Review article: gall-bladder motor function in obesity

Association between triglyceride glucose index-related indices with gallstone disease among US adults

BACKGROUND

Triglyceride glucose (TyG) index combined with obesity-related indicators [triglyceride glucose-body mass index (TyG-BMI), triglyceride glucose-waist to height ratio (TyG-WHtR), triglyceride glucose-waist circumference (TyG-WC)], represents emerging methodologies for assessing insulin resistance. The objective of this investigation was to explore the correlation between TyG-related indices and gallstone disease.

METHODS

The study included 3740 adults from the 2017-2020 period of the National Health and Nutrition Examination Survey. TyG-BMI, TyG-WC, and TyG-WHtR were integrated as both continuous and categorical variables within the multivariate logistic model, respectively to evaluate the connection between various TyG-related indices and gallstone disease. Additionally, restriction cubic splines and subgroup analysis were employed to deepen our understanding of this relationship.

RESULTS

When analyzed as continuous variables, positive correlations were observed between TyG-BMI, TyG-WC, TyG-WHtR and gallstone disease. The OR(95%CI) were 1.063(1.045,1.082) for TyG-BMI (per 10-unit), 1.026(1.018,1.034) for TyG-WC (per 10-unit) and 1.483(1.314,1.676) for TyG-WHtR (per 1-unit), respectively. When categorized into quartiles, these three TyG-related indices still show statistically significant associations with gallstone disease. Descending in order, the diagnostic capability for gallstone disease is demonstrated as follows: TyG-WHtR (AUC = 0.667), TyG-BMI (AUC = 0.647), and TyG-WC (AUC = 0.640).

CONCLUSION

There were significantly positive associations between TyG-related indices, including TyG-BMI, TyG-WC, and TyG-WHtR, and gallstone disease. Of these indices, TyG-WHtR demonstrated the most favorable performance in identifying the risk of gallstone disease.

A computer study of the risk of cholesterol gallstone associated with obesity and normal weight

Obese people differ from the people of normal weight in gall bladder motility and have a higher risk of cholesterol stone formation. In this study, using a mathematical model of cholesterol homeostasis, which also considers the enterohepatic circulation of bile as well as cholesterol, we investigated the risk of cholesterol stone formation in obese and normal-weight groups who had normal blood cholesterol levels. We associated the risk of stone formation with the amount of cholesterol released into bile and the amount of de novo-synthesized cholic acid. For both groups, we determined the conditions of low and high risk. In addition, we analyzed the potential effects of changes in gall bladder motility with increased weight. The results showed that the obese group exhibited increased kinetics of enterohepatic circulation, leading to a significant increase in blood cholesterol levels, which can be reduced by increasing the amount of cholesterol in bile. Based on this finding, we suggest that for obese people, it is beneficial to reduce the amount and change the composition of circulating bile through the inhibition of cholic acid synthesis along with cholesterol synthesis. Furthermore, obese people should maintain a triglyceride-lowering diet and consume small meals containing fat, preferably in combination with agents that can reduce bile output from the gall bladder.

Physiologically Based Pharmacokinetic/Pharmacodynamic Modeling to Support Waivers of In Vivo Clinical Studies: Current Status, Challenges, and Opportunities

Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) modeling has been extensively applied to quantitatively translate in vitro data, predict the in vivo performance, and ultimately support waivers of in vivo clinical studies. In the area of biopharmaceutics and within the context of model-informed drug discovery and development (MID3), there is a rapidly growing interest in applying verified and validated mechanistic PBPK models to waive in vivo clinical studies. However, the regulatory acceptance of PBPK analyses for biopharmaceutics and oral drug absorption applications, which is also referred to variously as "PBPK absorption modeling" [Zhang et al. CPT: Pharmacometrics Syst. Pharmacol. 2017, 6, 492], "physiologically based absorption modeling", or "physiologically based biopharmaceutics modeling" (PBBM), remains rather low [Kesisoglou et al. J. Pharm. Sci. 2016, 105, 2723] [Heimbach et al. AAPS J. 2019, 21, 29]. Despite considerable progress in the understanding of gastrointestinal (GI) physiology, in vitro biopharmaceutic and in silico tools, PBPK models for oral absorption often suffer from an incomplete understanding of the physiology, overparameterization, and insufficient model validation and/or platform verification, all of which can represent limitations to their translatability and predictive performance. The complex interactions of drug substances and (bioenabling) formulations with the highly dynamic and heterogeneous environment of the GI tract in different age, ethnic, and genetic groups as well as disease states have not been yet fully elucidated, and they deserve further research. Along with advancements in the understanding of GI physiology and refinement of current or development of fully mechanistic in silico tools, we strongly believe that harmonization, interdisciplinary interaction, and enhancement of the translational link between in vitro, in silico, and in vivo will determine the future of PBBM. This Perspective provides an overview of the current status of PBBM, reflects on challenges and knowledge gaps, and discusses future opportunities around PBPK/PD models for oral absorption of small and large molecules to waive in vivo clinical studies.

Association of Body Mass Index and Waist to Hip Ratio With Gallstone Disease in Patients Visiting Rural Tertiary Care Center in North India

Introduction. In India the prevalence of gall stone disease varies in different parts of India. Malhotra in 1996 conducted an epidemiological study in Indian Railway employees and showed that North Indians has 7 times higher prevalence of gall stones compared to South Indian employees. It is said that Gall bladder is a disease of "Fatty, Fertile, Females in their Forties". In our daily routine we observe that it is found not only in fatty females but common in average built patients also. Material and Methods. Study includes patients visiting to BPS GMC Khanpur Kalan with diagnosis of gall stone diseases and operated at our center with sample size of 135. Body mass index (BMI) and Waist to Hip ratio are calculated using their standard formulas. All data was compiled in IBM SPSS statistics (20.0). Result. Normal BMI is considered up to 25 and more than 50% patients lie in normal BMI range. Only 13% of cases lie in obese group that is BMI greater than 30. Waist to hip ratio, maximum patients that is BMI greater than 30. Waist to hip ratio, maximum patients that is (83%) lie in group more than 0.85. Minimum Waist to Hip ratio is .77 and maximum Waist to Hip ratio is 1.45. Out of 135 patients 90 patients are having high Waist to Hip ratio. Conclusion. Waist to Hip Ratio (abdominal adiposity) is better indicator of Gall stone diseases than BMI.

Effects of liraglutide on gallbladder emptying: A randomized, placebo-controlled trial in adults with overweight or obesity

AIMS

Treatment with liraglutide 3.0 mg has been associated with gallbladder-related adverse events. To conduct a single-centre, double-blind, 12-week trial comparing the effect of 0.6 mg liraglutide and steady-state liraglutide 3.0 mg with placebo on gallbladder emptying in adults with body mass index (BMI) ≥27 kg/m² and without diabetes.

METHODS

Participants were randomized 1:1 to once-daily subcutaneous liraglutide (n = 26) or placebo (n = 26), starting at 0.6 mg with 0.6-mg weekly increments to 3.0 mg, with nutritional and physical activity counselling. A 600-kcal (23.7 g fat) liquid meal test was performed at baseline, after the first dose and after 12 weeks. The primary endpoint was the 12-week maximum postprandial gallbladder ejection fraction (GBEF_max ), measured over 240 minutes after starting the meal.

RESULTS

Baseline characteristics were similar between groups (mean ± SD overall age 47.6 ± 10.0 years, BMI 32.6 ±3.4 kg/m² , 50% women). Mean 12-week GBEF_max (treatment difference -3.7%, 95% confidence interval [CI] -13.1, 5.7) and area under the GBEF curve in the first 60 minutes (-390% × min, 95% CI -919, 140) did not differ for liraglutide 3.0 mg (n = 23) vs placebo (n = 24). The median (range) time to GBEF_max was 151 (11-240) minutes with liraglutide 3.0 mg and 77 (22-212) minutes with placebo. Similar findings were noted after the first 0.6-mg liraglutide dose. Gastrointestinal disorders, notably nausea and constipation, were the most frequently reported adverse events.

