Low-density lipoprotein cholesterol and risk of gallstone disease: a Mendelian randomization study and meta-analyses

Metabolomic profiles of incident gallstone disease

BACKGROUND AND AIMS

Gallstone disease affects ≥40 million people in the USA and accounts for health costs of ≥$4 billion a year. Risk factors such as obesity and metabolic syndrome are well established. However, data are limited on relevant metabolomic alterations that could offer mechanistic and predictive insights into gallstone disease. This study prospectively identifies and externally validates circulating prediagnostic metabolites associated with incident gallstone disease.

METHODS

Female participants in Nurses' Health Study (NHS) and Nurses' Health Study II (NHS II) who were free of known gallstones (N=9960) were prospectively followed up after baseline metabolomic profiling with liquid chromatography-tandem mass spectrometry. Multivariable logistic regression and enrichment analysis were used to identify metabolites and metabolite groups associated with incident gallstone disease at PFDR<0.05. Findings were validated in 1866 female participants in the Women's Health Initiative and a comparative analysis was performed with 2178 male participants in the Health Professionals Follow-up Study.

RESULTS

After multivariate adjustment for lifestyle and putative risk factors, we identified and externally validated 17 metabolites associated with incident gallstone disease in women-nine triacylglycerols (TAGs) and diacylglycerols (DAGs) were positively associated, while eight plasmalogens and cholesterol ester (CE) were negatively associated. Enrichment analysis in male and female cohorts revealed positive class associations with DAGs, TAGs (≤56 carbon atoms and ≤3 double bonds) and de novo TAG biosynthesis pathways, as well as inverse associations with CEs.

CONCLUSIONS

This study highlights several metabolites (TAGs, DAGs, plasmalogens and CE) that could be implicated in the aetiopathogenesis of gallstone disease and serve as clinically relevant markers.

Multi-biobank Mendelian randomization analyses identify opposing pathways in plasma low-density lipoprotein-cholesterol lowering and gallstone disease

Plasma low-density lipoprotein (LDL)-cholesterol is positively associated with coronary artery disease risk while biliary cholesterol promotes gallstone formation. Different plasma LDL-cholesterol lowering pathways may have distinct effects on biliary cholesterol and thereby gallstone disease risk. We conducted a Mendelian randomization (MR) study using data from the UK Biobank (30,547 gallstone disease cases/336,742 controls), FinnGen (34,461 cases/301,383 controls) and Biobank Japan (9,305 cases/168,253 controls). We first performed drug-target MR analyses substantiated by colocalization to investigate the effects of plasma LDL-cholesterol lowering therapies on gallstone disease risk. We then performed clustered MR analyses and pathway analyses to identify distinct mechanisms underlying the association of plasma LDL-cholesterol with gallstone disease risk. For a 1-standard deviation reduction in plasma LDL-cholesterol, genetic mimics of statins were associated with lower gallstone disease risk (odds ratio 0.72 [95% confidence interval 0.62, 0.83]), but genetic mimics of PCSK9 inhibitors and targeting apolipoprotein B were associated with higher risk (1.11 [1.03, 1.19] and 1.23 [1.13, 1.35]). The association for statins was supported by colocalization (posterior probability 98.7%). Clustered MR analyses identified variant clusters showing opposing associations of plasma LDL-cholesterol with gallstone disease risk, with some evidence for ancestry-and sex-specific associations. Among variants lowering plasma LDL-cholesterol, those associated with lower gallstone disease risk were mapped to glycosphingolipid biosynthesis pathway, while those associated with higher risk were mapped to pathways relating to plasma lipoprotein assembly, remodelling, and clearance and ATP-binding cassette transporters. This MR study provides genetic evidence that different plasma LDL-cholesterol lowering pathways have opposing effects on gallstone disease risk.

[Establishment and Validation of a Predictive Model for Gallstone Disease in the General Population: A Multicenter Study]

Objective

Gallstone disease (GSD) is one of the common digestive tract diseases with a high worldwide prevalence. The effects of GSD on patients include but are not limited to the symptoms of nausea, vomiting, and biliary colic directly caused by GSD. In addition, there is mounting evidence from cohort studies connecting GSD to other conditions, such as cardiovascular diseases, biliary tract cancer, and colorectal cancer. Early identification of patients at a high risk of GSD may help improve the prevention and control of the disease. A series of studies have attempted to establish prediction models for GSD, but these models could not be fully applied in the general population due to incomplete prediction factors, small sample sizes, and limitations in external validation. It is crucial to design a universally applicable GSD risk prediction model for the general population and to take individualized intervention measures to prevent the occurrence of GSD. This study aims to conduct a multicenter investigation involving more than 90000 people to construct and validate a complete and simplified GSD risk prediction model.

