Factors associated with gallstone disease in the MICOL experience. Multicenter Italian Study on Epidemiology of Cholelithiasis

Elevated body mass index as a causal risk factor for symptomatic gallstone disease: a Mendelian randomization study

Elevated body mass index (BMI) is associated with an increased risk of gallstone disease. Whether this reflects a causal association is unknown. Using a Mendelian randomization approach, we studied 77,679 individuals from the general population. Of these, 4,106 developed symptomatic gallstone disease during up to 34 years of follow-up. Subjects were genotyped for three common variants known to associate with BMI: FTO(rs9939609); MC4R(rs17782313); and TMEM18(rs6548238). The number of BMI-increasing alleles was calculated for each participant. In observational analyses, mean baseline BMI was 55% (11.6 kg/m(2) ) increased in individuals in the fifth quintile versus the first quintile, similar in women and men. The corresponding multifactorially adjusted hazard ratio (HR) for symptomatic gallstone disease was 2.84 (95% confidence interval [CI]: 2.32-3.46) overall, 3.36 (95% CI: 2.62-4.31) in women, and 1.51 (95% CI: 1.09-2.11) in men (P trend: 0.001 to <0.001; P interaction: BMI*sex on risk = 0.01). In genetic analyses, carrying 6 versus 0-1 BMI-increasing alleles was associated with a 5.2% (1.3 kg/m(2) ) increase in BMI overall and with increases of 4.3% in women and 6.1% in men (all P trend: <0.001). Corresponding HRs for symptomatic gallstone disease were 1.43 (95% CI: 0.99-2.05) overall, 1.54 (95% CI: 1.00-2.35) in women, and 1.19 (95% CI: 0.60-2.38) in men (P trend = 0.007, 0.02, and 0.26, respectively; P interaction allele score*sex on risk = 0.49). The estimated causal odds ratio (OR) for symptomatic gallstone disease, by instrumental variable analysis for a 1 kg/m(2) increase in genetically determined BMI, was 1.17 (95% CI: 0.99-1.37) overall and 1.20 (95% CI: 1.00-1.44) and 1.02 (95% CI: 0.90-1.16) in women and men, respectively. Corresponding observational HRs were 1.07 (95% CI: 1.06-1.08), 1.08 (95% CI: 1.07-1.10), and 1.04 (95% CI: 1.02-1.07), respectively.

CONCLUSION

These results are compatible with a causal association between elevated BMI and increased risk of symptomatic gallstone disease, which is most pronounced in women.

Presence of coronary artery disease increases the risk of biliary events in patients with asymptomatic gallstones

BACKGROUND AND AIM

Propensity score indicates a probability of having a confounding factor. It is used to match each patient with the closest propensity score between two groups, which is known as propensity score matching. This study aimed to evaluate the gallstone-related biliary events, defined as biliary colic and acute cholecystitis between coronary artery disease (CAD) and non-CAD patients using propensity score matching.

METHODS

This retrospective cohort study evaluated 267 asymptomatic gallstone patients with CAD and 459 asymptomatic gallstone patients without CAD from March 2003 to December 2009 at two tertiary teaching hospitals in the Republic of Korea. After propensity score matching, total 378 patients, including 126 in study group (with CAD) and 252 in control group (without CAD), were evaluated.

RESULTS

During a median follow-up of 47 months, overall gallstone-related biliary event rate was 33.5% in the study group and 27.5% in the control group. The 5-year cumulative rates were 25.3% versus 17.7% in gallstone-related biliary event and 10.9% versus 1.6% in acute cholecystitis (study versus control group). After propensity score adjustment, the risk of gallstone-related biliary events in the CAD patients significantly increased (hazard ratio 2.11, 95% confidence interval 1.14-3.90, P = 0.017 in matched patients).

CONCLUSION

In patients with asymptomatic gallstones, the coexistence of CAD can increase the risk of gallstone-related biliary events, particularly acute cholecystitis. Therefore, gallstone patients with CAD should be carefully monitored, even if they are asymptomatic.

Current views on genetics and epigenetics of cholesterol gallstone disease

Cholesterol gallstone disease, one of the commonest digestive diseases in western countries, is induced by an imbalance in cholesterol metabolism, which involves intestinal absorption, hepatic biosynthesis, and biliary output of cholesterol, and its conversion to bile acids. Several components of the metabolic syndrome (e.g., obesity, type 2 diabetes, dyslipidemia, and hyperinsulinemia) are also well-known risk factors for gallstones, suggesting the existence of interplay between common pathophysiological pathways influenced by insulin resistance, genetic, epigenetic, and environmental factors. Cholesterol gallstones may be enhanced, at least in part, by the abnormal expression of a set of the genes that affect cholesterol homeostasis and lead to insulin resistance. Additionally, epigenetic mechanisms (mainly DNA methylation, histone acetylation/deacetylation, and noncoding microRNAs) may modify gene expression in the absence of an altered DNA sequence, in response to different lithogenic environmental stimuli, such as diet, lifestyle, pollutants, also occurring in utero before birth. In this review, we will comment on various steps of the pathogenesis of cholesterol gallstones and interaction between environmental and genetic factors. The epigenomic approach may offer new options for therapy of gallstones and better possibilities for primary prevention in subjects at risk.

Pediatric obesity and gallstone disease

OBJECTIVES

The aim of the present study was to investigate the association between childhood and adolescent obesity, the risk of gallstones, and the potential effect modification by oral contraceptive use in girls.

METHODS

For this population-based cross-sectional study, measured weight and height, oral contraceptive use, and diagnosis of cholelithiasis or choledocholithiasis were extracted from the electronic medical records of 510,816 patients ages 10 to 19 years enrolled in an integrated health plan, 2007-2009.

RESULTS

We identified 766 patients with gallstones. The adjusted odds ratios (95% CI) of gallstones for under-/normal-weight (reference), overweight, moderate obesity, and extreme obesity in boys were 1.00, 1.46 (0.94%-2.27%), 1.83 (1.17%-2.85%), and 3.10 (1.99%-4.83%) and in girls were 1.00, 2.73 (2.18%-3.42%), 5.75 (4.62%-7.17%), and 7.71 (6.13%-9.71%), respectively (P for interaction sex × weight class <0.001). Among girls, oral contraceptive use was associated with higher odds for gallstones (odds ratio 2.00, 95% CI 1.66%-2.40%). Girls who used oral contraceptives were at higher odds for gallstones than their counterparts in the same weight class who did not use oral contraceptives (P for interaction weight class × oral contraceptive use 0.023).

CONCLUSIONS

Due to the shift toward extreme childhood obesity, especially in minority children, pediatricians can expect to face increasing numbers of children and adolescents affected by gallstone disease.

Gallbladder and gastric motility in obese newborns, pre-adolescents and adults

BACKGROUND AND AIM

Impaired gallbladder and gastric motility have been associated with obesity in adults. The timing of appearance of this dysfunction, however, is unclear.

METHODS

Lean and obese subjects from three different age groups were studied noninvasively: 50 newborns (1-12 months old, six obese), 18 pre-adolescents (7-8 years old, seven obese), and 99 adults (22-80 years old, 32 obese) classified according to standard normal tables and body mass index. Changes of fasting/postprandial gallbladder and gastric motility were assessed simultaneously by functional ultrasonography in response to milk (newborns and pre-adolescents) and to a liquid test meal (adults).

RESULTS

In newborns, fasting and postprandial gallbladder volumes and gastric emptying were similar between obese and lean subjects. In pre-adolescents, obese subjects had a larger fasting gallbladder volume, with slower postprandial gastric emptying than lean subjects. In obese adults, the most evident dysfunction emerged, with larger fasting and postprandial residual gallbladder volume, and slower postprandial gastric emptying than lean subjects.

