs make them a primary target for treatments and as early biomarkers. In this study, the main focus will be to understand the regulation of PPARs through ncRNAs and their role in NAFLD.

Inflammatory signaling on cytochrome P450-mediated drug metabolism in hepatocytes

Cytochrome P450 (CYP450) enzymes are membrane-bound blood proteins that are vital to drug detoxification, cell metabolism, and homeostasis. CYP450s belonging to CYP families 1-3 are responsible for nearly 80% of oxidative metabolism and complete elimination of approximately 50% of all common clinical drugs in humans liver hepatocytes. CYP450s can affect the body's response to drugs by altering the reaction, safety, bioavailability, and toxicity. They can also regulate metabolic organs and the body's local action sites to produce drug resistance through altered drug metabolism. Genetic polymorphisms in the CYP gene alone do not explain ethnic and individual differences in drug efficacy in the context of complex diseases. The purpose of this review is to summarize the impact of new inflammatory-response signaling pathways on the activity and expression of CYP drug-metabolizing enzymes. Included is a summary of recent studies that have identified drugs with the potential to regulate drug-metabolizing enzyme activity. Our goal is to inspire the development of clinical drug treatment processes that consider the impact of the inflammatory environment on drug treatment, as well as provide research targets for those studying drug metabolism.

Association between Thyroid Hormones and Non-alcoholic Fatty Liver Disease and Non-alcoholic Steatohepatitis in Obese Individuals Undergoing Bariatric Surgery

Background: Non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), and hepatic fibrosis have emerged as one of the leading causes of chronic liver disease. The prevalence of the NAFLD spectrum has increased, which can be attributed to the rise in obesity. As NAFLD can ultimately lead to liver cirrhosis, it is imperative to identify modifiable risk factors associated with its onset and progression to provide timely intervention to prevent potentially disastrous consequences. Considering the pivotal role of the endocrine axis in several metabolic pathways such as obesity and insulin resistance, thyroid hormones are crucial in the pathophysiology of NAFLD. The study is focused on the identification of an association between thyroid function and radiographic and histological parameters of NAFLD in patients with severe obesity. Methods: Ninety patients were recruited for this study and underwent initial assessments, including demographic profiles, anthropometric measurements, hepatic biopsy, and basic laboratory tests. Liver stiffness was evaluated using two-dimensional shear wave elastography (2D-SWE) at least 2 weeks before liver biopsy. Results: Among the 90 participants, 80% were women. The mean age was 38.5±11.1 years, and the mean body mass index (BMI) was 45.46±6.26 kg/m2. The mean levels of serum T3 and free T4 in patients with positive histology were not statistically significant compared with patients with negative histology. Furthermore, there was no statistical significance in the mean T3 and free T4 levels between patients diagnosed with hepatic steatosis or fibrosis (on ultrasonography and elastography) and those with negative hepatic imaging. Serum levels of thyroid-stimulating hormone (TSH) were negatively correlated with ultrasonography (P=0.007). Binary logistic regression analysis revealed that none of the thyroid hormones was a predictive factor for liver histology in both adjusted and crude models. Conclusion: The results from our analysis did not suggest an association between thyroid hormones and NAFLD, which is in line with several previously published studies. However, the authors note that there are published data that do propose a link between the two entities. Therefore, well-designed large-scale clinical studies are required to clarify this discrepancy.

Liver abnormalities in Turner’s syndrome – the importance of estrogen replacement

Turner syndrome is one of the most frequently reported sex chromosomal abnormalities, affecting approximately 40 in every 100 000 live female births. The underlying chromosomal alteration is the complete or partial loss of X chromosome or mosaicism. Because of primary ovarian insufficiency, the synthesis of estrogen hormones is compromised, and patients require hormone substitution. Apart from the phenotypical presentation (short stature, primary amenorrhea), the effects of ovarian insufficiency can affect diverse organ systems (such as cardiovascular, endocrine, and lymphatic systems). Hepatobiliary pathology can present on a broad spectrum: from mild asymptomatic hypertransaminasemia to marked architectural changes. Estrogen hormone replacement therapy in these patients can improve the perturbations of laboratory values and can attenuate the progression of hepatic structural changes. Moreover, providing sufficient estrogen replacement has numerous benefits for other conditions of the patients as well. Both the all-cause mortality and deaths from cardiovascular complications are greatly increased in Turner syndrome, and hormone replacement might contribute to the decreased incidence of these events. The diagnostics of Turner syndrome are outside the scope of our paper, and we briefly discuss the cardiovascular complications because many the liver involvement partially involves alterations of vascular origin. Though we sought to highlight the importance of proper hormone replacement therapy, we did not attempt to write a comprehensive recommendation for exact treatment protocols. We provided an overview of preferred therapeutic approaches, as the treatment should be tailored according to the individual patient’s needs.

The Hepatoprotective and Hepatotoxic Roles of Sex and Sex-Related Hormones

Most liver diseases, including acute liver injury, drug-induced liver injury, viral hepatitis, metabolic liver diseases, and end-stage liver diseases, are strongly linked with hormonal influences. Thus, delineating the clinical manifestation and underlying mechanisms of the “sexual dimorphism” is critical for providing hints for the prevention, management, and treatment of those diseases. Whether the sex hormones (androgen, estrogen, and progesterone) and sex-related hormones (gonadotrophin-releasing hormone, luteinizing hormone, follicle-stimulating hormone, and prolactin) play protective or toxic roles in the liver depends on the biological sex, disease stage, precipitating factor, and even the psychiatric status. Lifestyle factors, such as obesity, alcohol drinking, and smoking, also drastically affect the involving mechanisms of those hormones in liver diseases. Hormones deliver their hepatic regulatory signals primarily via classical and non-classical receptors in different liver cell types. Exogenous sex/sex-related hormone therapy may serve as a novel strategy for metabolic liver disease, cirrhosis, and liver cancer. However, the undesired hormone-induced liver injury should be carefully studied in pre-clinical models and monitored in clinical applications. This issue is particularly important for menopause females with hormone replacement therapy (HRT) and transgender populations who want to receive gender-affirming hormone therapy (GAHT). In conclusion, basic and clinical studies are warranted to depict the detailed hepatoprotective and hepatotoxic mechanisms of sex/sex-related hormones in liver disease. Prolactin holds a promising perspective in treating metabolic and advanced liver diseases.

Bidirectional Association Between Psoriasis and Nonalcoholic Fatty Liver Disease: Real-World Evidence From Two Longitudinal Cohort Studies

Background

Association between nonalcoholic fatty liver disease (NAFLD) and future psoriasis has not yet been confirmed, although the two diseases partially share a common pathogenesis pathway. Studies have revealed an association between psoriasis and subsequent NAFLD; however, these studies were limited to small sample sizes and a cross-sectional study design. Hence, the main objective of this population-based longitudinal cohort study was to evaluate the bidirectional association between psoriasis and NAFLD.