Methods

A total of 123634 participants were included in the study between January 2015 and December 2020, of whom 43929 were from the First Affiliated Hospital of Chongqing Medical University (Chongqing, China), 11907 were from the First People's Hospital of Jining City (Shandong, China), 1538 were from the Tianjin Medical University Cancer Institute and Hospital (Tianjin, China), and 66260 were from the People's Hospital of Kaizhou District (Chongqing, China). After excluding patients with incomplete clinical medical data, 35976 patients from the First Affiliated Hospital of Chongqing Medical University were divided into a training data set (n=28781, 80%) and a validation data set (n=7195, 20%). Logistic regression analyses were performed to investigate the relevant risk factors of GSD, and a complete risk prediction model was constructed. Factors with high scores, mainly according to the nomograms of the complete model, were retained to simplify the model. In the validation data set, the diagnostic accuracy and clinical performance of these models were validated using the calibration curve, area under the curve (AUC) of the receiver operating characteristic curve, and decision curve analysis (DCA). Moreover, the diagnostic accuracy of these two models was validated in three other hospitals. Finally, we established an online website for using the prediction model (The complete model is accessible at https://wenqianyu.shinyapps.io/Completemodel/, while the simplified model is accessible at https://wenqianyu.shinyapps.io/Simplified/).

Results

After excluding patients with incomplete clinical medical data, a total of 96426 participants were finally included in this study (35876 from the First Affiliated Hospital of the Chongqing Medical University, 9289 from the First People's Hospital of Jining City, 1522 from the Tianjin Medical University Cancer Institute, and 49639 from the People's Hospital of Kaizhou District). Female sex, advanced age, higher body mass index, fasting plasma glucose, uric acid, total bilirubin, gamma-glutamyl transpeptidase, and fatty liver disease were positively associated with risks for GSD. Furthermore, gallbladder polyps, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and aspartate aminotransferase were negatively correlated to risks for GSD. According to the nomograms of the complete model, a simplified model including sex, age, body mass index, gallbladder polyps, and fatty liver disease was constructed. All the calibration curves exhibited good consistency between the predicted and observed probabilities. In addition, DCA indicated that both the complete model and the simplified model showed better net benefits than treat-all and treat-none. Based on the calibration plots, DCA, and AUCs of the complete model (AUC in the internal validation data set=74.1% [95% CI: 72.9%-75.3%], AUC in Shandong=71.7% [95% CI: 70.6%-72.8%], AUC in Tianjin=75.3% [95% CI: 72.7%-77.9%], and AUC in Kaizhou=72.9% [95% CI: 72.5%-73.3%]) and the simplified model (AUC in the internal validation data set=73.7% [95% CI: 72.5%-75.0%], AUC in Shandong=71.5% [95% CI: 70.4%-72.5%], AUC in Tianjin=75.4% [95% CI: 72.9%-78.0%], and AUC in Kaizhou=72.4% [95% CI: 72.0%-72.8%]), we concluded that the complete and simplified risk prediction models for GSD exhibited excellent performance. Moreover, we detected no significant differences between the performance of the two models (P>0.05). We also established two online websites based on the results of this study for GSD risk prediction.

Conclusions

This study innovatively used the data from 96426 patients from four hospitals to establish a GSD risk prediction model and to perform risk prediction analyses of internal and external validation data sets in four cohorts. A simplified model of GSD risk prediction, which included the variables of sex, age, body mass index, gallbladder polyps, and fatty liver disease, also exhibited good discrimination and clinical performance. Nonetheless, further studies are needed to explore the role of low-density lipoprotein cholesterol and aspartate aminotransferase in gallstone formation. Although the validation results of the complete model were better than those of the simplified model to a certain extent, the difference was not significant even in large samples. Compared with the complete model, the simplified model uses fewer variables and yields similar prediction and clinical impact. Hence, we recommend the application of the simplified model to improve the efficiency of screening high-risk groups in practice. The use of the simplified model is conducive to enhancing the self-awareness of prevention and control in the general population and early intervention for GSD.

[New Progress in Longitudinal Research on the Risk Factors for Cholelithiasis]

Cholelithiasis is a common disease of the digestive system. The risk factors for cholelithiasis have been reported and summarized many times in the published literature, which primarily focused on cross-sectional studies. Due to the inherent limitations of the study design, the reported findings still need to be validated in additional longitudinal studies. Moreover, a number of new risk factors for cholelithiasis have been identified in recent years, such as bariatric surgery, hepatitis B virus infection, hepatitis C virus infection, kidney stones, colectomy, osteoporosis, etc. These new findings have not yet been included in published reviews. Herein, we reviewed the 101 cholelithiasis-associated risk factors identified through research based on longitudinal investigations, including cohort studies, randomized controlled trials, and nested case control studies. The risk factors associated with the pathogenesis of cholelithiasis were categorized as unmodifiable and modifiable factors. The unmodifiable factors consist of age, sex, race, and family history, while the modifiable factors include 37 biological environmental factors, 25 socioenvironmental factors, and 35 physiochemical environmental factors. This study provides thorough and comprehensive ideas for research concerning the pathogenesis of cholelithiasis, supplying the basis for identifying high-risk groups and formulating relevant prevention strategies.

Inhibition of PCSK9 prevents and alleviates cholesterol gallstones through PPARα-mediated CYP7A1 activation

BACKGROUND & AIMS

Dysregulated cholesterol metabolism is the major factor responsible for cholesterol gallstones (CGS). Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a critical role in cholesterol homeostasis and its inhibitors secure approval for treating various cholesterol metabolic disorders such as hypercholesterolemia and cardiovascular diseases, but its role in CGS remains unclear. Our study aims to clarify mechanisms by which PCSK9 promotes CGS formation and explore the application of the PCSK9 inhibitor, alirocumab, in preventing and treating CGS.

