Big data and analysis of risk factors for gallbladder disease in the young generation of Korea

Gallbladder dysfunction caused by MYPT1 ablation triggers cholestasis-induced hepatic fibrosis in mice

BACKGROUND

The incidence of gallbladder diseases is as high as 20%, but whether gallbladder diseases contribute to hepatic disorders remains unknown.

METHODS

Here, we established an animal model of gallbladder dysfunction and assessed the role of a diseased gallbladder in cholestasis-induced hepatic fibrosis (CIHF).

RESULTS

Mice with smooth muscle-specific deletion of Mypt1, the gene encoding the main regulatory subunit of myosin light chain phosphatase (myosin phosphatase target subunit 1 [MYPT1]), had apparent dysfunction of gallbladder motility. This dysfunction was evidenced by abnormal contractile responses, namely, inhibited cholecystokinin 8-mediated contraction and nitric oxide-resistant relaxation. As a consequence, the gallbladder displayed impaired bile filling and biliary tract dilation comparable to the alterations in CIHF. Interestingly, the mutant animals also displayed CIHF features, including necrotic loci by the age of 1 month and subsequently exhibited progressive fibrosis and hyperplastic/dilated bile ducts. This pathological progression was similar to the phenotypes of the animal model with bile duct ligation and patients with CIHF. The characteristic biomarker of CIHF, serum alkaline phosphatase activity, was also elevated in the mice. Moreover, we observed that the myosin phosphatase target subunit 1 protein level was able to be regulated by several reagents, including lipopolysaccharide, exemplifying the risk factors for gallbladder dysfunction and hence CIHF.

CONCLUSIONS

We propose that gallbladder dysfunction caused by myosin phosphatase target subunit 1 ablation is sufficient to induce CIHF in mice, resulting in impairment of the bile transport system.

Comparison of Triglyceride-Glucose Index between Patients with Gallstone and Healthy Individuals

Background

Triglyceride-glucose index is a product of triglycerides and fasting plasma glucose (FPG) and is a new index of insulin resistance found to correlate with direct measurements. This study aimed to evaluate the relationship between gallstones and triglyceride-glucose index (TGI).

Methods

A total of 210 patients were included in this retrospective study. Overall, 105 patients with gallstones were included in the patient group. Patients with diabetes mellitus, chronic diseases, malignant diseases, and patients using cholesterol-lowering drugs were excluded from the study. Healthy individuals (105 cases) were selected for the control group. TGI was calculated separately for each individual using the following formula: (TGI) = ln (fasting TG (mg/dL) × fasting glucose (mg/dL)/2).

Results

Plasma triglyceride levels were significantly higher in patients with gallstones compared to the control group (P=0.001). Plasma HDL, LDL, and total cholesterol did not differ between the groups (P>0.05). Fasting blood glucose was significantly higher in patients with gallstones compared to the control group (P=0.001). The triglyceride glucose index was significantly higher in patients with gallstones compared to the control group (P<0.001). When the relationship between body mass index and TGI was analyzed, TGI was lower in patients with normal BMI compared to overweight or obese patients (P<0.001).

Conclusion

Increased triglyceride/glucose index in patients with gallstones is an indicator of insulin resistance. It is instrumental in demonstrating the presence of insulin resistance in patients with gallstones and may be a useful guide in earlier detection, prevention, and treatment of insulin resistance.

Global, regional, and national burden of gallbladder and biliary diseases from 1990 to 2019

BACKGROUND

Gallbladder and biliary diseases (GABDs) are a major public health issue.

AIM

To analysis the cause-specific incidence, prevalence, and years lived with disability (YLDs) and its temporal trends of GABDs at the global, regional, and national level. Data on GABD were available from the Global Burden of Disease study 2019.

METHODS

The estimated annual percentage change (EAPC) was used to quantify temporal trend in GABD age-standardized incidence rates (ASIRs), age-standardized prevalence rate (ASPR), and age-standardized YLD rate (ASYR) by region, sex. We analyzed the relationship between the GABD burden and country development level using the human development index (HDI).