CONCLUSIONS

Obese subjects display abnormal gallbladder and gastric motility patterns, which first appear in pre-adolescents and deteriorate in adults. Such abnormalities are absent in obese newborns. Functional ultrasonography can detect altered cholecysto-gastric motility at the earliest stage. Our findings suggest an age-related decline of motility, probably secondary to excessive fat and insulin-resistance.

Serum organochlorine pesticide residues and risk of gallstone disease: a case-control study in Xiamen

PURPOSE

To investigate the association between serum organochlorine pesticide residues and risk of gallstone disease.

METHODS

A 1:1, pair-matched, case-control study was designed. Data from 150 patients with gallstones diagnosed by abdominal ultrasonography at a single hospital from June 2009 to June 2010 were collected. A total of 150 patients without gallstones during the same period at the same hospital were recruited as the control group. Capillary gas chromatography was employed to measure the serum concentrations of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) residues. Multiple-factor conditional logistic regression analysis was conducted to estimate the relative risk of gallstones in relation to organochlorine pesticide residues in serum.

RESULTS

The percentages of p,p'-DDD and o,p'-DDT in serum of patients were significantly higher than those in serum of controls. The p,p'-DDE, α-HCH, and δ-HCH residues in serum of patients were also significantly increased compared with those in serum of controls. Multiple-factor conditional logistic regression analysis showed that high levels of p,p'-DDE and p,p'-DDT residues were risk factors for gallstone disease.

CONCLUSIONS

A high level of organochlorine pesticide residues in serum is a potential risk factor for gallstone disease, which suggests that environmental exposure to organochlorine pesticides should be evaluated with respect to gallstone formation.

Therapy of gallstone disease: What it was, what it is, what it will be

Cholesterol gallstone disease is a common clinical condition influenced by genetic factors, increasing age, female gender, and metabolic factors. Although laparoscopic cholecystectomy is currently considered the gold standard in treating patients with symptomatic gallstones, new perspectives regarding medical therapy of cholelithiasis are currently under discussion, also taking into account the pathogenesis of gallstones, the natural history of the disease and the analysis of the overall costs of therapy. A careful selection of patients may lead to successful non-surgical therapy in symptomatic subjects with a functioning gallbladder harboring small radiolucent stones. The classical oral litholysis by ursodeoxycholic acid has been recently paralleled by new experimental observations, suggesting that cholesterol-lowering agents which inhibit cholesterol synthesis (statins) or intestinal cholesterol absorption (ezetimibe), or drugs acting on specific nuclear receptors involved in cholesterol and bile acid homeostasis, might be proposed as additional approaches for treating cholesterol gallstones. In this review we discuss old, recent and future perspectives on medical treatment of cholesterol cholelithiasis.

Beneficial effect of sulphate-bicarbonate-calcium water on gallstone risk and weight control

AIM: To investigate the effect of drinking sulphate-bicarbonate-calcium thermal water (TW) on risk factors for atherosclerosis and cholesterol gallstone disease.

METHODS: Postmenopausal women with functional dyspepsia and/or constipation underwent a 12 d cycle of thermal (n = 20) or tap (n = 20) water controlled drinking. Gallbladder fasting volume at ultrasound, blood vitamin E, oxysterols (7-β-hydroxycholesterol and 7-ketocholesterol), bile acid (BA), triglycerides, total/low density lipoprotein and high density lipoprotein cholesterol were measured at baseline and at the end of the study. Food consumption, stool frequency and body weight were recorded daily.

RESULTS: Blood lipids, oxysterols and vitamin E were not affected by either thermal or tap water consumption. Fasting gallbladder volume was significantly (P < 0.005) smaller at the end of the study than at baseline in the TW (15.7 ± 1.1 mL vs 20.1 ± 1.7 mL) but not in the tap water group (19.0 ± 1.4 mL vs 19.4 ± 1.5 mL). Total serum BA concentration was significantly (P < 0.05) higher at the end of the study than at baseline in the TW (5.83 ± 1.24 μmol vs 4.25 ± 1.00 μmol) but not in the tap water group (3.41 ± 0.46 μmol vs 2.91 ± 0.56 μmol). The increased BA concentration after TW consumption was mainly accounted for by glycochenodeoxycholic acid. The number of pasta (P < 0.001), meat (P < 0.001) and vegetable (P < 0.005) portions consumed during the study and of bowel movements per day (P < 0.05) were significantly higher in the TW than in the tap water group. Body weight did not change at the end of the study as compared to baseline in both groups.

CONCLUSION: Sulphate-bicarbonate-calcium water consumption has a positive effect on lithogenic risk and intestinal transit and allows maintenance of a stable body weight despite a high food intake.

Clinical characteristics and risk factors for symptomatic pediatric gallbladder disease

OBJECTIVE

Our center previously reported its experience with pediatric gallbladder disease and cholecystectomies from 1980 to 1996. We aimed to determine the current clinical characteristics and risk factors for symptomatic pediatric gallbladder disease and cholecystectomies and compare these findings with our historical series.

STUDY DESIGN

Retrospective, cross-sectional study of children, 0 to 18 years of age, who underwent a cholecystectomy from January 2005 to October 2008.

RESULTS

We evaluated 404 patients: 73% girls; 39% Hispanic and 35% white. The mean age was 13.10 ± 0.91 years. The primary indications for surgery in patients 3 years or older were symptomatic cholelithiasis (53%), obstructive disease (28%), and biliary dyskinesia (16%). The median BMI percentile was 89%; 39% were classified as obese. Of the patients with nonhemolytic gallstone disease, 35% were obese and 18% were severely obese; BMI percentile was 99% or higher. Gallstone disease was associated with hemolytic disease in 23% (73/324) of patients and with obesity in 39% (126/324). Logistic regression demonstrated older age (P = .019) and Hispanic ethnicity (P < .0001) as independent risk factors for nonhemolytic gallstone disease. Compared with our historical series, children undergoing cholecystectomy are more likely to be Hispanic (P = .003) and severely obese (P < .0279).

CONCLUSION

Obesity and Hispanic ethnicity are strongly correlated with symptomatic pediatric gallbladder disease. In comparison with our historical series, hemolytic disease is no longer the predominant risk factor for symptomatic gallstone disease in children.

Diabetes mellitus and the risk of cholecystectomy

BACKGROUND

Whether diabetes mellitus is associated with an increased risk of cholecystectomy remains controversial.

AIMS

To explore the association between diabetes mellitus and the risk of cholecystectomy.

METHODS

Population-based case-control analysis using UK-based General Practice Research Database. Cases of cholecystectomy and up to four controls per case, matched on age, sex, BMI, general practice, calendar time, and years of history in the database were identified between 1994 and 2008. Conditional logistic regression was used to estimate the risk of cholecystectomy in diabetics compared to non-diabetics. Odds ratios (ORs) were calculated, adjusted for smoking, alcohol consumption, statin use, and additional confounders.

RESULTS

Amongst 22,574 cases with cholecystectomy and 72,476 controls, 1068 (4.7%) and 3270 (4.5%) had diabetes, respectively, yielding an adjusted OR for developing gallstone disease followed by cholecystectomy of 0.88, 95% CI 78-1.00, p=0.05) in association with diabetes mellitus. Neither glycaemic control, nor increasing diabetes duration or oral antidiabetic therapies were associated with an altered risk of cholecystectomy. Use of statins was protective in patients with (adj. OR 0.66, 95% CI 0.54-0.80, p<0.0001) or without diabetes (adj. OR 0.70, 95% CI 0.62-0.78, p<0.0001).

CONCLUSIONS

Diabetes mellitus was not associated with an altered risk of cholecystectomy.