APPROACH & RESULTS

The expressions of PCSK9 were notably increased in CGS patients' serum, bile, and liver tissues compared to those without gallstones. Moreover, among CGS patients, hepatic PCSK9 was positively correlated with hepatic cholesterol and negatively correlated with hepatic bile acids (BAs), suggesting PCSK9 was involved in disrupted hepatic cholesterol metabolism related to CGS. Mechanistically, in vitro experiments demonstrated that inhibition of PCSK9 enhanced nuclear expression of PPARα by diminishing its lysosomal degradation and subsequently activated CYP7A1 transcription. Finally, inhibition of PCSK9 prevented CGS formation and dissolved the existing stones in CGS mice by elevating the conversion of cholesterol into BAs through PPARα-mediated CYP7A1 activation. Additionally, serum PCSK9 level may function as a prognostic signature to evaluate the therapeutic efficacy of PCSK9 inhibitors.

CONCLUSIONS

Inhibition of PCSK9 exerts preventive and therapeutic effects on CGS by activating PPARα-mediated CYP7A1 expression and facilitating the conversion of cholesterol into BAs, which highlights the potential of PCSK9 inhibition as a promising candidate for preventing and treating CGS in clinical applications.

IMPACT AND IMPLICATIONS

PCSK9 plays a pivotal role in cholesterol metabolism and its inhibitors are approved for clinical use in cardiovascular diseases. Our study observes inhibition of PCSK9 prevents and dissolves CGS by activating PPARα-mediated CYP7A1 expression and facilitating the conversion of cholesterol into BAs. Mechanistically, PCSK9 inhibition enhanced the nuclear expression of PPARα by diminishing its lysosomal degradation and subsequently activated CYP7A1 transcription. Our study sheds light on the new function and mechanism of PCSK9 in CGS, providing a novel preventive and therapeutic target with potential clinical applications.

Novel insights into causal effects of serum lipids and lipid-modifying targets on cholelithiasis

OBJECTIVE

Different serum lipids and lipid-modifying targets should affect the risk of cholelithiasis differently, however, whether such effects are causal is still controversial and we aimed to answer this question.

DESIGN

We prospectively estimated the associations of four serum lipids with cholelithiasis in UK Biobank using the Cox proportional hazard model, including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG). Furthermore, we estimated the causal associations of the genetically predicted serum lipids with cholelithiasis in Europeans using the Mendelian randomisation (MR) design. Finally, both drug-target MR and colocalisation analyses were performed to estimate the lipid-modifying targets' effects on cholelithiasis, including HMGCR, NPC1L1, PCSK9, APOB, LDLR, ACLY, ANGPTL3, MTTP, PPARA, PPARD and PPARG.

RESULTS

We found that serum levels of LDL-C and HDL-C were inversely associated with cholelithiasis risk and such associations were linear. However, the serum level of TC was non-linearly associated with cholelithiasis risk where lower TC was associated with higher risk of cholelithiasis, and the serum TG should be in an inverted 'U-shaped' relationship with it. The MR analyses supported that lower TC and higher TG levels were two independent causal risk factors. The drug-target MR analysis suggested that HMGCR inhibition should reduce the risk of cholelithiasis, which was corroborated by colocalisation analysis.

CONCLUSION

Lower serum TC can causally increase the risk of cholelithiasis. The cholelithiasis risk would increase with the elevation of serum TG but would decrease when exceeding 2.57 mmol/L. The use of HMGCR inhibitors should prevent its risk.

Can Lipid-Lowering Drugs Reduce the Risk of Cholelithiasis? A Mendelian Randomization Study

Background and Aims

Cholelithiasis etiology intricately involves lipid metabolism. We sought to investigate the plausible causal link between genetically proxied lipid-lowering medications-specifically HMGCR inhibitors, PCSK9 inhibitors, and NPC1L1 inhibitors-and cholelithiasis risk.

Methods

Our study utilized two genetic instruments for exposure to lipid-lowering drugs. These instruments encompassed genetic variants linked to low-density lipoprotein (LDL) cholesterol within or in proximity to drug target genes, along with loci governing gene expression traits of these targets. Effect estimates were derived through Inverse-variance-weighted MR (IVW-MR) and summary-data-based MR (SMR) methods.

Results

Higher HMGCR-mediated LDL cholesterol levels (IVW-MR, OR = 2.15, 95% CI = 1.58-2.94; P = 0.000) and increased HMGCR expression (SMR, OR = 1.19, 95% CI = 1.04-1.37; P = 0.014) are linked to elevated cholelithiasis risk, suggesting potential benefits of HMGCR inhibition. In contrast, higher PCSK9-mediated LDL cholesterol levels (IVW-MR, OR = 0.72, 95% CI = 0.56-0.94; P = 0.015) and increased PCSK9 expression (SMR, OR = 0.90, 95% CI = 0.82-0.99; P = 0.035) both correlate with lower cholelithiasis risk, indicating that PCSK9 inhibition may elevate this risk. Nevertheless, no substantial link emerged between NPC1L1-mediated LDL cholesterol or NPC1L1 expression and cholelithiasis in both IVW-MR and SMR analyses.

