Gallstone disease in non-alcoholic fatty liver: prevalence and associated factors

Association between metabolic dysfunction associated steatotic liver disease and gallstones in the US population using propensity score matching

The novel diagnostic term Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) requires at least one cardiovascular risk factor for diagnosis. While the relationship between gallstones and Non-Alcoholic Fatty Liver Disease (NAFLD) has been debated, the association between MASLD and gallstones remains unclear. This cross-sectional study aimed to explore this relationship using National Health and Nutrition Examination Survey (NHANES) data from 2017 to 2020. Participants were stratified into two groups based on MASLD diagnosis, and propensity score matching (PSM) was employed to reduce biases. Of 15,560 participants, 7922 met the inclusion criteria, with 2697 (34.0%) diagnosed with MASLD. Gallstone prevalence was higher in the MASLD group (14.2%) compared to the non-MASLD group (8.5%). After PSM, 4536 participants were analyzed, revealing a significant association between MASLD and gallstones (OR = 1.30, 95% CI 1.09-1.56, P = 0.003). This association remained robust across crude and adjusted analyses, with subgroup and sensitivity analyses further supporting the findings. In conclusion, MASLD is significantly associated with an increased risk of gallstones in the US population. These findings highlight the need to consider this relationship in clinical strategies for prevention and management of gallstone disease.

Leptin/Melanocortin Pathway in Cholelithiasis Patients: A Diagnostic Perspective

BACKGROUND

Cholelithiasis is the most prevalent inflammatory condition of the gallbladder. The regulation of biological processes, including energy homeostasis, and control of body weight are key mechanisms that the leptin and melanocortin pathways play a role in Cholelithiasis is the most prevalent inflammatory condition of the gallbladder. There are various risk factors for the development of gallstone disease, especially weight gain, and obesity is just one of them. This risk factor can be minimized by maintaining appetite and energy balance. Here, leptin and melanocortin pathways are the key mechanisms in maintaining appetite and energy homeostasis.

OBJECTIVES

The aim of this study was to investigate the relationship between the levels of LEP, LEPR, TrkB, BDNF, POMC, and MC4R proteins in patients with Cholelithiasis. This study aims to determine the relationship between LEP, LEPR, TrkB, BDNF, POMC, and MC4R protein levels, which play a role in maintaining appetite and energy homeostasis, and cholelithiasis.

METHODS

This study examined 44 patients diagnosed with Cholelithiasis and 44 healthy control subjects who had not previously been diagnosed with any form of Cholelithiasis. The levels of leptin (LEP), Leptin Binds To Leptin Receptors (LEPR), Tropomyosin Receptor Kinase B (TrkB), Brain-Derived Neurotrophic Factor (BDNF), Pro-OpioMelanoCortin (POMC), and Melanocortin- 4 Receptors (MC4R) molecules were analyzed using the Enzyme-Linked Immunosorbent Assay (ELISA) method. The results were analyzed using the SPSS Software (Version 22.0) program and GraphPad Prism 8.0.1 software.

RESULTS

The study found a statistically significant decrease (p < 0.05) in MC4R, TrkB, BDNF, and POMC protein levels in Cholelithiasis patients compared to the control group. There was no statistically significant difference in LEP and LEPR concentration values between the two groups (p = 0.247, p = 0.674).

CONCLUSION

The proteins MC4R, TrkB, BDNF, and POMC, which are involved in the leptin and melanocortin pathways may play a significant role in Cholelithiasis disease. However, more detailed research on the relevant proteins is needed. Nevertheless, this research will guide new studies.

Gallstones increase the risk of nonalcoholic fatty liver: A case-control study

Background

Nonalcoholic fatty liver disease (NAFLD) and gallstones are generally seen together, and many of the risk factors for fatty liver and gallstones are common and similar. Therefore, this study aims to investigate the relationship between NAFLD and gallstones.

Methods

This case-control study was conducted in patients referred to Imam Khomeini and Golestan hospitals of Ahvaz University of Medical Sciences in 2023, whose ultrasound showed fatty liver. Patients who were diagnosed with NAFLD by ultrasound were considered as the case group, and patients who did not have diagnostic findings of fatty liver in ultrasound were considered as the control group. Finally, the information recorded in the checklists was statistically analyzed using SPSS version 26 (SPSS Inc.).

Results

Three hundred patients were included in our study, 150 as cases and 150 as controls. There was no significant difference between the groups in terms of gender and age (gender P-value: 0.817/age P-value: 0.102). A statistically significant relationship was found between obesity, diabetes mellitus (DM), the presence of gallstones, and NAFLD (weight p-value < 0.001/DM p-value < 0.001/gallstones P-value: 0.03). In addition, based on binary logistic regression analysis, the presence of gallstones increases the odds of NAFLD by 2.33 times (P-value: 0.035). Furthermore, having DM and increasing each BMI unit increases the odds of NAFLD by 16 times and 30%, respectively (BMI p-value < 0.001/DM p-value < 0.001).

Conclusion

Based on the results of our study, gallstones are an important risk factor for NAFLD. The possible mechanisms are the existence of common risk factors between gallstones and NAFLD and the reduction of motility and flow of bile in the bile ducts with the presence of gallstones.

Predictive Models for Non-Alcoholic Fatty Liver Disease Diagnosis in Mexican Patients with Gallstone Disease: Sex-Specific Insights

(1) Background: Evidence regarding Non-Alcoholic Fatty Liver Disease (NAFLD) diagnosis is limited in the context of patients with gallstone disease (GD). This study aimed to assess the predictive potential of conventional clinical and biochemical variables as combined models for diagnosing NAFLD in patients with GD. (2) Methods: A cross-sectional study including 239 patients with GD and NAFLD diagnosed by ultrasonography who underwent laparoscopic cholecystectomy and liver biopsy was conducted. Previous clinical indices were also determined. Predictive models for the presence of NAFLD stratified by biological sex were obtained through binary logistic regression and sensitivity analyses were performed. (3) Results: For women, the model included total cholesterol (TC), age and alanine aminotransferase (ALT) and showed an area under receiver operating characteristic curve (AUC) of 0.727 (p < 0.001), sensitivity of 0.831 and a specificity of 0.517. For men, the model included TC, body mass index (BMI) and aspartate aminotransferase (AST), had an AUC of 0.898 (p < 0.001), sensitivity of 0.917 and specificity of 0.818. In both sexes, the diagnostic performance of the designed equations was superior to the previous indices. (4) Conclusions: These models have the potential to offer valuable guidance to healthcare providers in clinical decision-making, enabling them to achieve optimal outcomes for each patient.

Is hyperleptinemia associated with gallstone disease? A systematic review and meta-analysis

BACKGROUND

Obesity is one of the risk factors for gallstone disease (GD). Leptin hormone is known to regulate central obesity. Thus, hyperleptinemia may also be involved in gallstone disease pathogenesis. In the present study, a meta-analysis was performed to compare the leptin levels in GD and controls.

METHODS

The authors reviewed studies till April 12, 2021, which reported the serum leptin levels in gallstone patients and healthy controls. The online search involved ScienceDirect and PubMed databases. The data obtained from the research articles was scrutinized for selection criteria. Only those articles which fulfilled the inclusion criteria were subjected to meta-analysis.

RESULTS

Of 2047 articles, a total of eight studies met the inclusion and exclusion criteria and were considered for the meta-analysis. After meta-analysis, it was observed that the patients with GD  had high leptin levels as compared to healthy controls. A significant level of heterogeneity was observed in the included studies (I2 = 89%, p < 0.01). There was no publication bias.

CONCLUSION

High leptin levels might be involved in GD pathogenesis.

Elevated Serum Low-Density Lipoproteins-Cholesterol Levels and B1B2/B2B2 CETP Genotype Are Positively Associated with Nonalcoholic Fatty Liver Disease in Women with Gallstone Disease

Background: Nonalcoholic fatty liver disease (NAFLD) is generated by the interaction between environmental and genetic factors, and the presence of metabolic alterations. Since Taq1B cholesteryl ester transfer protein (CETP) polymorphism is associated with abnormal serum lipid values, it could be related to NAFLD. The aim of this study was to determine the role of the Taq1B CETP polymorphism with serum lipids, anthropometric variables, and the extent of steatosis in Mexican-mestizo women with gallstone disease (GD). Methods: Sixty-two women were enrolled in this cross-sectional study. Serum lipids were determined by dry chemistry. The Taq1B CETP polymorphism was determined by allelic discrimination. CETP serum levels were measured by enzyme-linked immunosorbent assay, and the extent of steatosis with a biopsy staining with Oil-Red-O. Results: Subjects with the B1B2/B2B2 genotype had higher percentage of degree of steatosis than those with B1B1 (11.95% vs. 2.19%, P = 0.008). The B1B2/B2B2 genotype (odds ratio [OR] 3.90 [confidence interval {CI} 95% 1.891-8.536], P = 0.04) and an elevated low-density lipoproteins (LDL)-cholesterol (OR 3.54 [CI 95% 1.042-2.058, P = 0.039) significantly increase the risk for NAFLD. Conclusions: This study provides evidence that the B1B2/B2B2 genotype of CETP and the elevated LDL-cholesterol serum levels increase the risk of NAFLD in women with GD.