CONCLUSIONS

Treatment with liraglutide did not affect the GBEF_max but appeared to prolong the time to GBEF_max .

Determinants for clinical events in gallstone carriers unaware of their gallstones

BACKGROUND AND AIM

Knowledge about determinants for clinical events in gallstone carriers is missing. The aim of this cohort study was to identify determinants of clinical gallstone events during long-term follow-up of a population unaware of their gallstones.

METHODS

Three randomly selected groups from the general population of Copenhagen (n = 6 037) underwent ultrasound examinations to detect gallstones in the period 1982-1994. Participants unaware of gallstone (n = 595) were followed up for clinical gallstone events through central registers until December 31, 2011. Follow-up length was median 17.5 years and 99.8% complete. Cox regression analyses were performed.

RESULTS

Gallstone events occurred in 16.6% participants of whom 7.2% were complicated and 9.4% were uncomplicated. Total events were associated with body mass index. Complicated events were associated with coffee consumption, vocational training, and inversely association to a higher physical activity level when compared with being sedentary. Multiple adjusted models confirmed association for total events and body mass index and for complicated events and physical activity. No significant associations were identified for alcohol, coffee, diet, smoking, or visits to general practitioner and clinical events.

CONCLUSIONS

Body mass index, vocational training, and physical activity level were associated with clinical events in long-term follow-up of unaware gallstone carriers. Future trials should investigate clinical effects of lifestyle and medical interventions in gallstone carriers.

Determinants for gallstone formation - a new data cohort study and a systematic review with meta-analysis

OBJECTIVE

Only few determinants of gallstone formation have been identified in cohort studies. The aim was to identify further determinants for gallstones in a Danish cohort and to perform a meta-analysis of results from existing cohorts.

MATERIAL AND METHODS

Data from a cohort study was used. Gallstone incidence was assessed through repeated ultrasound examinations. Body mass index (BMI), blood pressure, self-rated health, lifestyle variables, blood lipids, and use of female sex hormones were measured at the baseline examination. Statistical analyses included logistic regression. Based on a prospective protocol, a systematic review of the literature was performed identifying all articles dealing with determinants of incident gallstones. Meta-analyses of comparable determinants were performed through fixed effect models.

RESULTS

Participants with no gallstones at baseline and with at least one re-examination were followed-up completely (mean 11.6 years, N = 2848). The overall cumulative incidence of gallstones was 0.60% per year. Independent positive determinants for incident gallstones were age, female sex, non-high density lipoprotein (non-HDL) cholesterol, and gallbladder polyps. In addition, BMI was positively associated in men. The systematic review additionally identified associations for comorbidities, parity, and dietary factors. Meta-analysis confirmed the significant associations for incident gallstones and age, female sex, BMI, and non-HDL cholesterol. No significant associations were found for blood pressure, smoking, alcohol consumption, HDL cholesterol, or triglycerides in meta-analyses.

CONCLUSIONS

Age, female sex, BMI, non-HDL cholesterol, and polyps are independent determinants for gallstone formation. Incident gallstones and the metabolic syndrome share common risk factors. More studies are needed for further exploration.

Clinical Relationship between Steatocholecystitis and Gallbladder Contractility Measured by Cholescintigraphy