RESULTS

In 2019, the incident cases of GABD were 52003772, with an ASIR of 63432/100000 population. Globally, the number of incident cases and ASIR of GABD increased 97% and 58.9% between 1990 and 2019. Although, the ASPR and ASYR decreased from 1990 to 2019, the number of prevalent and YLDs cases increased. The highest ASIR was observed in Italy, and the highest ASPR and ASYR was observed in United Kingdom. The highest burden of GABD was found in low-SDI region, and the burden in female was significantly higher than males. A generally negative correlation (ρ = -0.24, P < 0.05) of GABD with the EAPC and human development index (HDI) (in 2021) were observed for ASIR. What's more, no correlation in ASPR (ρ = -0.06, P = 0.39) and ASYR (ρ = -0.07, P = 0.36) of GABD with the EAPC and HDI (in 2021) were observed, respectively.

CONCLUSION

GABD remain a major global public health challenge; however, the burden of GABD varies geographically. Globally, the number of incident cases and ASIR of GABD increased between 1990 and 2019. The results of our study provide insight into the global disease burden of GABD and may assist policymakers in formulating effective policies to mitigate modifiable risk factors.

Evidence-based clinical practice guidelines for cholelithiasis 2021

The Japanese Society of Gastroenterology first published evidence-based clinical practice guidelines for cholelithiasis in 2010, followed by a revision in 2016. Currently, the revised third edition was published to reflect recent evidence on the diagnosis, treatment, and prognosis of cholelithiasis conforming to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Following this revision, the present English version of the guidelines was updated and published herein. The clinical questions (CQ) in the previous version were reviewed and rearranged into three newly divided categories: background questions (BQ) dealing with basic background knowledge, CQ, and future research questions (FRQ), which refer to issues that require further accumulation of evidence. Finally, 52 questions (29 BQs, 19 CQs, and 4 FRQs) were adopted to cover the epidemiology, pathogenesis, diagnosis, treatment, complications, and prognosis. Based on a literature search using MEDLINE, Cochrane Library, and Igaku Chuo Zasshi databases for the period between 1983 and August 2019, along with a manual search of new information reported over the past 5 years, the level of evidence was evaluated for each CQ. The strengths of recommendations were determined using the Delphi method by the committee members considering the body of evidence, including benefits and harms, patient preference, and cost-benefit balance. A comprehensive flowchart was prepared for the diagnosis and treatment of gallbladder stones, common bile duct stones, and intrahepatic stones, respectively. The current revised guidelines are expected to be of great assistance to gastroenterologists and general physicians in making decisions on contemporary clinical management for cholelithiasis patients.

Analysis of Risk Factors for Cholelithiasis: A Single-Center Retrospective Study

Objectives Cholelithiasis poses a considerable medical burden worldwide. While its pathogenesis is multifactorial, identifying the key risk factors is essential for understanding the disease and improving patient care. This study aims to investigate the potential associations between demographic, clinical, and laboratory variables and the development of cholelithiasis. Methods This single-center retrospective study was conducted at Malla Reddy Institute of Medical Sciences, Hyderabad, India, over one month. A total of 200 patients diagnosed with cholelithiasis were included. Data were extracted from electronic health records and the patients using a questionnaire, including demographic information (age, gender), clinical data including body mass index (BMI), and comorbidities. Statistical analyses were conducted to determine the associations between risk factors and cholelithiasis. Results The frequency of cholelithiasis is found to be higher in the female gender and patients with obesity, sedentary lifestyle and hypertension as compared to male patients, and the risk of cholelithiasis also increases with age. Females demonstrated a higher prevalence of cholelithiasis, with an odds ratio (OR) and confidence interval (CI) of 1.4, 95% CI [1.1, 1.7], p < 0.05). Obese individuals (BMI ≥ 30) had 2.2 times higher odds of cholelithiasis compared to those with normal BMI (< 24.9) (OR = 2.2, 95% CI [1.7, 2.9], p < 0.001). The presence of diabetes significantly increased the odds of cholelithiasis by 1.6 times (OR = 1.6, 95% CI [1.2, 2.1], p < 0.01). Overweight individuals (BMI: 25-29.9) were associated with 1.4 times higher odds of cholelithiasis (OR = 1.4, 95% CI [1.1, 1.9], p < 0.05). Conclusion Our study identified age, gender, BMI, diabetes, and obesity as significant risk factors for cholelithiasis. These findings underscore the importance of targeted interventions and lifestyle modifications to mitigate cholelithiasis risk and improve patient outcomes. Further research, including prospective multicentric studies, must validate these findings and explore potential underlying mechanisms.