The aetiology of symptomatic gallstones quantification of the effects of obesity, alcohol and serum lipids on risk. Epidemiological and biomarker data from a UK prospective cohort study (EPIC-Norfolk)

OBJECTIVE

The development of gallstones is influenced by obesity and alcohol. This study aimed to precisely quantify these risks and investigate whether the aetiological mechanism may involve serum lipids, for the first time using a European prospective cohort study.

METHODS

The European Prospective Investigation into Cancer-Norfolk, recruited 25 639 men and women, aged 40 to 74 years, between 1993 and 1997. At enrolment weight, height and alcohol intake were recorded and nonfasting blood samples taken to measure serum triglycerides, cholesterol, high-density lipoproteins and low-density lipoproteins. The cohort was monitored for 14 years for symptomatic gallstones. Cox regression estimated sex-specific hazard ratios (HRs) for symptomatic gallstones adjusted for covariates.

RESULTS

Symptomatic gallstones developed in 296 people (67.9% women). For each additional unit of BMI, the HR in men was 1.08 [95% confidence interval (CI)=1.02-1.14]; in women the HR was 1.08 (95% CI=1.06-1.11). Every unit of alcohol consumed per week decreased risk in men by 3% (HR=0.97, 95% CI=0.95-0.99) with no effect in women. Serum triglycerides increased risk in men (highest vs. lowest quarter HR=2.02, 95% CI=1.03-3.98) and women (HR=2.43, 95% CI=1.52-3.90). Increased high-density lipoprotein was associated with a decreased risk in men (highest vs. lowest quarter HR=0.22, 95% CI=0.09-0.52) and women (HR=0.55, 95% CI=0.36-0.85). No effects were found for serum cholesterol and low-density lipoprotein.

CONCLUSION

Obesity and alcohol influence gallstone formation, possibly in part through their effects on serum lipids. Reducing obesity may prevent gallstones in the population, as 38% of incident cases of gallstones were associated with a BMI of more than 25.

Long-term statin use and the risk of gallstone disease: A population-based case-control study

Most gallstones originate from cholesterol-supersaturated bile. Statins inhibit hepatic cholesterol biosynthesis and therefore may reduce the risk of gallstone disease. Population-based evidence, however, is sparse. Thus, the authors conducted a population-based case-control study using medical databases from northern Denmark (1.7 million inhabitants) to identify 32,494 cases of gallstones occurring between 1996 and 2008 and to identify age-, sex-, and county-matched population controls for each case. Cases and their matched controls who were exposed to lipid-lowering drugs were categorized as current users if their last prescription was redeemed ≤90 days before the case's diagnosis date; otherwise, they were categorized as former users. Conditional logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals for gallstone disease in patients treated with lipid-lowering drugs. In current users, the adjusted odds ratios associating statin use with the occurrence of gallstone disease were 1.17 (95% confidence interval (CI): 1.06, 1.30) for those who had 1-4 prescriptions, 0.89 (95% CI: 0.80, 0.97) for those who had 5-19 prescriptions, and 0.76 (95% CI: 0.69, 0.84) for those who had ≥20 total prescriptions. In former users, the corresponding adjusted odds ratios were 1.24 (95% CI: 1.11, 1.39), 0.97 (95% CI: 0.86, 1.10), and 0.79 (95% CI: 0.64, 0.97), respectively. The use of other lipid-lowering drugs showed no similar association.

Hereditary liver disease: gallstones

Gallstones are common in Western countries and due to pain and complications pose a substantial burden on health care systems. In general, cholesterol gallstones are distinguished from bilirubin gallstones. Bilirubin gallstones form if the ion product of unconjugated bilirubin and calcium in gallbladder bile exceeds the solubilisation capacities of mixed micelles and vesicles. Cholesterol gallstones develop if the amount of cholesterol in gallbladder bile exceeds the maximum concentration that is soluble at the given concentration of bile salts and phospholipids. In addition, cholesterol gallstone formation requires hypomotility of the gallbladder and a mucin gel as nucleation matrix for monohydrate crystals. The individual risk of gallstone formation is determined by interactions of lithogenic alleles of gallstone susceptibility genes and multiple environmental factors. For asymptomatic gallstones, expectant management is recommended, whereas an episode of gallstone-associated pain substantially increases the risk of complications such as cholecystitis, cholangitis and pancreatitis and therefore necessitates cholecystectomy.

Diabetes in relation to biliary tract cancer and stones: a population-based study in Shanghai, China

BACKGROUND

Biliary tract cancers are rare but fatal malignancies. Diabetes has been related to biliary stones, but its association with biliary tract cancers is less conclusive.

METHODS

In a population-based case-control study of 627 cancers, 1037 stones, and 959 controls in Shanghai, China, we examined the association between diabetes and the risks of biliary tract cancer and stones, as well as the effect of potential mediating factors, including serum lipids and biliary stones (for cancer), contributing to the causal pathway from diabetes to biliary diseases.

RESULTS

Independent of body mass index (BMI), diabetes was significantly associated with gallbladder cancer and biliary stones ((odds ratio (OR) (95% confidence interval)=2.6 (1.5-4.7) and 2.0 (1.2-3.3), respectively). Biliary stones and low serum levels of high-density lipoprotein (HDL) were significant mediators of the diabetes effect on gallbladder cancer risk, accounting for 60 and 17% of the diabetes effect, respectively. High-density lipoprotein was also a significant mediator of the diabetes effect on biliary stones, accounting for 18% of the diabetes effect.

CONCLUSIONS

Independent of BMI, diabetes is a risk factor for gallbladder cancer, but its effect is mediated in part by biliary stones and serum HDL levels, suggesting that gallbladder cancer risk may be reduced by controlling diabetes, stones, and HDL levels.

Targets for current pharmacologic therapy in cholesterol gallstone disease

Gallstone disease is a frequent condition throughout the world and, cholesterol stones are the most frequent form in Western countries. The standard treatment of symptomatic gallstone subjects is laparoscopic cholecystectomy. The selection of patients amenable for nonsurgical, medical therapy is of key importance; a careful analysis should consider the natural history of the disease and the overall costs of therapy. Only patients with mild symptoms and small, uncalcified cholesterol gallstones in a functioning gallbladder with a patent cystic duct are considered for oral litholysis by hydrophilic ursodeoxycholic acid, in the hope of achieving cholesterol desaturation of bile and progressive stone dissolution. Recent studies have raised the possibility that cholesterol-lowering agents that inhibit hepatic cholesterol synthesis (statins) or intestinal cholesterol absorption (ezetimibe), or drugs acting on specific nuclear receptors involved in cholesterol and bile acid homeostasis, may offer, alone or in combination, additional medical therapeutic tools for treating cholesterol gallstones. Recent perspectives on medical treatment of cholesterol gallstone disease are discussed in this article.

Incidence of and potential risk factors for gallstone disease in a general population sample

BACKGROUND

Several epidemiological studies have been published, but there are few reports on relations between gallstone incidence, symptomatology and risk factors.

METHODS

Of 621 randomly selected individuals aged 35-85 years in a general population who had been screened previously with ultrasonography and found to have no gallbladder stones, 503 (81.0 per cent) were re-examined after a minimum interval of 5 years. At baseline and re-examination, heredity for gallstone disease was explored and body mass index, digestive symptoms including abdominal pain, quality of life, alcohol and smoking habits, use of non-steroidal anti-inflammatory drugs and oestrogen, parity and blood lipid levels were recorded.

RESULTS

Forty-two (8.3 per cent) of the 503 subjects developed stones. Subjects were followed for a total of 3025.8 person-years, yielding an incidence for newly developed gallstones of 1.39 per 100 person-years. A positive association for gallstone development was found only for length of follow-up and plasma low-density lipoprotein-cholesterol levels at baseline. Weekly alcohol consumption was inversely related to gallstone development.

