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

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.

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

BACKGROUND

Insulin resistance is a risk factors for non-alcoholic fatty liver disease (NAFLD) and for gallstone disease (GD). Aims of the present study were to assess the prevalence of and factors associated with GD in unselected patients with NAFLD.

METHODS

A total of 161 consecutive patients with NAFLD diagnosed through compatible ultrasonography in the absence of known etiologies of liver disease (in all patients) and/or confirmed histologically (in 61 patients), was studied. Gallstone disease was diagnosed through ultrasound scanning or on the basis of previous cholecystectomy. Anthropometric and biochemical variables and concurrent diseases were compared in 32 NAFLD-GD patients and in 129 NAFLD patients without GD (controls) according to gender.

RESULTS

The overall prevalence of GD was 19.88%, higher in female patients (P < 0.05), who were older (P < 001). The overall percentage of GD increased with age (P < 0.05). The GD patients had higher uric acid (men), total cholesterol and apolipoprotein B (apo-B) serum concentrations (women; P < 0.05); women also had a higher prevalence of hypertriglyceridemia (P < 0.05). The age-corrected odds ratio of having GD by tertiles increased significantly with increasing uric acid (men) and with increasing total cholesterol, triglycerides and apo-B (women). At univariate continuous analysis GD was associated with insulin 120 min and uric acid in male patients; and with body mass index, insulin 120 min, apo-B, total cholesterol and triglycerides in female patients. On multivariate analysis it was found that among these factors only uric acid in men and apo-B in women were independently associated with GD in NAFLD.

CONCLUSIONS

The prevalence of GD in NAFLD is more elevated than reported in the general population. The factors independently associated with GD in NAFLD are different from those reported in the general population and vary according to the gender.

Glycemic load, glycemic index, and carbohydrate intake in relation to risk of cholecystectomy in women

BACKGROUND & AIMS

High-carbohydrate diets with a high glycemic response may exacerbate the metabolic consequences of the insulin-resistance syndrome. The effect on the incidence of gallstone disease is not clear.

METHODS

We examined the associations between high-carbohydrate diets with a high glycemic response and the risk of cholecystectomy in a cohort of women who were aged from 35 to 61 years in 1984 and had no history of gallstone disease. As part of the Nurses' Health Study, the women reported on questionnaires mailed to them every 2 years both their carbohydrate intake and whether they had undergone cholecystectomy.

RESULTS

During 16 years of follow-up, we ascertained 5771 new cases of cholecystectomy. After adjusting for age and other known or suspected risk factors in a multivariate model, the relative risk for the highest compared with the lowest quintile of dietary carbohydrate was 1.35 (95% CI: 1.17-1.55, P for trend < .0001). The relative risks for the highest compared with the lowest quintile were 1.50 for glycemic load (95% CI: 1.32-1.71, P for trend < .0001) and 1.32 for glycemic index (95% CI: 1.20-1.45, P for trend < .0001). Independent positive associations were also seen for intakes of starch and sucrose.

CONCLUSIONS

Our findings suggest that a higher intake of carbohydrate, dietary glycemic load, and glycemic index may enhance risk of cholecystectomy in women.

Aspirin use and risk of biliary tract cancer: a population-based study in Shanghai, China

The association of gallbladder and bile duct cancers with gallstones, cholecystitis, and cholangitis suggest that chronic inflammation contributes to the carcinogenic process. However, the effect of nonsteroidal anti-inflammatory drugs, such as aspirin, on biliary tract cancer has not been well studied. In a population-based case-control study conducted in Shanghai, China, we examined the relationship between aspirin use and the risk of biliary disease. A total of 627 patients with biliary tract cancer, including cancers of the gallbladder (n = 368), extrahepatic bile duct (n = 191), and ampulla of Vater (n = 68); 1,037 patients with biliary stones; and 958 healthy adults were included in the study. Self-reported data on aspirin use was collected from study participants by in-person interview. The prevalence of aspirin use was low, with 5.7% of the population controls being regular users. After controlling for age, sex, education, and biliary stone status, aspirin use was associated with a reduced risk of gallbladder cancer [odds ratio (OR), 0.37; 95% confidence interval (CI), 0.17-0.88]. An inverse relationship was also observed for frequency and duration of use and with younger age when starting use. In addition, there was a nonsignificant reduction in the risk of bile duct (OR, 0.48; 95% CI, 0.19-1.19) and ampullary cancers (OR, 0.22; 95% CI, 0.03-1.65) associated with aspirin use, whereas no clear association was seen with biliary stones (OR, 0.92; 95% CI, 0.59-1.44). Further studies of biliary tract cancer in other populations are needed to confirm these results and to elucidate the mechanisms that underlie the reduced risk associated with use of aspirin and possibly other nonsteroidal anti-inflammatory drugs.