Rapid detection of cholecystitis by serum fluorescence spectroscopy combined with machine learning

While cholecystitis is a critical public health problem, the conventional diagnostic methods for its detection are time consuming, expensive and insufficiently sensitive. This study examined the possibility of using serum fluorescence spectroscopy and machine learning for the rapid and accurate identification of patients with cholecystitis. Significant differences were observed between the fluorescence spectral intensities of the serum of cholecystitis patients (n = 74) serum and those of healthy subjects (n = 71) at 455, 480, 485, 515, 625 and 690 nm. The ratios of characteristic fluorescence spectral peak intensities were first calculated, and principal component analysis (PCA)-linear discriminant analysis (LDA) and PCA-support vector machine (SVM) classification models were then constructed using the ratios as variables. Compared with the PCA-LDA model, the PCA-SVM model displayed better diagnostic performance in differentiating cholecystitis patients from healthy subjects, with an overall accuracy of 96.55%. This exploratory study showed that serum fluorescence spectroscopy combined with the PCA-SVM algorithm has significant potential for the development of a rapid cholecystitis screening method.

Effect of nicotine on cholesterol gallstone formation in C57BL/6J mice fed on a lithogenic diet

Gallstones are diseases of the biliary system caused by cholesterol supersaturation and/or deficiency in bile salts in bile. Early studies have shown that symptomatic gallstones are primarily a disease of non-smokers, raising the possibility that nicotine can prevent gallstone formation. The present study investigated the effect of nicotine on the formation of cholesterol gallstone in C57BL/6J mice. C57BL/6J mice (eight-weeks-old) were fed a normal or lithogenic diet (basic feed 82.45%, fat 15.8%, cholesterol 1.25% and sodium cholate 0.5%) and divided into five groups: normal diet (ND); ND + high dose nicotine (H); lithogenic diet (LD); LD + low dose nicotine (L) and LD + nicotine (H). They were treated with or without nicotine injection for 10 weeks. Nicotine treatment did not change the rate of cholesterol gallstone formation. There was no difference in TNFα, IL-1β and IL-6 among the five groups. The LD group showed the highest cholesterol levels and there was significant suppression of the total cholesterol, low-density lipoprotein-cholesterol and total bile acid levels in the serum of the nicotine-treated mice. Quantitative PCR showed nicotine altered few bile acid metabolism-related genes expression in liver tissue and significantly altered cholesterol-metabolism genes in gallbladder tissue. Hematoxylin and eosin staining and western blotting showed that protein levels of farnesoid X receptor (FXR) and megalin in the gallbladder increased in the lithogenic-diet mice, which was significantly suppressed in the nicotine-treated mice. In vitro studies using gallbladder epithelial cells showed that chenodeoxycholic acids increased megalin expression, which could be attenuated by nicotine. Nicotine could regulate bile acid metabolism via the FXR-megalin/cubilin pathways, which potentially contribute to cholesterol nucleation and subsequent gallstone formation.

The increasing incidence and high body mass index-related burden of gallbladder and biliary diseases-A results from global burden of disease study 2019

BACKGROUND

Gallbladder and biliary diseases are common gastrointestinal conditions associated with huge socioeconomic costs and are considered risk factors for cardiovascular diseases and digestive system cancers. The prevalence and incidence of gallbladder and biliary diseases have not received enough attention from 1990 to 2019. Several non-communicable diseases were associated with the incidence of gallbladder and biliary diseases. It is necessary to clarify the change in the incidence and disability burden of gallbladder and biliary diseases worldwide.

METHODS

Data on high body mass index (BMI)-related disease burden and incidence, years of life lost prematurely, and years lived with disability (YLDs) due to gallbladder and biliary diseases were obtained from the Global Burden of Disease 2019. The estimated annual percentage change was calculated to qualify the gallbladder and biliary disease burden change.