Conclusion

This MR investigation affirms the causal link between the utilization of HMGCR inhibitors and a diminished risk of cholelithiasis. Additionally, it indicates a causal link between PCSK9 inhibitors use and increased cholelithiasis risk. However, no significant correlation was found between NPC1L1 inhibitors use and cholelithiasis risk.

Cardiac complications caused by biliary diseases: A review of clinical manifestations, pathogenesis and treatment strategies of cholecardia syndrome

Gallbladder and biliary diseases (GBDs) are one of the most common digestive diseases. The connections between GBDs and several organs other than the liver have gradually surfaced accompanied by the changes in people's diet structure and the continuous improvement of medical diagnosis technology. Among them, cholecardia syndrome that takes the heart as the important target of GBDs complications has been paid close attention. However, there are still no systematic report about its corresponding clinical manifestations and pathogenesis. This review summarized recent reported types of cholecardia syndrome and found that arrhythmia, myocardial injury, acute coronary syndrome and heart failure are common in the general population. Besides, the clinical diagnosis rate of intrahepatic cholestasis of pregnancy (ICP) and Alagille syndrome associated with gene mutation is also increasing. Accordingly, the underlying pathogenesis including abnormal secretion of bile acid, gene mutation, translocation and deletion (JAG1, NOTCH2, ABCG5/8 and CYP7A1), nerve reflex and autonomic neuropathy were further revealed. Finally, the potential treatment measures and clinical medication represented by ursodeoxycholic acid were summarized to provide assistance for clinical diagnosis and treatment.

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.

Exploration of the Causal Association Between Behavioral Risk Factors and Gallstone Disease Development in Two European Ancestry Populations

Introduction Risk factors for developing gallstones are related to disturbances in either cholesterol or bilirubin metabolism in the biliary tract. The risk of forming gallstones can be associated with chronic illnesses, dietary habits, reduced gallbladder motility, and medications. Our study aims to explore the causal relationship between multiple risk factors, including nutritional habits (cheese intake, salad intake, processed meat intake, coffee drinking), smoking behavior, overall obesity measured by body mass index (BMI), lipid biomarkers, total bilirubin and maternal diabetes mellitus (DM) and the development of gallstone disease in two different populations of European ancestry (United Kingdom Biobank (UKB) and FinnGen). Materials and methods Using publicly available genome-wide association studies (GWAS) data, we performed a two-sample Mendelian randomization (MR) to examine the association between risk factors and gallstone development. Exposures used in this study included age of smoking initiation, smoking intensity, coffee intake, cheese intake, salad intake, processed meat intake, BMI, and lipid biomarkers (cholesterol, low-density lipoproteins (LDL), triglycerides (TG), and high-density lipoproteins (HDL)). Current analyses were based on 93 single nucleotide polymorphisms (SNPs) for smoking initiation, four SNPs for smoking intensity, 65 SNPs for cheese intake, three SNPs for coffee intake, 22 SNPs for salad intake, 23 SNPs for processed meat intake, 79 SNPs for BMI, 26 SNPs for maternal DM, 89 SNPs for total bilirubin, 46 SNPs for cholesterol, 41 SNPs for LDL, 55 SNPs for TG, and 89 SNPs for HDL. The outcome in this study is gallstones/cholelithiasis. To evaluate the causal relationships between these risk factors and gallstones, two-sample MR methods were used. TwoSampleMR package in R software version 4.0.5 (R Foundation for Statistical Computing, Vienna, Austria) was used to obtain MR analyses and sensitivity analyses. Results  In the UKB, genetic predispositions to smoking initiation, BMI, and total bilirubin were significantly associated with an increased risk of gallstones. The odds of gallstones would increase per 1-SD increase of genetically estimated smoking initiation (OR: 1.004, P=0.008), BMI (OR: 1.02, P<0.001), and total bilirubin (OR: 1.0001, P=0.025). Conversely, genetic predispositions to cheese intake, coffee intake, cholesterol, LDL, and TG were statistically significantly associated with a decreased risk of gallstones (OR=0.99, P=0.014; OR=0.97, P=0.009; OR=0.99, P=0.006; OR=0.99, P=0.01; and OR=0.99, P<0.001, respectively). In FinnGen, genetic predispositions to BMI and total bilirubin were significantly associated with an increased risk of gallstones. The odds of gallstones would increase per 1-SD increase of genetically estimated BMI (OR: 1.7, P<0.001) and total bilirubin (OR: 1.02, P=0.002). Conversely, genetic predispositions to cheese intake, coffee intake, cholesterol, LDL, and TG were statistically significantly associated with a decreased risk of gallstones (OR=0.23, P=0.006; OR=0.42, P=0.041; OR=0.77, P=0.034; OR=0.88, P=0.008; and OR=0.70, P=0.005, respectively). Conclusion  Genetically estimated BMI and total bilirubin levels were associated with increased risk of gallstones among the two populations while genetically estimated cheese intake, coffee intake, and cholesterol, LDL, and TG levels factors were consistently associated with reduced risk of gallstones among the two populations.