Complex impacts of gallstone disease on metabolic syndrome and nonalcoholic fatty liver disease

BACKGROUND

Patients with gallstone disease (GSD) often have highly co-occurrence with metabolic syndrome (MetS) and Nonalcoholic fatty liver disease (NAFLD) both associated with insulin resistance (IR). Meanwhile, highly prevalence of NAFLD was found in patients who received cholecystectomy. However, the associations of GSD with MetS, NAFLD is inconsistent in the published literature. And risk of cholecystectomy on NAFLD is unclear.

METHODS

We searched the Medline EMBASE and WOS databases for literature that met our study topic. To be specific, studies with focus on associations between GSD and MetS/NAFLD, and risk evaluation on cholecystectomy and NAFLD incidence were enrolled for further analysis. The random effect model was used to calculate the combined relative ratio (RR) and odds ratio (OR)and 95% confidence interval (CI).

RESULTS

Seven and six papers with focus on connections between GSD and NAFLD/MetS prevalence. Correspondingly, seven papers with focus on risk of cholecystectomy on NAFLD occurrence were also enrolled into meta-analysis. After pooling the results from individual study, patients with GSD had higher risk of MetS (OR:1.45, 95%CI: 1.23-1.67, I2 = 41.1%, P=0.165). Risk of GSD was increased by 52% in NAFLD patients (pooled OR:1.52, 95%CI:1.24-1.80). And about 32% of increment on NAFLD prevalence was observed in patients with GSD (pooled OR: 1.32, 95%CI:1.14-1.50). With regard to individual MetS components, patients with higher systolic blood pressure were more prone to develop GSD, with combined SMD of 0.29 (96%CI: 0.24-0.34, P<0.05). Dose-response analysis found the GSD incidence was significantly associated with increased body mass index (BMI) (pooled OR: 1.02, 95%CI:1.01-1.03) in linear trends. Patients who received cholecystectomy had a higher risk of post-operative NAFLD (OR:2.14, 95%CI: 1.43-2.85), P<0.05). And this impact was amplified in obese patients (OR: 2.51, 95%CI: 1.95-3.06, P<0.05).

CONCLUSION

Our results confirmed that controls on weight and blood pressure might be candidate therapeutic strategy for GSD prevention. And concerns should be raised on de-novo NAFLD after cholecystectomy.

Causal associations between changes in lipid profiles and risk of gallstone disease: a two-sample Mendelian randomization study

Background

Nonalcoholic fatty liver disease (NAFLD) has been linked to gallstone disease (GSD) in observational studies; however, the relationships between certain lipid profiles and GSD remain unclear.

Methods

We adopted a two-sample Mendelian randomization (MR) framework by applying different statistical methods to assess causalities between lipid profiles and GSD. We identified single-nucleotide polymorphisms (SNPs) for blood lipids and NAFLD from separate previous genome-wide association studies (GWASs).

Results

We retrieved GSD SNPs attributed to 10,520 cases and 361,194 controls and validated our estimates using GWAS summary data from UK Biobank. We also performed sex-stratified analyses. Based on the summary estimates of 41, 59, 35, and 2 SNPs for low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), triglycerides (TGs), and NAFLD, respectively, we found no evidence of a causal relationship between genetically-predicted lipid profiles and GSD. The odds ratios were 0.995 for LDLC [95% confidence interval (CI): 0.994-0.998] per 0.98 mmol/L, 0.999 for HDLC (95% CI: 0.996-1.003) per 0.41 mmol/L, 0.997 for TGs (95% CI: 0.994-1.001) per 1 mmol/L, and 0.993 for NAFLD (95% CI: 0.984-1.003). No evidence of associations between lipid profile s and GSD in validation MR analyses or the sex-stratification analyses was noted.

Conclusions

Genetically predicted hyperlipidemia or NAFLD is not causally associated with GSD.

A clinical overview of non-alcoholic fatty liver disease: A guide to diagnosis, the clinical features, and complications-What the non-specialist needs to know

Non-alcoholic fatty liver disease (NAFLD) has a rapidly rising prevalence worldwide and is the most common cause of liver disease in developed countries. In this article, we discuss the spectrum of disease of NAFLD with a focus on the earlier spectrum of the disease that is commonly encountered by non-specialists, as well as the hepatic and extra-hepatic associations of the disease. We discuss in detail the two common presentations of NAFLD, incidentally detected hepatic steatosis and asymptomatic raised liver enzymes, and provide an algorithm for management and continued to follow up for these patients. Considerations for the management of cardiovascular comorbidities in these patients are also discussed. Finally, we cover the topic of screening for NAFLD in high-risk populations.

Gallstone Disease in Cirrhosis-Pathogenesis and Management

Gallstones are more common in patients with cirrhosis of the liver, and the incidence increases with severity of liver disease. Pigment stones are the most frequent type of gallstones (GSs) in cirrhotics, and majority remain asymptomatic. Hepatitis C virus infection and nonalcoholic fatty liver disease are the underlying etiologies of liver diseases that most often associated with GSs. Multiple altered mechanisms in cirrhosis such as chronic hemolysis due to hypersplenism, reduced bile acid synthesis and transport, decreased cholesterol secretion, decreased apolipoprotein A-I and A-II secretion, gallbladder hypo-motility, autonomic dysfunction, and portal hypertension collectively lead to increased risk of lithogenesis. Asymptomatic GSs should be followed up closely and offered laparoscopic cholecystectomy once symptomatic in Child-Pugh class A and B patients. The model for the end-stage liver disease score is the best predictor of the outcome after cholecystectomy. In patients of Child-Pugh class C, conservative or minimally invasive approaches should be used to treat complications of GSs.

Gallstone disease and nonalcoholic fatty liver disease in patients with type 2 diabetes: a cross-sectional study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and gallstone disease (GSD) often coexist in the general population owing to shared risk factors. This study explored the relationship between NAFLD and GSD in patients with type 2 diabetes.

METHODS

We conducted a retrospective cross-sectional analysis of 4325 patients with type 2 diabetes. GSD and NAFLD were confirmed using ultrasonography. GSD was defined as either asymptomatic gallstones or previous cholecystectomy, and each was analyzed separately.

RESULT

There was no significant difference in the prevalence of GSD between patients with and without NAFLD (23.8% vs. 21.2%, P = 0.15). After case-control matching (1:1) of baseline data such as age, sex, duration of diabetes, and HbA1c between patients with and without NAFLD, there was still no significant difference in the prevalence of GSD (25.5% vs. 23.6%, P = 0.15). The prevalence of NAFLD in patients with asymptomatic gallstones was lower than that of patients without GSD (38.6% vs. 47.3%, P < 0.001), whereas the prevalence in those who had undergone cholecystectomy was much higher (61.2% vs. 47.3%, P < 0.001). The ratio of cholecystectomy to asymptomatic gallstone in patients with or without NAFLD was 1.97 and 0.79, respectively. The rate of cholecystectomy was higher in the patients with NAFLD than in those without NAFLD (15.8% vs. 9.3%, P < 0.001), consistent with the result after case-control matching (17.3% vs. 11.2%, P < 0.001). Multivariate logistic regression analysis, after adjusting for numerous potential confounding factors, revealed that GSD (OR = 1.241, 95%CI: 1.036-1.488, P = 0.002) and cholecystectomy (OR = 1.946, 95%CI: 1.546-2.445, P < 0.001) were both strongly associated with NAFLD. However, asymptomatic gallstone (OR = 0.663, 95%CI: 0.513-0.856, P = 0.002) seemed to be negatively correlated with NAFLD.

CONCLUSIONS

The prevalence of GSD was similar in patients with type 2 diabetes with and without NAFLD. The higher proportion of cholecystectomy and lower proportion of asymptomatic gallstones in patients with NAFLD suggests that NAFLD may increase the risk of complications of GSD.

Functional gastrointestinal disorders. Overlap syndrome Clinical guidelines of the Russian Scientific Medical Society of Internal Medicine and Gastroenterological Scientific Society of Russia

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Pancreatobiliary manifestations of nonalcoholic fatty liver disease: a retrospective case-control multicenter study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has become a major cause of chronic liver disease. Several extrahepatic manifestations have been reported in relation to NAFLD. However, data regarding pancreatobiliary manifestation are scarce.

AIM

We aimed to explore the association of pancreatobiliary manifestation with NAFLD.