RESULTS

The global age-standardized incidence rate has increased from 585.35 per 100,000 (95% UI: 506.05-679.86) in 1990 to 634.32 per 100,000 (95% UI: 540.21-742.93) in 2019. And the increase in incidence was positively correlated with rising high BMI-related summary exposure value. The high BMI-related YLDs of gallbladder and biliary diseases have increased worldwide over time. Globally, the 25-49 age group suffered a rapid rise in incidence and high BMI attributable to the YLDs rate of gallbladder and biliary diseases.

CONCLUSION

The global incidence and high BMI-related YLDs of gallbladder and biliary diseases remain prominent to increase over the past 30 years. Notably, the incidence and high BMI-related YLDs among people aged 25-49 years have rapidly increased over time. Therefore, high BMI should be emphasized in strategic priorities for controlling gallbladder and biliary diseases.

Trends in Gallbladder Disease in Young Adults: A Growing Concern

Millennials (age: 25-32 years) and Generation-Z individuals (age: 10-25 years) exhibit a shift in the occurrence of gallbladder diseases, which may be related to changes in lifestyle and genetics. In light of these findings, we performed a retrospective observational study on patients who underwent gallbladder surgeries to determine the trend in gallbladder diseases in young adults. Both categorical and continuous data on 90 patients were collected between January 2020 and June 2021 and analysed retrospectively, with differences considered significant at a p-value of 0.05. The diagnosis of gallstones in young adults is presently complicated, as the signs and symptoms of biliary tract sickness differ significantly between those under and over 30 years of age. We observed that gallbladder diseases and their complications were highly common in individuals between the ages of 21 and 25 years. We discovered that gallstones were more common in teenagers than previously thought. Delays in intervention resulted in future complications which could have been avoided.

Chronological trends in patients undergoing cholecystectomy in Korea: a nationwide health insurance claims study

Purpose

The incidence of gallstone disease and cholecystectomy is increasing worldwide. The aim of this study was to determine trends in the incidence of cholecystectomy in Korea.

Methods

The National Health Insurance Services database was used to determine patterns in proportion of cholecystectomy and cholecystostomy in the total population of Korea from 2003 to 2017. The age-standardized rate (ASR) was calculated to compare the cholecystectomy and cholecystostomy according to changes in the population structure over time. The ASR was investigated according to patient age, sex, socioeconomic status, use of computed tomography, and type of hospital to identify trends.

Results

The ASR per 100,000 based on the 2010 population of cholecystectomy cases increased markedly from 67.7 to 211.4 between 2003 and 2017. The ASR was consistently higher in female than male (71.9 vs. 63.6 in 2003, 221.8 vs. 201.8 in 2017). Furthermore, the ASR for cholecystectomy increased with age, and surgery for gallstone disease was performed more often at a specialized center than at other medical facilities. The length of hospital stay of cholecystectomy decreased steadily from 10.6 days in 2003 to 6.9 days in 2017.

Conclusion

This study shows that the incidence of cholecystectomy and cholecystostomy has steadily increased over the years in Korea, with a trend toward older age and higher socioeconomic status in patients undergoing cholecystectomy. Increasing use of computed tomography investigations could be a primary cause for this trend. An integrated strategy is needed to manage the increase in older patients undergoing cholecystectomy and shorten their hospital stay with medical safety.