Objective. Contractility of gallbladder is known to be decreased in fatty gallbladder diseases. However, clinical estimation data about this relationship is still lacking. The aim of this study was to investigate the association between steatocholecystitis and contractility of gallbladder. Methods. Patients with cholecystitis (steatocholecystitis versus nonsteatocholecystitis) who underwent cholescintigraphy before cholecystectomy were retrospectively evaluated in a single teaching hospital of Korea. The association of steatocholecystitis with contractility of gallbladder, measured by preoperative cholescintigraphy, was assessed by univariable and multivariable analysis. Results. A total of 432 patients were finally enrolled (steatocholecystitis versus nonsteatocholecystitis; 75 versus 357, calculous versus acalculous cholecystitis; 316 versus 116). In the multivariable analysis, age (OR: 0.94, 95% CI: 0.90-0.99, P = 0.01) and total serum cholesterol (OR: 1.02, 95% CI: 1.01-1.04, P = 0.04) were related to steatocholecystitis in patients with acalculous cholecystitis. Only age (OR: 0.97, 95% CI: 0.94-0.99, P = 0.004) was significantly related to steatocholecystitis in patients with calculous cholecystitis. However, ejection fraction of gallbladder reflecting contractility measured by cholescintigraphy was not related to steatocholecystitis irrespective of presence of gallbladder stone in patients with cholecystitis. Conclusion. Ejection fraction of gallbladder measured by cholescintigraphy cannot be used for the detection or confirmation of steatocholecystitis.

A relationship between migraine and biliary tract disorders: findings in two Swedish samples of elderly twins

OBJECTIVES

To investigate whether there is a relationship between the clinical occurrence of migraine and biliary tract disorders (BTD) and to study whether there is a genetic influence on such an association.

MATERIALS AND METHODS

The near lifetime morbidity for migraine and BTD was examined in two Swedish twin-samples: OCTO-Twin (149 MZ and 202 DZ pairs; 234 men, 468 women; 80 years of age or older at inclusion), and the GENDER study (249 unlike-sex DZ-pairs; 70-80 years of age at inclusion). The diagnosis of BTD was established by perusal of medical records from the last twenty years. The diagnosis of migraine was based on iterated questionnaires and personal interviews.

RESULTS

The odds ratio (OR) of BTD among OCTO-Twin subjects suffering from migraine was 3.5 (1.9-6.7) in monozygotic pairs and 1.7 (1.0-2.9) in dizygotic pairs The corresponding figures among the GENDER unlike-sex DZ-pairs was 2.7 (1.6-4.5). Migraine was associated with female sex and waist circumference.

CONCLUSIONS

There is a relationship between the occurrence of migraine and BTD, also when controlling for the fact that both disorders are more frequent in women. The association appears to be partly attributable to genetic influences.

Management of gallstones and gallbladder disease in patients undergoing gastric bypass

The appropriate management of gallstones and gallbladder disease in patients undergoing gastric bypass remains unknown. Several therapeutic modalities are used and include performing cholecystectomy on all patients at the time of gastric bypass, performing concomitant cholecystectomy only when patients have gallstones and performing cholecystectomy only in the presence of both symptoms and gallstones. Some groups administer ursodeoxycholic acid for gallstone prevention in the postoperative period. All treatment modalities are analyzed and their results and rationality are discussed.

Steatocholecystitis and fatty gallbladder disease

Obesity has become an epidemic worldwide. It is accompanied by a multitude of medical complications including metabolic syndrome. Obesity may lead to fatty infiltration of multiple internal organs including liver, heart, kidney, and pancreas, causing organ dysfunctions. Fatty infiltration leads to chronic inflammation and tissue damage. Fatty infiltration in the liver results in nonalcoholic fatty liver disease, which is increasingly common nowadays. Recent studies in animals and humans indicate that obesity also is associated with fatty infiltration of gallbladder, resulting in cholecystosteatosis. The increased gallbladder lipids include free fatty acids, phospholipids, and triglycerides. Enhanced inflammation with an increased amount of fat in the gallbladder results in an abnormal wall structure and decreased contractility. In support of this notion, a recent experiment on the effect of Ezetimibe, which is a novel drug that inhibits intestinal fat absorption, on fatty gallbladder disease reveals that Ezetimibe can ameliorate cholecystosteatosis and restore in vivo gallbladder contractility. The proportion of cholecystectomies performed for chronic acalculous cholecystitis has increased significantly over the past two decades. An increase in gallbladder fat, which leads to poor gallbladder emptying and biliary symptoms, may partly explain this phenomenon. Although dietary carbohydrates have been demonstrated to be associated with fatty gallbladder disease, other potential modifiable environmental factors are not clear. The pathogenesis and prognosis of fatty gallbladder disease, including steatocholecystitis, and the relations of fatty gallbladder disease to nonalcoholic fatty liver disease, including steatohepatitis, and other components of metabolic syndrome are largely unknown. More research is needed to answer these questions.