Prevalence of gallbladder disease among persons with hepatitis C virus infection in the United States

Although cirrhosis is a known risk factor for gallstones, little is known about gallbladder disease (GBD) in individuals with hepatitis C virus (HCV) infection. We determined the association between chronic HCV infection and GBD in a representative sample of adults in the United States. Data on HCV infection and GBD were available for 13,465 persons 20 to 74 years of age who participated in the Third National Health and Nutrition Examination Survey. The presence of GBD (gallstones or cholecystectomy) was determined using abdominal ultrasonography, and HCV infection was assessed via a positive HCV antibody test and a positive HCV RNA test. Overall, 1.6% of adults (95% CI, 1.1-2.1) had chronic HCV infection and 12.5% (95% CI, 11.3-13.7) had GBD. After adjusting for potential confounding variables, the odds of gallstones (OR = 3.20; 95% CI, 1.08-9.45) and cholecystectomy (OR = 4.57; 95% CI, 1.57-13.27) among HCV-positive men was significantly higher compared with HCV-negative men. In contrast, the adjusted odds of gallstones (OR = 2.55; 95% CI, 0.58-11.25) and cholecystectomy (OR = 0.70; 95% CI, 0.21-2.37) among HCV-positive women was not significantly higher. The odds of GBD increased significantly with the severity of liver disease as assessed via elevated serum bilirubin levels and low levels of serum albumin and platelets. In conclusion, chronic HCV infection was strongly associated with GBD among men but not women in the United States, and GBD was more common in adults with severe liver disease.

Frequent nut consumption and decreased risk of cholecystectomy in women

BACKGROUND

Gallstone disease is a major source of morbidity in the developed countries. Nuts are rich in several compounds that may protect against gallstone disease.

OBJECTIVE

The association between nut intake and cholecystectomy was examined in a large cohort of women.

DESIGN

We prospectively studied nut (peanuts, other nuts, and peanut butter) consumption in relation to the risk of cholecystectomy in a cohort of 80,718 women from the Nurses' Health Study who were 30-55 y old in 1980 and had no history of gallstone disease. As part of the Nurses' Health Study, the women reported on questionnaires mailed to them every 2 y both their consumption of nuts and whether they had undergone cholecystectomy. The women were followed through 2000.

RESULTS

During 1,393,256 person-years of follow-up from 1980 to 2000, we documented 7831 cholecystectomies. After adjustment for age and other known or suspected risk factors, women who consumed > or =5 units of nuts (1 unit = 1 oz or 28.6 g nuts)/wk (frequent consumption) had a significantly lower risk of cholecystectomy (relative risk: 0.75; 95% CI: 0.66, 0.85; P for trend < 0.0001) than did women who never ate nuts or who ate <1 unit/mo (rare consumption). Further adjustment for fat consumption (saturated fat, trans fat, polyunsaturated fat, and monounsaturated fat) did not materially alter the relation. In analyses examining consumption of peanuts and other nuts separately, both were associated with a lower risk of cholecystectomy.

CONCLUSION

In women, frequent nut consumption is associated with a reduced risk of cholecystectomy.

Prospective study of abdominal adiposity and gallstone disease in US men

BACKGROUND

Obesity is an established risk factor for gallstones, but whether abdominal adiposity contributes independently to the risk, particularly in men, remains unclear.

OBJECTIVE

The purpose of the study was to examine the associations of abdominal circumference and waist-to-hip ratio, as measures of abdominal adiposity, with the risk of symptomatic gallstone disease in men.

DESIGN

We prospectively studied measures of abdominal obesity in relation to the incidence of symptomatic gallstone disease in a cohort of 29 847 men who were free of prior gallstone disease and who provided complete data on waist and hip circumferences. Data on weight, height, and waist and hip circumferences were collected in 1986 and in 1987 through self-administered questionnaires. As part of the Health Professionals Follow-Up Study, men reported newly diagnosed symptomatic gallstone disease on questionnaires mailed to them every 2 y.

RESULTS

We documented 1117 new cases of symptomatic gallstone disease during 264 185 person-years of follow-up. After adjustment for body mass index and other known or suspected risk factors for gallstones, men with a height-adjusted waist circumference > or = 102.6 cm (40.4 in) had a relative risk of 2.29 (95% CI: 1.69, 3.11; P for trend < 0.001) compared with men with a height-adjusted waist circumference < 86.4 cm (34 in). Men with a waist-to-hip ratio > or = 0.99 had a multivariate relative risk of 1.78 (1.38, 2.28; P for trend < 0.001) compared with men with a waist-to-hip ratio < 0.89.

CONCLUSIONS

Our data suggest the presence of a significant association between abdominal adiposity and the incidence of symptomatic gallstone disease. As measures of abdominal adiposity, abdominal circumference and waist-to-hip ratio predict the risk of developing gallstones independently of body mass index.