Symptomatic Gallstones in Young Patients Under the Age of 30 Years

Introduction Gallstones are deposits of digestive fluid that is hardened into small pellets. Gallstones can be symptomatic or asymptomatic. The present study assessed the sociodemographic and clinical characteristics of patients under the age of 30 years old with symptomatic gallstones. Methodology A prospective, observational study was conducted at Surgical Unit-3, at Jinnah Postgraduate Medical Centre (JPMC), Pakistan, from July 2020 to July 2021. All patients suspected of having gallstone disease underwent ultrasonic examination. A diagnosis of gallstone disease was made if the gallbladder showed a hyperechoic mass casting a posterior acoustic shadow, with a change of position. All of the patients with gallstone disease were hospitalized. The patients were asked about their age, past history (with special emphasis on last pregnancy and years of oral contraceptive use, if any), socioeconomic status, and other demographic data. The patients were treated with a cholecystectomy, either laparoscopic or open. Postcholecystectomy complications, if any, were recorded. Results A total of 210 patients under the age of 30 years were included. The mean age of patients was 25 ± 3 years. The majority of the population were females, i.e., 170 (81%). Upon assessing the risk factors, it was found that 31.84% of the female patients had used oral contraceptives, 32.96% were pregnant at the time of presentation, 20.48% had diabetes mellitus, and 27.14% had a history of gallstones. Furthermore, it was found that about 114 (54.29%) patients were overweight with a body mass index (BMI) of 25-30 kg/m2. High triglyceride levels and high cholesterol levels were found in 108 (51.43%) and 115 (54.76%) of the patients, respectively, indicating a link between symptomatic gallstones and younger age. Conclusion Our study indicated that young people are prone to symptomatic gallstones. The rate of disease was considerably high among females and in patients with high cholesterol and triglyceride levels and abnormal body mass index. Further exploratory studies are needed to determine the cause of gallstones.

Obesity and Gallstones

BACKGROUND

The prevalence of obesity has been increasing globally and represents the main risk factor for the development of gallstone disease (GD).

SUMMARY

Excess body weight represents the main cause for the development of GD; nevertheless, there have been described multiple risk factors for its development, among them modifiable risk factors as diet, lifestyle, physical inactivity, and non-modifiable risk factors as ethnicity, female sex, advanced age, parity, and genetic mutations. Body mass index, abdominal perimeter, and waist-hip index have been used to determine the degree of adiposity of a person. Hence, central abdominal fat has been mostly associated with insulin resistance with the consequent increase in the hepatic cholesterol secretion; contributing as one of the multiple mechanisms associated with the development of gallstones. This disease has a low mortality; however, it has been associated with multiple diseases such as cardiovascular diseases, carotid atherosclerosis, metabolic associated fatty liver disease, and gallbladder cancer, probably because they share many of the risk factors.

KEY MESSAGES

GD continues to be considered a disease with a high medical burden, in which it is sought to intervene in modifiable risk factors to reduce its development.

Gallbladder Polyps Increase the Risk of Ischaemic Heart Disease Among Korean Adults

Background: Gallbladder (GB) polyps and ischaemic heart disease (IHD) share some common risk factors. We investigated the longitudinal effects of gallbladder (GB) polyps, as a surrogate metabolic indicator, on IHD.

Methods: We enrolled 19,612 participants from the health risk assessment study (HERAS) and Korean Health Insurance Review and Assessment Service (HIRA) database. The primary outcome was IHD, which consisted of angina pectoris (ICD-10 code I20) or acute myocardial infarction (ICD-10 code I21) that occurred after enrolment into the study. We calculated hazard ratios (HRs) with 95% confidence intervals (CIs) for IHD according to the presence of GB polyps using multivariate Cox proportional hazards regression models.

Results: The median follow-up period was 29.9 months and a total of 473 individuals (2.4%, 473/19,612) developed IHD. Individuals with GB polyps had an increased risk of IHD compared with the control group after adjusting for potential confounding variables (HR = 1.425; 95% CI, 1.028–1.975). Furthermore, the coexistence of hypertension or dyslipidaemia resulted in an increased risk (HR = 2.14, 95% CI, 1.34–3.44 or HR = 2.09, 95% CI, 1.32–3.31, respectively) of new-onset IHD in the GB polyp group.

Conclusions: GB polyps was an independent risk factor of IHD. Awareness of these associations will inform clinicians on the need to include cardiovascular risk management as part of the routine management of patients with GB polyps.