Anthropometric measurements, physical activity, and the risk of symptomatic gallstone disease in Chinese women

PURPOSE

Gallstone disease is more common among overweight individuals, particularly in women. We conducted a cross-sectional case-control study of Chinese women nested in the Shanghai Women's Health Study (SWHS) to evaluate the association of gallstone disease with body mass index (BMI), waist to hip ratio (WHR), and physical activity (PA).

METHODS

The study included 8,485 women with self-reported, physician-diagnosed, prevalent gallstone disease and 16,970 frequency-matched controls by birth year and age at gallstone diagnosis (4-year intervals). Information on height, weight history, waist and hip circumferences, physical activities, and other exposures was obtained by in-person interview.

RESULTS

: Usual BMI (p trend < 0.001) and WHR (p trend < 0.001) were both related to a high prevalence of gallstone disease, and a significant interaction between BMI and WHR on gallstone risk was found (odds ratio [OR] = 3.82, 95%CI [95% confidence interval] 2.47-5.23 for those with both highest BMI and WHR relative to those with lowest BMI and WHR, p interaction = 0.03). Gallstone risk was positively associated with cumulative occupational sitting time (p trend = 0.01) and inversely associated with occupational cumulative energy expenditure (p trend = 0.03) as well as with household PA (p trend = 0.02).

CONCLUSIONS

Our findings further support that overall and central excessive adiposity is an independent risk factor for gallstones in women. In addition, regardless of adiposity level, being physically active may ameliorate the risk of this disease.

Gallbladder motility in children with chronic constipation

OBJECTIVE

The aim of this study was to evaluate gallbladder motility in constipated children.

PATIENTS AND METHODS

A cross-sectional study was conducted on pediatric patients with refractory constipation examined in a pediatric gastroenterology unit of a teaching hospital between January 2005 and August 2006. All of the patients seen during the period were included (age range, 2-16 years). The control group, matched for sex and age, was selected among patients seen at the same basic health units where patients were seen before being referred to pediatric gastroenterologists. A gallbladder contractility index was calculated based on fasting and postprandial gallbladder areas, using an ultrasonographic method. Ultrasonography studies were performed prospectively and blindly by the same physician. Measurements obtained in patients were compared with those obtained in controls.

RESULTS

A total of 132 constipated children and the same number of healthy controls were included in the study. Median and mean fasting gallbladder areas were similar in patients and controls. Postprandial gallbladder areas were larger in the patient group, mean +/- SD = 594.8 +/- 206.4 mm, median, 562.5 mm, than in the control group, mean +/- SD = 541.1 +/- 156.1 mm, median, 530.5 mm; P = .031. Logistic regression showed that the risk of a contractility index <25% was 5.2 times greater in patients (odds ratio [OR] 5.2; 95% confidence interval [CI] 2.5-10.81) than in controls. Age was found to be a protective factor (OR 0.79; 95% CI 0.71-0.88).

CONCLUSIONS

Gallbladder motility disorder was identified in a group of children with severe constipation. This finding may contribute to the understanding of functional constipation in children.

Body mass index, alcohol, tobacco and symptomatic gallstone disease: a Swedish twin study

BACKGROUND/AIMS

Both genetic and environmental factors are involved in the pathogenesis of gallstone disease (GD). We aimed to examine the association between symptomatic GD and overweight (body mass index, BMI, 25-30 kg m(-2)), obesity (BMI > 30 kg m(-2)), alcohol, smoking and smoke-free tobacco by analysing a large twin population.