METHODS

A retrospective multicenter study that included all patients who underwent an endoscopic ultrasound performed for hepatobiliary indications and for whom the endosonographer reported on the presence or absence of fatty liver. The endoscopic ultrasound reports were reviewed and all pathological findings were reported.

RESULTS

Overall, 545 patients were included in the study, among them, 278 patients had fatty liver (group A) as compared to 267 who did not have (group B). The average age in group A was 64.5 ± 13.5 years vs. 61.2 ± 14.7 years in group B. Male sex constituted 49.6 and 58% in groups A and B, respectively. On multivariate analysis, fatty pancreas [odds ratio (OR) 4.02; P = 0.001], serous cystadenoma (SCA) (OR 5.1; P = 0.0009), mucinous cystadenoma (MCA) (OR 9.7; P = 0.005), side-branch intraductal papillary mucinous neoplasm (IPMN) (OR 2.76; P < 0.0001), mixed-type IPMN (OR 16.4; P = 0.0004), pancreatic neuroendocrine tumor (NET) (OR 8.76; P < 0.0001), gallbladder stones (OR 1.9; P = 0.02) and hilar lymphadenopathy (OR 6.8; P < 0.0001) were significantly higher among patients with NAFLD. After adjustment for fatty pancreas, the association remained significant for SCA (OR 3; P = 0.01), MCA (OR 4.6; P = 0.03), side-branch IPMN (OR 1.7; P = 0.02), mixed-type IPMN (OR 5.5; P = 0.01) and pancreatic NET (OR 4.5; P = 0.001).

CONCLUSION

Pancreatobiliary manifestations are common among patients with NAFLD. Assessment of these coexistent manifestations should be considered in the setting of patients with NAFLD.

The Asian Pacific Association for the Study of the Liver clinical practice guidelines for the diagnosis and management of metabolic associated fatty liver disease

Metabolic associated fatty liver disease (MAFLD) is the principal worldwide cause of liver disease and affects nearly a quarter of the global population. The objective of this work was to present the clinical practice guidelines of the Asian Pacific Association for the Study of the Liver (APASL) on MAFLD. The guidelines cover various aspects of MAFLD including its epidemiology, diagnosis, screening, assessment, and treatment. The document is intended for practical use and for setting the stage for advancing clinical practice, knowledge, and research of MAFLD in adults, with specific reference to special groups as necessary. The guidelines also seek to improve patient care and awareness of the disease and assist stakeholders in the decision-making process by providing evidence-based data. The guidelines take into consideration the burden of clinical management for the healthcare sector.

Cholecystectomy as a risk factor for non-alcoholic fatty liver disease development

BACKGROUND

Hepatic steatosis and gallstone disease are highly prevalent in the general population; the shared risk factors are age, ethnicity, obesity, insulin resistance, metabolic syndrome, atherosclerosis, risk of cardiovascular disease, and mortality. The presence of insulin resistance is the critical element in this association because it represents a crucial link between metabolic syndrome and non-alcoholic fatty liver disease, as well as a higher susceptibility to gallstone formation.

METHODS

An exhaustive search engine investigation of gallstone disease, cholecystectomy, and liver steatosis latest literature was made.

RESULTS

Clinical studies and systematic reviews suggest an association between gallstone disease, cholecystectomy, and hepatic steatosis.

CONCLUSION

The bidirectional relationship between liver steatosis and gallstone disease and cholecystectomy is summarized in the role of insulin resistance, lipid metabolism, bile acids signaling pathways regulated by transcription factors expression, and to the gallbladder physiological role; however, more epidemiological and experimental studies should be complemented.

[Clinical features of the comorbid course of non-alcoholic fatty liver disease and gallstone disease]

AIM

To determine the diagnostic value of clinical features of the comorbid course of non-alcoholic fatty liver disease (NAFLD) and gallstone disease (GD) to improve the effectiveness of patient management.

MATERIALS AND METHODS

183 patients with NAFLD were included into the open comparative study. The main group was represented by patients with NAFLD and GD (n=88), of which 53 patients underwent cholecystectomy (CE). The comparison group was represented by patients with NAFLD without GD (n=95). A standard laboratory and instrumental examinations were performed, including elastometry to assess of the stage of liver fibrosis.

RESULTS

There were more women in the main group (2=8.48; p0.01). There were positive correlations between the age of patients and the duration of NAFLD with the presence of GD and CE (rs=0.135; p0.01 and rs=0.168; p0.01 respectively). Patients of the main group had the general weakness and fatigue (2=11.33, rs=0.234; p0.01 and 2=15.68, rs=0.281; p0.01 respectively), as well as a bitter taste in the mouth (2=11.66; p0.01; rs=0.147; p0.01). Coronary heart disease was diagnosed more often among people suffering from NAFLD and GD (25% vs 9.47% in patients of the comparison group, p0.01). Both of NAFLD and GD were associated with the development of type 2 diabetes (rs=0.164; p0.01). Individuals suffering from GD after CE had higher LDL and GGT values (rs=0.228; p0.01 and rs=0.298; p0.01 respectively). The number of people with advanced fibrosis were significantly higher (26.31%) in the GD group, especially among people after CE (30.18%). The stage of liver fibrosis had a positive significant relationship with CE (rs=0.366; p0.01).

CONCLUSION

Patients suffering from GD and NAFLD had a symptom of dyspepsia and general weakness. High prevalence of type 2 diabetes and сoronary heart disease, high level of LDL and GGT were found in patients with GD and after CE. CE in patients suffering from GD and NAFLD was associated with the formation of progressive stages of liver fibrosis.

Physical Activity Modulating Lipid Metabolism in Gallbladder Diseases

Physical activity encompasses a series of overall benefits on cardiovascular health and metabolic disorders. Research has recently focused on the hepatobiliary tract, as an additional target of the health-related outcomes of different types of physical exercise. Here, we focus on the global features of physical activity with respect to exercise modality and intensity, and on studies linking physical activity to lipid metabolism, gallbladder diseases (gallstones, symptoms, complications and health-related quality of life), gallbladder motor-function, enterohepatic circulation of bile acids, and systemic metabolic inflammation. Additional studies need to unravel the pathophysiological mechanisms involved in both beneficial and harmful effects of physical activity in populations with different metabolic conditions.

Fatty liver increases gallstone disease risk in younger Chinese patients

We investigated possible associations between fatty liver and gallstone disease (GD) in a Chinese population.This cross-sectional study included 897 people who visited the clinical center and underwent ultrasonography at The First Hospital of Jilin University between January 2018 and June 2018.The overall prevalence of GD was 8.8%; the between-sex difference (9.3% in men, 8.4% in women) was not statistically significant. The risk of GD was similar for men and women across all age groups. GD prevalence increased steadily with increasing age, from 2.1% in patients ≤30 years of age to 15.4% in those >70 years of age. Older age (≥50 years) and fatty liver were associated with GD development. Diabetes mellitus (adjusted odds ratio [AOR]: 3.066; 95% confidence interval [CI]: 1.563-6.013) was associated with GD in female but not in male subjects. In younger patients (<50 years), fatty liver (AOR: 5.268; 95% CI: 1.832-15.147) was associated with GD development.The factors older age and fatty liver predicted GD risk in Chinese individuals. Further studies are required to explore differences in lithogenesis according to sex.

Clinical and Pathogenetic Parallels of Nonalcoholic Fatty Liver Disease and Gallstone Disease

Aim:to analyze the data that has so far been accumulated on the pathogenetic association of gallstone disease (GD) and non-alcoholic fatty liver disease (NAFLD), as well as to assess the effect of cholecystectomy on the NAFLD course.

Key findings.The relationship between GD and NAFLD is very complex and seems to be mutually aggravating. There is no doubt that there is an increased risk of GB in NAFLD patients, which is primarily associated with common pathogenetic mechanisms. These include central and peripheral insulin resistance, changes in the expression of transcription factors (liver X-receptor and farnesoid X-receptor) and the bile acid membrane receptors (TGR5). Conversely, the effect of GD on the NAFLD course is assumed, although the pathogenetic factors of this association are still unknown. In recent years, convincing data has emerged concerning the role of cholecystectomy in the NAFLD progression, which may be connected with the development of small intestinal bacterial overgrowth, as well as with the disruption of the endocrine balance and the signal function of bile acids.

Conclusion.The connection between NAFLD, GD and cholecystectomy is complex and multifaceted. The study of this connection will allow new methods of treatment to be developed.