Methods

Data were retrieved from Taiwan’s National Health Insurance Research Database. Patients with new-onset NAFLD and psoriasis were respectively enrolled in two cohorts. For each comparison cohort, propensity-score-matched controls with no record of NAFLD or psoriasis were selected. An adjusted hazard ratio (aHR) was applied to evaluate subsequent risks.

Results

The risk of patients with new-onset NAFLD developing psoriasis was statistically significant, with an HR of 1.07 (95% CI, 1.01–1.14). For younger patients with NAFLD, the risk of developing psoriasis was 1.3-fold higher. The risk of patients with new-onset psoriasis developing NAFLD in the future was 1.28-fold higher than that of patients without psoriasis (95% CI, 1.21–1.35), and patients in younger psoriasis subgroups below the age of 40 years were at a higher risk than those in older subgroups, with an aHR of 1.55 (95% CI, 1.40–1.71).

Conclusion

Evidence supports a bidirectional association between NAFLD and psoriasis, especially in patients below the age of 40 years. The correlation between the two diseases and the subsequent risk of disease development should be considered when caring for patients.

Nonalcoholic Fatty Liver Disease and Endocrine Axes—A Scoping Review

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease. NAFLD often occurs associated with endocrinopathies. Evidence suggests that endocrine dysfunction may play an important role in NAFLD development, progression, and severity. Our work aimed to explore and summarize the crosstalk between the liver and different endocrine organs, their hormones, and dysfunctions. For instance, our results show that hyperprolactinemia, hypercortisolemia, and polycystic ovary syndrome seem to worsen NAFLD’s pathway. Hypothyroidism and low growth hormone levels also may contribute to NAFLD’s progression, and a bidirectional association between hypercortisolism and hypogonadism and the NAFLD pathway looks likely, given the current evidence. Therefore, we concluded that it appears likely that there is a link between several endocrine disorders and NAFLD other than the typically known type 2 diabetes mellitus and metabolic syndrome (MS). Nevertheless, there is controversial and insufficient evidence in this area of knowledge.

Tissue-Specific Expression Pattern in Ancherythroculter nigrocauda, a Sexually Size Dimorphic Fish

Certain members of the Actinopterygii class are known to exhibit sexual dimorphism (SD) that results in major phenotypic differences between male and female fishes of a species. One of the most common differences between the two sexes is in body weight, a factor with a high economic value in aquaculture. In this study, we used RNA sequencing (RNA-seq) to study the liver and brain transcriptomes of Ancherythroculter nigrocauda, a fish exhibiting SD. Females attain about fourfold body weight of males at sexual maturity. Sample clustering showed that both sexes were grouped well with their sex phenotypes. In addition, 2,395 and 457 differentially expressed genes (DEGs) were identified in the liver and brain tissues, respectively. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses predicted the association of PPAR signaling, cytochrome P450, and steroid hormone biosynthesis to the differences in sexual size. In addition, weighted gene co-expression network analyses (WGCNA) were conducted, and the green module was identified to be significantly correlated with sexual size dimorphism (SSD). Altogether, these results improve our understanding of the molecular mechanism underlying SSD in A. nigrocauda.

Progressive Liver Fibrosis in Non-Alcoholic Fatty Liver Disease

Non-alcoholic steatohepatitis (NASH) is a chronic and progressive form of non-alcoholic fatty liver disease. Its global incidence is increasing and makes NASH an epidemic and a public health threat. Non-alcoholic fatty liver disease is associated with major morbidity and mortality, with a heavy burden on quality of life and liver transplant requirements. Due to repeated insults to the liver, patients are at risk for developing hepatocellular carcinoma. The progression of NASH was initially defined according to a two-hit model involving an initial development of steatosis, followed by a process of lipid peroxidation and inflammation. In contrast, current evidence proposes a “multi-hit” or “multi-parallel hit” model that includes multiple pathways promoting progressive fibrosis and oncogenesis. This model includes multiple cellular, genetic, immunological, metabolic, and endocrine pathways leading to hepatocellular carcinoma development, underscoring the complexity of this disease.

Metabolic causes and consequences of nonalcoholic fatty liver disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is a multifactorial metabolic disorder that was first described in 1980. It has been prevalent and on the rise for many years and is associated with other metabolic disorders such as obesity and type 2 diabetes mellitus (T2DM). NAFLD can be best described as a metabolic dysfunction that stems from insulin resistance-induced hepatic lipogenesis. This lipogenesis increases oxidative stress and hepatic inflammation and is often potentiated by genetic and gut microbiome dysfunction. As NAFLD progresses from simple steatosis to non-alcoholic steatohepatitis (NASH) and to cirrhosis and hepatocellular carcinoma (HCC), the odds of complications including cardiovascular disease (CVD), chronic kidney disease (CKD), and overall mortality increase. The aim of this review is to describe the metabolic causes and consequences of NAFLD while examining the risks that each stage of NAFLD poses. In this review, the etiology of "lean" NAFLD, the impact of obesity, T2DM, genetics, and microbiome dysbiosis on NAFLD progression are all explored. This review will also discuss the core issue behind the progression of NAFLD: insulin resistance (IR). Upon describing the causes and consequences of NAFLD, the effectiveness of diet modification, lifestyle changes, and glucagon-like peptide 1 receptor (GLP-1) agonists to retard NAFLD progression and stem the rate of complications is examined.

Hypothyroidism-Associated Dyslipidemia: Potential Molecular Mechanisms Leading to NAFLD

Thyroid hormones control lipid metabolism by exhibiting specific effects on the liver and adipose tissue in a coordinated manner. Different diseases of the thyroid gland can result in hypothyroidism. Hypothyroidism is frequently associated with dyslipidemia. Hypothyroidism-associated dyslipidemia subsequently results in intrahepatic accumulation of fat, leading to nonalcoholic fatty liver disease (NAFLD), which leads to the development of hepatic insulin resistance. The prevalence of NAFLD in the western world is increasing, and evidence of its association with hypothyroidism is accumulating. Since hypothyroidism has been identified as a modifiable risk factor of NAFLD and recent data provides evidence that selective thyroid hormone receptor β (THR-β) agonists are effective in the treatment of dyslipidemia and NAFLD, interest in potential therapeutic options for NAFLD targeting these receptors is growing. In this review, we summarize current knowledge regarding clinical and molecular data exploring the association of hypothyroidism, dyslipidemia and NAFLD.