An overview on possible links between aflatoxin B1 exposure and gallbladder cancer

Gallbladder cancer (GBC) is one of the most common sites for biliary tract cancers. It has a worldwide distribution being endemic in South America and Southern Asia. These high GBC rates have previously been linked to the determinants of health such as nutrition, genetics, lifestyle, and environment. Exposure to aflatoxin B₁ (AFB₁), a human carcinogen, is suggested to be involved with GBC development. This work aims to analyse the interplay of social, lifestyle, and genetic predisposing factors to GBC. AFB₁ plays a pivotal role in carcinogenic onset by genetic and epigenetic modifications. AFB₁ can induce molecular changes involved in the GBC pathogenesis, such as overexpression of UCHL1 gene, mutagenesis of TP53 gene, abnormal expression of oncogenes BCL-2, and aberrantly methylation of ERBB family receptors. However, a large-scale scientific cooperation is needed to confirm these molecular links through which AFB₁ may increase the GBC risk. For that, monitoring AFB₁ exposure through AF-albumin and AFB1-lysine will clarify the level of exposure of the population to AFB₁ in the GBC hotspot. Further, analyses of AFB1-adduct concentrations in GBC cases (fatal and non-fatal) are needed to understanding if AF contamination can trigger gallbladder cancer.

Risk factors for cholesterol polyp formation in the gallbladder are closely related to lipid metabolism

Background

The purpose of this study was to assess the risk factors for cholesterol polyp formation in the gallbladder.

Methods

This was a multicenter retrospective study based on pathology. From January 2016 to December 2019, patients who underwent cholecystectomy and non-polyp participants confirmed by continuous ultrasound follow-ups were reviewed. Patients in the cholesterol polyp group were recruited from three high-volume centers with a diagnosis of pathologically confirmed cholesterol polyps larger than 10 mm. Population characteristics and medical data were collected within 24 h of admission before surgery. The non-polyp group included participants from the hospital physical examination center database. They had at least two ultrasound examinations with an interval longer than 180 days. Data from the final follow-up of the non-polyp group were analyzed. The risk factors for cholesterol polyp formation were analyzed by comparing the two groups.

Results

A total of 4714 participants were recruited, including 376 cholesterol polyp patients and 4338 non-polyp participants. In univariate analysis, clinical risk factors for cholesterol polyps were age, male sex, higher body mass index (BMI), higher low-density lipoprotein (LDL), lower high-density lipoprotein (HDL), and higher aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. In multivariate logistic analysis, independent risk factors were age > 50 years (odds ratio [OR] = 3.02, 95% confidence interval [CI] 2.33–3.91, P < 0.001], LDL > 2.89 mmol/L (OR = 1.38, 95% CI 1.08–1.78, P = 0.011), lower HDL (OR = 1.78 95% CI 1.32–2.44, P < 0.001), AST > 40 IU/L (OR = 3.55, 95% CI 2.07–6.07, P < 0.001), and BMI > 25 kg/m ² (OR = 1.32, 95% CI 1.01–1.72, P = 0.037).

Conclusions

Age, LDL, HDL, AST, and BMI are strong risk factors for cholesterol polyp formation. Older overweight patients with polyps, accompanied by abnormal lipid levels, are at high risk for cholesterol polyps.

Gallbladder stone incidence and prevalence in Germany: a population-based study

BACKGROUND

 We aimed to determine the prevalence and incidence of gallbladder stones in a random population-based collective in Germany.

METHODS

 We determined the prevalence and incidence rates of gallbladder stones in a random population sample of 1909 individuals from the Echinococcus-multilocularis in Leutkirch (EMIL) study in 2002 and 380 individuals in a follow-up analysis in the year 2013. The sonographic analysis was performed with a Philipps HDI 5000 (2002) and IU 22 (2013) (Netherlands) transducer 1-5 MHz. Statistical analysis was performed using SAS Version 9.4.

RESULTS

 The prevalence of gallbladder stones was 3.8 % (69/1909) in 2002 and 10.8 % (41/380) in 2013. In 2013, the gallbladder stone prevalence was 15.1 % (26/172) in women, compared to 7.2 % (15/208) in men. No gallbladder stones were found in participants in the 18-30 or 31-40 age groups. The average annual incidence was 1.03 % in the 41-50 age group, 0.79 % in the 51-65 age group, and 0.63 % in the > 65 age group. The annual incidence was higher among women (1.04 %) than men (0.53 %). The age-associated annual incidence rates for women and men were 1.93 % and 0.5 % in the 41-50 age group, 0.8 % and 0.78 % in the 51-65 age group, and 1.06 % and 0.30 % in the > 65 age group.