Bidirectional Association between Nonalcoholic Fatty Liver Disease and Gallstone Disease: A Cohort Study

Nonalcoholic fatty liver disease (NAFLD) and gallstone disease (GD) are often found to coexist but the sequential relationship of NAFLD and GD to each other remains controversial. We prospectively evaluated the bidirectional relationship of NAFLD with GD. A cohort study was performed on Korean adults who underwent a health checkup and were followed annually or biennially for a mean of 6.0 years. Fatty liver and gallstones were diagnosed by ultrasound. NAFLD was defined as hepatic steatosis on ultrasonography in the absence of excessive alcohol use or other identifiable causes. The NAFLD severity was determined by non-invasive fibrosis markers. Among 283,446 participants without either gallstones or cholecystectomy at baseline, 6440 participants developed gallstones. Among 219,641 participants without NAFLD at baseline, 49,301 participants developed NAFLD. The multivariable-adjusted hazard ratio (95% confidence interval) for incident gallstone comparing the NAFLD group vs. the non-NAFLD group was 1.26 (1.17–1.35). Increased non-invasive fibrosis markers of NAFLD were positively associated with an increased incidence of gallstones in a graded and dose-responsive manner (p-trend < 0.01). The multivariable-adjusted hazard ratios (95% confidence intervals) for incident NAFLD comparing gallstone and cholecystectomy to no GD were 1.14 (1.07–1.22) and 1.17 (1.03–1.33), respectively. This large-scale cohort study of young and middle-aged individuals demonstrated a bidirectional association between NAFLD and GD. NAFLD and its severity were independently associated with an increased incidence of gallstones, while GD and cholecystectomy were also associated with incident NAFLD. Our findings indicate that the conditions may affect each other, requiring further studies to elucidate the potential mechanisms underlying this association.

Exercising the hepatobiliary-gut axis. The impact of physical activity performance

BACKGROUND

Physical inactivity puts the populations at risk of several health problems, while regular physical activity brings beneficial effects on cardiovascular disease, mortality and other health outcomes, including obesity, glycaemic control and insulin resistance. The hepatobiliary tract is greatly involved in several metabolic aspects which include digestion and absorption of nutrients in concert with intestinal motility, bile acid secretion and flow across the enterohepatic circulation and intestinal microbiota. Several metabolic abnormalities, including nonalcoholic fatty liver as well as cholesterol cholelithiasis, represent two conditions explained by changes of the aforementioned pathways.

MATERIALS AND METHODS

This review defines different training modalities and discusses the effects of physical activity in two metabolic disorders, that is nonalcoholic fatty liver disease (NAFLD) and cholelithiasis. Emphasis is given to pathogenic mechanisms involving intestinal bile acids, microbiota and inflammatory status.

RESULTS

A full definition of physical activity includes the knowledge of aerobic and endurance exercise, metabolic equivalent tasks, duration, frequency and intensity, beneficial and harmful effects. Physical activity influences the hepatobiliary-gut axis at different levels and brings benefits to fat distribution, liver fat and gallbladder disease while interacting with bile acids as signalling molecules, intestinal microbiota and inflammatory changes in the body.

CONCLUSIONS

Several beneficial effects of physical activity are anticipated on metabolic disorders linking liver steatosis, gallstone disease, gut motility, enterohepatic circulation of signalling bile acids in relation to intestinal microbiota and inflammatory changes.

Hypoxic Signaling and Cholesterol Lipotoxicity in Fatty Liver Disease Progression

Cholesterol is the only lipid whose absorption in the gastrointestinal tract is limited by gate-keeping transporters and efflux mechanisms, preventing its rapid absorption and accumulation in the liver and blood vessels. In this review, I explored the current data regarding cholesterol accumulation in liver cells and key mechanisms in cholesterol-induced fatty liver disease associated with the activation of deleterious hypoxic and nitric oxide signal transduction pathways. Although nonalcoholic fatty liver disease (NAFLD) affects both obese and nonobese individuals, the mechanism of NAFLD progression in lean individuals with healthy metabolism is puzzling. Lean NAFLD individuals exhibit normal metabolic responses, implying that liver damage is not associated with impaired metabolism per se and that direct lipotoxic effects are crucial for disease progression. Several redox and oxidant signaling pathways involving cholesterol are at play in fatty liver disease development. These include impairment of the mitochondrial and lysosomal function by cholesterol loading of the inner-cell membranes; formation of cholesterol crystals and hepatocyte degradation; and crown-like structures surrounding degrading hepatocytes, activating Kupffer cells, and evoking inflammation. The current review focuses on the induction of liver inflammation, fibrosis, and steatosis by free cholesterol via the hypoxia-inducible factor 1α (HIF-1α), a main oxygen-sensing transcription factor involved in all stages of NAFLD. Cholesterol loading in hepatocytes can result in chronic HIF-1α activity because of the decreased oxygen availability and excessive production of nitric oxide and mitochondrial reactive oxygen species.

Cholelithiasis and choledocholithiasis in children; risk factors for development

PURPOSE

To compare anthropometric data (body mass index [BMI]) in patients without lithiasis to patients with symptomatic simple cholelithiasis or choledocholithiasis.

METHODS

We retrospectively reviewed data from 147 patients undergoing laparoscopic cholecystectomy between 2001-2015. Complete growth data from 98 patients was compared with anthropometric data from the population of the Czech Republic and a control group (BMI of 100 consecutive patients without biliary stones in abdominal ultrasound who were admitted to a surgical department for suspected appendicitis).

RESULTS

The BMI of 75 children with simple cholelithiasis and 23 with choledocholithiasis was compared to the standard Czech pediatric population and to the control group. The median age (simple cholelithiasis and choledocholithiasis) was 16 years, and 35 patients (24%) had a family history of gallstones. Types of lithiasis included multiple (n = 120), solitary (n = 11), and sludge (n = 10). Five cases had polyps and one had gallbladder dysplasia. Patients with simple cholelithiasis had significantly higher BMI compared to the control group without cholelithiasis (p<0.0001) and the standard Czech population (p = 0.03). Patients with choledocholithiasis had a mean BMI significantly higher than that of the general population (p = 0.001) and the control group (p = 0.0001). Patients with choledocholithiasis had significantly higher BMI than those with simple cholelithiasis (p = 0.03).

CONCLUSION

Patients with cholelithiasis had significantly higher BMI than the general population, and patients with choledocholithiasis had significantly higher BMI than patients with simple lithiasis. Elevated BMI is a risk factor for developing choledocholithiasis. ERCP and early laparoscopic cholecystectomy in patients with choledocholithiasis offer equivalent outcomes in patients with simple cholelithiasis.

Mouse models of gallstone disease

PURPOSE OF REVIEW

The establishment of mouse models of gallstones, and the contribution of mouse models to genetic studies of gallstone disease, as well as the latest advances in the pathophysiology of gallstones from mouse experiments are summarized.

RECENT FINDINGS

The combined uses of genomic strategies and phenotypic studies in mice have successfully led to the identification of many Lith genes, which pave the way for the discovery of human LITH genes. The physical-chemical, genetic, and molecular biological studies of gallstone disease in mice with knockout or transgene of specific target genes have provided many novel insights into the complex pathophysiological mechanisms of this very common hepatobiliary disease worldwide, showing that interactions of five primary defects play a critical role in the pathogenesis of cholesterol gallstones. Based on mouse studies, a new concept has been proposed that hepatic hypersecretion of biliary cholesterol is induced by multiple Lith genes, with insulin resistance as part of the metabolic syndrome interacting with cholelithogenic environmental factors to cause the phenotype.

SUMMARY

The mouse model of gallstones is crucial for elucidating the physical-chemical and genetic mechanisms of cholesterol crystallization and gallstone formation, which greatly increase our understanding of the pathogenesis of this disease in humans.

Nonalcoholic fatty liver disease, cholesterol gallstones, and cholecystectomy: new insights on a complex relationship

PURPOSE OF REVIEW

Gallstone disease (GSD) and nonalcoholic fatty liver disease (NAFLD often coexist in a given patient and both conditions are associated to obesity and insulin resistance. The relationship between GSD and NAFLD is complex and bidirectional. In the present review, we summarize the existing information on the complex link between GSD and NAFLD and the potential implications for patient care.

RECENT FINDINGS

Several clinical studies and systematic reviews have addressed the association between NAFLD and GSD underscoring that NAFLD is an independent risk factor for GSD. Conversely, GSD has been found also to be an independent risk factor for NAFLD with GSD potentially being linked to greater disease severity. In addition to the data showing association of NAFLD and GSD, recent evidence has also showed that cholecystectomy may itself be a risk factor for NAFLD development. The complex and bidirectional relationship between these diseases is partially explained by a number of common pathogenic links but the precise underlying mechanisms of the association of GSD and NAFLD need to be better delineated. Also, although the mechanisms of the promotional effect of cholecystectomy on NAFLD development are unknown, recent findings unveiling new aspects of gallbladder physiology and endocrine actions of bile acids provide a framework to advance research in this field.

