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

Altered biliary microbial and metabolic profile reveals the crosstalk between NAFLD and cholelithiasis

BACKGROUND

The relationship between non-alcoholic fatty liver disease (NAFLD) and cholelithiasis is intricate, with alterations in the microenvironment potentially mediating this interplay. Thus, this study aimed to explore the biliary microbiota and metabolites of patients with cholelithiasis and detect changes induced by comorbid NAFLD.

METHODS

In this study, 16S rRNA gene sequencing and metabolome analysis were performed on biliary samples collected from 35 subjects. Then, patients were stratified into two groups: the comorbidity group (n = 18), consisting of cholelithiasis patients with NAFLD, and the non-comorbidity group (n = 17), comprising cholelithiasis patients without NAFLD.

RESULTS

Comorbid NAFLD did not significantly increase α-diversity but affected β-diversity. A statistically significant difference was observed in the abundance of biliary metabolites between the two groups. Specifically, differences in the abundance of 4 phyla, 19 genera, and 28 metabolites were significant between the two groups. Correlation analysis demonstrated positive associations among 12α-hydroxylated bile acid levels, Pyramidobacter and Fusobacterium abundance, AST levels, and the fibrosis-4 index (p < 0.05, r > 0.3), all of which were increased in patients with cholelithiasis and comorbid NAFLD.

CONCLUSIONS

The relationship between cholelithiasis and NAFLD influences the biliary microbial and metabolic profile, creating a detrimental microenvironment that promotes the disease progression.

Cholesterol Gallstones and Long-Term Use of Statins: Is Gut Microbiota Dysbiosis Bridging over Uncertainties?

A total of 300 research participants-200 consecutive patients diagnosed with dyslipidemia (100 statin (+), treated for at least five years, and 100 statin (-)) and 100 healthy controls-were included in this observational study. The aim of the study was to deliver insights into the relationship between the long-term use of statins for dyslipidemia and gallstone disease (GSD), as well as insights into the background particularities of the gut microbiota. All study participants underwent clinical examination, laboratory workups, stool microbiology/stool 16S r RNA, next-generation sequencing, and abdominal ultrasound/CT exams. Results: The research participants presented with similarities related to age, gender, and location. Patients displayed comparable heredity for GSs, metabolic issues, and related co-morbidities. Gut dysbiosis (DB) was present in 54% of the statin (-) patients vs. 35% of the statin (+) patients (p = 0.0070). GSs were present in 14% of patients in the statin (-) group vs. 5% of patients in the statin (+) group (p = 0.0304). Severe dysbiosis, with a significant reduction in biodiversity, an increase in LPS (+) bacteria, and a notable decrease in mucin-degrading bacteria, mucosa-protective bacteria, and butyrate-producing bacteria were observed in the statin (-) group. Strong positive correlations between GSD and diabetes/impaired glucose tolerance (r = 0.3368, p = 0.0006), obesity (r = 0.3923, p < 0.0001), nonalcoholic fatty liver disease (r = 0.3219, p = 0.0011), and DB (r = 0.7343, p < 0.0001), as well as significant negative correlations between GSD and alcohol use (r = -0.2305, p = 0.0211), were observed. The multiple regression equation demonstrated that only DB (95% CI: 0.3163 to 0.5670; p < 0.0001) and obesity (95% CI: 0.01431 to 0.2578; p = 0.0289) were independent risk factors predicting GSD in the group of patients treated with statins. Conclusion: The long-term use of statins in dyslipidemic patients was associated with a low risk of developing GSs. The gut microbiota associated with a long-term use of statins in dyslipidemic patients was characterized by a low risk of developing an imbalance of various functional bacteria and alterations in the metabolic microbiota. DB and obesity were found to be independent risk factors predicting GSD in statin (+) patients.

Elevated LDL-c may warn of the risk of gallbladder stones in the patients with metabolic dysfunction-associated steatotic liver disease: A case-control study

PURPOSE

This study aimed to explore the relationship between metabolic dysfunction-associated steatotic liver disease (MASLD) and the development of new-onset gallbladder stone disease (GSD) and to identify factors that influence the occurrence of new-onset GSD in patients with MASLD.

METHODS

In this retrospective case-control study, patients who underwent asymptomatic GSD screening during annual routine health check-ups at two hospitals in China between August 2017 and July 2022 were included. Patients with new-onset GSD and controls without GSD were matched 1:1 based on age, sex, race, occupation, diet, drinking habits, systolic blood pressure, diastolic blood pressure, and fasting blood glucose levels.