Relationship Between Non-Alcoholic Fatty Liver Disease and Abdominal and Pericardial Adipose Tissue in Middle-Aged and Elderly Subjects

Objective

The present study aimed to explore the relationship between non-alcoholic fatty liver disease (NAFLD) and abdominal and pericardial adipose tissue in middle-aged and elderly subjects.

Methods

Between July 2019 and July 2020, 471 subjects attending the Health Care Medical Department of Peking Union Medical College Hospital for a medical examination were enrolled in the study. The volume and distribution of abdominal adipose tissue together with the volume of pericardial adipose tissue were calculated according to the results of the abdominal computed tomography. The differences between subjects with NAFLD and the normal population were analyzed.

Results

The volume of pericardial adipose tissue, abdominal visceral and subcutaneous adipose tissue, the total volume of abdominal adipose tissue, and volume of pelvic visceral adipose tissue were all significantly increased in subjects with NAFLD. For every 100 cm³ increase in the volume of abdominal visceral adipose tissue, the incidence of developing NAFLD increased by 9.4%. According to the results of the receiver operating curve, the cut-off point of abdominal visceral adipose tissue for the diagnosis of NAFLD was 2691.1 cm³.

Conclusion

Overall, the risk of NAFLD increases significantly with the increase in the volume of adipose tissue.

A Case of Sheehan Syndrome 7 Years Postpartum with Transaminitis and Hyperlipidemia

Patient: Female, 46-year-old

Final Diagnosis: Sheehan syndrome

Symptoms: Fatigue • light-headedness

Medication: —

Clinical Procedure: —

Specialty: Endocrinology and Metabolic

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.

Natural Progression of Non-Alcoholic Steatohepatitis to Hepatocellular Carcinoma

Non-alcoholic steatohepatitis (NASH) is a chronic and progressive form of non-alcoholic fatty liver disease (NAFLD). Its global incidence is increasing which makes NASH an epidemic and a public health threat. Due to repeated insults to the liver, patients are at risk for developing hepatocellular carcinoma (HCC). The progression of NASH to HCC was initially defined according to a two-hit model which involved the development of steatosis, followed by lipid peroxidation and inflammation. However, current research defines a “multi-hit” or “multi-parallel hit” model which synthesizes several contributing pathways involved in progressive fibrosis and oncogenesis. This perspective considers the effects of cellular, genetic, immunologic, metabolic, and endocrine pathways leading up to HCC which underscores the complexity of this condition. This article will provide an updated review of the pathogenic mechanisms leading from NASH to HCC as well as an exploration of the role of biomarkers and screening.

Association between Nonalcoholic Fatty Liver Disease and Endocrinopathies: Clinical Implications

Nonalcoholic fatty liver disease (NAFLD) has a rising prevalence worldwide. Its potential for evolution towards liver cirrhosis and hepatocellular carcinoma, as well as associations with extrahepatic manifestations, represents a double burden for patients and physicians alike. Recently, there has been increasing evidence of the association between NAFLD and a number of endocrinopathies, such as hypothyroidism, polycystic ovarian syndrome (PCOS), hypopituitarism, growth hormone deficiency (GHD), hypogonadism, and hypercortisolism. Definite correlations are supported by clear evidence so far, but further studies are needed in order to completely clarify the pathogenic mechanisms and, especially, to identify therapeutic implications. In this review, we present the main relationships between NAFLD and endocrinopathies, emphasizing the reciprocal causality, evolutive interconnections, and current clinical scenarios of presentations of which the clinicians should be aware.

Physiopathology of Lifestyle Interventions in Non-Alcoholic Fatty Liver Disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is a major health problem, and its prevalence has increased in recent years. Diet and exercise interventions are the first-line treatment options, with weight loss via a hypocaloric diet being the most important therapeutic target in NAFLD. However, most NAFLD patients are not able to achieve such weight loss. Therefore, the requisite is the investigation of other effective therapeutic approaches. This review summarizes research on understanding complex pathophysiology underlying dietary approaches and exercise interventions with the potential to prevent and treat NAFLD.

Thyroid Function and the Risk of Fibrosis of the Liver, Heart, and Lung in Humans: A Systematic Review and Meta-Analysis

Background: Fibrotic diseases have an unclear etiology and poor prognosis. Fluctuations in thyroid function may play a role in the development of fibrosis, but evidence is fragmented and inconclusive. This systematic review and meta-analysis aimed to investigate the association of thyroid function with fibrotic diseases of the liver, heart, and lung in humans. Methods: We searched PubMed, Medline Ovid, Embase Ovid, and Web-of-Science for studies published from inception to 14 June 2019, to identify observational studies that investigated the association of thyroid function with fibrosis of the liver, heart, and lung in humans. Study quality was evaluated by the Newcastle-Ottawa Scale. The Mantel-Haenszel method was used to pool the odds ratios (ORs) of studies investigating the association of hypothyroidism with liver fibrosis. Results: Of the 2196 identified articles, 18 studies were included in the systematic review, of which 11 studies reported on liver fibrosis, 4 on myocardial fibrosis, and 3 on pulmonary fibrosis. The population sample size ranged from 36 to 7259 subjects, with median mean age 51 years (range, 36-69) and median percentage of women 53 (range, 17-100). The risk of bias of studies was low to moderate to high. Higher serum thyrotropin and lower thyroid hormone levels were generally associated with higher likelihood of fibrosis. Compared with euthyroidism, overt and subclinical hypothyroidism was associated with a higher likelihood of fibrosis in the liver (six of seven studies), heart (three of three studies), and lung (three of three studies). Based on the results of the seven studies included in the meta-analysis, overt and subclinical hypothyroidism was associated with an increased risk of liver fibrosis (pooled OR, 2.81; 95% confidence interval [CI], 1.74-4.53; heterogeneity, I² 31.4%; pooled OR, 2.12; CI, 1.45-3.12; heterogeneity, I² 0%; respectively), without evidence of publication bias. Conclusions: This study suggests that low thyroid function is associated with increased likelihood of chronic fibrotic diseases of the liver, heart, and lung. However, the evidence is mainly based on cross-sectional data. Prospective studies and randomized clinical trials are needed to investigate the potential efficacy of thyroid hormone and its analogs on the occurrence and progression of fibrosis.