METHODS

The Swedish Twin Registry (STR) was linked to the Swedish Hospital Discharge and Causes of Death Registries for GD and GD-surgery related diagnoses. Weight, height, use of alcohol, smoking and smoke-free tobacco were provided by STR and analysed for possible associations by conditional logistic regression.

RESULTS

Overweight and obesity were associated with a significantly higher risk for symptomatic GD in the whole study population (OR 1.86 and OR 3.38; CI: 1.52-2.28 and 2.28-5.02 respectively). High alcohol consumption was associated with a lower risk for GD in the whole population (OR 0.62; CI: 0.51-0.74) with no difference between discordant monozygotic and dizygotic twins (OR 1.08 and OR 0.96; CI: 0.82-1.42 and 0.79-1.16). Smoking or smoke-free tobacco was not correlated with GD.

CONCLUSION

Consistent with epidemiological studies, we found positive associations between BMI and the development of symptomatic GD. High alcohol consumption was associated with a decreased risk against GD. Tobacco use has no impact on GD.

Correlação entre hipomotilidade da vesícula biliar e desenvolvimento de colecistolitíase após operação bariátrica

OBJETIVO: O objetivo deste estudo foi determinar se existe associação entre a hipomotilidade da vesícula biliar em obesos, antes da cirurgia bariátrica e o desenvolvimento da litíase biliar após perda de peso. MÉTODO: No período de setembro de 2002 a janeiro de 2005, utilizando ultra-sonografia em tempo real, com medidas do volume em jejum e 60 minutos após ingestão de dieta, avaliamos a vesícula biliar de noventa e seis pacientes obesos com indicação de cirurgia bariátrica. Estes pacientes foram reavaliados um ano após a cirurgia com ultra-sonografia para detecção de litíase biliar. RESULTADOS: Vinte e sete (28,12%) apresentaram hipomotilidade da vesícula, destes, sete (29,62%) apresentaram litíase. Dezoito (18,75%) da amostra total, desenvolveram litíase biliar no período pós-operatório. CONCLUSÕES: Não foi encontrada diferença estatisticamente significante no desenvolvimento de litíase no grupo de pacientes com hipomotilidade e naqueles com motilidade normal da vesícula biliar.

Biliary lipids, cholesterol and bile synthesis: different adaptive mechanisms to dietary cholesterol in lean and obese subjects

BACKGROUND

Increased biliary cholesterol secretion together with elevated cholesterol synthesis may predispose obese subjects to cholesterol gallstone formation.

AIM

To investigate whether processing of dietary cholesterol is altered in obesity, we enrolled eight lean and seven obese subjects in a double-blind crossover study.

METHODS

Cholesterol consumption was 300 mg/day on low and 1300 mg/day on high cholesterol diet. After 3 weeks on either diet, hepatic bile was collected to determine biliary lipid secretion, and bile salt composition by high-performance liquid chromatography and cholesterol saturation index was calculated. Cholesterol synthesis was measured employing mass isotopomer distribution analysis. Bile acid synthesis via neutral and acidic pathway was assessed by serum levels of 7alpha-hydroxy-4-cholesten-3-one and 27-hydroxycholesterol.

RESULTS

Cholesterol synthesis was increased in obese compared with lean and feedback inhibited only in obese. On low cholesterol diet, cholesterol secretion was doubled in obese but bile acid composition and synthesis was similar between the two groups. After high cholesterol diet, cholesterol saturation index and bile secretion were unchanged. In contrast to obese, lean increased bile acid synthesis only via the acidic pathway.

CONCLUSIONS

Dietary cholesterol appears to preferentially induce bile acid synthesis via the acidic pathway in lean, whereas cholesterol synthesis was inhibited in obese. Thus, stable cholesterol saturation index may be achieved by different mechanisms.

Gallbladder motor function, plasma cholecystokinin and cholecystokinin receptor of gallbladder in cholesterol stone patients

AIM: To study the interactive relationship of gallbladder motor function, plasma cholecystokinin (CCK) and cholecystokinin A receptor (CCK-R) of gallbladder in patients with cholesterol stone disease.