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.

Insights into modifiable risk factors of cholelithiasis: A Mendelian randomization study

BACKGROUND AND AIMS

The risk factors of cholelithiasis have not been clearly identified, especially for total cholesterol. Here, we try to identify these causal risk factors.

APPROACH AND RESULTS

We obtained genetic variants associated with the exposures at the genome-wide significance (p < 5 × 10^-8 ) level from corresponding genome-wide association studies. Summary-level statistical data for cholelithiasis were obtained from FinnGen and UK Biobank (UKB) consortia. Both univariable and multivariable Mendelian randomization (MR) analyses were conducted to identify causal risk factors of cholelithiasis. Results from FinnGen and UKB were combined using the fixed-effect model. In FinnGen, the odds of cholelithiasis increased per 1-SD increase of body mass index (BMI) (OR = 1.631, p = 2.16 × 10^-7 ), together with body fat percentage (OR = 2.108, p = 4.56 × 10^-3 ) and fasting insulin (OR = 2.340, p = 9.09 × 10^-3 ). The odds of cholelithiasis would also increase with lowering of total cholesterol (OR = 0.789, p = 8.34 × 10^-5 ) and low-density lipoprotein-cholesterol (LDL-C) (OR = 0.792, p = 2.45 × 10^-4 ). However, LDL-C was not significant in multivariable MR. In UKB, the results of BMI, body fat percentage, total cholesterol, and LDL-C were replicated. In meta-analysis, the liability to type 2 diabetes mellitus and smoking could also increase the risk of cholelithiasis. Moreover, there were no associations with other predominant risk factors.

CONCLUSIONS

Our MR study corroborated the risk factors of cholelithiasis from previous MR studies. Furthermore, lower total cholesterol level could be an independent risk factor.

Choledocholithiasis characteristics with periampullary diverticulum and endoscopic retrograde cholangiopancreatography procedures: Comparison between two centers from Lanzhou and Kyoto

BACKGROUND

Most of study regarding periampullary diverticulum (PAD) impact on endoscopic retrograde cholangiopancreatography (ERCP) therapy for choledocholithiasis based on data from one endoscopy center and lacked to compare the clinical characteristic of choledocholithiasis with PAD from different geographical patients.

AIM

To compare the choledocholithiasis clinical characteristics between two regional endoscopy centers and analyze impacts of clinical characteristics on ERCP methods for choledocholithiasis patients with PAD.

METHODS

Patients seen in two endoscopy centers (The First Hospital of Lanzhou University, Lanzhou, Gansu Province, China, and Kyoto Second Red Cross Hospital, Kyoto, Japan) underwent ERCP treatment for the first time between January 2012 and December 2017. The characteristics of choledocholithiasis with PAD were compared between the two centers, and their ERCP procedures and therapeutic outcomes were analyzed.

RESULTS

A total of 829 out of 3608 patients in the Lanzhou center and 241 out of 1198 in the Kyoto center had choledocholithiasis with PAD. Lots of clinical characteristics were significantly different between the two centers. The common bile duct (CBD) diameter was wider, choledocholithiasis size was lager and multiple CBD stones were more in the Lanzhou center patients than those in the Kyoto center patients (14.8 ± 5.2 mm vs 11.6 ± 4.2 mm, 12.2 ± 6.5 mm vs 8.2 ± 5.3 mm, 45.3% vs 20.3%, P < 0.001 for all). In addition, concomitant diseases, such as acute cholangitis, gallbladder stones, obstructive jaundice, cholecystectomy, and acute pancreatitis, were significantly different between the two centers (P = 0.03 to < 0.001). In the Lanzhou center, CBD diameter and choledocholithiasis size were lower, and multiple CBD stones and acute cholangitis were less in non-PAD patients than those in PAD patients (13.4 ± 5.1 mm vs 14.8 ± 5.2 mm, 10.3 ± 5.4 mm vs 12.2 ± 6.5, 39% vs 45.3%, 13.9% vs 18.5%, P = 0.002 to < 0.001). But all these characteristics were not significantly different in the Kyoto center. The proportions of endoscopic sphincterotomy (EST), endoscopic balloon dilatation (EPBD), and EST+EPBD were 50.5%, 1.7%, and 42.5% in the Lanzhou center and 90.0%, 0.0%, and 0.4% in the Kyoto center, respectively. However, the overall post-ERCP complication rate was not significantly different between the two centers (8.9% in the Lanzhou and 5.8% in the Kyoto. P = 0.12). In the Lanzhou center, the difficulty rate in removing CBD stones in PAD was higher than in non-PAD group (35.3% vs 26.0%, P < 0.001). But the rate was no significant difference between the two groups in Kyoto center. The residual rates of choledocholithiasis were not significantly different between the two groups in both centers. Post-ERCP complications occurred in 8.9% of the PAD patients and 8.1% of the non-PAD patients in the Lanzhou Center, and it occurred in 5.8% in PAD patients and 10.0% in non-PAD patients in the Kyoto center, all P > 0.05.