Perspectives of nonalcoholic fatty liver disease research: a personal point of view

Rational government of patient fluxes from primary care to hepatology clinic is a priority of nonalcoholic fatty liver disease (NAFLD) research. Estimating pre-test probability of disease, risk of fibrosis progression, and exclusion of competing causes of liver disease must be addressed. Here we propose a novel taxonomic classification of NAFLD based on hepatic, pathogenic and systemic features of disease in the individual patient. The variable course of disease in any given patient remains a clinical enigma. Therefore, future studies will have to better characterize the role of genetic polymorphisms, family and personal history, diet, alcohol, physical activity and drugs as modifiers of the course of disease and clues to the early diagnosis of hepatocellular carcinoma. A better understanding of these, together with a taxonomic diagnosis, may prompt a more accurate personalization of care. For example, understanding the putative role of psycho-depression in NAFLD promises to revolutionize disease management in a proportion of cases. Similarly, sex differences in outcome and response to treatment are insufficiently characterized. More studies are awaited regarding those forms of NAFLD which occur secondary to endocrine derangements. The intersections between NAFLD and the lung must better be defined. These include the bi-directional associations of NAFLD and chronic obstructive pulmonary disease and sleep apnoea syndrome, as well as the totally unexplored chapter of NAFLD and coronavirus disease 2019 (COVID-19). Finally, the therapeutic roles of intermittent fasting and anticoagulation must be assessed. In conclusion, over the last 20 years, NAFLD has taught us a lot regarding the pathogenic importance of insulin resistance, the limitations of correcting this in the treatment of NAFLD, the root causes of diabetes and the metabolic syndrome, sex differences in disease and the role of nuclear receptors. However, the overwhelming COVID-19 pandemic is now expected to reset the priorities of public health.

Perspectives of nonalcoholic fatty liver disease research: a personal point of view

Rational government of patient fluxes from primary care to hepatology clinic is a priority of nonalcoholic fatty liver disease (NAFLD) research. Estimating pre-test probability of disease, risk of fibrosis progression, and exclusion of competing causes of liver disease must be addressed. Here we propose a novel taxonomic classification of NAFLD based on hepatic, pathogenic and systemic features of disease in the individual patient. The variable course of disease in any given patient remains a clinical enigma. Therefore, future studies will have to better characterize the role of genetic polymorphisms, family and personal history, diet, alcohol, physical activity and drugs as modifiers of the course of disease and clues to the early diagnosis of hepatocellular carcinoma. A better understanding of these, together with a taxonomic diagnosis, may prompt a more accurate personalization of care. For example, understanding the putative role of psycho-depression in NAFLD promises to revolutionize disease management in a proportion of cases. Similarly, sex differences in outcome and response to treatment are insufficiently characterized. More studies are awaited regarding those forms of NAFLD which occur secondary to endocrine derangements. The intersections between NAFLD and the lung must better be defined. These include the bi-directional associations of NAFLD and chronic obstructive pulmonary disease and sleep apnoea syndrome, as well as the totally unexplored chapter of NAFLD and coronavirus disease 2019 (COVID-19). Finally, the therapeutic roles of intermittent fasting and anticoagulation must be assessed. In conclusion, over the last 20 years, NAFLD has taught us a lot regarding the pathogenic importance of insulin resistance, the limitations of correcting this in the treatment of NAFLD, the root causes of diabetes and the metabolic syndrome, sex differences in disease and the role of nuclear receptors. However, the overwhelming COVID-19 pandemic is now expected to reset the priorities of public health.

Effects of Prunus cerasus L. Seeds and Juice on Liver Steatosis in an Animal Model of Diet-Induced Obesity

The accumulation of adipose tissue increases the risk of several diseases. The fruits-intake, containing phytochemicals, is inversely correlated with their development. This study evaluated the effects of anthocyanin-rich tart cherries in diet-induced obese (DIO) rats. DIO rats were exposed to a high-fat diet with the supplementation of tart cherry seeds powder (DS) and seed powder plus juice (DJS). After 17 weeks, the DIO rats showed an increase of body weight, glycaemia, insulin, and systolic blood pressure. In the DS and DJS groups, there was a decrease of systolic blood pressure, glycaemia, triglycerides, and thiobarbituric reactive substances in the serum. In the DJS rats, computed tomography revealed a decrease in the spleen-to-liver attenuation ratio. Indeed, sections of the DIO rats presented hepatic injury characterized by steatosis, which was lower in the supplemented groups. In the liver of the DIO compared with rats fed with a standard diet (CHOW), a down-regulation of the GRP94 protein expression and a reduction of LC3- II/LC3-I ratio were found, indicating endoplasmic reticulum stress and impaired autophagy flux. Interestingly, tart cherry supplementation enhanced both unfolded protein response (UPR) and autophagy. This study suggests that tart cherry supplementation, although it did not reduce body weight in the DIO rats, prevented its related risk factors and liver steatosis.

Sarcopenia in chronic liver diseases: a translational overview

INTRODUCTION

Sarcopenia refers to a progressive and generalized muscle mass and strength loss. In liver diseases, it has been related to worse outcomes and high risk of decompensations.

AREAS COVERED

Sarcopenia is caused by a set of cellular processes in the muscle such as denervation, mitochondrial dysfunction, endotoxemia and inflammation; which are manifested through the alteration of several proteolytic pathways such as lysosomal, proteasomal and caspase systems. In autophagy, myostatin and oxidative stress; such as hyperammonemia, contributes importantly to liver sarcopenia through loss of muscle mass already demonstrated in in vitro and in vivo models. In addition, hormones and the regulation of the intestinal microbiota, influence in a not less important magnitude. In the clinical setting, early identification of sarcopenia has been established as a mandatory item to prevent progression of muscle mass loss; however, diagnostic methods have extreme variation according to methodology, population, etiology and severity of liver disease. Reversing sarcopenia should be an integral therapeutic strategy.

EXPERT OPINION

Clinical and nutritional interventions should be adapted to liver injury etiology and stage of disease, each of them shares a similar sarcopenia development pathway. There are specific biomarkers that condition or exacerbate loss of skeletal muscle.

CHD is Associated With Higher Grades of NAFLD Predicted by Liver Stiffness

BACKGROUND AND AIM

Accumulating clinical and epidemiologic evidence indicates that nonalcoholic fatty liver disease (NAFLD) is not only associated with liver-related morbidity and mortality, but also with a greater risk of coronary heart disease (CHD). However, there is currently no diagnostic parameter for NAFLD that has been determined to reliably indicate the presence of CHD as a co-morbidity. We evaluated the liver stiffness and visceral fat thickness of NAFLD patients ultrasonographically to explore the relationship between liver stiffness, visceral fat thickness, and CHD, aiming to find explore the relationship between the liver stiffness and CHD.

METHODS

We enrolled 120 consecutive patients who had been initially diagnosed with CHD on the basis of their symptoms. All patients underwent coronary angiography or computed tomography angiography, and were classified into a CHD group and a non-CHD group on the basis of the results. All patients underwent liver ultrasonography, shear-wave elastography, and visceral fat thickness measurement.