CONCLUSION

The incidence of gallstones in this population was 1.39 per 100 person-years. Gallstone development was related to length of follow-up and LDL-cholesterol levels, and inversely related to alcohol consumption.

Lithogenesis and bile metabolism

Gallstone disease exacts a considerable financial and social burden worldwide leading to frequent physician visits and hospitalizations. Based on their composition, gallstones are categorized as cholesterol, black pigment, and brown pigment, with each category having a unique structural, epidemiologic, and risk factor profile. Cholesterol crystal formation requires the presence of one or more of the following: (a) cholesterol supersaturation, (b) accelerated nucleation, or (c) gallbladder hypomotility/bile stasis. Some risk factors for cholesterol stones include age, gender, genetics, obesity, rapid weight loss, and ileal disease. Generally, pigment stones are formed by the precipitation of bilirubin in bile, with black stones associated with chronic hemolytic states, cirrhosis, Gilbert syndrome, or cystic fibrosis, and brown stones associated with chronic bacterial or parasitic infections.

Gallstones, cholecystectomy and irritable bowel syndrome (IBS) MICOL population-based study

BACKGROUND

Subjects with irritable bowel syndrome may undergo an excess of cholecystectomy. It is not known, however, whether the cholecystectomy rate parallels an increased risk of gallstones.

AIM

Aim was to assess the prevalence and the incidence of gallstones and cholecystectomy in subjects with irritable bowel syndrome symptoms.

SUBJECTS AND METHODS

In this population-based study, 29,139 subjects (63.2% of 46,139 randomly selected subjects, age 30-69 years) underwent a physical examination, an interview on gastrointestinal symptoms and an upper abdominal ultrasonography. An identical survey was carried out 7.8+/-1.0 (M+/-S.D.) years later on 8460 gallstone-free subjects at the first survey. Prevalence and incidence of gallstones and cholecystectomy were assessed in subjects with (1) irritable bowel syndrome; (2) abdominal pain and normal bowel; (3) altered bowel and no abdominal pain and (4) asymptomatic controls; univariate and multivariate regression logistic models were used for statistical analysis.

RESULTS

Prevalence odds of gallstones and cholecystectomy were significantly higher in irritable bowel syndrome and abdominal pain and normal bowel than in controls. Irritable bowel syndrome and abdominal pain and normal bowel subjects were more aware of gallstones than controls (p<0.001), and the prevalence of gallstones in irritable bowel syndrome subjects unaware of their gallbladder status was not significantly different from the controls. The incidence of gallstone disease in irritable bowel syndrome, abdominal pain and normal bowel, and altered bowel and no abdominal pain subjects did not differ from the controls. The incidence of cholecystectomy was higher in irritable bowel syndrome and abdominal pain and normal bowel groups than in controls and altered bowel and no abdominal pain group.

CONCLUSIONS

Irritable bowel syndrome subjects have an increased risk of cholecystectomy that is not due to an increased risk of gallstones, but rather to abdominal pain, awareness of having gallstones, and inappropriate surgical indications.

Gallbladder cancer incidence among American Indians and Alaska Natives, US, 1999-2004

BACKGROUND

Gallbladder cancer (GBC) is rare; however, it disproportionately affects the American Indian and Alaska Natives (AI/AN) population. The purpose of the study was to characterize GBC among AI/AN in the US population.

METHODS

Cases of GBC diagnosed between 1999 and 2004 and collected by state-based cancer registries were included. Registry records were linked with Indian Health Service (IHS) administration records to decrease race misclassification of AI/AN. GBC rates and/or percent distributions for AI/AN and non-Hispanic whites (NHW) were calculated by sex, IHS region, age, and stage for all US counties and IHS Contract Health Service Delivery Area (CHSDA) counties, in which approximately 56% of US AI/AN individuals reside.

RESULTS

In CHSDA counties, the GBC incidence rate among AI/AN was 3.3 per 100,000, which was significantly higher than that among NHW (P < .05). Rates varied widely among IHS regions and ranged from 1.5 in the East to 5.5 in Alaska. Rates were higher among AI/AN females than males in all regions, except the Northern Plains. Higher percentages of GBC were diagnosed among AI/AN aged <65 years compared with NHW. GBC was most often diagnosed at the regional stage among AI/AN, whereas GBC was most often diagnosed at regional or distant stages among NHW.

CONCLUSIONS

To the authors' knowledge to date, this is the most comprehensive study of GBC incidence among AI/AN in the US. The accurate characterization of GBC in this population could help inform the development of interventions aimed at reducing morbidity and mortality from this disease.

Cytokine genotypes in acute pancreatitis: association with etiology, severity, and cytokine levels in blood

The circumstances that determine how acute pancreatitis (AP) becomes severe are unknown. Differences in cytokine genetic encoding may determine the severity or influence the etiology of AP. This article investigates the relationship between different polymorphisms of tumor necrosis factor alpha (TNF-alpha), interleukin 1 (IL-1), IL-1 receptor antagonist, IL-6, and IL-10 with the severity and etiology of AP and the serum levels of the cytokine encoded.

METHODS

Patients with AP were included prospectively. Severity of the disease was determined according to Atlanta classification. Serum levels of these cytokines were determined within the first 72 hours after the onset of symptoms. The following polymorphisms were determined by polymerase chain reaction: IL-1a -889, IL-1b +3954, IL-1b -511, variable number tandem repeats, IL-6 -174, IL-6 -597, IL-10 -592, TNF-alpha 308, TNF-alpha 238, and TNF-B250.

RESULTS

Eighty-four patients were included. The GA genotype of the TNF-alpha 238 polymorphism was associated with more frequent respiratory failure and shock than the GG genotype. Gallstone pancreatitis was associated with the CC genotype of the IL-6 -174 CC polymorphism.

CONCLUSIONS

AG genotype of the TNF-alpha 238 polymorphism is associated with organic failure in patients with AP. The CC genotype of the IL-6 174 polymorphism is associated with biliary etiology of acute pancreatitis.

Incidence of gallstone disease in Italy: Results from a multicenter, population-based Italian study (the MICOL project)

AIM: To evaluate gallstone incidence and risk factors in a large population-based study.

METHODS: Gallstone incidence and risk factors, were evaluated by structured questionnaire and physical examination, respectively, in 9611 of 11 109 (86.5%) subjects who were gallstone-free at the cross-sectional study.

RESULTS: Six centers throughout Italy enrolled 9611 subjects (5477 males, 4134 females, aged 30-79 years), 9517 of whom were included into analysis: 424 subjects (4.4%) had gallstones and 61 (0.6%) had been cholecystectomized yielding a cumulative incidence of 0.67% per year (0.66% in males, 0.81% in females). Increasing age, a high body mass index (BMI), a history of diabetes, peptic ulcer and angina, and low cholesterol and high triglyceride levels were identified as risk factors in men while, in females, the only risk factors were increasing age and a high BMI. Increasing age and pain in the right hypochondrium in men and increasing age in females were identified as predictors of gallstones. Pain in the epigastrium/right hypochondrium was the only symptom related to gallstones; furthermore, some characteristics of pain (forcing to rest, not relieved by bowel movements) were significantly associated with gallstones. No correlation was found between gallstone characteristics and clinical manifestations, while increasing age in men and increasing age and BMI in females were predictors of pain.

CONCLUSION: Increasing age and BMI represent true risk factors for gallstone disease (GD); pain in the right hypochondrium and/or epigastrium is confirmed as the only symptom related to gallstones.