SUMMARY

In this review, we address the different aspects of the complex association between NAFLD and GSD. The potential underlying mechanisms and recent information on endocrine actions of bile acids and the gallbladder are reviewed.

Nonalcoholic fatty liver was associated with asymptomatic gallstones in a Chinese population

The aim of this study was to determine the association between nonalcoholic fatty liver disease (NAFLD) and asymptomatic gallstones in a Chinese population.The study had a cross-sectional design and enrolled 7583 subjects who visited the physical check-up center at Sir Run Run Shaw Hospital between 2009 and 2011. Colorimetric methods were used to measure the levels of cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), whereas fasting plasma glucose (FPG) level was measured using a dextrose-oxidizing enzyme method. Subjects who completed a questionnaire and underwent a medical and ultrasound examinations were included in the study.The prevalence of NAFLD was significantly higher in patients with asymptomatic gallstones than in those without asymptomatic gallstones (58.98% vs 46.58%, respectively; P < .0001). The age-adjusted odds ratio (OR) for NAFLD being accompanied by asymptomatic gallstones was 1.35 [95% confidence interval (CI), 1.13-1.61; P = .0009] in male and 1.92 (95% CI, 1.45-2.54; P < .0001) in female subjects. Asymptomatic gallstones were associated with NAFLD in subjects aged < 50 years (OR = 1.74, 95% CI, 1.44-2.12; P < .0001), but not in subjects aged > 50 years (OR = 1.17, 95% CI, 0.92-1.48; P = .2040). The OR of NAFLD for asymptomatic gallstones was 1.28 after multivariate logistic regression analysis (95% CI, 1.07-1.52; P = .006).Our results indicated that asymptomatic gallstones are strongly associated with NAFLD in the Chinese study population.

Activation of the Hypoxia Inducible Factor 1α Subunit Pathway in Steatotic Liver Contributes to Formation of Cholesterol Gallstones

BACKGROUND & AIMS

Hypoxia-inducible factor 1α subunit (HIF1A) is a transcription factor that controls the cellular response to hypoxia and is activated in hepatocytes of patients with nonalcoholic fatty liver disease (NAFLD). NAFLD increases the risk for cholesterol gallstone disease by unclear mechanisms. We studied the relationship between HIF1A and gallstone formation associated with liver steatosis.

METHODS

We performed studies with mice with inducible disruption of Hif1a in hepatocytes via a Cre adenoviral vector (inducible hepatocyte-selective HIF1A knockout [iH-HIFKO] mice), and mice without disruption of Hif1a (control mice). Mice were fed a diet rich in cholesterol and cholate for 1 or 2 weeks; gallbladders were collected and the number of gallstones was determined. Livers and biliary tissues were analyzed by histology, quantitative reverse-transcription polymerase chain reaction, immunohistochemistry, and immunoblots. We measured concentrations of bile acid, cholesterol, and phospholipid in bile and rates of bile flow. Primary hepatocytes and cholangiocytes were isolated and analyzed. HIF1A was knocked down in Hepa1-6 cells with small interfering RNAs. Liver biopsy samples from patients with NAFLD, with or without gallstones, were analyzed by quantitative reverse-transcription polymerase chain reaction.

RESULTS

Control mice fed a diet rich in cholesterol and cholate developed liver steatosis with hypoxia; levels of HIF1A protein were increased in hepatocytes around central veins and 90% of mice developed cholesterol gallstones. Only 20% of the iH-HIFKO mice developed cholesterol gallstones. In iH-HIFKO mice, the biliary lipid concentration was reduced by 36%, compared with control mice, and bile flow was increased by 35%. We observed increased water secretion from hepatocytes into bile canaliculi to mediate these effects, resulting in suppression of cholelithogenesis. Hepatic expression of aquaporin 8 (AQP8) protein was 1.5-fold higher in iH-HIFKO mice than in control mice. Under hypoxic conditions, cultured hepatocytes increased expression of Hif1a, Hmox1, and Vegfa messenger RNAs (mRNAs), and down-regulated expression of AQP8 mRNA and protein; AQP8 down-regulation was not observed in cells with knockdown of HIF1A. iH-HIFKO mice had reduced inflammation and mucin deposition in the gallbladder compared with control mice. Liver tissues from patients with NAFLD with gallstones had increased levels of HIF1A, HMOX1, and VEGFA mRNAs, compared with livers from patients with NAFLD without gallstones.

CONCLUSIONS

In steatotic livers of mice, hypoxia up-regulates expression of HIF1A, which reduces expression of AQP8 and concentrates biliary lipids via suppression of water secretion from hepatocytes. This promotes cholesterol gallstone formation. Livers from patients with NAFLD and gallstones express higher levels of HIF1A than livers from patients with NAFLD without gallstones.

PPAR-γ agonist ameliorates liver pathology accompanied by increasing regulatory B and T cells in high-fat-diet mice

OBJECTIVE

Peroxisome proliferator-activated receptor (PPAR)-γ plays critical roles in human metabolic disorders. However, the mechanism remains incompletely understood. Regulatory cells contribute to these metabolic improvements; therefore, whether PPAR-γ agonist regulates regulatory cells was investigated.

METHODS

C57BL/6J mice received a normal or high-fat diet (HFD) with or without pioglitazone treatment. Mice were sacrificed for detecting the metabolic parameters. Lymphocytes from spleen and visceral adipose tissue (VAT) were collected and analyzed for ST2⁺ Tregs and Bregs by flow cytometry. IL-10 in the liver or VAT was detected by immunofluorescence and ELISA. Correlation analysis between IL-10 and liver weight or serum total cholesterol was made by Pearson correlation analysis.

RESULTS

Pioglitazone increased VAT weight but reduced serum total cholesterol, hepatic steatosis, and cholesterol crystallization formation. Pioglitazone treatment enhanced ST2⁺ Tregs and Bregs in the VAT and spleen of HFD-fed mice (all P < 0.05). Pioglitazone treatment increased IL-10 in the livers or VAT of HFD-fed mice (all P < 0.05). The expression of IL-10 in the liver was significantly negatively correlated with liver weight or serum total cholesterol in pioglitazone-treated HFD-fed mice (r²  = 0.74, P < 0.05; r²  = 0.58, P < 0.05).

CONCLUSIONS

PPAR-γ signaling plays a critical role in the regulation of metabolic disorders through promoting regulatory cell response.

Clinical features and natural history of cryptogenic cirrhosis compared to hepatitis C virus-related cirrhosis

AIM

To characterize natural history of cryptogenic cirrhosis (CC) and compare its clinical features and outcomes to those of hepatitis C virus (HCV)-related cirrhosis.

METHODS

A prospective cohort of 102 consecutive patients at their first diagnosis of CC were enrolled in this study. The clinical data and outcomes were compared to an age- and Child-Pugh class-matched cohort of 110 patients with HCV-related cirrhosis. Diagnosis of cirrhosis was based on compatible clinical and laboratory parameters, ultrasound/endoscopic parameters and, whenever possible, on histological grounds and transient elastography. All cases of cirrhosis without a definite etiology were enrolled in the CC group. The parameters assessed were: (1) severity of liver disease at the time of first diagnosis; (2) liver decompensation during follow-up; (3) hepatocellular carcinoma (HCC); (4) orthotopic liver transplantation; and (5) death. The independent associated factors were evaluated by multiple logistic regression analysis, and survival and its determinants by the Kaplan-Meier model, log-rank test and Cox regression.

RESULTS

At the first observation, median age was 66 and 65 years and male gender was 36% and 58% for CC and HCV cirrhosis, respectively. CC showed Child-Pugh class A/B/C of 47%/31%/22%, respectively. Compared to HCV cirrhosis, CC exhibited a significantly higher prevalence of metabolic syndrome (12% vs 54%, respectively), overweight/obesity, high BMI, impaired glucose tolerance, high blood pressure, dyslipidemia, hyperuricemia, cardiovascular diseases, extrahepatic cancer, and gallstones. Over a median period of 42 mo of follow-up, liver decompensation, HCC development and death for CC and HCV-related cirrhosis were 60.8%, and 54.4%, 16.7% and 17.2%, 39.2% and 30%, respectively. The median survival was 60 mo for CC. Independent predictors of death were age and Child-Pugh class at diagnosis. CC showed an approximately twofold higher incidence of HCC in Child-Pugh class A.

CONCLUSION

Undiagnosed nonalcoholic fatty liver disease has an etiologic role in CC that is associated with a poor prognosis, early HCC development, high risk of cardiovascular disease and extrahepatic cancer.

Cholecystectomy Causes Ultrasound Evidence of Increased Hepatic Steatosis

BACKGROUND

Cholecystectomy might contribute to the development of hepatic steatosis through metabolic changes. The biologic alteration of the enterohepatic circulation of bile acids and the alteration of the metabolic activity of bile acid that follows cholecystectomy may contribute to hepatic steatosis. This prospective study was conducted to clarify the possibility of steatosis development after cholecystectomy.