Polymorphisms at cholesterol 7α-hydroxylase, apolipoproteins B and E and low density lipoprotein receptor genes in patients with gallbladder stone disease

AIM: To investigate the relationship between gallbladder stone disease (GSD) and single nucleotide polymorphisms of cholesterol 7α-hydroxylase (CYP7A) gene promoter, apolipoprotein (APO) B gene exon 26, APOE gene exon 4 or microsatellite polymorphism of low density lipoprotein receptor (LDLR) gene exon 18.

METHODS: Genotypes of CYP7A, APOB, APOE and LDLR genes were determined in 105 patients with GSD diagnosed by B-mode ultrasonography and 274 control subjects. Serum lipids were analyzed with HITACHI 7060 automaic biochemical analyzer.

RESULTS: Body mass index (BMI) was significantly higher in patients with GSD (24.47 ± 3.09) than in controls (23.50 ± 2.16). Plasma total cholesterol was lower in patients with GSD (4.66 ± 0.92 mmol/L) than in controls (4.91 ± 0.96 mmol/L), P < 0.01 after adjusted for age, sex and BMI. The significantly higher frequency of A allele of CYP7A gene polymorphism and X+ allele of APOB gene polymorphism was seen in GSD patients. Percentages of A allele in patients and controls were 62.86% and 54.38% (P < 0.05) and those of X+ allele 8.57% and 4.01% (P < 0.01). Subjects with A allele had significantly lower plasma total cholesterol and LDL cholesterol than subjects with CC homozygote. In a multiple variable logistic regression model, the BMI (OR = 1.13, 95%CI: 1.05-1.22), A allele (OR = 1.48, 95%CI: 1.05-2.09) and X+ allele (OR = 2.28, 95%CI: 1.14-4.59) were positively associated with GSD (P < 0.05). Plasma total cholesterol (OR = 0.69, 95%CI: 0.64-0.74) was negatively related to GSD (P < 0.05).

CONCLUSION: With an association analysis, it was determined that A allele of CYP7A gene and X+ allele of APOB gene might be considered as risk genes for GSD. These alleles are related with differences of serum lipids among subjects. Multiple-variable logistic regression model analysis showed that besides BMI, GSD was affected by polygenetic factors. But the mechanism for these two alleles responsible for GSD requires further investigations.

Gallbladder motility in obesity, diabetes mellitus and coeliac disease

We reviewed data on gallbladder motility in obesity, diabetes and coeliac disease. In obesity, a condition characterised by increased risk of gallstone(s), decreased gallbladder motility has heterogeneously been reported as a consequence of the different type of meals used to induce gallbladder contraction, characteristics of the population studied, technique used, and proportion of patients with hyperinsulinaemia. Moreover, recent studies have evaluated the effect of dietary restriction on gallbladder motility in obese patients. A two- to three-fold increase in the risk of cholesterol gallstone(s) has been reported in diabetic patients, mainly in relation to obesity and hypertriglyceridaemia. Furthermore, decreased gallbladder motility has been described and attributed to other factors, including underlying autonomic neuropathy, reduced gallbladder sensitivity to cholecystokinin and/or reduced number of cholecystokinin receptors on the gallbladder wall. Impaired gallbladder motility has been reported also in patients with coeliac disease in relation to reduced secretion of enteric hormones and/or decreased gallbladder sensitivity to them. In particular, untreated coeliacs, when compared to controls, showed low postprandial cholecystokinin and increased fasting somatostatin levels. Interestingly, the correlation between fasting somatostatin levels and gallbladder size has clearly been confirmed in patients affected by somatostatinoma or treated with somatostatin or its analogues. Gallbladder motility can be affected by various clinical conditions, such as obesity, diabetes mellitus and coeliac disease.

Cholesterol gallstone formation in overweight mice establishes that obesity per se is not linked directly to cholelithiasis risk

The relationship between obesity and cholesterol cholelithiasis is not well understood at physiologic or genetic levels. To clarify whether obesity per se leads to increased prevalence of cholelithiasis, we examined cholesterol gallstone susceptibility in three polygenic (KK/H1J, NON/LtJ, NOD/LtJ) and five monogenic [carboxypeptidase E (Cpe (fat)), agouti yellow (A(y)), tubby (tub), leptin (Lep(ob)), leptin receptor (Lepr (db))] murine models of obesity during ingestion of a lithogenic diet containing dairy fat, cholesterol, and cholic acid. At 8 weeks on the diet, one strain of polygenic obese mice was resistant whereas the others revealed low or intermediate prevalence rates of cholelithiasis. Monogenic obese mice showed distinct patterns with either high or low gallstone prevalence rates depending upon the mutation. Dysfunction of the leptin axis, as evidenced by the Lep(ob) and the Lepr (db) mutations, markedly reduced gallstone formation in a genetically susceptible background strain, indicating that in mice with this genetic background, physiologic leptin homeostasis is a requisite for cholesterol cholelithogenesis. In contrast, the Cpe (fat) mutation enhanced the prevalence of cholelithiasis markedly when compared with the background strain. Since CPE converts many prohormones to hormones, a deficiency of biologically active cholecystokinin is a likely contributor to enhanced susceptibility to cholelithiasis through compromising gallbladder contractility and small intestinal motility. Because some murine models of obesity increased, whereas others decreased cholesterol gallstone susceptibility, we establish that cholesterol cholelithiasis in mice is not simply a secondary consequence of obesity per se. Rather, specific genes and distinct pathophysiological pathways are responsible for the shared susceptibility to both of these common diseases.