CONCLUSION

Many clinical characteristics of choledocholithiasis patients with PAD were significantly different between the Lanzhou and Kyoto centers. The patients had larger and multiple stones, wider CBD diameter, and more possibility of acute cholangitis and obstructive jaundice in the Lanzhou center than those in the Kyoto center. The ERCP procedures to manage native duodenal papilla were different depending on the different clinical characteristics while the overall post-ERCP complications were not significantly different between the two centers. The stone residual rate and post-ERCP complications were not significantly different between choledocholithiasis patients with PAD and without PAD in each center.

Association of apolipoprotein B XbaI (rs693) polymorphism and gallstone disease risk based on a comprehensive analysis

BACKGROUND

Our aim was to investigate the association between XbaI gene polymorphisms in the apolipoprotein B (APOB) gene and gallstone disease (GD) risk through a comparison of the allele and genotype distribution frequencies at this site using meta-analysis.

METHODS

A literature search was performed using PubMed and Wanfang through Jun 1, 2020. Odds ratios (ORs) and 95 % confidence intervals (CIs) were used to assess the strength of associations.

RESULTS

After a comprehensive search, 14 different articles that met the inclusion criteria were selected, with 1583 cases and 1794 controls. Individuals carrying the A-allele or AA genotype of the rs693 polymorphism were determined to possibly have an increased risk of GD. For example, there was a significant relationship between the rs693 polymorphism and increased GD risk in the whole group (OR: 1.40, 95 % CI: 1.05-1.87 in the allelic contrast model), the Asian population (OR: 1.58, 95 % CI: 1.48-2.84 in the heterozygote model), and the hospital-based source of the control (OR: 1.79, 95 % CI: 1.13-2.84 in the dominant model).

CONCLUSIONS

This study suggests that the APOB rs693 polymorphism is potentially associated with GD susceptibility, which might offer a detection marker for use in future large scale clinic research.

The association between apolipoprotein E and gallstone disease: an updated meta-analysis

BACKGROUND

Gallstone disease (GSD) is a common biliary tract disease worldwide. Previous studies have investigated the association of apolipoprotein E (APOE) E4 with GSD and reported inconsistent results.

METHODS

In this paper, we conducted meta-analyses to examine whether APOE E4 is associated with the risk of GSD. A systematic literature search was performed in PubMed, Cochrane Library, EMBASE, and Google Scholar using the following inclusion criteria: 1) Studies on human subjects; 2) subjects in the control group must undergo ultrasound GSD screening, and presence of GSD in the experiment group can be clearly determined, e.g., diagnosis of GSD through ultrasound screening or a previous history of cholecystectomy or cholelithiasis; 3) the studies reported APOE genotype data (APOE E4+ vs. E4-) for subjects with and without GSD. In all the meta-analyses, we used random-effects models to calculate the odds ratios (ORs) as a measure of association as well as the corresponding confidence intervals (CIs).

RESULTS

Our literature search found 13 publications with 14 studies, including a total of 1632 GSD patients and 5001 controls, that met the eligibility criteria and were included in the meta-analyses. We did not find a significant association between APOE E4 and risk of GSD (OR = 1.23, 95% CI: 0.89-1.68; p = 0.205). No significant associations were observed in subgroup analyses by gender and mean age. We obtained similar insignificant findings if an additive model was used, if subjects who had E2E4 genotype were excluded, or if low-quality studies were excluded.

CONCLUSION

Our meta-analysis found insufficient evidence for the effect of APOE E4 on GSD risk. Future studies with large sample sizes that control for important confounding/risk factors are needed to validate our findings and to explore other genetic loci that might affect GSD risk.

Genome-wide association meta-analysis yields 20 loci associated with gallstone disease

Gallstones are responsible for one of the most common diseases in the Western world and are commonly treated with cholecystectomy. We perform a meta-analysis of two genome-wide association studies of gallstone disease in Iceland and the UK, totaling 27,174 cases and 736,838 controls, uncovering 21 novel gallstone-associated variants at 20 loci. Two distinct low frequency missense variants in SLC10A2, encoding the apical sodium-dependent bile acid transporter (ASBT), associate with an increased risk of gallstone disease (Pro290Ser: OR = 1.36 [1.25-1.49], P = 2.1 × 10-12, MAF = 1%; Val98Ile: OR = 1.15 [1.10-1.20], P = 1.8 × 10-10, MAF = 4%). We demonstrate that lower bile acid transport by ASBT is accompanied by greater risk of gallstone disease and highlight the role of the intestinal compartment of the enterohepatic circulation of bile acids in gallstone disease susceptibility. Additionally, two low frequency missense variants in SERPINA1 and HNF4A and 17 common variants represent novel associations with gallstone disease.

High prevalence of gallstone disease in rheumatoid arthritis: A new comorbidity related to dyslipidemia?

OBJECTIVE

To assess the prevalence of gallstone disease and identify associated risk factors in rheumatoid arthritis (RA) patients compared to the general population.

METHODS

Eighty-four women with rheumatoid arthritis were included in the study. Each patient was assessed via a structured interview, physical examination, abdominal ultrasound and blood test including lipid profile. The prevalence of gallstone disease in rheumatoid arthritis was compared with data from a study of the Spanish population matched by age groups.