METHODS: Gallbladder motility was studied by ultrasonography in 33 patients with gallbladder stone and 10 health subjects as controls. Plasma CCK concentration was measured by radioimmunoassay in fasting status (CCK-f) and in 30 min after lipid test meal (CCK-30). Radioligand method was employed to analyze the amount and activity of CCK-R from 33 gallstone patients having cholecystectomy and 8 persons without gallstone died of severe trauma as controls.

RESULTS: The percentage of cholesterol in the gallstone composition was more than 70%. The cholesterol stone type was indicated for the patients with gallbladder stone in this study. Based on the criterion of gallbladder residual fraction of the control group, 33 gallstone patients were divided into two subgroups, contractor group (14 cases) and non-contractor group (19 cases). The concentration of CCK-30 was significantly higher in non-contractor group than that in both contractor group and control group (55.86±3.86 pmol/L vs 37.85±0.88 pmol/L and 37.95±0.74 pmol/L, P<0.01), but there was no difference between contractor group and control group. Meanwhile no significant difference of the concentration of CCK-f could be observed among three groups. The amount of CCK-R was lower in non-contractor group than those in both control group and contractor group (10.27±0.94 fmol/mg vs 24.59±2.39 fmol/mg and 22.66±0.55 fmol/mg, P<0.01). The activity of CCK-R shown as KD in non-contractor group decreased compared to that in control group and contractor group. Only was the activity of CCK-R lower in contractor group than that in control group. The ejection fraction correlated closely with the amount of CCK-R (r = 0.9683, P<0.01), and the concentration of CCK-30 correlated negatively with the amount of CCK-R closely (r = -0.9627, P<0.01).

CONCLUSION: The distinctive interactive relationship of gallbladder emptying, plasma CCK and CCK-R in gallbladder from this study suggested that the defect of CCK-R may be a key point leading to the impairment of gallbladder motor function and the pathogenesis of cholesterol gallstone formation may differ in two subgroups of gallstone patient, gallbladder non-contractor group or contractor group.

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.

Sonographic evaluation of gallbladder volume and ejection fraction in obese women without gallstones

PURPOSE

Obese people have an increased incidence of gallstones. Although the exact pathogenic mechanisms of gallstone development are unknown, impaired gallbladder emptying has been suggested as a possible underlying mechanism. Our aim was to investigate this possibility by evaluating gallbladder motility and related factors in obese and nonobese women without gallstones.

METHODS

This study included 79 obese women and 25 nonobese healthy women. Using real-time sonography, we evaluated fasting and postprandial (15th-, 30th-, 45th-, 60th-, 75th-, 90th-, 120th-, and 150th-minute) gallbladder volumes and ejection fractions. The smallest postprandial volume was considered the residual volume.

RESULTS

Mean (+/- standard deviation) fasting and residual gallbladder volumes were 43.2 +/- 18.3 cm(3) and 21.4 +/- 11.2 cm(3), respectively, in the obese women and 28.1 +/- 12.3 cm(3) and 7.9 +/- 3.4 cm(3), respectively, in the nonobese women. Maximal ejection fraction was 49 +/- 19% in obese women and 63 +/- 29% in nonobese women (p = 0.001). The fasting and residual volumes and the postprandial volumes at all time points were higher in obese women than in nonobese women (p < 0.001). In addition, 15th-, 30th-, 45th-, 60th-, 75th-, and 90th-minute postprandial ejection fractions were lower in obese women than in nonobese women (p < 0.001). Positive correlations were found between fasting gallbladder volume and body mass index and body fat weight and between residual volume and body mass index, waist circumference, body fat percentage, and body fat weight (p < 0.05 for all comparisons).

CONCLUSIONS

Our results show that fasting and postprandial gallbladder volumes are higher and that postprandial gallbladder motility is lower in obese than in nonobese women. There are positive correlations between fasting gallbladder volume and body weight, body mass index, and body fat weight.

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.