Hepatic insulin resistance directly promotes formation of cholesterol gallstones

Despite the well-documented association between gallstones and the metabolic syndrome, the mechanistic links between these two disorders remain unknown. Here we show that mice solely with hepatic insulin resistance, created by liver-specific disruption of the insulin receptor (LIRKO mice) are markedly predisposed toward cholesterol gallstone formation due to at least two distinct mechanisms. Disinhibition of the forkhead transcription factor FoxO1, increases expression of the biliary cholesterol transporters Abcg5 and Abcg8, resulting in an increase in biliary cholesterol secretion. Hepatic insulin resistance also decreases expression of the bile acid synthetic enzymes, particularly Cyp7b1, and produces partial resistance to the farnesoid X receptor, leading to a lithogenic bile salt profile. As a result, after twelve weeks on a lithogenic diet, all of the LIRKO mice develop gallstones. Thus, hepatic insulin resistance provides a crucial link between the metabolic syndrome and increased cholesterol gallstone susceptibility.

Serum lipid levels and the risk of biliary tract cancers and biliary stones: A population-based study in China

Biliary tract cancers, encompassing the gallbladder, extrahepatic bile ducts and ampulla of Vater, are rare but highly fatal malignancies. Gallstones, the predominant risk factor for biliary cancers, are linked with hyperlipidemia. As part of a population-based case-control study conducted in Shanghai, China, we examined the associations of serum lipid levels with biliary stones and cancers. We included 460 biliary cancer cases (264 gallbladder, 141 extrahepatic bile duct, and 55 ampulla of Vater), 981 biliary stone cases and 858 healthy individuals randomly selected from the population. Participants completed an in-person interview and gave overnight fasting blood samples. Participants in the highest quintile of triglycerides (>/=160 mg/dl) had a 1.4-fold risk of biliary stones (95% CI = 1.1-1.9), a 1.9-fold risk of gallbladder cancer (95% CI = 1.3-2.8), and a 4.8-fold risk of bile duct cancer (95% CI = 2.8-8.1), compared to the reference group (third quintile: 90-124 mg/dl). Participants in the lowest quintile of high-density lipoprotein (HDL) (<30 mg/dl) had a 4.2-fold risk of biliary stones (95% CI = 3.0-6.0), an 11.6-fold risk of gallbladder cancer (95% CI = 7.3-18.5), and a 16.8-fold risk of bile duct cancer (95% CI = 9.1-30.9), relative to the reference group (third quintile: 40-49 mg/dl). In addition, total cholesterol, low-density lipoprotein (LDL) and apolipoprotein A (apo A) were inversely associated with biliary stones; whereas low levels as well as high levels of total cholesterol, LDL, apo A and apolipoprotein B (apo B) were associated with excess risks of biliary tract cancers. Our findings support a role for serum lipids in gallstone development and biliary carcinogenesis.

Polymorphisms of genes in the lipid metabolism pathway and risk of biliary tract cancers and stones: a population-based case-control study in Shanghai, China

Biliary tract cancers, encompassing the gallbladder, extrahepatic bile duct, and ampulla of Vater, are uncommon yet highly fatal malignancies. Gallstones, the primary risk factor for biliary cancers, are linked with hyperlipidemia. We examined the associations of 12 single nucleotide polymorphisms of five genes in the lipid metabolism pathway with the risks of biliary cancers and stones in a population-based case-control study in Shanghai, China. We included 235 gallbladder, 125 extrahepatic bile duct, and 46 ampulla of Vater cancer cases, 880 biliary stone cases, and 779 population controls. Subjects completed an in-person interview and gave blood. Genotyping was conducted by TaqMan assay using DNA from buffy coats. The effects of APOE IVS1+69 (rs440446) and APOB IVS6+360C>T (rs520354) markers were limited to men. Men carrying the G allele of APOE IVS1+69 had a 1.7-fold risk of stones [95% confidence interval (95% CI), 1.2-2.4], a 1.8-fold risk of gallbladder cancer (95% CI, 1.0-3.3), a 3.7-fold risk of bile duct cancer (95% CI, 2.0-7.0), and a 4-fold risk of ampullary cancer (95% CI, 1.4-12.4). Male carriers of the T allele of APOB IVS6+360C>T had a 2-fold risk of bile duct cancer (95% CI, 1.2-3.4). The APOB T-T haplotype (APOB IVS6+360C>T, EX4+56C>T) was associated with a 1.6-fold risk of bile duct cancer (95% CI, 1.1-2.3). Male and female carriers of the T allele of LDLR IVS9-30C>T (rs1003723) had a 1.5-fold risk of bile duct cancer. Our findings suggest that gene variants in the lipid metabolism pathway contribute to the risk of biliary tract stones and cancers, particularly of the bile duct.

Association between promoter and coding region mutations of UDP-glucuronosyltransferase 1A1 and beta-thalassemia/Hb E with cholelithiasis

BACKGROUND AND OBJECTIVES

Cholelithiasis has been observed with high incidence in beta-thalassemia/hemoglobin E (beta-thal/Hb E). Recent studies have shown that a variant TATA-box in the promoter region of the UDP-glucuronosyltransferase 1A1 (UGT1A1) gene is associated with the development of cholelithiasis. The coding region mutation (G71R) of the UGT1A1 gene was higher in Asians than those in Caucasians. The relationship between the variant UGT1A1 promoter and coding region gene and cholelithiasis in beta-thal/Hb E subjects were investigated.

METHODS

One hundred and seventeen beta-thal/Hb E subjects entered this study. The TATA-box and G71R mutations were analyzed by fragment size analysis and restriction fragment length polymorphism methods, respectively.

RESULTS

The incidence of cholelithiasis was higher in heterozygous (68.3%) and homozygous (100%) subjects compared with normal UGT1A1 haplotype (61.4%). Total bilirubin level (6.0 +/- 2.03 mg/dL) in the homozygous group was significantly higher than that of wild type (3.31 +/- 1.83 ng/dL). Prevalence of cholelithiasis increased with age (OR = 1.1, 95% CI = 1.03-1.12, P < 0.001). Female gender (OR = 3.7, 95% CI = 1.3-10.6, P < 0.01) and elevated liver enzyme (OR = 1.02, 95%CI = 1.0-1.04, P < 0.02) were two other risk factors for cholelithiasis in beta-thal/Hb E.

CONCLUSION

This study shows that the combined TATA-box variants and G71R mutations of the UGT1A1 is associated with cholelithiasis in beta-thal/Hb E.

Arg64 variant of the beta3-adrenergic receptor is associated with gallstone formation

OBJECTIVES

The beta3-adrenergic receptor (ADRB3) is a transmembrane receptor highly expressed in adipose tissue and thought to be involved in the regulation of lipolysis. ADRB3 is also highly expressed in gallbladder tissue where it may be involved in gallbladder contraction. Because polymorphisms of ADRB3 are present in populations with a high prevalence of gallstones (e.g., Pima-Indians, obese subjects), we hypothesized that known polymorphisms for ADRB3 (Trp64Arg) may represent an independent risk factor for gallstone disease.

METHODS

The EMIL cross-sectional study investigated the health behavior and prevalence of chronic diseases in a small Southwestern German town of 12,475 inhabitants. From 3,893 randomly selected citizens 2,147 subjects were enrolled and screened for gallstones employing ultrasonography. Blood samples were drawn for biochemical analysis and isolation of genomic DNA. ADBR3 genotypes were determined by TaqMan SNP Assay.

RESULTS

We identified 171 (8%) gallstone carriers of whom 143 participated (46 male, 97 female), with a mean age of 51.4, and mean BMI of 29.3 kg/m2. For these subjects an age, gender and BMI matched partner without gallstones was recruited from the study population. Genotyping for ADRB3 revealed an Arg64 allele frequency of 5.9 versus 0.7% (HR = 11.9, P < 0.05) compared with controls.

CONCLUSIONS

Our results indicate that the ADRB3 Trp64Arg polymorphism is associated with gallstone disease thereby representing a genetic marker that identifies subjects at higher risk for gallstone formation.