RESULTS

NAFLD and visceral fat thickness were significantly positively correlated with CHD and Gensini score (P<0.001). Multivariate regression showed that age, male, cholesterol, liver stiffness, and visceral fat thickness were determinants of CHD. Age, cholesterol, liver stiffness, and visceral fat thickness cut-off points for the prediction of CHD were above 50 years old [area under the curve (AUC): 0.678; sensitivity, 87%; specificity, 42.6%], >3.76 mmol/L (AUC: 0.687; sensitivity, 68.4%; specificity, 64.8%), >6.1 kPa (AUC: 0.798; sensitivity, 50%; specificity, 92.6%), and >7.41 cm (AUC: 0.694; sensitivity, 52.6%; specificity, 87%), respectively. Compared with the use of age, gender, and cholesterol (model 1), the addition of the liver stiffness cut-off to model 1 resulted in a stronger predictive value (P=0.005).

CONCLUSIONS

High-grade NAFLD is more present in symptomatic CHD. The higher degree of liver stiffness in patients with NAFLD, the higher risk of CHD in these NAFLD patients.

Relationship between nonalcoholic fatty liver disease and muscle quality as well as quantity evaluated by computed tomography

BACKGROUND & AIMS

Sarcopenia is reported to be associated with nonalcoholic fatty liver disease (NAFLD). Evaluation of skeletal muscle attenuation and area by computed tomography (CT) may represent a promising approach for evaluation of the risk of NAFLD. We examined the association between skeletal muscle characteristics and NAFLD and investigated the combined effect of these parameters on the prevalence of NAFLD.

METHODS

In this cross-sectional study, we analysed data from 632 middle-aged Japanese subjects without daily alcohol intake (353 men and 279 women) from a cohort of employees undergoing annual health examinations. The cross-sectional skeletal muscle area was evaluated on the basis of CT data at the level of the third lumbar vertebrae, and the skeletal muscle index (SMI) and density (SMD) were calculated. The subjects were divided into four study groups according to their SMI and SMD relative to median values.

RESULTS

One hundred forty men and forty-three women had NAFLD. Total SMI (odds ratio [OR] per 1.0 cm² /kg/m² increase 0.43, 95% confidence interval [CI] 0.29-0.64 in men and OR 0.21, 95% CI 0.10-0.42 in women) and total SMD (OR, per 1.0 Hounsfield Unit increase 0.88, 95% CI 0.83-0.93 in men and 0.88, 0.82-0.95 in women) were significantly associated with the prevalence of NAFLD after adjusting for covariates. The subgroup with simultaneous presence of low SMI and low SMD was associated with a significantly higher prevalence of NAFLD compared with other groups.

CONCLUSIONS

Both SMI and SMD are independently associated with the prevalence of NAFLD.

Network Modeling Approaches and Applications to Unravelling Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a progressive condition of the liver encompassing a range of pathologies including steatosis, non-alcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma. Research into this disease is imperative due to its rapid growth in prevalence, economic burden, and current lack of FDA approved therapies. NAFLD involves a highly complex etiology that calls for multi-tissue multi-omics network approaches to uncover the pathogenic genes and processes, diagnostic biomarkers, and potential therapeutic strategies. In this review, we first present a basic overview of disease pathogenesis, risk factors, and remaining knowledge gaps, followed by discussions of the need and concepts of multi-tissue multi-omics approaches, various network methodologies and application examples in NAFLD research. We highlight the findings that have been uncovered thus far including novel biomarkers, genes, and biological pathways involved in different stages of NAFLD, molecular connections between NAFLD and its comorbidities, mechanisms underpinning sex differences, and druggable targets. Lastly, we outline the future directions of implementing network approaches to further improve our understanding of NAFLD in order to guide diagnosis and therapeutics.

Beneficial and Deleterious Effects of Female Sex Hormones, Oral Contraceptives, and Phytoestrogens by Immunomodulation on the Liver

The liver is considered the laboratory of the human body because of its many metabolic processes. It accomplishes diverse activities as a mixed gland and is in continuous cross-talk with the endocrine system. Not only do hormones from the gastrointestinal tract that participate in digestion regulate the liver functions, but the sex hormones also exert a strong influence on this sexually dimorphic organ, via their receptors expressed in liver, in both health and disease. Besides, the liver modifies the actions of sex hormones through their metabolism and transport proteins. Given the anatomical position and physiological importance of liver, this organ is evidenced as an immune vigilante that mediates the systemic immune response, and, in turn, the immune system regulates the hepatic functions. Such feedback is performed by cytokines. Pro-inflammatory and anti-inflammatory cytokines are strongly involved in hepatic homeostasis and in pathological states; indeed, female sex hormones, oral contraceptives, and phytoestrogens have immunomodulatory effects in the liver and the whole organism. To analyze the complex and interesting beneficial or deleterious effects of these drugs by their immunomodulatory actions in the liver can provide the basis for either their pharmacological use in therapeutic treatments or to avoid their intake in some diseases.

The relationship between nonalcoholic fatty liver disease and pediatric congenital hypothyroidism patients

Previous studies have shown hypothyroidism was independently associated with nonalcoholic fatty liver disease (NAFLD) in adults, but few studies examined their relationships in pediatric populations. This study aimed to investigate the prevalence of NAFLD in pediatric congenital hypothyroidism (CHT) patients and to identify the association between CHT and NAFLD. This study enrolled pediatric CHT patients receiving levothyroxine treatment at one medical center from 2013 to 2014. Euthyroid subjects (ET) and transient hypothyroidism (THT) patients weaned off medication successfully after age 3 were selected for further comparison. Laboratory data including thyroid functions, liver functions, and metabolic profiles were obtained. The major outcome was the occurrence of NAFLD, diagnosed based on the findings of abdominal ultrasonography. One-hundred and twenty-nine subjects (47 in CHT, 47 in THT, and 35 in ET groups) were enrolled. The analysis showed higher fasting serum glucose, insulin, thyroxine (T4), and mean thyroid-stimulating hormone (TSH) levels in the CHT group. NAFLD prevalence was higher in the CHT (23.4%) group than in the THT (8.5%) and the ET (5.7%) groups, demonstrating an increasing trend across three strata (X² _{linear-by-linear} = 5.9, P < .05). The multivariate regression analysis showed obesity (β-coefficient = 5.52, P < .05), CHT (β-coefficient = 2.92, P < .05) and mean TSH levels (β-coefficient = 0.24, P < .05) were independent risk factors for NAFLD. A positive correlation was found between TSH level and lipid profiles. CHT patients had higher risk of NAFLD despite treatment being initiated early in life. Close monitoring of metabolic profiles is warranted. Further research should examine ways to optimize the treatment for CHT patients in terms of prevention against NAFLD.