RESULTS

The study comprised 1200 patients with new-onset GSD and 1200 controls without GSD. Patients with new-onset GSD had higher rates of MASLD (33.8% vs. 22.2 %, P < 0.001) and hypercholesterolemia (12.6% vs. 7.2 %, P < 0.001) compared to controls. Waist circumference (WC) (OR = 1.042, 95 % CI: 1.022-1.063, P < 0.001), high-density lipoprotein cholesterol (HDL-c) (OR = 0.048, 95 % CI: 0.037-0.062, P < 0.001), triglycerides (OR = 0.819, 95 % CI: 0.699-0.958, P = 0.013), and hypercholesterolemia (OR = 5.023, 95 % CI: 2.735-9.225, P < 0.001) were independently associated with new-onset GSD. Among patients with MASLD, WC (OR = 1.075, 95 % CI: 1.026-1.127, P = 0.003), total cholesterol (TC) (OR = 2.094, 95 % CI: 1.259-3.484, P = 0.004), HDL-c (OR = 0.088, 95 % CI: 0.054-0.142, P < 0.001), and low-density lipoprotein cholesterol (LDL-c) (OR = 4.056, 95 % CI: 2.669-6.163, P < 0.001) were independently associated with new-onset GSD.

CONCLUSIONS

The findings indicate that hypercholesterolemia is independently associated with GSD. Among patients with MASLD, hypercholesterolemia also showed an independent association with GSD. Notably, this study is the first to identify serum LDL-c levels as potentially the most significant risk factor for GSD, highlighting that elevated LDL-c could serve as an important indicator for individuals with MASLD.

Gallstone and Gallbladder Disease: Biliary Tract and Cholangiopathies

Cholestatic liver diseases are named primarily due to the blockage of bile flow and buildup of bile acids in the liver. Cholestasis can occur in cholangiopathies, fatty liver diseases, and during COVID-19 infection. Most literature evaluates damage occurring to the intrahepatic biliary tree during cholestasis; however, there may be associations between liver damage and gallbladder damage. Gallbladder damage can manifest as acute or chronic inflammation, perforation, polyps, cancer, and most commonly gallstones. Considering the gallbladder is an extension of the intrahepatic biliary network, and both tissues are lined by biliary epithelial cells that share common mechanisms and properties, it is worth further evaluation to understand the association between bile duct and gallbladder damage. In this comprehensive article, we discuss background information of the biliary tree and gallbladder, from function, damage, and therapeutic approaches. We then discuss published findings that identify gallbladder disorders in various liver diseases. Lastly, we provide the clinical aspect of gallbladder disorders in liver diseases and ways to enhance diagnostic and therapeutic approaches for congruent diagnosis. © 2023 American Physiological Society. Compr Physiol 13:4909-4943, 2023.

2019 Global NAFLD Prevalence: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The increasing rates of obesity and type 2 diabetes mellitus may lead to increased prevalence of nonalcoholic fatty liver disease (NAFLD). We aimed to determine the current and recent trends on the global and regional prevalence of NAFLD.

METHODS

Systematic search from inception to March 26, 2020 was performed without language restrictions. Two authors independently performed screening and data extraction. We performed meta-regression to determine trends in NAFLD prevalence.

RESULTS

We identified 17,244 articles from literature search and included 245 eligible studies involving 5,399,254 individuals. The pooled global prevalence of NAFLD was 29.8% (95% confidence interval [CI], 28.6%-31.1%); of these, 82.5% of included articles used ultrasound to diagnose NAFLD, with prevalence of 30.6% (95% CI, 29.2%-32.0%). South America (3 studies, 5716 individuals) and North America (4 studies, 18,236 individuals) had the highest NAFLD prevalence at 35.7% (95% CI, 34.0%-37.5%) and 35.3% (95% CI, 25.4%-45.9%), respectively. From 1991 to 2019, trend analysis showed NAFLD increased from 21.9% to 37.3% (yearly increase of 0.7%, P < .0001), with South America showing the most rapid change of 2.7% per year, followed by Europe at 1.1%.

CONCLUSIONS

Despite regional variation, the global prevalence of NAFLD is increasing overall. Policy makers must work toward reversing the current trends by increasing awareness of NAFLD and promoting healthy lifestyle environments.

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.

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.

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.

Physical activity can reduce the prevalence of gallstone disease among males: An observational study

Several previous studies have reported that physical activity (PA) levels can independently affect the prevalence of gallstone disease (GD) in Western countries. However, this association has not been reported in Eastern countries. Therefore, this study aimed to determine whether PA is an independent determinant of GD prevalence in a Korean population, according to the World Health Organizations Global Recommendations on PA for Health.A total of 8908 subjects who completed a questionnaire underwent medical examination and ultrasound scanning at the Health Promotion Center of the Jeju National University Hospital between January 2009 and December 2018. GD and fatty liver disease were diagnosed by abdominal ultrasound. Biochemical parameters and body mass index were determined, and metabolic syndrome status, age, and PA levels were extracted from medical records. Univariate and multivariate analyses were performed to identify independent factors affecting GD.The estimated rates of PA and GD among male subjects were 23.7% and 4.6%, whereas the rates among females were 18.4% and 4.2%, respectively. Multivariate analysis suggested that no PA, old age, and higher aspartate aminotransferase level in males and nonalcoholic fatty liver disease status in females were independent factors affecting GD.In our study, PA was associated with a reduction in GD among males but not females.