METHODS

From October 2013 to July 2014, 82 consecutive patients with a presumptive diagnosis of gallbladder disease were cholecystectomized. Liver parenchymal steatosis was measured using ultrasound and the hepatic steatosis index.

RESULTS

In all 82 patients, the hepatic steatosis index was found to be significantly correlated with the US fatty liver grade (Spearman's correlation r (2) = 0.331, P < 0.001). A total of 62 patients were followed up for 3 months. Comparison with the initial grade showed that 12 (18.5 %) patients had worsened from normal to mild (n = 10), from mild to moderate (n = 1), and from mild to severe (n = 1). The other patients stayed at their initial grade except one patient who improved (from moderated to mild). Analysis of laboratory findings showed that white blood cell count, aspartate transaminase, alanine transaminase level, and total bilirubin level were decreased. However, serum albumin and high-density lipoprotein cholesterol levels significantly increased.

CONCLUSIONS

Hepatic steatosis significantly developed 3 months after cholecystectomy. Therefore, cholecystectomy might be considered a risk factor for hepatic steatosis, but the relationship should be confirmed with long-term follow-up from a large group of patients.

Gallstones in Patients with Chronic Liver Diseases

With prevalence of 10-20% in adults in developed countries, gallstone disease (GSD) is one of the most prevalent and costly gastrointestinal tract disorders in the world. In addition to gallstone disease, chronic liver disease (CLD) is also an important global public health problem. The reported frequency of gallstone in chronic liver disease tends to be higher. The prevalence of gallstone disease might be related to age, gender, etiology, and severity of liver disease in patients with chronic liver disease. In this review, the aim was to identify the epidemiology, mechanisms, and treatment strategies of gallstone disease in chronic liver disease patients.

Interval increase in the prevalence of symptomatic cholelithiasis-associated non-alcoholic fatty liver disease over a ten-year period in an Asian population

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is frequently associated with cholelithiasis. The prevalence of NAFLD in Asia has been on the rise, but the magnitude of this increase had not been studied previously.

METHODS

A retrospective cohort study was conducted on consecutive patients who underwent laparoscopic or open cholecystectomy from November 2001 to November 2004 (Cohort 1) and from November 2011 to November 2014 (Cohort 2) at Singapore General Hospital. Preoperative diagnostic scans (e.g. ultrasonography, computed tomography and magnetic resonance imaging) and clinical data were reviewed for the presence of fatty liver. Statistical analysis was performed.

RESULTS

In Cohorts 1 and 2, 127 patients and 99 patients were operated on, respectively. Cohort 2 had significantly higher proportions of patients with NAFLD (56.6% vs. 40.2%; p < 0.015) and hyperlipidaemia (45.5% vs. 18.9%; p < 0.001) as compared to Cohort 1. Binary logistic regression analysis showed that hypertension (odds ratio [OR] 2.558; p < 0.004) and Indian ethnicity (OR 5.448; p < 0.043) were significantly associated with NAFLD.

CONCLUSION

Similar to other international studies, we found a significant increase in the prevalence of patients with NAFLD presenting symptomatically for cholecystectomy over an interval of ten years in Singapore. Hypertension and Indian ethnicity were significantly associated with NAFLD in both time periods. This trend supports the need for concerted public health intervention to stem the increasing incidence of NAFLD and prevent its progression to more advanced liver disease.

Significant Association Between Gallstone Disease and Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Gallstone disease (GD) and nonalcoholic fatty liver disease (NAFLD) are common digestive disorders worldwide. Both conditions share certain risk factors including obesity, insulin resistance and diabetes. Several epidemiologic studies have reported the relationship between these two conditions.

AIM

We conducted a systematic review and meta-analysis to characterize the association between GD and NAFLD.

METHODS

A comprehensive search of the databases MEDLINE and EMBASE was performed from inception through November 2015. The inclusion criterion was the observational studies' assessment of the association between GD and NAFLD in adult participants. Pooled odds ratio (OR) and 95 % confidence interval (CI) were calculated using a random-effects model.

RESULTS

Data were extracted from 12 observational studies (9 cross-sectional studies, 1 case-control study and 2 cohort studies). The pooled OR of NAFLD in patients who had GD was 1.55 (95 % CI 1.31-1.82). The statistical between-studies heterogeneity (I (2)) was 64 %. The association remained significant when limited to cohort studies with pooled OR 1.33 (95 % CI 1.14-1.55, I (2) = 0 %).

CONCLUSION

Our meta-analysis demonstrated that GD is significantly associated with NAFLD. Further prospective studies exploring the underlying mechanism of this association should be pursued.

Impaired Gallbladder Motility and Increased Gallbladder Wall Thickness in Patients with Nonalcoholic Fatty Liver Disease

BACKGROUND/AIMS

Nonalcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease worldwide. Along with the increase in the incidence of NAFLD and associated obesity, an increase in gallbladder disease (GD) has been noted. This has led to the identification of a new disease entity called fatty GD. There is a gap in the literature on the dynamics of gallbladder function in patients with NAFLD.

METHODS

An observational case-control study, a total of 50 patients with biopsy proven NAFLD without gallbladder stone/sludge and 38 healthy comparison subjects were enrolled. Fasting, postprandial gallbladder volumes (PGV), gallbladder ejection fraction (GEF), and fasting gallbladder wall thickness (FGWT) were measured by real-time 2-dimensional ultrasonography.

RESULTS

Fasting gallbladder wall thickness, fasting gallbladder volumes and PGV were significantly higher in patients with NAFLD than control subjects (P < 0.001, P = 0.006, and P < 0.001, respectively). Gallbladder ejection fraction was significantly lower in the NAFLD group than the controls (P = 0.008). The presence of NAFLD was an independent predictor for GEF, PGV, and FGWT. Also, steatosis grade was an independent predictor for GEF, and GEF was significantly lower in the nonalcoholic steatohepatitis (NASH) subgroup than the controls.

CONCLUSIONS

Gallbladder dysfunction and increase in gallbladder wall thickness exists in asymptomatic (without stone/sludge and related symptoms) patients with NAFLD and are useful in identifying fatty GD. Measurement of these variables in NAFLD patients may be useful in identifying those at higher risk for GD.

Epidemiological modifiers of non-alcoholic fatty liver disease: Focus on high-risk groups

An improved understanding of non-alcoholic fatty liver disease epidemiology would lead to identification of individuals at high risk of developing chronic liver disease and extra-hepatic complications, thus contributing to more effective case finding of non-alcoholic fatty liver disease among selected groups. We aimed to illustrate the epidemiology of non-alcoholic fatty liver disease in high-risk groups, which were identified based on existing literature. To this end, PubMed was searched to retrieve original articles published until May 2015 using relevant and pertinent keywords "nonalcoholic fatty liver disease" and "diabetes", "obesity", "hyperlipidaemia", "familial heterozygous hypobetalipoproteinaemia", "hypertension", "metabolic syndrome", "ethnicity", "family history" or "genetic polymorphisms". We found that age, sex and ethnicity are major physiological modifiers of the risk of non-alcoholic fatty liver disease, along with belonging to "non-alcoholic fatty liver disease families" and carrying risk alleles for selected genetic polymorphisms. Metabolic syndrome, diabetes, obesity, mixed hyperlipidaemia and hypocholesterolaemia due to familial hypobetalipoproteinaemia are the major metabolic modifiers of non-alcoholic fatty liver disease risk. Compared with these metabolic conditions, however, arterial hypertension appears to carry a relatively more modest risk of non-alcoholic fatty liver disease. A better understanding of the epidemiology of non-alcoholic fatty liver disease may result in a more liberal policy of case finding among high-risk groups.

Treatment of experimental non-alcoholic steatohepatitis by targeting α7 nicotinic acetylcholine receptor-mediated inflammatory responses in mice

Non‑alcoholic fatty liver disease (NAFLD) is one of the most common types of liver disease, affecting up to 30% of the general population worldwide. Non‑alcoholic steatohepatitis (NASH) is a severe form of NAFLD without any effective therapies available. The present study showed that activation of α7‑nicotinic acetylcholine receptor (α7 nAChR) may be a novel potential strategy for NASH therapy. Treatment with the α7 nAChR agonist nicotine for three weeks obviously attenuated hepatic steatosis in a high-fat diet‑induced mouse model of NASH. Investigation of the underlying mechanism showed that nicotine reduced the secretion of the pro‑inflammatory cytokines tumor necrosis factor α and interleukin 6 in vitro and in vivo. Inflammation is an integral part of NASH and is the most prevalent form of hepatic pathology found in the general population; therefore, the effect of α7 nAChR activation against NASH may be ascribed to its anti‑inflammatory effects. In addition, the present study showed that nicotine‑stimulated α7 nAChR activation led to a significant downregulation of nuclear factor kappa B (NK‑κB) and extracellular signal-regulated kinase (ERK). It therefore appeared that activation of α7 nAChR suppressed the production of pro‑inflammatory cytokines through NK‑κB and ERK pathways. In conclusion, the present study indicated that targeting α7 nAChR may represent a novel treatment strategy for NASH.