NAFLD in Some Common Endocrine Diseases: Prevalence, Pathophysiology, and Principles of Diagnosis and Management

Secondary nonalcoholic fatty liver disease (NAFLD) defines those complex pathophysiological and clinical consequences that ensue when the liver becomes an ectopic site of lipid storage owing to reasons other than its mutual association with the metabolic syndrome. Disorders affecting gonadal hormones, thyroid hormones, or growth hormones (GH) may cause secondary forms of NAFLD, which exhibit specific pathophysiologic features and, in theory, the possibility to receive an effective treatment. Here, we critically discuss epidemiological and pathophysiological features, as well as principles of diagnosis and management of some common endocrine diseases, such as polycystic ovary syndrome (PCOS), hypothyroidism, hypogonadism, and GH deficiency. Collectively, these forms of NAFLD secondary to specific endocrine derangements may be envisaged as a naturally occurring disease model of NAFLD in humans. Improved understanding of such endocrine secondary forms of NAFLD promises to disclose novel clinical associations and innovative therapeutic approaches, which may potentially be applied also to selected cases of primary NAFLD.

Tissue Changes in the Development of Fatty Liver by Chronic Ingestion of Sucrose Associated with Obesity and Dyslipidemia in Rats

A diet high in sucrose, which is a common food constituent, induces obesity and non- alcoholic fatty liver (NFLD) caused by high caloric intake; however, it is important to investigate those sequential changes in the hepatic parenchyma related to sugar consumption which are associated to obesity and dyslipidemia. We analyzed the effects of long-term sucrose intake on fatty liver development, by the administration of 30% sucrose in drinking water in healthy Wistar rats during 30 weeks. Serum variables, body fat index, caloric intake and microscopic examination of liver tissue were monitored. In the first week, grade 1 steatosis was observed with ballooned hepatocytes, with a caloric intake of 125 ± 1.90 kcal / day / 100 g of body weight; together with a gain of 71% in abdominal fat with respect to the control group and dyslipidemia. During the 10 to 20 weeks period, steatosis grade 2 with noticeable inflammation (steatohepatitis), polymorphic cells and ballooned hepatocytes were evident. After 10 weeks, the caloric intake was 72.9 ± 5.99 kcal / day / 100 g of body weight with 199% of gain in abdominal fat in SUC groups with respect control group (p < 0.01) and moderate dyslipidemia; while after 20 weeks, the caloric intake was 61.6 ± 4.65 kcal / day / 100 g of body weight with 208% of gain in abdominal fat and also moderate dyslipidemia. After 30 weeks steatosis grade 3 with marked inflammation (steatohepatitis), periportal fibrosis, globose and fat-filled hepatocytes were observed, with a caloric intake of 52.3 ± 3.05 kcal / day / 100 g of body weight and 232% of gain in abdominal fat that was related to severe dyslipidemia. In conclusion, the sequential changes in the development of NAFLD were associated with the ingestion of sucrose and obesity since the first week of administration.

IGF1 suppresses cholesterol accumulation in the liver of growth hormone-deficient mice via the activation of ABCA1

Recently, several clinical studies have suggested that adult growth hormone (GH) deficiency that also has low concentration of IGF1 is associated with an increased prevalence of fatty liver (FL). ATP-binding cassette transporter A1 (ABCA1) is a pivotal regulator of lipid efflux from cells to apolipoproteins and plays an important role on formation of FL. In this study, we determined the effects of IGF1 on ABCA1 expression in GH-deficient mice to clarify its effects on FL. Western blotting, real-time PCR, and a luciferase assay were employed to examine the effect of IGF1. The binding of FoxO1 to the ABCA1 promoter was assessed by chromatin immunoprecipitation (ChIP) assay. Cholesterol accumulation was analyzed by Oil Red O stain and cholesterol content measurement. We confirmed that IGF1 upregulated the ABCA1 expression. The activity of a reporter construct containing the ABCA1 promoter was induced by IGF1, and this effect was blocked by LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K). Constitutively active Akt stimulated the ABCA1 promoter activity, and a dominant-negative mutant of Akt or mutagenesis of the FoxO1 response element abolished the effect of IGF1. A ChIP assay indicated that FoxO1 mediated IGF1 transcriptional activity by directly binding to the ABCA1 promoter region. For in vivo experiments, we used an inhibitor for the GH receptor (Pegvisomant) to reduce the IGF1 level. A high-fat diet induced FL in mice (C57BL/6J) given Pegvisomant treatment. IGF1 treatment stimulated ABCA1 expression to improve cholesterol accumulation in these mice. These results show that the PI3K/Akt/FoxO1 pathway contributes to the regulation of ABCA1 expression in response to IGF1 stimulation that suppressed FL in GH-deficient mice.

Reduced expression of thyroid hormone receptor β in human nonalcoholic steatohepatitis

Hepatic thyroid hormone signaling has an important role in the development and progression of nonalcoholic steatohepatitis (NASH). While the systemic levels of thyroid hormone might remain stable, there is evidence that the intracellular signaling machinery consisting of transporters, deiodinases and receptors could be altered in NASH. However, clinical material from human liver biopsies of individuals with NASH has not been studied to date. In a cross-sectional study, we analyzed 85 liver biopsies from patients with different stages of NASH that underwent bariatric surgery. Using qPCR, we analyzed gene expression of thyroid hormone transporters NTCP (SLC10A1), MCT8 (SLC16A2) and OATP1C1 (SLCO1C1), thyroid hormone receptor α and β (THRA and THRB) and deiodinase type I, II and III (DIO1, DIO2, DIO3). The expression was correlated with serum TSH, triglyceride, HbA1c and NASH score and corrected for age or gender if required. While DIO2, DIO3 and SLCO1C1 were not expressed in human liver, we observed a significant negative correlation of THRB and DIO1 with age, and SLC16A2 with gender. THRB expression was also negatively associated with serum triglyceride levels and HbA1c. More importantly, its expression was inversely correlated with NASH score and further declined with age. Our data provide unique insight into the mRNA expression of thyroid hormone transporters, deiodinases and receptors in the human liver. The findings allow important conclusions on the intrahepatic mechanisms governing thyroid hormone action, indicating a possible tissue resistance to the circulating hormone in NASH, which becomes more prominent in advanced age.

mTOR Activation in Liver Tumors Is Associated with Metabolic Syndrome and Non-Alcoholic Steatohepatitis in Both Mouse Models and Humans

Non-alcoholic steatohepatitis (NASH) can cause liver fibrosis and cirrhosis, with final progression to hepatocellular carcinoma (HCC) in some cases. Various factors have been suggested to be involved in the development of NASH. Considering the many possible contributing factors, we postulated that mechanisms of progression from NASH to HCC could differ depending on the risk factors. In the present study, we applied two mouse models of NASH⁻HCC and performed histopathological and proteome analyses of mouse liver tumors. Furthermore, to compare the mechanisms of NASH⁻HCC progression in mice and humans, we investigated HCCs in humans with a background of metabolic syndrome and NASH, as well as HCCs associated with hepatitis virus infection by immunohistochemistry. It was demonstrated that upstream regulators associated with the mammalian target of rapamycin (mTOR) pathway were altered in liver tumors of mice with metabolic syndrome characteristics (TSOD mice) using proteome analysis. Immunohistochemical analysis showed that mTOR was characteristically phosphorylated in liver tumors of TSOD mice and HCCs from metabolic syndrome cases in humans. These results indicated that the mTOR pathway is characteristically activated in liver tumors with metabolic syndrome and NASH, unlike liver tumors with other etiologies.