Gallstones: genetics versus environment

OBJECTIVE

The aim of this study was to determine if a significant genetic component contributes to the pathogenesis of symptomatic gallstones.

SUMMARY BACKGROUND DATA

Gallstones represent a polygenic disorder that affects more than 30,000,000 Americans and results in more than 750,000 cholecystectomies in the United States annually. Risk factors include age, gender, race, parity, obesity, and diabetes. A family history of gallstones also has been identified as a risk factor suggesting that genetics play a role in gallstone formation. However, the role of genetics in the pathogenesis of gallstone formation has not been determined.

METHODS

A gallbladder disease-specific questionnaire was administered to 904 healthy unrelated adult volunteers (association study). The questionnaire ascertained a history of cholecystectomy and gallstone disease in first-degree relatives, as well as medical history, demographic, and anthropometric data. A logistic regression model was used to identify risk factors for symptomatic gallstone disease in a multivariate analysis. A maximum likelihood based variance decomposition approach was then used in 1,038 individuals from 358 families (family study) to estimate the additive genetic heritability of symptomatic gallstone disease.

RESULTS

In the association study significant risk factors for symptomatic gallstone disease were female gender (relative risk 8.8, P <.003), obesity (BMI > 30, relative risk 3.7, P <.001), age > 50 (relative risk 2.5, P <.001), and a positive family history of previous cholecystectomy in a first-degree family member (relative risk 2.2, P <.01). In the family study the additive genetic heritability of symptomatic gallstones was 29% (P <.02), age and gender were significant covariates and explained 9.3% of the phenotypic variation in gallbladder disease.

CONCLUSIONS

These data suggest that genetic factors are responsible for at least 30% of symptomatic gallstone disease. However, the true role of heredity in gallstone pathogenesis is probably higher because data based on symptomatic gallbladder disease underestimates the true prevalence in the population.

Gallstone disease prevalence in Western Siberia: cross-sectional ultrasound study versus autopsy

BACKGROUND

The aims of this study were: (i) to evaluate the prevalence of gallstones in a Western Siberian urban population; and (ii) to compare the results of ultrasonographic screening of the living population with hospital autopsy data.

METHODS

A representative sample of 842 men and 870 women (aged 25-64 years) living in Novosibirsk, Western Siberia, was screened for the presence of gallstones by gallbladder ultrasonography. Participants were considered to have gallstone disease if they had already had cholecystectomy or if gallstones were revealed during the survey. Hospital autopsy data (n = 1124) were reviewed retrospectively for the 8-year period in the same region.

RESULTS

The prevalence of gallstone disease was significantly higher in women than in men and increased with age. Age-adjusted prevalence rates of gallstone disease for the 25-64-year age group were 1.9% in men and 9.5% in women in a cross-sectional ultrasonographic study. Corresponding values in the autopsy series were 2.2% in men and 11.2% in women.

CONCLUSIONS

The present report shows that the prevalence of gallstone disease in the female population is in the range of that reported from Western countries, whereas that in the male population is lower than that in other countries. The results of the ultrasonographic survey of the living population and of hospital autopsy data were comparable, with slightly higher gallstone detection rates in the autopsy study.

Structural and mechanical remodelling of the common bile duct after obstruction

Biliary obstruction in man, most often caused by cholelithiasis, induces remodelling of the bile ducts. Obstruction-induced structural remodelling of the common bile duct (CBD) has been previously described. The mechanical changes that accompany the structural remodelling, however, have not been studied in detail. The aim of this study is to quantify the structural and mechanical changes in the CBD at different time intervals after acute obstruction. The CBD was ligated in the pig, near the duodenum, and studied after 3 h, 12 h, 2 days, 8 days and 32 days (n=5 in each group). One additional animal in each group was sham-operated. At each scheduled time, the CBD was mechanically tested in vitro with a computer-controlled volume infusion system to study the pressure-volume relationship of the CBD segment. A video camera provided simultaneous measurements of the outer dimensions of the CBD at the various pressures. The diameter and wall thickness of the CBD increased about three-fold in the 32-day group compared to the sham group (P < 0.001). The circumferential stress-strain relationship differed between groups (P < 0.001); it was shifted to the right, indicating softening, in the 3-h, 12-h, and 2-day groups and to the left, indicating stiffening, in the 8-day and 32-day group, compared to the sham group. The longitudinal stress-strain curves were all shifted to the left of the circumferential stress-strain curves (P < 0.05). The collagen area increased during obstruction (P < 0.001) but no correlation between the size of the collagen area and the biomechanical parameters was found. A practical implication of the present study serves as a warning to surgeons. A reduction in the wall stiffness in the first several days of obstruction along with an increased duct diameter and a decreased wall thickness suggest that operative procedures such as suturing, anastomosis and procedures related to ERCP must be performed with special care to avoid damage to the CBD.