HCV infection is a risk factor for gallstone disease in liver cirrhosis: an Italian epidemiological survey

We assessed the prevalence of gallbladder disease (i.e. gallstones plus cholecystectomy) among patients with liver disease and its association with the severity and aetiology of hepatic injury. Subjects, referred to 79 Italian hospitals, were enrolled in a 6-month period. The independent effect of the severity and aetiology of liver disease on gallstone disease prevalence was assessed by multiple logistic regression analysis. Overall, 4867 subjects tested anti-hepatitis C virus (HCV) positive alone, 839 were hepatitis B virus surface antigen (HBsAg) alone, and 652 had an excessive alcohol intake. The prevalence of gallstone disease was 23.3% in anti-HCV-positive patients, 12.4% in HBsAg positive and 24.2% in subjects reporting excessive alcohol intake, respectively. Gallstone disease prevalence increased by age in each aetiological category. The proportion of patients with gallstone disease who had a cholecystectomy was the highest in HCV+ subjects. After adjusting for the confounding effect of age and body mass index, compared with patients with less severe liver disease, subjects with HCV-related cirrhosis, but not those with alcohol-related cirrhosis, were more likely to have gallstone disease. Subjects with HCV-related cirrhosis (OR 2.13, 95% CI: 1.38-3.26) were more likely to have gallstone disease when compared with those with HBV-related cirrhosis. HCV infection is a risk factor for gallstone disease. In Italy, the high prevalence of HCV infection among cirrhotic patients has important implications, as cholecystectomy in these subjects is associated with high risk of morbidity and mortality.

Haplotype analysis of signal peptide (insertion/deletion) and XbaI polymorphisms of the APOB gene in gallbladder cancer

PURPOSE

The incidence of gallbladder cancer (GBC) is usually paralleled by the prevalence of gallstone disease, and genes of cholesterol metabolism have been implicated in gallstone disease. The XbaI and insertion/deletion (ins/del) polymorphism of Apolipoprotein B (APOB) appears to influence cholesterol homoeostasis and possibly risk for gallstone disease. We examined the effect of these polymorphisms individually as well as their haplotypes on GBC and gallstone patients in North Indian population.

METHODS

The study comprises 123 consecutive cases of proven GBC, 172 cases of gallstone and 232 healthy subjects of similar age and sex. The genomic DNA was extracted from peripheral blood leucocytes and genotyping was performed using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism.

RESULTS

In a case-control study, APOB XbaI and ins/del polymorphisms were not significantly associated with risk of GBC. Using the expectation maximization algorithm, four haplotypes were obtained, and haplotype X(+),D was found to be significantly higher in GBC patients without stone in comparison with healthy subjects [odds ratio (OR) 2.9, 95% confidence interval 1.2-6.6 P=0.012].

CONCLUSIONS

The X(+),D haplotype of APOB is associated with increased risk for development of GBC and the risk is not modified in the presence of gallstones.

Defects in the Leptin Axis Reduce Abundance of the ABCG5-ABCG8 Sterol Transporter in Liver

ABGG5 (G5) and ABCG8 (G8) are ABC half-transporters that dimerize within the endoplasmic reticulum, traffic to the cell surface, and mediate cholesterol excretion into bile. Mice harboring defects in the leptin axis (db/db and ob/ob) have reduced biliary cholesterol concentrations. Rapid weight loss brought about by administration of leptin or dietary restriction increases biliary cholesterol excretion. We hypothesized that the reduction in biliary cholesterol in mice harboring defects in the leptin axis is associated with a reduction in G5G8 transporters and that levels of the transporter would increase with leptin administration and dietary restriction. We examined mRNA and protein levels for G5 and G8 in db/db and ob/ob mice. In both models G5 and G8 protein levels were reduced. In ob/ob mice, both leptin administration and dietary restriction increased G5 and G8 protein and biliary cholesterol concentrations. Finally, we examined the effects of tauroursodeoxycholate, which has been shown to increase biliary cholesterol excretion and function as a molecular chaperone. Tauroursodeoxycholate increased G5 and G8 protein and biliary cholesterol concentrations in both wild-type and db/db mice. Our results indicate that the mechanism for reduced biliary cholesterol excretion in db/db and ob/ob mice involves reductions in G5 and G8 protein levels and that this may occur at the level of G5G8 heterodimer assembly within the endoplasmic reticulum.

Gallstone disease

Gallstone disease is one of the most prevalent gastrointestinal diseases with a substantial burden to health care systems that is supposed to increase in ageing populations at risk. Aetiology and pathogenesis of cholesterol gallstones still are not well defined, and strategies for prevention and efficient nonsurgical therapies are missing. This review summarizes current concepts on the pathogenesis of cholesterol gallstones with focus on the uptake and secretion of biliary lipids and special emphasis on recent studies into the genetic background.

Increased activity of hepatic microsomal triglyceride transfer protein and bile acid synthesis in gallstone disease

A strong interrelationship exists between the regulation of bile acid (BA) metabolism and hepatic very low density lipoprotein (VLDL) production. We have recently shown that BA synthesis is increased in gallstone disease. We investigated the activity of hepatic microsomal triglyceride transfer protein (MTTP) as a surrogate of VLDL production, BA synthesis, and mRNA expression levels of proteins that regulate fatty acid (FA) metabolism in the liver of gallstone (GS) patients compared with GS-free patients. Twenty-seven volunteers subjected to elective surgery; 9 were GS-free and 18 with GS agreed to have a liver biopsy. We quantified by a fluorescence assay the activity of MTTP and by quantitative reverse-transcription PCR (RT-PCR) the mRNA content of hepatic MTTP and genes that regulate hepatic sterol and FA metabolism. Plasma was assayed for lathosterol and 7alpha-hydroxy-4-cholesten-3-one. Liver histology was normal in GS and GS-free patients. Serum VLDL triglycerides and apoB were significantly increased in GS. Hepatic triglycerides tripled in GS (P<0.001) compared with GS-free. MTTP activity increased 70% (P<0.001). Serum lathosterol and hepatic cholesterol concentrations, and mRNA expressions of MTTP, CD36, and FABP1 were similar in GS-free and GS patients. Hepatic mRNA expression of hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) and 3-hydroxyl-3-methyl-glutaryl-CoA synthase (HMGS) were significantly decreased--40% and 27%, respectively--in GS. Serum 7alpha-hydroxy-4-cholesten-3-one was 75% higher, and mRNA expression of CYP7A1 was increased sevenfold (P<0.001) in GS.

CONCLUSION

Hepatic MTTP activity and BA synthesis are increased in GS. Results suggest that hepatic VLDL production and trafficking of BA are increased in gallstone patients.

Gender and gallstone disease

Gallstone disease is a common disorder all over the world. In the Western societies about 80 % of the gallstones are composed primarily of cholesterol. Several risk factors for gallstone formation have been identified. One of the most important risk factors is female gender. Rates of gallstones are two to three times higher among women than men. But this is primarily a phenomenon of the childbearing age. Pregnancy is also a major risk factor for gallstone formation. The risk is related to the number of pregnancies. Sex hormones are most likely to be responsible for the increased risk. Estrogen increases biliary cholesterol secretion causing cholesterol supersaturation of bile. Thus, hormone replacement therapy in postmenopausal women and oral contraceptives have also been described to be associated with an increased risk for gallstone disease. However, the effect of estrogen is dose-dependent and new oral contraceptives with a low estrogen dose do not seem to increase the rate of gallstone formation. The present article focuses on the mentioned risk factors associated with female sex hormones.

Prevalence and risk factors of gallstone disease in an adult population of Taiwan: an epidemiological survey

BACKGROUND AND AIMS

The aim of this study was to determine the prevalence and risk factors of gallstone disease (GSD) in an adult population of Taiwan through a population-based screening study.