RESULTS

Twenty-eight of the 84 women had gallstone disease (33.3%). RA women with and without gallstone disease were similar in most of the variables assessed, except for older age and menopausal status in the former. A greater prevalence of gallstone disease was seen in rheumatoid arthritis patients compared to the general population of the same age; however, the differences were significant only in women aged 60 or older (45.5% versus 23.1% respectively, P-value .008). The age-adjusted OR of developing gallstone disease in RA women compared with general population women was 2,3 (95% CI: 1.3-4.1). A significantly higher HDL3-c subfraction and higher apoA-I/HDL and HDL3-c/TC ratios were observed in patients with gallstone disease.

CONCLUSION

Women with rheumatoid arthritis may have a predisposition to gallstones that can manifest in middle or older age compared with women in the general population. This situation could be related to chronic inflammation and HDL metabolism.

Genetics of Lipid and Lipoprotein Disorders and Traits

PURPOSE OF REVIEW

Plasma lipids, namely cholesterol and triglyceride, and lipoproteins, such as low-density lipoprotein (LDL) and high-density lipoprotein, serve numerous physiological roles. Perturbed levels of these traits underlie monogenic dyslipidemias, a diverse group of multisystem disorders. We are on the verge of having a relatively complete picture of the human dyslipidemias and their components.

RECENT FINDINGS

Recent advances in genetics of plasma lipids and lipoproteins include the following: (1) expanding the range of genes causing monogenic dyslipidemias, particularly elevated LDL cholesterol; (2) appreciating the role of polygenic effects in such traits as familial hypercholesterolemia and combined hyperlipidemia; (3) accumulating a list of common variants that determine plasma lipids and lipoproteins; (4) applying exome sequencing to identify collections of rare variants determining plasma lipids and lipoproteins that via Mendelian randomization have also implicated gene products such as NPC1L1, APOC3, LDLR, APOA5, and ANGPTL4 as causal for atherosclerotic cardiovascular disease; and (5) using naturally occurring genetic variation to identify new drug targets, including inhibitors of apolipoprotein (apo) C-III, apo(a), ANGPTL3, and ANGPTL4.

SUMMARY

Here, we compile this disparate range of data linking human genetic variation to plasma lipids and lipoproteins, providing a "one stop shop" for the interested reader.

Cholelithiasis and the risk of intrahepatic cholangiocarcinoma: a meta-analysis of observational studies

Background

The etiological factor for intrahepatic cholangiocarcinoma (ICC) is not clear. Although it has been widely accepted that intrahepatic biliary tree stone is associated with increased risk of ICC, the role of extrahepatic biliary tree stone in the incidence of ICC is controversial. In the present study we aim to evaluate the association between pre-existing choledocholithiasis and cholecystolithiasis and the risk of ICC.

Methods

PubMed, Embase, and Web of Science were searched to identify cohort and case–control studies on the association between choledocholithiasis or cholecystolithiasis and the risk of ICC. Studies that met the inclusion criteria were subjected to a meta-analysis performed with Stata statistical software. Either a fixed or random effect model was used, depending on the heterogeneity within the studies. Egger’s test was performed to assess publication bias.

Results

Seven case–control studies met our inclusion criteria. Of the 123,771 participants, 4763 (3.85 %) were patients with ICC, and 119,008 were tumor-free controls. The presence of pre-existing bile duct stones (choledocholithiasis alone or choledocholithiasis accompanied by hepatolithiasis) was associated with the risk of ICC (odds ratio [OR] 17.64, 95 % confidence interval [CI] 11.14–27.95). Even the presence of choledocholithiasis alone (in the absence of hepatolithiasis) was associated with a high risk of ICC (OR 11.79, 95 % CI 4.17–33.35). Cholecystolithiasis may possibly contributed to the incidence of ICC (OR 2.00, 95 % CI 1.16–3.42), with large heterogeneity within studies (I² = 78.5 %).

Conclusions

Bile duct stones including choledocholithiasis are important risk factors for ICC. Careful surveillance of patients with extrahepatic biliary tree stone should be considered.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1870-0) contains supplementary material, which is available to authorized users.

Mendelian randomization studies: a review of the approaches used and the quality of reporting

BACKGROUND

Mendelian randomization (MR) studies investigate the effect of genetic variation in levels of an exposure on an outcome, thereby using genetic variation as an instrumental variable (IV). We provide a meta-epidemiological overview of the methodological approaches used in MR studies, and evaluate the discussion of MR assumptions and reporting of statistical methods.

METHODS

We searched PubMed, Medline, Embase and Web of Science for MR studies up to December 2013. We assessed (i) the MR approach used; (ii) whether the plausibility of MR assumptions was discussed; and (iii) whether the statistical methods used were reported adequately.

RESULTS

Of 99 studies using data from one study population, 32 used genetic information as a proxy for the exposure without further estimation, 44 performed a formal IV analysis, 7 compared the observed with the expected genotype-outcome association, and 1 used both the latter two approaches. The 80 studies using data from multiple study populations used many different approaches to combine the data; 52 of these studies used some form of IV analysis; 44% of studies discussed the plausibility of all three MR assumptions in their study. Statistical methods used for IV analysis were insufficiently described in 14% of studies.