Evaluation of Proinflammatory Cytokines in Obese vs Non-obese Patients with Metabolic Syndrome

BACKGROUND

Obesity is one of the most common yet neglected public health problems in both the developed and developing countries. Metabolic syndrome (MS) is a multiplex of risk factor for the development of type 2 diabetes (T2D) and cardiovascular disease (CVD) and it reflects the clustering of multiple risk factors resulting from obesity and insulin resistance. Despite its predominance in obese individuals, MS does occur in non-obese individuals. Many individuals characterised as normal weight as per their body mass index (BMI), have increased visceral adiposity thereby leading to an unfavourable inflammatory cytokine profile. There are limited studies from India with respect to inflammatory cytokines in obesity and MS in general and non-obese patients with MS in particular.

MATERIALS AND METHODS

An observational cross-sectional study was carried out in patients with MS with or without obesity. Anthropometric parameters such as height, weight and waist girth were measured and BMI was calculated. Serum levels of TNF-α, IL-6 and adiponectin were measured by using the enzyme-linked immunosorbent assay.

RESULTS

A significant proportion of individuals categorised as normal weight had an increased waist circumference which correlated with BMI, acanthosis nigricans (AN) and fatty liver. There was no statistically significant difference in the cytokine levels in obese and non-obese patients with MS; similarly among non-obese patients with MS, cytokine levels were comparable in patients with or without abdominal obesity. However, triglycerides inversely correlated with adiponectin levels and there was no significant correlation between the cytokines and other parameters of MS.

CONCLUSION

There was no significant difference in various metabolic and inflammatory parameters between obese and non-obese patients with MS. Even in non-obese group, there were no differences in metabolic and inflammatory markers between individuals with or without abdominal obesity. This finding indicates that apart from adipose tissue, other factors are also responsible for the development of MS and its associated proinflammatory profile. There could be a significant contribution of genetic and epigenetic factors which needs to be further explored.

Association between Thyroid-Stimulating Hormone Levels and Non-Alcoholic Fatty Liver Disease Is Not Independent from Metabolic Syndrome Criteria

INTRODUCTION

Thyroid hormones are involved in the regulation of body composition, lipid metabolism, and insulin resistance. Thus, it is possible that they might play a role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). However, the role of thyroid function on NAFLD is not well defined. In this study, we evaluated the relationship between thyroid-stimulating hormone (TSH) levels, within the reference range, and presence of NAFLD in asymptomatic individuals.

STUDY DESIGN

We included all individuals evaluated at a preventive clinic of the Hospital Israelita Albert Einstein, between 2014 and 2015. The prevalence of NAFLD (analyzed by abdominal ultrasound), according to TSH quartiles, within the reference range, was determined. The association between TSH quartiles and NAFLD was analyzed by logistic regression adjusted for possible confounders.

RESULTS

We evaluated 10,539 individuals (73% male, age 43.4 ± 9.4 years). The prevalence of NAFLD was 34, 38, 38, and 39% in the first to the fourth TSH quartiles (0.46-1.44, 1.45-1.97, 1.98-2.68, and 2.69-4.68 mUI/L, respectively, p for trend < 0.001). At univariate analysis, higher TSH levels were associated with the diagnosis of NAFLD. When data were adjusted for the metabolic syndrome characteristics (waist circumference, HDL-cholesterol and triglycerides levels, presence of diabetes, and systemic arterial hypertension), the association was no longer significant.

CONCLUSIONS

Although the TSH variability within the reference range is associated with NAFLD in univariable models, once adjusted for metabolic syndrome factors no significant association is noted.

Association Between Primary Hypothyroidism and Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

BACKGROUND

It is currently uncertain whether primary hypothyroidism is associated with nonalcoholic fatty liver disease (NAFLD). We performed a meta-analysis of relevant studies to quantify the magnitude of association between primary hypothyroidism and risk of NAFLD.

METHODS

We searched PubMed, Web of Science and Scopus databases from January 2000 to March 2018 using predefined keywords to identify observational cross-sectional, case-control, and longitudinal studies in which NAFLD was diagnosed by imaging or biopsy. Data from selected studies were extracted and meta-analysis was performed using random-effects modeling.

RESULTS

A total of 12 cross-sectional and 3 longitudinal studies enrolling 44,140 individuals were included in the final analysis. Hypothyroidism (defined either by self-reported history of hypothyroidism with use of levothyroxine replacement therapy or by presence of abnormal thyroid function tests) was associated with an increased risk of prevalent NAFLD (n = 12 studies; random-effects odds ratio 1.42 [95% confidence interval (CI) 1.15-1.77]; I² = 51.2%), independently of age, sex, body mass index and other common metabolic risk factors. The magnitude of risk paralleled the underlying severity of NAFLD histology (n = 3 studies; random-effects odds ratio 2.73 [CI 1.90-3.93]; I² = 0%), and tended to increase across the different definitions used for diagnosing hypothyroidism. Meta-analysis of data from the three longitudinal studies showed that subclinical hypothyroidism was not independently associated with risk of incident ultrasound-defined NAFLD over a median of 5 years (random-effects hazard ratio 1.29 [CI 0.89-1.86]; I² = 83.9%). Sensitivity analyses did not alter these findings. Funnel plot did not reveal significant publication bias.

CONCLUSIONS

This large and updated meta-analysis shows that the presence of variably defined hypothyroidism is significantly associated with the presence and severity of NAFLD. However, the observational design of the eligible studies does not allow for proving causality.