METHODS

A cross-sectional community study in a rural village of Taiwan was conducted in 3333 Chinese adults (aged > or = 18 years) undergoing ultrasonography. A questionnaire on personal history was completed to ascertain whether the removed gallbladder contained stones in all cholecystectomized subjects, the dietary habits (vegetarian/non-vegetarian diet), the history of GSD in the participant's first-degree relatives, the history of gastrointestinal surgery (vagotomy, gastrectomy for peptic ulcer disease, or ileal resection), parity, and use of oral contraceptives. The demographic characteristics and biochemical parameters were recorded.

RESULTS

The overall prevalence of GSD was 5.0% (4.6% in men, 5.4% in women) with no significant sex differences (men/women: odds ratio [OR] 0.71, 95% confidence interval [CI] 0.50-1.01, P = 0.058). Logistic regression analysis showed that increasing age (men: 40-64 years, OR 7.38, 95% CI 2.59-21.01, P < 0.001 and > or = 65 years, OR 14.16, 95% CI 4.84-41.47, P < 0.001; women: 40-64 years, OR 4.08, 95% CI 1.90-8.75, P < 0.001 and > or = 65 years, OR 6.78, 95% CI 2.97-15.46, P < 0.001) and the presence of fatty liver evidenced by ultrasonography (men: OR 2.24, 95% CI 1.32-3.80, P = 0.003; women: OR 2.13, 95% CI 1.33-3.42, P = 0.002) were risk factors for GSD. Additionally, fasting plasma glucose > or = 126 mg/dL (OR 2.11, 95% CI 1.16-3.83, P = 0.014), history of GSD in the first-degree relatives (OR 7.47, 95% CI 2.22-25.12, P = 0.001), and use of oral contraceptives (OR 10.71, 95% CI 3.06-37.49, P < 0.001) were risk factors for GSD in women, but fasting plasma glucose > or = 126 mg/dL was only correlated to GSD without controlling for other confounding factors in men. Other demographic characteristics and biochemical parameters, such as high body mass index (> or = 25 kg/m2), increased parity, hypercholesterolemia, hypertriglyceridemia, hyperuricemia, hepatitis C infection and cirrhosis, did not exhibit any correlation to GSD in logistic regression analysis, although they appeared to be related to GSD in women in univariate analysis.

CONCLUSIONS

Age and fatty liver in both sexes were found to be risk factors for GSD in the study population. The finding of a correlation between fatty liver and GSD is an important addition to the literature concerning the risk factors of GSD. Diabetes mellitus, history of GSD in the first-degree relatives, and use of oral contraceptives were also risk factors for GSD in women.

Risk factors for gallstone-related hospitalization during pregnancy and the postpartum

OBJECTIVES

Gallbladder disease is a leading nonobstetrical cause for hospitalization in the first year postpartum. The aim of this study was to define the incidence and risk factors for postpartum hospitalization as a result of gallstone-related disease.

METHODS

We identified 6,670 women with discharge diagnoses related to biliary disease from linked birth certificate and hospital discharge databases for Washington State from 1987 through 2001. Cases were women with gallstone-related diagnoses at delivery or as primary diagnosis in the postpartum. Four controls who were within 1 yr postpartum were randomly selected for each case and matched for year of delivery. From the birth certificates, we obtained data about patient demographics, reproductive history, and pregnancy-related risk factors. In a retrospective case-control study, we developed multiple logistic regression models to identify independent risk factors for hospitalization.

RESULTS

We identified 6,211 women as cases (0.5% of all births) during the study period. The median time to hospitalization was 95 days (interquartile range 46-191 days), with a median length of stay of 3 days. Seventy-six percent were diagnosed with uncomplicated cholelithiasis, 16% with pancreatitis, 9% with acute cholecystitis, and 8% with cholangitis. Seventy-three percent of hospitalized women underwent cholecystectomy, and 5% underwent endoscopic retrograde cholangiopancreatography (ERCP). On multivariate analysis, independent risk factors for hospitalization included maternal race, age, being overweight or obese prepregnancy, pregnancy weight gain, and estimated gestational age.

CONCLUSIONS

Hospitalization for gallstone-related disease is common in the first year postpartum, most commonly for uncomplicated cholelithiasis. Risk factors for hospitalization include prepregnancy body mass index, race, Hispanic ethnicity, and maternal age.

Acute effect of smoking on gallbladder emptying and refilling in chronic smokers and nonsmokers: A sonographic study

AIM: To ultrasonographicaly evaluate the acute effects of smoking on gallbladder contraction and refilling in chronic smokers and nonsmokers.

METHODS: Fifteen chronic smokers (21-30 years old) and fifteen nonsmokers (21-35 years old) participated in this study. Chronic smokers were selected among the volunteers who had been smoking for at least 5 years and 10 cigarettes per day (mean 17.5/d). Examinations were performed in two separate days. In the first day, basal gallbladder (GB) volumes of volunteers were measured after 8-h fasting. After the examinations, participants had a meal containing at least 30-40 gram fat. Gallbladder volume was assessed at 5, 15, 30, 60, 120 and 180 min after the meal. In the second day, participants smoked 2 cigarettes after 8-h fasting. Then, they had the same meal, and gallbladder measurements were repeated at the same time points. Same procedures were applied to both groups.

RESULTS: The mean starving GB volumes were 23.3 ± 3.3 mL in the first day, 21.9 ± 3.0 mL in the second day in nonsmoker group and 18.3 ± 3.0 mL in the first day, 19.5 ± 2.8 mL in second day in smoker group. There was no significant difference between starving GB volumes. We did not find any significant difference between the GB volumes measured at 5, 15, 30, 60, 120 and 180 min in the first and second days in nonsmoker group. In smokers, post cigarette GB volume was found significantly higher at 5, 15 and 30 min which corresponded to GB contraction phase (P < 0.05). Control GB volume measurements were not significantly different between the two groups. Post-smoking GB volumes were also not significantly different between the two groups.

CONCLUSION: Smoking prolongs the maximal GB emptying time both in smokers and in nonsmokers though it is not significant. It delays GB contraction in chronic smokers and causes a significant decrease in GB emptying volume. Smoking causes no significant delay in GB refilling in both smokers and nonsmokers. These effects of smoking observed in acute phase result in bile stasis in GB. Bile stasis is the underlying cause of most GB disorders in chronic process.

Gallbladder disease is associated with insulin resistance in a high risk Hispanic population

BACKGROUND/AIMS

We tested whether cholesterol gallstone disease (GS) is associated to insulin resistance and serum C-reactive protein (CRP) in a high risk population.

METHODS

This was a nested case-control study on 881 Chilean subjects that included clinical examination, abdominal ultrasound and blood chemistries. Insulin resistance was determined by the homeostasis model assessment index (IR-HOMA).

RESULTS

Compared to controls (n = 582), age and sex adjusted median IR-(HOMA) was significantly elevated in subjects with GS (n = 299) (P < 0.001). Risks of GS in subjects with insulin resistance and different body mass index (BMI) were: BMI < 25, 2.2 (1.1-4.7); BMI 25-30, 1.5 (0.9-2.5) and BMI > 30, 1.7 (1.0-2.9). Risk of GS in subjects with metabolic syndrome was 1.7 (CI, 1.2-2.5) and with fatty liver, 1.5 (1.1-2.2). Risk of GS in subjects with CRP > 1 mg/dL was 1.0 (0.7-1.7).

CONCLUSIONS

GS is associated to insulin resistance, fatty liver and to metabolic syndrome, but not to serum CRP in a high risk Hispanic population. Insulin resistance could have a major role in the pathogenesis of GS favoring the production of cholesterol supersaturated bile and altering gallbladder function.