Interacting QTLs for cholesterol gallstones and gallbladder mucin in AKR and SWR strains of mice

We employed quantitative trait locus (QTL) mapping in a backcross between gallstone-susceptible SWR/J and gallstone-resistant AKR/J inbred mice to identify additional susceptibility loci for cholesterol gallstone formation. After 12 wk of feeding the mice a lithogenic diet, we phenotyped 330 backcross progeny for gallstones, gallbladder mucin accumulation, liver weight, and body weight. Marker-based regression analysis revealed significant single QTLs associated with gallstone formation on chromosome 9 and the liver weight/body weight ratio on chromosomes 5 and X. A search for gene pairs detected significant gene-gene interactions for mucin accumulation between loci on chromosomes 5 and 11 and suggestive gene-gene interactions linked to gallstone formation between the QTL on chromosome 9 and loci on chromosomes 6 and 15. These findings uncover new QTLs for cholesterol gallstones, reveal independent loci for mucin accumulation, and demonstrate the importance of considering gene-gene interactions in cholesterol cholelithiasis. According to standard nomenclature, the gallstone QTL on chromosome 9 is named Lith5.

Hyperinsulinemia, dyslipidemia, and obesity as risk factors for hospitalized gallbladder disease. A prospective study

PURPOSE

Prospective studies of gallbladder disease have investigated a limited number of risk factors and have been conducted predominantly in women. Determinants of hospitalized gallbladder disease were examined in a large, population-based cohort of men and women.

METHODS

Subjects, aged 45-64 years, were participants in the Atherosclerosis Risk in Communities (ARIC) Study who reported no history of gallbladder disease at baseline (n = 12,773). Incident cases of gallbladder disease were identified through surveillance of hospital discharges between the baseline visit (1987-1989) and 1996.

RESULTS

The crude incidence rate of hospitalized gallbladder disease was 3.8 per 1000 person-years. In women, increasing risk was observed for increasing levels of body-mass index and waist-to-hip ratio, whereas in men, increased risk was observed only in the morbidly obese (BMI >or= 35). Fasting serum insulin, low HDL cholesterol, elevated triglycerides, and hormone replacement therapy were all positively associated with gallbladder disease risk. The relative risks associated with having one, two, or three or more components of the "multiple metabolic syndrome" in men were 1.45 (95% CI = 0.9-2.3), 2.17 (1.3-3.6), and 2.34 (1.3-4.3), respectively.

CONCLUSIONS

In men, hyperinsulinemia and dyslipidemia may have some role in the etiology of gallbladder disease beyond their association with obesity, whereas in women, increased body size, central adiposity, and hormone replacement therapy may be more important determinants of gallbladder disease.

Liver disease in the elderly

Ageing of the liver mainly affects the sinusoids and the Kupffer cells. Pseudocapillarization, manifested by reduced sinusoidal fenestration and subendothelial collagen deposition, causes a reduction in oxygen-dependent hepatocyte functions such as oxidative drug metabolism. The liver mass in old people is somewhat reduced and the liver blood flow is diminished. This causes a reduction in the clearance of rapidly cleared drugs, but the clearance of slowly cleared drugs is not affected. The overall capacity of the liver to regenerate is maintained in old people. Therefore, hepatic resections for hepatocellular carcinoma can be carried out in non-cirrhotic elderly people. For liver transplantations, biological age is more important than calendar age. Transplantations in frail old people and in elderly people with very poor liver function are associated with increased morbidity and limited survival. In relatively healthy old people, the results are as good as those in younger age groups. An increased prevalence of hepatitis C associated cirrhosis and hepatocellular carcinoma in the elderly population is to be expected, at least in the next 20 years. There is a high prevalence of gallstones among old people, in particular among females. For symptomatic choledocholithiasis in elderly patients, endoscopic bile duct clearance does not necessarily need to be followed by cholecystectomy.

Gallbladder hypomotility in diabetic polyneuropathy

This study was performed to evaluate the gallbladder motility in long-standing diabetes mellitus. The gallbladder function of diabetic patients was measured by means of quantitative hepatobiliary scintigraphy, and the severity of the associated autonomic and sensory polyneuropathy was determined. The presence of a marked gallbladder hypomotility was established, and a positive correlation was observed between the severity of the autonomic disturbance and the contractile disorder. This study underlines the important role of the neuropathy in the development of gallbladder hypomotility accompanying long-term diabetes mellitus.