Clinical relevance of liver histopathology and different histological classifications of NASH in adults

Nonalcoholic fatty liver disease (NAFLD) encompasses simple steatosis and steatohepatitis (NASH) with or without fibrosis/cirrhosis and hepatocellular carcinoma. NAFLD occurs epidemically in most areas of the world, contributes to cardiovascular events and liver-related mortality and therefore exacts a major economic toll. Areas covered: Here we summarize what clinicians should know about NAFLD histopathology in adults. We report on the individual histological features and scoring systems of NAFLD: the NAFLD activity score (NAS) introduced by the NASH-Clinical Research Network, the 'Fatty Liver Inhibition of Progression' algorithm and Steatosis, Activity, and Fibrosis (SAF) score. Pros and cons of histological classifications in NASH are discussed. Special emphasis is given to liver histopathology in some high-risk patient groups, such as those with severe obesity and type 2 diabetes. Moreover, we also examine the relationship between liver histopathology and clinical features, and the impact of liver histopathology on the long-term prognosis of NAFLD. Finally, we propose an integrated diagnostic approach which utilizes both non-invasive tools and liver biopsy in those individual patients with suspected NAFLD. Expert commentary: Based on expert opinions, we conclude with a research agenda on NAFLD which focuses on the most burning topics to be addressed over the next five years.

Lower levels of dehydroepiandrosterone sulfate are associated with more advanced liver fibrosis in chronic hepatitis C

Chronic infection with the hepatitis C virus induces liver fibrosis, but it is unknown why some patients progress to advanced fibrosis while others remain with mild disease. Recently, an inverse association between serum levels of dehydroepiandrosterone sulphate (DHEA-S) and liver fibrosis in patients with nonalcoholic fatty liver disease was described, and it was postulated that dehydroepiandrosterone (DHEA) has antifibrotic effects. Our aim was to compare serum DHEA-S levels with liver fibrosis in hepatitis C patients. We collected serum samples from hepatitis C patients at the same day they underwent a liver biopsy. S-DHEA was compared to different stages of fibrosis. Binary logistic regression models were applied to evaluate independent variables associated to fibrosis. We included 287 patients (43.9% male). According to fibrosis stages 0, 1, 2, 3 and 4, median serum DHEA-S levels were 103 (26-462), 73 (5-391), 46 (4-425), 35 (6-292) and 28 (2-115) μg/dL, respectively (P < .001). Median serum DHEA-S levels were 74 (5-462) vs 36 (2-425) μg/dL for mild (F0-1) vs significant (F2-4) fibrosis, respectively (P < .001). Median serum DHEA-S levels were 64 (4-462) vs 31 (2-292) μg/dL for non advanced (F0-2) vs advanced fibrosis (F3-4), respectively (P < .001). The same association was found when the subgroup of HCV patients with and without steatosis or steatohepatitis was analysed. The association between lower DHEA-S levels and advanced fibrosis was independent of age, gender, diabetes mellitus, obesity and steatosis. Lower circulating DHEA-S levels are associated with more advanced stages of liver fibrosis in hepatitis C patients.

High regenerative capacity of the liver and irreversible injury of male reproductive system in carbon tetrachloride-induced liver fibrosis rat model

BACKGROUND

Liver fibrosis (LF) is a chronic disease, associated with many collateral diseases including reproductive dysfunction. Although the normal liver has a large regenerative capacity the complications of LF could be severe and irreversible. Hormone and sex-related issues of LF development and interactions with male reproductive have not been finally studied. The aim was to study the reproductive function of male rats in experimental CCl4-induced liver fibrosis rat model, and the capability for restoration of both the liver and male reproduction system.

MATERIALS

Studies were conducted on 20 3-month old Wistar male rats. The experimental animals were injected with freshly prepared 50% olive oil solution of carbohydrate tetrachloride (CCl4). On the 8th week after injection we noted the manifestations of liver fibrosis. The rats were left to self-healing of the liver for 8 weeks. All male rats underwent ultrasound and biopsy of the liver and testes on the 8th and 16th weeks. The male rats were mated with healthy females before CCl4 injection, after modeling LF on the 8th week, and after self-healing of the liver. Pregnancy was monitored on ultrasound.

RESULTS

On the 8th week of experiment we observed ultrasound manifestation of advanced liver fibrosis, including hepatosplenomegaly, portal hypertension. Ultrasound exam of the rat testes showed testicular degeneration, hydrocele, fibrosis, scarring, petrifications, size reduction, and restriction of testicular descent; testes size decreased from 1.24 ± 0.62 ml to 0.61 ± 0.13, p < 0.01. Liver histology showed granular dystrophy of hepatocytes, necrotic areas, lipid inclusions in parenchyma. Rats with liver fibrosis demonstrated severe injury of the reproductive system and altering of fertility: the offspring of male rats with advanced LF was 4.71 ± 0.53 born alive vs 9.55 ± 0.47 born from mating with healthy males, p < 0.001. Eight weeks after last CCl4 injection, we revealed signs of liver regeneration, significant recovery of its structure. The ALT and AST levels significantly decreased and reached background measurements. As a result of the second interbreeding after liver self-healing no significant difference was found vs previous mating.

CONCLUSION

Carbohydrate tetrachloride induces injury of liver parenchyma evoking fast and severe liver fibrosis, and is associated with irreversible structural and functional changes in testes, reducing fertility, decreasing potential pregnancy rate, and affecting its development. Liver showed high potential to regenerate, however the self-restoring after liver fibrosis was not accompanied with recovery of the reproductive system.

Impact of bariatric surgery on non-alcoholic fatty liver disease

Introduction; p to 300 million people have the body mass index (BMI) greater than 30 kg/m2. Obesity is the cause of many serious diseases, such as type 2 diabetes, hypertension, and non-alcoholic fatty liver disease (NAFLD). Bariatric surgery is the only effective method of achieving weight loss in patients with morbid obesity.

OBJECTIVES

The aim of the study was to assess the impact of bariatric surgery on non-alcoholic fatty liver disease in patients operated on due to morbid obesity.

MATERIAL AND METHODS

We included 20 patients who were qualified for bariatric procedures based on BMI &gt; 40 kg/ m2 or BMI &gt; 35kg/m2 with the presence of comorbidities. The average body weight in the group was 143.85kg, with an average BMI of 49.16kg/m2. Before the procedure, we evaluated the severity of non-alcoholic fatty liver disease in each patient using the Sheriff-Saadeh ultrasound scale. We also evaluated the levels of liver enzymes. Follow-up evaluation was performed twelve months after surgery.

RESULTS

Twelve months after surgery, the average weight was 102.34 kg. The mean %WL was 33.01%, %EWL was 58.8%, and %EBMIL was 61.37%. All patients showed remission of fatty liver disease. Liver damage, evaluated with ultrasound imaging, decreased from an average of 1.85 on the Sheriff-Saadeh scale, before surgery, to 0.15 twelve months after surgery (p &lt; 0.001). As regards liver enzymes, the level of alanine aminotransferase decreased from 64.5 (U/l) to 27.95 (U/l) (p &lt; 0.001), and the level of aspartate aminotransferase decreased from 54.4 (U/l) to 27.2 (U/l).

CONCLUSIONS

Bariatric procedures not only lead to a significant and lasting weight loss, but they also contribute to the reduction of fatty liver disease and improve liver function.