Prevalence of biopsy-proven nonalcoholic fatty liver among patients with gallstone disease

BACKGROUND/AIM

Gallstone disease (GD) and nonalcoholic fatty liver disease (NAFLD) are associated with metabolic syndrome. Despite the benign nature of NAFLD, 10% of patients may develop advanced fibrosis and cirrhosis. We aimed to identify the prevalence and factors associated with NAFLD among GD patients in the Saudi population.

PATIENTS AND METHODS

This is a single-center, observational cohort study that included patients seen in general surgery clinics at our institution from 2011 to 2017. All liver biopsies were taken at the same time as the cholecystectomy. Demographical and clinical data were prospectively collected from the study population.

RESULTS

Of the 301 GD patients in the study, 15% had a normal body mass index (BMI), 29% were overweight, and 56% were obese. There were 143 (47.8%) patients with NAFLD, of which 125 (41.8%) showed steatosis and 18 (6%) had nonalcoholic steatohepatitis. There was a significant positive correlation between NAFLD and age (r = 0.243; P < 0.0001), and BMI (r = 0.242; P < 0.0001). Obese patients with BMI 30-40 kg/m[2] were 2.403 (P = 0.039) more likely to have NAFLD compared with normal BMI patients, and this value increased to 6.145 (P = 0.002) in patients with BMI >40 kg/m[2]. Additionally, patients with T2DM were 2.839 times (P = 0.015) more likely to have NAFLD compared with those who did not.

CONCLUSIONS

The prevalence of NAFLD among GD patients is high. High BMI and diabetes are independent factors associated with NAFLD in GD patients. The results suggest that there may be a need for routine liver biopsy in selected patients during cholecystectomy.

Association Between Non-Alcoholic Fatty Liver Disease and Metabolic Syndrome with Gallstone Disease, South Iran: A Population-Based Study

AIM

Gallstone disease (GSD), non-alcoholic fatty liver disease (NAFLD), and metabolic syndrome (MetS) are common problems. The aim of this study was to investigate the association between NAFLD, MetS and its components with GSD.

MATERIALS AND METHODS

This cross-sectional study was conducted as a part of the Kavar Cohort Study (KCS) affiliated to Shiraz University of Medical Sciences, Shiraz, Iran between January 2012 and January 2018. A total of 2239 participants of the general population of the KCS were selected randomly. Ultrasonography for GSD and NAFLD diagnosis and clinical and laboratory assaying for MetS evaluation were performed for the participants. The National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATP-III) and Criteria for Clinical Diagnosis of MetS in Iranian Adults (CCDMIA) were used for diagnosis of MetS.

RESULTS

Overall, 59 patients with GSD and 177 age- and sex- matched participants without gallstones as a comparison group were enrolled. According to GSD groups, NAFLD was observed in 42.4% and 22.6% of patients with and without GSD, respectively, and the difference between the two groups was statistically significant (P = 0.003). MetS was present in 33.9% and 39.0% of GSD subjects, compared with 32.8% and 33.3% of the non-GSD group, based on NCEP/ATPIII and CCDMIA, respectively. Although the mean of all components of MetS except HDL-cholesterol were higher in the GSD group than in the non-GSD group,  the difference was only significant in waist circumference (P = 0.041).

CONCLUSION

The present study found an obvious association between NAFLD and GSD. This study also showed a significant association between increasing waist circumference and risk of GSD. We recommend that patients with GSD should be evaluated for the likelihood of NAFLD and its treatment in addition to lifestyle changes to gain proper weight. However, further researches are needed to clarify the relationship between the nature of GSD, NAFLD, and obesity.

The grade of nonalcoholic fatty liver disease is an independent risk factor for gallstone disease: An observational Study

There have been reports linking nonalcoholic fatty liver disease (NAFLD) with gallstone disease (GD) owing to shared risk factors. However, there are no reported associations between the different NAFLD grades and GD. This study aimed to determine whether NAFLD grade is an independent risk factor for GD in a Korean population.This study enrolled 7886 participants who completed a questionnaire and underwent medical examination and ultrasound scanning at the Health Promotion Center of Jeju National University Hospital in Korea, from January 2009 to December 2017. Fatty liver grading and presence of gallstones were investigated using abdominal ultrasound. Body mass index and biochemical parameters were measured, and age, sex, and metabolic syndrome status were collected from medical records. Univariate and multivariate analyses were performed to identify risk factors for GD.The estimated prevalences of NAFLD and GD were 40.6% and 4.5%, respectively. In the univariate analysis, factors associated with GD were age; NAFLD; presence of metabolic syndrome; and levels of fasting blood glucose, high-density lipoproteins, aspartate aminotransferase, and alanine aminotransferase. Multivariate logistic regression analysis revealed older age and higher NAFLD grade as independent risk factors for GD.Older age and higher grade of NAFLD were independent risk factors for GD in our cohort. There was a strong correlation between grade of NAFLD on abdominal ultrasonography and GD.