Cholesterol gallstone disease

With a prevalence of 10-15% in adults in Europe and the USA, gallstones are the most common digestive disease needing admission to hospital in the West. The interplay between interprandial and postprandial physiological responses to endogenous and dietary lipids underscores the importance of coordinated hepatobiliary and gastrointestinal functions to prevent crystallisation and precipitation of excess biliary cholesterol. Indeed, identifying the metabolic and transcriptional pathways that drive the regulation of biliary lipid secretion has been a major achievement in the field. We highlight scientific advances in protein and gene regulation of cholesterol absorption, synthesis, and catabolism, and biliary lipid secretion with respect to the pathogenesis of cholesterol gallstone disease. We discuss the physical-chemical mechanisms of gallstone formation in bile and the active role of the gallbladder and the intestine. We also discuss gaps in our knowledge of the pathogenesis of gallstone formation and the potential for gene targeting in therapy.

Insulin resistance causes human gallbladder dysmotility

Obesity, diabetes, and hyperlipidemia are known risk factors for the development of gallstones. A growing body of animal and human data has correlated insulin resistance with organ dysfunction. The relationship among obesity, diabetes, hyperlipidemia, and abnormal gallbladder motility remains unclear. Therefore, we designed a study to investigate the association among obesity, insulin resistance, hyperlipidemia, and gallbladder dysmotility. One hundred ninety-two healthy adult nondiabetic volunteers were studied. Gallbladder ultrasounds were performed before and after a standardized fatty meal. A gallbladder ejection fraction (EF) was calculated, and an EF of < 25% was considered abnormal. Serum was analyzed for cholesterol, triglycerides, cholecystokinin, leptin, glucose, and insulin. The homeostasis assessment model (HOMA) was used to determine insulin resistance. The volunteers had a mean age of 38 years (range, 18-77), and 55% were female. Thirty subjects (15%) had gallstones and were excluded from the study. Thirty subjects (19%) had abnormal gallbladder motility (EF < 25%). In lean subjects (n = 96) fasting glucose was significantly increased in the 16 subjects with gallbladder EF < 25% versus the 80 subjects with gallbladder EF > 25% (109 +/- 20 mg/dl versus 78 +/- 2 mg/dl, P < 0.05). Similarly, the HOMA index was significantly greater in subjects with gallbladder EF < 25% versus gallbladder EF >25% (3.3 +/- 1.2 versus 2.0 +/- 0.2, P < 0.05). In obese subjects (n = 66), fasting glucose, insulin, and insulin resistance were not associated with a gallbladder EF < 25%. These data suggest that in lean, nondiabetic volunteers without gallstones, gallbladder dysmotility is associated with an elevated fasting glucose as well as a high index of insulin resistance. We conclude that insulin resistance alone may be responsible for gallbladder dysmotility that may result in acalculous cholecystitis or gallstone formation.

Hyperleptinaemia and hypoadiponectinaemia are associated with gallstone disease

BACKGROUND

Gallstone disease has been regarded as an obesity-related disease. Therefore, we hypothesized that leptin and adiponectin, mainly produced by adipose tissue, may play roles in gallstone disease.

PATIENTS AND METHODS

The RIA method was used to analyze serum leptin and adiponectin levels of 90 gallstone patients and 91 healthy subjects.

RESULTS

Our results showed that BMI, fasting glucose, serum AST and ALT, and leptin were significantly increased in the gallstone patients as compared with the healthy subjects (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P = 0.013, respectively). Intriguingly, serum adiponectin was the only variable to be significantly decreased in the gallstone patients (P = 0.002). Furthermore, serum AST, leptin, and adiponectin were significantly associated with gallstone disease (P < 0.001, P = 0.021, and P = 0.006, respectively). Overweight (BMI >or= 25 kg m(-2)), but not normal-weight, gallstone patients had an increased serum leptin and a decreased serum adiponectin level as compared with matched healthy subjects (P < 0.001 and P = 0.024, respectively). In addition, serum leptin was positively correlated with BMI and serum cholesterol, while serum adiponectin was inversely correlated with serum triglyceride in the gallstone patients.

CONCLUSIONS

Our study indicated that hyperleptinaemia and hypoadiponectinaemia might be involved in the occurrence of gallstone disease. However, the causal relationship of hyperleptinaemia and hypoadiponectinaemia with gallstone disease might require further investigation.

Gallstone disease: Epidemiology of gallbladder stone disease

Gallstone disease is common: >700,000 cholecystectomies and costs of approximately 6.5 billion dollars annually in the U.S. The burden of disease is epidemic in American Indians (60-70%); a corresponding decrease occurs in Hispanics of mixed Indian origin. Ten to fifteen per cent of white adults in developed countries harbour gallstones. Frequency is further reduced in Black Americans, East Asia and sub-Saharan Africa. In developed countries, cholesterol gallstones predominate; 15% are black pigment. East Asians develop brown pigment stones in bile ducts, associated with biliary infection or parasites, or in intrahepatic ducts (hepatolithiasis). Certain risk factors for gallstones are immutable: female gender, increasing age and ethnicity/family (genetic traits). Others are modifiable: obesity, the metabolic syndrome, rapid weight loss, certain diseases (cirrhosis, Crohn's disease) and gallbladder stasis (from spinal cord injury or drugs like somatostatin). The only established dietary risk is a high caloric intake. Protective factors include diets containing fibre, vegetable protein, nuts, calcium, vitamin C, coffee and alcohol, plus physical activity.

Prevalence of gallstone disease in first-degree relatives of patients with cholelithiasis

AIM: To evaluate the influence of familiality on the prevalence of gallstone disease (GD) in Italy.

METHODS: Families of 79 subjects with gallstones (cases) and of 79 subjects without gallstones (controls) were investigated for the presence of gallstones by ultrasonography. Index cases and index controls were matched for age, sex, and operative unit. Sixty-three and sixty-two husbands and wives of index cases and index controls, respectively, were also studied.

RESULTS: Overall,the prevalence of GD was significantly higher ( χ²=14.52, P<0.001) in the 202 first-degree relatives of subjects with gallstones than that in the 201 first-degree relatives of subjects without gallstones (28.6% vs 12.4%, relative risk (RR) 1.80, 95% confidence interval (CI) 1.29-2.63). In particular, prevalence of GD was significantly higher in mothers, fathers, and sisters of index cases than that in the respective family members of index controls. The highest RR was observed in mothers (RR=2.35, 95%CI 1.38-4.3). Prevalence of GD was not obviously different in brothers and also in husbands and wives of index cases and index controls. Family members of index cases did not differ from family members of control cases with respect to the most important risk factors for gallstones (age, diabetes, BMI, and number of pregnancies) with an exception of a higher prevalence of diabetes in fathers of index controls than in fathers of index cases.

CONCLUSION: This study confirms that familiality plays a very important role in the pathogenesis of gallstones.

Epidemiology and risk factors for gallstone disease: has the paradigm changed in the 21st century?

Gallstone disease is common and costly, creating over 700,000 cholecystectomies annually. Its complications consume approximately $6.5 billion in the United States. Surveys using noninvasive ultrasonography have identified its true prevalence and the associated risk factors. In developed countries, at least 10% of white adults harbor cholesterol gallstones; women have twice the risk, and age further increases the prevalence in both sexes. Gallstones reach epidemic proportions in the North and South American Indian populations, accompanied by an increased risk for gallbladder cancer. In contrast, the rate in sub-Saharan Africa and Asia is quite low. Obesity, a major risk factor, likely relates to insulin resistance (the metabolic syndrome). Evolution and circumstance in American Indians may have ironically selected those with "thrifty" genes that conserve energy. Our abundant access to food places us at the increased risk of obesity and cholelithiasis. The general rise in obesity in many countries raises the specter of heightened disease, best identified by epidemiologic studies.