Prevalence of gallstone disease in Iran

BACKGROUND

Prevalence of gallstone disease is different depending on the geographic region involved. Few studies, in Asia but not from Iran, about the frequency of gallstone disease have been published. The aim of this study is to examine the prevalence of gallstone disease in Iran.

METHODS

Four hundred and seventy-seven nomads from southern Iran, 513 industrial laborers older than 34 years, and 421 laborers from a pharmaceutical company above 30 years of age, and 471 elderly persons from three nursing homes near Tehran underwent abdominal sonography.

RESULTS

There were 1373 men and 509 women. Eighty-nine subjects had gallstone disease and 10.1% of them were cholecystectomized. While the prevalence in the men and women in the age group 31-40 years was very low (0.3% in men and 1.8% in women), it increases sharply in men older than 60 years and women older than 50 years to more than 10-fold (12.5 and 24.6% in male and female with an age 71-80 years, respectively).

CONCLUSION

In Iran, gallstone disease is very uncommon in middle-aged people, but increases sharply in older people. However, this does not reach the high prevalence seen in Western countries. The intake of a high fiber-containing diet, a low number of overweight people, smoking habit and hyperlipidemia are probably the cause for this low prevalence.

Quantitative trait loci mapping for cholesterol gallstones in AKR/J and C57L/J strains of mice

Quantitative trait locus (QTL) mapping was used to locate genes that determine the difference in cholesterol gallstone disease between the gallstone-susceptible strain C57L/J and the gallstone-resistant strain AKR/J. Gallstone weight was determined in 231 male (AKR x C57L) F(1) x AKR backcross mice fed a lithogenic diet containing 1% cholesterol, 0.5% cholic acid, and 15% butterfat for 8 wk. Mice having no stones and mice having the largest stones were genotyped at approximately 20-cM intervals to find the loci determining cholesterol gallstone formation. The major locus, Lith1, mapped near D2Mit56 and was confirmed by constructing a congenic strain, AK. L-Lith1(s). Another locus, Lith2, mapped near D19Mit58 and was also confirmed by constructing a congenic strain AK.L-Lith2(s). Other suggestive, but not statistically significant, loci mapped to chromosomes 6, 7, 8, 10, and X. The identification of these Lith genes will elucidate the pathophysiology of cholesterol gallstone formation.

Gallstones and cholecystectomy in modern Britain

BACKGROUND

It has been suggested that gallstone disease is now commoner, and that this might explain an increase in cholecystectomy rates, though conclusive evidence has been lacking.

METHODS

All the non-forensic necropsy results for Dundee 1953-98 were examined to assess the prevalence of gallstone disease. The NHS Scotland annual cholecystectomy figures were extracted from their earliest availability in 1961 up to the present. The subgroup of patients from Dundee was analysed separately, as were laparoscopic procedures, which were recorded from 1991.

RESULTS

Gallstone disease was much commoner in 1974-98 than in 1953-73. Increasing age was the main determinant of gallstone disease. Though gallstone disease was commoner in women than men aged 40-89, there was no sex difference under 40 or over 90 years. Cholecystectomy became much commoner in the 1960s when frequency of gallstone disease did not change. It increased further in the 1970s, peaking in 1977-8. There was a gradual fall in rates in the 1980s when gallstone prevalence remained high. There was a further moderate rise in the 1990s after the wide introduction of laparoscopic cholecystectomy. Cholecystectomy is now much commoner in young women and this change started in the 1960s. By contrast, cholecystectomy in men has become more prevalent in the older age group.

CONCLUSIONS

Gallstones were definitely more common in both sexes at all ages over 40 in the last 25 years. Changes in the cholecystectomy rates are only partly explained by changes in gallstone prevalence, and are more determined by surgical practice.

Review article: gall-bladder motor function in diabetes mellitus

Although some controversy exists, diabetic patients generally are thought to have a two- to threefold increased risk of cholesterol gallstones. From previous studies there is no convincing evidence for a supersaturated bile in diabetics, whereas several reports indicate that impaired gall-bladder emptying could be one of the important factors in the increased incidence of gallstones in diabetics. However, studies of gall-bladder motility in diabetics have yielded conflicting results, probably because of substantial heterogeneity in the patients studied, emptying stimulus and technique used to assess gall-bladder motor function. The mechanism of the gall-bladder emptying abnormality in diabetics is not completely understood, although it has been proposed that it could represent a manifestation of denervation caused by visceral neuropathy. Based on normal post-prandial cholecystokinin release, it can be ruled out that impaired cholecystokinin release is the mechanism responsible for reduced gall-bladder emptying in diabetics. Other possible explanations for impaired gall-bladder contraction in diabetics include a decreased sensitivity of the smooth muscle of the gall-bladder to plasma cholecystokinin, and/or decreased cholecystokinin receptors on the gall-bladder wall.