CONCLUSIONS

Most MR studies either use the genotype as a proxy for exposure without further estimation or perform an IV analysis. The discussion of underlying assumptions and reporting of statistical methods for IV analysis are frequently insufficient. Studies using data from multiple study populations are further complicated by the combination of data or estimates. We provide a checklist for the reporting of MR studies.

Leptin levels and lipoprotein profiles in patients with cholelithiasis

Objective

To determine the relationships between serum leptin and levels of lipoprotein(a) [Lp(a)], apolipoprotein A-1 (ApoA-1) and apolipoprotein B (ApoB) in patients with cholelithiasis.

Methods

Patients with ultrasound-confirmed cholelithiasis and controls frequency-matched for age, sex, body mass index, fasting blood glucose and haemoglobin A1c levels were recruited. Fasting blood samples from all study participants were assayed for glucose, haemoglobin A1c, total cholesterol, high density lipoprotein-cholesterol (HDL-C) and triglyceride. Serum Lp(a), ApoA-1 and ApoB levels were measured using nephelometric assays; serum leptin was measured using an enzyme-linked immunosorbent assay.

Results

A total of 90 patients with cholelithiasis and 50 controls were included in the study. Serum levels of leptin, Lp(a), total cholesterol, triglyceride and ApoB were significantly increased, and levels of ApoA-1 and HDL-C were significantly decreased, in patients with cholelithiasis compared with controls. Serum leptin in patients with cholelithiasis were significantly positively correlated with Lp(a) and ApoB and negatively correlated with ApoA-1.

Conclusions

Patients with cholelithiasis have higher leptin levels and an altered lipoprotein profile compared with controls, with increased leptin levels being associated with increased Lp(a) and ApoB levels, and decreased ApoA-1 levels, in those with cholelithiasis.

Prevalence of and risk factors for gallstones in Uighur and Han Chinese

AIM: To perform a single-centre survey of the prevalence of and possible risk factors for gallstones in Uighur and Han Chinese.

METHODS: Complete medical data for 9455 patients were collected from the medical centre of our hospital, and the overall prevalence of gallstones as well as the prevalence in different ethnic groups was studied. The risk factors for gallstones in different ethnic groups were identified in a univariate analysis, and variables with statistical significance were analysed by unconditional multiple logistic regression, to primarily explore the similarities and differences in gallstone risk factors between different ethnic groups.

RESULTS: The prevalence of gallstones was significantly higher in the Uighur population than in the Han population (22.87% vs 11.64%, P < 0.05). Further analysis of risk factors for gallstones based on the different ethnic areas revealed that age was a risk factor for gallstones in both groups; triglycerides, body-mass index (BMI) and high-density lipoprotein were risk factors for gallstones in the Han population, while total cholesterol (TC), gender and fatty liver were risk factors in the Uighur population. The Uighur patients were older than the Han patients, and had higher BMI, TC, low-density lipoprotein, female rate and fatty liver rate, while the incidence of hypertension was lower than that in the Han patients.

CONCLUSION: The prevalence of and risk factors for gallstones differ between the Uighur and Han populations.

The ABCG5/8 cholesterol transporter and myocardial infarction versus gallstone disease

OBJECTIVES

The study sought to test the hypothesis that genetic variation in ABCG5/8, the transporter responsible for intestinal and hepatobiliary cholesterol efflux, may simultaneously influence plasma and biliary cholesterol levels, and hence risk of myocardial infarction (MI) and gallstone disease in opposite directions.

BACKGROUND

High plasma levels of low-density lipoprotein (LDL) cholesterol are a causal risk factor for MI, whereas high levels of biliary cholesterol promote gallstone formation.

METHODS

A total of 60,239 subjects from Copenhagen were included, including 5,647 with MI and 3,174 with symptomatic gallstone disease. Subjects were genotyped for 6 common, nonsynonymous and functional variants in ABCG5/8, and a combined weighted genotype score was calculated.

RESULTS

Combined, weighted genotype scores were associated with stepwise decreases in LDL cholesterol of up to 5.9% (0.20 mmol/l) for individuals with a score ≥8.0 (prevalence = 11%) versus <2.0 (prevalence = 9%; p for trend across 5 groups = 2 × 10E-35). The cumulative incidences of MI and gallstone disease as a function of age and increasing genotype score were decreased and increased (log-rank ps for trend: 6 × 10E-4 and 9 × 10E-45), respectively. The multifactorially adjusted odds ratios were 0.83 (95% confidence interval: 0.73 to 0.94) for MI and 2.85 (95% confidence interval: 2.39 to 3.39) for symptomatic gallstone disease for individuals with a genotype score ≥8.0 versus <2.0.

CONCLUSIONS

Genetic variation in ABCG5/8, which associates with decreased levels of plasma LDL cholesterol protects against MI, but increases the risk of symptomatic gallstone disease. These results suggest that MI and gallstones, 2 seemingly unrelated diseases, are intrinsically linked via the function of the ABCG5/8 cholesterol transporter.