Helicobacter pylori infection is associated with gallstones: Epidemiological survey in China

AIM

To elucidate the prevalence and risk factors for gallstones, primarily focusing on Helicobacter pylori (H. pylori) infection.

METHODS

A total of 10016 Chinese subjects, who had undergone physical examination, fasting (13)C urea breath test and abdominal ultrasonography, had sufficient blood test data, and had finished a questionnaire, were included in this cross-sectional study. Participants (n = 1122) who had previous eradication of H. pylori were studied separately.

RESULTS

Gallstones were discovered in 9.10% of men and 8.58% of women, with no significant sex difference. Multivariate analyses displayed that age, aspartate aminotransferase, total cholesterol, H. pylori infection, hepatitis C virus (HCV) infection, and fatty liver had a significant association with gallstones (P < 0.05). Successive multiple logistic regression analysis including index of odds ratio (OR) and standardized coefficient (β) indicated that older age (OR/β = 1.056/0.055), H. pylori infection (OR/β = 1.454/0.109), HCV infection (OR/β = 1.871/0.123), and fatty liver (OR/β = 1.947/0.189) had a significant positive association with gallstones. After age stratification, H. pylori infection and fatty liver still had a significant positive association with gallstones in any age-specific groups, whereas HCV infection had a significant positive association in patients aged > 40 years. The prevalence of gallstones among H. pylori-positive, H. pylori-eradicated, and H. pylori-negative subjects was 9.47%, 9.02%, and 8.46%, respectively. The matched analysis showed that gallstones among H. pylori eradicated subjects was significantly lower compared with H. pylori-positive subjects (P < 0.05).

CONCLUSION

H. pylori infection and fatty liver have a significant positive association with gallstones. H. pylori eradication may lead to prevention of gallstones.

Cholecystectomy is independently associated with nonalcoholic fatty liver disease in an Asian population

AIM

To investigate the relationship between gallstone disease and nonalcoholic fatty liver disease (NAFLD) in a large Asian population.

METHODS

A cross-sectional study including 17612 subjects recruited from general health check-ups at the Seoul National University Hospital, Healthcare System Gangnam Center between January 2010 and December 2010 was conducted. NAFLD and gallstone disease were diagnosed based on typical ultrasonographic findings. Subjects who were positive for hepatitis B or C, or who had a history of heavy alcohol consumption (> 30 g/d for men and > 20 g/d for women) or another type of hepatitis were excluded. Gallstone disease was defined as either the presence of gallstones or previous cholecystectomy, and these two entities (gallstones and cholecystectomy) were analyzed separately. Clinical parameters including body mass index, waist circumference, hypertension, diabetes, smoking status, and regular physical activity were reviewed. Laboratory parameters, including serum levels of gamma-glutamyl transpeptidase, alanine aminotransferase, aspartate aminotransferase, fasting glucose, fasting insulin, total cholesterol, triglycerides, and high-density lipoprotein, were also reviewed.

RESULTS

The mean age of the subjects was 48.5 ± 11.3 years, and 49.3% were male. Approximately 30.3% and 6.1% of the subjects had NAFLD and gallstone disease, respectively. The prevalence of gallstone disease (8.3% vs 5.1%, P < 0.001), including both the presence of gallstones (5.5% vs 3.4%, P < 0.001) and a history of cholecystectomy (2.8% vs 1.7%, P < 0.001), was significantly increased in the NAFLD group. In the same manner, the prevalence of NAFLD increased with the presence of gallstone disease (41.3% vs 29.6%, P < 0.001). Multivariate regression analysis showed that cholecystectomy was associated with NAFLD (OR = 1.35, 95%CI: 1.03-1.77, P = 0.028). However, gallstones were not associated with NAFLD (OR = 1.15, 95%CI: 0.95-1.39, P = 0.153). The independent association between cholecystectomy and NAFLD was still significant after additional adjustment for insulin resistance (OR = 1.45, 95%CI: 1.01-2.08, P = 0.045).

CONCLUSION

This study shows that cholecystectomy, but not gallstones, is independently associated with NAFLD after adjustment for metabolic risk factors. These data suggest that cholecystectomy may be an independent risk factor for NAFLD.

Gallstone disease does not predict liver histology in nonalcoholic fatty liver disease

Background/Aims

We sought to examine whether the presence of gallstone disease (GD) in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD) is associated with liver fibrosis and histological nonalcoholic steatohepatitis (NASH) score.

Methods

We included 441 Turkish patients with biopsy-proven NAFLD. GD was diagnosed in the presence of sonographic evidence of gallstones, echogenic material within the gallbladder with constant shadowing and little or no visualization of the gallbladder or absence of gallbladder at ultrasonography, coupled with a history of cholecystectomy.

Results

Fifty-four patients (12.2%) had GD (GD+ subjects). Compared with the GD- subjects, GD+ patients were older, had a higher body mass index and were more likely to be female and have metabolic syndrome. However, GD+ patients did not have a higher risk of advanced fibrosis or definite NASH on histology. After adjustment for potential confounding variables, the prevalence of GD in NAFLD patients was not associated with significant fibrosis (≥2) (odds ratio [OR], 1.06; 95% confidence interval [CI], 0.53 to 2.21; p=0.68) or definite NASH (OR, 1.03; 95% CI, 0.495 to 2.12; p=0.84).

Conclusions

The presence of GD is not independently associated with advanced fibrosis and definite NASH in adult Turkish patients with biopsy-proven NAFLD.

Non-alcoholic fatty liver disease associated with gallstones in females rather than males: a longitudinal cohort study in Chinese urban population

Background

Whether non-alcoholic fatty liver disease (NAFLD) is a risk factor for gallstones remains uncertain. Few longitudinal or cohort studies have been used to identify this relationship. The aim of this study was to confirm the association between NAFLD and gallstones in a longitudinal cohort of urban dwellers in China.

Methods

To elucidate the association between NAFLD and gallstones, we fitted a generalized estimating equation (GEE) model in a large-scale longitudinal cohort over 6 years, which included 11,200 participants with at least three regular health check-ups.

Results

A total of 498 cases of gallstones occurred during the 6-year follow-up, which resulted in a total incidence density of 12.73 per 1000 person-years (498/39, 135.5 person-years). The GEE analyses confirmed and clarified the association between NAFLD and gallstones (relative risk (RR) = 1.2381, 95% confidence interval (CI) = 1.003–1.528, P = 0.047) after adjusting for other potential confounding factors, especially in females (RR = 1.707, 95% CI = 1.245–2.341, P = 0.001).

Conclusions

NAFLD is associated with gallstones in an urban Chinese population from the middle to upper socioeconomic strata. Moreover, this association is more strongly apparent in females than in males. Further cohort studies must be conducted to confirm this association in the general population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-014-0213-y) contains supplementary material, which is available to authorized users.

Moderate to severe, but not mild, nonalcoholic fatty liver disease associated with increased risk of gallstone disease

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) and gallstone disease (GSD) share some of the same risk factors. The association between NAFLD and GSD was inconsistent. Moreover, there are no studies on the association between GSD and the severity of NAFLD in the literature. The aim of this study was to determine the relationship between the severity of NAFLD and GSD in a Taiwanese population.

MATERIALS AND METHODS

A total of 12,033 subjects were enrolled. The diagnoses of GSD and NAFLD were based on the finding of abdominal ultrasonography. The severity of NAFLD was divided into mild, moderate, and severe.

RESULTS

Compared with the non-GSD group, the GSD one was older and had a higher BMI, blood pressure, fasting plasma glucose, cholesterol, triglyceride, and higher prevalence of diabetes and hypertension, but they had a lower eGFR and HDL-C level and less prevalence of current smoking and alcohol drinking. There was a significant difference in the severity of NAFLD between subjects with and without GSD. Based on logistic regression, age ≥65 versus <40 years, 40-64.9 versus <40 years, female, current alcohol drinking, diabetes, hypertension, HDL-C level and moderate to severe NAFLD, but not mild NAFLD, were the independently associated risk factors of GSD.

CONCLUSION

Moderate to severe, but not mild, NAFLD was associated with an increased risk of GSD, independent of the traditional cardio-metabolic risk factor. Age, female, diabetes, and hypertension were also related to a higher risk of GSD, but HDL-C level and moderate alcohol drinking showed a lower risk.

Nonalcoholic fatty liver disease and cholesterol gallstones: which comes first?