Apolipoprotein E genotype and the risk of gallbladder disease in pregnancy

The E4 allele of apolipoprotein E (apoE4) has previously been associated with symptomatic gallstone disease. The aim of this study was to determine if apoE4 is associated with the development of gallbladder sludge and/or stones during pregnancy. We conducted a nested case-control study based on an ongoing cohort study of gallbladder disease in pregnancy. Women in this study receive gallbladder ultrasounds in each trimester of pregnancy. Cases (n = 52) were defined as women with incident gallbladder sludge or stones diagnosed at the third trimester ultrasound. Controls (n = 104) were defined as women without gallbladder sludge or stones on any of 3 study ultrasounds. ApoE genotyping was performed from stored white blood cell pellets. Data were analyzed by stratified analysis and multivariate logistic regression. Cases and controls were similar in baseline characteristics. Forty-two women had sludge, 6 had gallstones, and 4 had both sludge and stones. After adjusting for risk factors such as age, parity, and body mass index, the odds ratio (OR) for the association between heterozygosity or homozygosity for the apoE4 allele and incident gallbladder sludge or stones was 0.91 (95% confidence interval [CI], 0.41-2.02). Further adjustment for family medical history and serum lipid levels did not substantially change these results (OR, 0.73; 95% CI, 0.29-1.82). In conclusion, apoE4 appears to have little or no overall association with the development of new gallbladder sludge or stones in pregnancy. However, an effect could not be ruled out in certain subgroups, such as blacks or women who are homozygous for apoE4.

Clinical manifestations of gallstone disease: evidence from the multicenter Italian study on cholelithiasis (MICOL)

Despite the many efforts to delineate the clinical manifestations of gallbladder disease, the precise symptom complex associated with gallstones is still a matter of debate, and even the existence of gallstone-specific symptoms has been questioned. We carried out a large population-based cross-sectional study (MICOL) to identify symptoms significantly related to gallstones. Fourteen centers throughout Italy enrolled 29,504 subjects aged 30 to 69 years. All subjects were administered an ultrasonographic examination of the upper abdomen and a precoded questionnaire. All subjects were divided into 4 groups: 25,374 (86.0%) gallstone-free subjects (GF), 1,832 (6.2%) patients with gallstones not previously diagnosed (GNPD), 638 (2.2%) patients with gallstones previously diagnosed (GPD), 1,660 (5.6%) patients with a history of cholecystectomy for gallstones (CC). In logistic regression analysis, pain at epigastrium and, even more, pain at right hypocondrium were significantly associated with gallstones. For pain at right hypocondrium, this association progressively increased from GNPD (OR = 1.60, 95% CI = 0.97-2.65) to GPD (OR = 8.77, 95% CI = 5.27-14.61) to CC (OR = 59.40, 95% CI = 43.87-80.42). Absence of heartburn combined with right hypocondrium or epigastrium pain and intolerance to fried or fatty food were also significantly related to gallstones. We also found some pain characteristics significantly associated with gallstones, i.e., pain radiated to the right shoulder, forcing the patient to rest, occurring soon after meals or unrelated to meals, not relieved by bowel movements, and frequently accompanied by gallstone-related morbidities. We developed a probability tree reporting the cumulative probability of having gallstones for each combination of those symptoms and characteristics of pain significantly associated with gallstones. In conclusion, we have identified symptoms and signs significantly associated with gallstones. We have shown that there is an increase in frequency and severity of these symptoms and signs across the different stages of gallstone disease. We have proposed a complex of symptoms and signs significantly associated with gallstones that might help physicians in clinical decision making.

Prevalence of gallstone disease in a Swedish population sample. Relations to occupation, childbirth, health status, life style, medications, and blood lipids

BACKGROUND

There are only a few Swedish studies on the prevalence of gallstone disease in selected age groups, and none including possible risk factors.

METHODS

Of a population sample of 1200 individuals (age, 35-85 years), 857 participated in the study. The study subjects were asked to answer a questionnaire about potential risk factors (occupation, childbirth, life style, and so forth), symptoms, and quality of life. Cholecystectomy had previously been done in 115 subjects, leaving 742 for ultrasound examination of the gallbladder.

RESULTS

The prevalence of gallstone disease increased with age, and at 75 years or more, 53% of the women and 32% of the men either had gallstones or had previously undergone cholecystectomy (32% and 13%, respectively). When comparing subjects with and without gallstones, there were no differences with regard to any variable, including blood lipid levels. The odds ratio of previous cholecystectomy was increased in subjects with an occupation requiring no specific education and reduced in subjects using wine or spirits every week. The odds ratio of abdominal pain was increased after previous cholecystectomy. Women in this group also experienced a lower quality of life.