The fibrogenic process and the unleashing of acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a life-threatening condition characterized by a rapid deterioration of previously well-compensated chronic liver diseases. One of the main obstacles in ACLF is the lack of knowledge of the pathogenesis and specific broad-spectrum treatments. An excessive systemic inflammatory response has been proposed to explain the pathogenesis of ACLF; this hypothesis involves stellate cells, which are implicated in many liver homeostatic functions that include vitamin A storage, regulation of sinusoidal blood flow, local inflammation, maintenance of the hepatocyte phenotype and extracellular matrix remodeling. However, when there is damage to the liver, these cells are the main target of the inflammatory stimulus, as a result, the secretion of the extracellular matrix is altered. Activated hepatic stellate cells raise the survival of neutrophils by the stimulation of granulocytes colonies and macrophages, which exacerbates liver inflammation and promotes damage to hepatocytes. Elevation of pathogen-associated molecular patterns is related to liver damage by different pathophysiological mechanisms of decompensation, showing ballooning degeneration and cell death with a predominance of cholestatic infection. Moreover, patients with ACLF present a marked elevation of C-reactive protein together with an elevation of the leukocyte count. Chronic liver disease is a complex pathological state with a heterogeneous pathophysiology in which genetic factors of the host and external triggers interact and culminate in hepatic insufficiency. The better understanding of such interactions should lead to a better comprehension of the disease and to the discovery of new treatment targets that will make acute decompensations preventable and even decrease mortality.

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.

Cholesterol cholelithiasis: part of a systemic metabolic disease, prone to primary prevention

Cholesterol gallstone disease have relationships with various conditions linked with insulin resistance, but also with heart disease, atherosclerosis, and cancer. These associations derive from mechanisms active at a local (i.e. gallbladder, bile) and a systemic level and are involved in inflammation, hormones, nuclear receptors, signaling molecules, epigenetic modulation of gene expression, and gut microbiota. Despite advanced knowledge of these pathways, the available therapeutic options for symptomatic gallstone patients remain limited. Therapy includes oral litholysis by the bile acid ursodeoxycholic acid (UDCA) in a small subgroup of patients at high risk of postdissolution recurrence, or laparoscopic cholecystectomy, which is the therapeutic radical gold standard treatment. Cholecystectomy, however, may not be a neutral event, and potentially generates health problems, including the metabolic syndrome. Areas covered: Several studies on risk factors and pathogenesis of cholesterol gallstone disease, acting at a systemic level have been reviewed through a PubMed search. Authors have focused on primary prevention and novel potential therapeutic strategies. Expert commentary: The ultimate goal appears to target the manageable systemic mechanisms responsible for gallstone occurrence, pointing to primary prevention measures. Changes must target lifestyles, as well as experimenting innovative pharmacological tools in subgroups of patients at high risk of developing gallstones.

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.

Recent advances in understanding and managing cholesterol gallstones

The high prevalence of cholesterol gallstones, the availability of new information about pathogenesis, and the relevant health costs due to the management of cholelithiasis in both children and adults contribute to a growing interest in this disease. From an epidemiologic point of view, the risk of gallstones has been associated with higher risk of incident ischemic heart disease, total mortality, and disease-specific mortality (including cancer) independently from the presence of traditional risk factors such as body weight, lifestyle, diabetes, and dyslipidemia. This evidence points to the existence of complex pathogenic pathways linking the occurrence of gallstones to altered systemic homeostasis involving multiple organs and dynamics. In fact, the formation of gallstones is secondary to local factors strictly dependent on the gallbladder (that is, impaired smooth muscle function, wall inflammation, and intraluminal mucin accumulation) and bile (that is, supersaturation in cholesterol and precipitation of solid crystals) but also to "extra-gallbladder" features such as gene polymorphism, epigenetic factors, expression and activity of nuclear receptors, hormonal factors (in particular, insulin resistance), multi-level alterations in cholesterol metabolism, altered intestinal motility, and variations in gut microbiota. Of note, the majority of these factors are potentially manageable. Thus, cholelithiasis appears as the expression of systemic unbalances that, besides the classic therapeutic approaches to patients with clinical evidence of symptomatic disease or complications (surgery and, in a small subgroup of subjects, oral litholysis with bile acids), could be managed with tools oriented to primary prevention (changes in diet and lifestyle and pharmacologic prevention in subgroups at high risk), and there could be relevant implications in reducing both prevalence and health costs.