CONCLUSION

 For the investigated German collective from 2002 to 2013, the average annual incidence of gallbladder stones was 0.75 %, with a higher incidence rate among women. These results are consistent with data from comparable international studies.

Smoking habits and gallbladder disease: a systematic review and meta-analysis study

BACKGROUND

It has been claimed that smoking is linked with an increased risk for gallbladder disease (GBD); however, related issues need further consolidation and clarification. The present systematic review and meta-analysis aimed to further investigate the potent correlation between GBD and smoking.

METHODS

We conducted a comprehensive literature review to identify every study published from January 1989 to December 2019, reporting risk estimates regarding GBD and smoking. The random-effect, generic inverse variance method, according to description by DerSimonian and Laird, was used to compute pooled estimates. We used the Newcastle-Ottawa quality assessment scale to appraise the included studies' quality.

RESULTS

Thirty published case-control, cross-sectional, and cohort studies including 4,623,435 individuals met the eligibility criteria and were considered for data synthesis. Compared to the non-smokers, ever smokers had 1.25 times higher odds of developing GBD [95 % confidence interval (CI): 1.09-1.44]; however, increased heterogeneity was observed (I² =96 %, 95 % CI: 62-100 %, p <0.001). Publication bias was non-significant (Eggers' regression p =0.072). The main sources of heterogeneity, as detected by meta-regression analyzing study characteristics, biases and confounders, were non-adjustment for family history (p =0.007) and alcohol (p =0.020), respectively. Subgroup analysis indicated a comparable risk for GBD as far as current, former and ever smokers are concerned (p =0.520). Quantitative analysis suggested a dose-effect for current smoking and GBD (p =0.010).

CONCLUSIONS

Non-smokers were demonstrated to be at a lower risk of presenting GBD when compared with ever smokers; all relevant risk estimates necessitate adjustment for family history and alcohol intake. HIPPOKRATIA 2020, 24(4): 147-156.

Association between the non-HDL-cholesterol-to-HDL-cholesterol ratio and the risk of gallbladder polyp formation among men: a retrospective cohort study

Background

Dyslipidaemia and male sex are associated with gallbladder polyp (GBP) formation. However, the potential relation between the non-high-density lipoprotein-cholesterol-to-high-density lipoprotein-cholesterol (non-HDL-c/HDL-c) ratio and GBPs in men is unclear.

Methods

A total of 1866 eligible subjects were selected for this retrospective cohort study from Wuhan Union Hospital between April 1, 2013, and November 30, 2014. Clinical and laboratory data of subjects were collected. Patients with GBPs or cholecystectomy at baseline, with missing data for baseline lipid profiles, following abdominal ultrasonography or taking lipid-lowering drugs were excluded. The patients were divided into five groups based on their non-HDL-c/HDL-c ratios, and descriptive analyses of the baseline data were performed. A Cox proportional hazards model was applied to estimate the relationship between the non-HDL-c/HDL-c ratio and GBPs.

Results

After a median follow-up of 1 year, 7.34% (n = 137) of the subjects developed GBPs. Compared with subjects without GBPs, those who developed GBPs after follow-up had significantly higher triglyceride (TG) levels and non-HDL-c/HDL-c ratios. The prevalence of GBPs showed a linearity increment with age, peaked in the 30–39 years group, 40–49 years group and 50–59 years group, and then declined slightly. The results of univariate analysis showed that the non-HDL-c/HDL-c ratio (hazard ratio (HR) = 1.29, 95% confidence interval (CI), 1.05–1.60, P = 0.0159) was positively correlated with GBPs. In the fully adjusted Cox regression model, the HRs were 2.24 for quintile 2 (95% CI: 1.13–4.44, P = 0.0203), 1.50 for quintile 3 (95% CI: 0.73–3.10, P = 0.269), 2.52 for quintile 4 (95% CI: 1.26–5.01, P = 0.0087) and 2.13 for quintile 5 (95% CI: 1.04–4.37, P = 0.0397). No interaction was found among the subgroups.

Conclusions

A higher non-HDL-c/HDL-c ratio is independently related to a higher risk of GBP formation in Chinese men. Further research is needed to investigate whether this association exists in different regions and races.