CONCLUSIONS

The age and sex distribution of gallstone disease was in the order of the magnitude seen in other Scandinavian countries. None of the studied variables differed between subjects with and without gallstones. Subjects previously operated on with cholecystectomy did worse with regard to symptoms and quality of life.

Gallbladder contents and fasting gallbladder volumes during and after pregnancy

BACKGROUND

A high risk of developing sludge or gallstones has been associated with pregnancy. The aim of this study was to relate the prevalence of sludge and gallstones during and shortly after pregnancy to fasting gallbladder volume as an indicator of gallbladder motility.

METHODS

The population included 114 apparently healthy pregnant women from the Outpatient Clinic of Obstetrics of a large regional hospital and from the practices of regional midwives. Ultrasonography of the gallbladder was performed at weeks 15, 25, and 35 of gestation and at week 3 and month 6 postpartum.

RESULTS

At gestational week 15, 3 women had gallstones and 10 had sludge (mean volume, 33.8 ml), and 99 women had a normal gallbladder (mean volume, 30.5 ml). At week 25, 1 woman with a normal gallbladder formed gallstones and underwent cholecystectomy shortly after, and 22 women had sludge, of whom 13 had a normal gallbladder at first examination (mean volume, 33.2 ml). In 88 women with normal gallbladders (of whom 2 had sludge at week 15) mean volume was 31.9 ml. At week 35, 2 women had gallstones, and 21 had sludge (mean volume, 30.5 ml). In the remaining 79 women the gallbladders were clear (mean volume, 29.5 ml). Eight women developed sludge and two women gallstones in normal gallbladders at week 25. Seven women with sludge at week 25 had a normal gallbladder at week 35. Three weeks postpartum only 10 of 100 women had sludge (mean volume, 29.1 ml). Of these 10, 9 women had a normal gallbladder at week 35. Twenty of 21 women with sludge at week 35 had normal gallbladders week 3 postpartum. Gallstones found at week 35 had disappeared. In the women with a normal gallbladder the mean volume was decreased to 19.7 ml (P < 0.0001). Six months postpartum, sludge was found in 6 (mean volume, 18.4 ml) of 93 women (mean volume, 20.3 ml), of whom 5 had a normal gallbladder at week 3 postpartum. Only 61 women showed a normal gallbladder at each examination of the study. No differences in patient characteristics were found between women with normal gallbladders and those with sludge or gallstones.

CONCLUSIONS

Fasting gallbladder volume was increased in all pregnant women. This could not explain the formation of sludge or gallstones during gestation. Decrement of gallbladder volumes after delivery was faster in normal, clear gallbladders. More than a prerequisite, increased fasting gallbladder volume seemed to be a permissive factor of pregnancy-associated gallstone formation.

Diet and gallstones in Italy: the cross-sectional MICOL results

Fifteen thousand nine hundred ten men and 13,674 women (age, 30-69 years) were enrolled in an epidemiological survey of the general population, between December 1984 and April 1987. Each participant was submitted to ultrasonography (US) of the gallbladder and completed a food-frequency questionnaire, covering 38 food items. A common portion size was identified and subjects were asked how often each item was consumed. Nutrient intake was computed by multiplying the intake frequency and nutrient content per portion for each item, and then by summing the product over all foods. Each nutrient intake was adjusted for energy intake. Alcohol intake was calculated by summing the consumption of wine, beer, and liquor. Having excluded subjects aware of having gallstones (GS) or previously submitted to cholecystectomy (to avoid prothopatic bias), 787 males and 1,014 females with GS and 14,272 males and 10,836 females without GS were available for analysis. Relative risks (RR) of GS were computed by quintiles of nutrient intake. The overnight fasting period was calculated as the difference between the specified time of dinner and the time of the next meal (breakfast or lunch). A significant negative association was found between RR of GS and total energy intake for males (chi2 for trend = 8.37; P = .004), fiber intake for females (chi2 = 5.45; P = .02), and daily alcohol consumption for males (chi2 = 10.86; P = .001). A positive association was observed between RR of GS and carbohydrate (chi2 = 5.95; P = .01 for males; chi2 = 9.39; P = .002 for females) and protein intake only for males (chi2 = 10.92; P = .01). Prevalence of GS was higher among subjects who had an overnight fasting period of over 12 hours than subjects with that of less than 12 hours. (RR: 1.35; 95% CI: 1.01-1.80 for males; RR: 1.28; 95% CI: 1.03-1.60 for females). These data do not confirm that high energy intake is associated with an increased risk of GS. Factors protecting against GS comprise: low carbohydrate (males and females) and protein (males) intakes, high fiber (females) and moderate alcohol intake (males) consumption, and a shorter overnight fasting period for both sexes.