Nonalcoholic fatty liver disease (NAFLD) and gallstone disease (GD) are both highly prevalent in the general population and are associated with obesity, insulin resistance, dyslipidemia, and high dietary cholesterol intake. Insulin resistance is a key feature of both NAFLD and GD. Hepatic insulin resistance provides a crucial link between the metabolic syndrome, NAFLD, and increased cholesterol gallstone susceptibility. Hepatic insulin resistance is not only associated with accumulation of hepatic fat but also has a crucial role in supersaturation and excessive production of bile salts. It is not yet clear whether NAFLD is a precursor of GD or whether the presence of GD possibly indicates the presence of long-standing features of metabolic syndrome that accelerates the progression of NAFLD. Recent reports suggested the association between gallstones and nonalcoholic steatohepatitis and liver fibrosis. Importantly, both NAFLD and GD are both associated with high incidence of cardiovascular disease (CVD) and mortality. Emerging evidence suggests a potential benefit of statin therapy in NAFLD and GD. Further research is needed to determine (i) how the presence of NAFLD and GD is associated with CVD (ii) and whether the presence of GD in association with NAFLD increases the risk of liver fibrosis, and (iii) the impact of therapy of NAFLD in the incidence of GD.

Hard clinical outcomes in patients with NAFLD

Non-alcoholic fatty liver disease (NAFLD), once regarded as an innocuous condition, is now considered to be the most common cause of chronic liver disease worldwide. Evidence suggests a strong association between NAFLD and other potentially life-threatening diseases. A significant proportion of these patients develops progressive liver injury leading to cirrhosis and hepatocellular carcinoma. Unrecognized NAFLD constitutes a substantial proportion of patients with cryptogenic cirrhosis. Several large community-based studies have found increased mortality in NAFLD patients compared to the expected mortality of the general population of the same age and sex. Cardiovascular disease is an important cause of morbidity and mortality in patients with NAFLD and accounts for up to 30 % of overall death. Cardiovascular mortality does not seem to differ between simple steatosis and non-alcoholic steatohepatitis. NAFLD is associated with increased risk of both hepatic and extra-hepatic malignancy. Malignancy is among the most important causes of death in NAFLD patients. NAFLD is a risk factor for liver cancer even without cirrhosis. The steatotic liver has poor ability to regenerate after volume loss, which may lead to the development of liver failure and increased mortality after extended liver resection. Also, transplantation of steatotic liver results in an increased rate of poor graft function, primary graft non-function, and poorer outcome. There is a high recurrence rate of fatty liver disease in patients transplanted for NASH.

Relationship of non-alcoholic fatty liver disease with cholecystectomy in the US population

OBJECTIVES

Other than weight-related conditions, risk factors for non-alcoholic fatty liver disease (NAFLD) are not well defined. We investigated the association of gallstones and cholecystectomy with NAFLD in a large, national, population-based study.

METHODS

Among adult participants in the third US National Health and Nutrition Examination Survey, 1988-1994, ultrasonography for gallstone disease was performed, and videotapes were subsequently evaluated for NAFLD. Odds ratios (ORs) for the association of gallstone disease with NAFLD were calculated using logistic regression analysis to adjust for common associated factors.

RESULTS

Among 12,232 participants without viral hepatitis or significant alcohol intake, the prevalence of gallstones was 7.4%, cholecystectomy 5.6%, and NAFLD 20.0%. Participants with cholecystectomy had higher age-sex-adjusted prevalence of NAFLD (48.4%) than those with gallstones (34.4%) or without gallstone disease (17.9%) (P<0.01 for all comparisons). Controlling for numerous factors associated with both NAFLD and gallstone disease, multivariate-adjusted analysis confirmed the association of NAFLD with cholecystectomy (OR=2.4; 95% confidence interval (CI): 1.8-3.3), but not with gallstones (OR=1.1; 95% CI: 0.84-1.4).

CONCLUSIONS

The association of NAFLD with cholecystectomy, but not with gallstones, indicates that cholecystectomy may itself be a risk factor for NAFLD.

Utility of noninvasive methods for the characterization of nonalcoholic liver steatosis in the family practice. The "VARES" Italian multicenter study

The diagnostic utilities of ultrasonography (US), fatty liver index (FLI) and an algorithm of nine serum markers (Fibromax) were evaluated in family practice to noninvasively characterize patients with nonalcoholic fatty liver disease (NAFLD). A multicenter study was conducted by enrolling 259 consecutively observed patients (age 51 ± 10 years) with clinical and ultrasonographic features of NAFLD . Patients had mild (16.2%), moderate (69.9%), or severe (13.9%) liver steatosis and 60.2% had hypertransaminasemia. The percent of patients with overweight, obesity, diabetes, hypertension, and dyslipidemia were 42.7%, 46.5% (4.2% severe obesity), 24.7%, 40.9%, and 56.4% , respectively. Lean patients (10.8%) had normal transaminases in two/thirds of the cases. A multivariate logistic regression (including age > 50 yrs, BMI > 30 kg/m2, HOMA > 3, and hypertransaminasemia) identified 12.3% of patients at risk for steatohepatitis. With a sensitivity of 50% and specificity of 94.7%, Fibromax identified 34 patients (13.1%) with likely advanced fibrosis and found that over 28% of patients with moderate (ultrasonographic) steatosis were likely to be carrying severe steatosis. Steatotest score was significantly associated with BMI, waist circumference, ALT, triglycerides, and FLI. Fibrotest correlated only with ALT. FLI identified 73.4% of patients as likely to be carrying a fatty liver. In conclusion, NAFLD should be systematically searched and characterized in all patients with metabolic disturbances and cardiovascular risk. Asymptomatic subjects at risk also should be screened for NAFLD. Fibromax is a promising noninvasive diagnostic tool in family medicine for identifying patients at risk for NAFLD who require targeted follow-up.

Gallstone disease is associated with more severe liver damage in patients with non-alcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and gallstone disease (GD) are both highly prevalent in the general population and associated with obesity and insulin resistance. We aimed to evaluate the prevalence of GD in a cross sectional study of NAFLD patients and to define whether the presence of GD is associated with diabetes and predicts more severe liver disease.

METHODOLOGY/PRINCIPAL FINDINGS

We merged databases of four Liver Units, comprising 524 consecutive biopsy-proven NAFLD (373 males) observed between January 2003 and June 2010. GD was diagnosed in 108 (20%), and 313 cases (60%) were classified by liver biopsy as nonalcoholic steatohepatitis (NASH). The GD subgroup was characterized by a significantly higher prevalence of females, prediabetes/diabetes, abdominal obesity and metabolic syndrome, older age, higher BMI, fasting glucose, HOMA-IR and lower ALT. The prevalence of GD progressively increased with advancing fibrosis and with the severity of necroinflammatory activity (p for trend  = 0.0001 and  = 0.01, respectively), without differences in the severity of steatosis. At multivariate analysis GD was associated with female gender (OR 1.37, 95% CI 1.04-1.8), age (OR 1.027, 95% CI1.003-1.05), fasting glucose (OR 1.21, 95% CI 1.10-1.33) and NASH (OR 1.40,95% CI 1.06-1.89), whereas ALT levels were associated with a lower GD risk (OR 0.98, 95% CI 0.97-0.99). When subjects with cirrhosis were excluded from analysis, the association between GD and fasting glucose, female gender, and NASH was maintained.

CONCLUSION

Patients with NAFLD have a high prevalence of GD, which characterizes subjects with altered glucose regulation and more advanced liver disease.

Epidemiology of gallbladder disease: cholelithiasis and cancer

Diseases of the gallbladder are common and costly. The best epidemiological screening method to accurately determine point prevalence of gallstone disease is ultrasonography. Many risk factors for cholesterol gallstone formation are not modifiable such as ethnic background, increasing age, female gender and family history or genetics. Conversely, the modifiable risks for cholesterol gallstones are obesity, rapid weight loss and a sedentary lifestyle. The rising epidemic of obesity and the metabolic syndrome predicts an escalation of cholesterol gallstone frequency. Risk factors for biliary sludge include pregnancy, drugs like ceftiaxone, octreotide and thiazide diuretics, and total parenteral nutrition or fasting. Diseases like cirrhosis, chronic hemolysis and ileal Crohn's disease are risk factors for black pigment stones. Gallstone disease in childhood, once considered rare, has become increasingly recognized with similar risk factors as those in adults, particularly obesity. Gallbladder cancer is uncommon in developed countries. In the U.S., it accounts for only ~ 5,000 cases per year. Elsewhere, high incidence rates occur in North and South American Indians. Other than ethnicity and female gender, additional risk factors for gallbladder cancer include cholelithiasis, advancing age, chronic inflammatory conditions affecting the gallbladder, congenital biliary abnormalities, and diagnostic confusion over gallbladder polyps.