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

Non-linear relationship between the first meal time of the day and gallstone incidence in American adults: a population-based cross-sectional study

Background

Irregular meal time is associated with gallstones. The time-dose effect between meal time and gallstone formation remains unknown.

Objective

This study aimed to investigate the association between the first meal time (FMT) of the day and the prevalence of gallstones.

Methods

Based on data from the National Health and Nutrition Examination Survey from 2017 to March 2020, the associations between the FMT of the day and the prevalence of gallstones were analyzed via multivariable logistic regression, restricted cubic spline curves, subgroup analysis, and interaction tests.

Results

A total of 6,547 participants were included. The fully adjusted model indicated a positive correlation between the FMT of the day and the prevalence of gallstones (odds ratio [OR] = 1.05, 95% confidence interval [CI] = 1.02 ~ 1.08); this association was consistent across subgroups. The risk of developing gallstones was the greatest when the FMT was between 09:00 and 14:00 (OR [95% CI] = 1.49 [1.24 ~ 1.77]). There was a non-linear relationship between the FMT and gallstone incidence (P for non-linearity = 0.042), with an inflection point at 13.4 h. After the 13.4-h mark, the risk of developing gallstones did not increase further.

Conclusion

The FMT of the day is positively correlated with the prevalence of gallstones, and there is a non-linear relationship and threshold effect between the two. Skipping breakfast is associated with a greater risk of developing gallstones. This study provides new evidence for the dietary prevention of gallstones.

Associations between temporal eating patterns and energy distribution patterns with gallstones: a cross-sectional study based on NHANES 2017-2018

BACKGROUND

Gallstones are strongly associated with eating occasion (EO) and energy distribution, but few studies have addressed this aspect. Therefore, we utilize the data from 2017 to 2018 National Health and Nutrition Examination Survey (NHANES) to explore the association between temporal eating patterns and energy distribution patterns with the incidence of gallstones.

METHODS

Our study comprised participants who completed the NHANES dietary intake interview and self-reported health questionnaire at age 20 or older. The self-report method for gallstones (have you ever been told by a doctor) was used. We use the latent class analysis (LCA) identified temporal eating patterns, and identified energy distribution patterns through latent profile analysis (LPA). The association between temporal eating patterns, energy distribution patterns, and gallstones was examined using logistic regression modeling.

RESULTS

The study included a total of 4,692 participants. LCA identified four temporal eating patterns labeled as "Conventional," "Early breakfast," "Later breakfast," and "Grazing." Compared to the "Conventional" pattern, the "Early breakfast" pattern (OR 0.809, 95%CI 0.808-0.811) was associated with a reduced risk of gallstones, while the "Later breakfast" (OR 1.435, 95%CI 1.432-1.438) and "Grazing" (OR 1.147, 95%CI 1.145-1.148) patterns were associated with an increased risk of gallstones. LPA identified four energy distribution patterns labeled as "Guideline," "High carbohydrates," "Carbs-fat balance," and "High fat." The "High carbohydrates" pattern (OR 1.329, 95%CI 1.326-1.331) was associated with an increased risk of gallstones compared to the "Guideline" pattern. The "Carbs-fat balance" pattern (OR 0.877, 95%CI 0.876-0.879) and the "High fat" pattern (OR 0.848, 95%CI 0.846-0.850) were significantly and negatively associated with the risk of gallstones.

CONCLUSIONS

To summarize, inappropriate timing of eating and energy sources are associated with gallstones. As a dietary prevention measure for gallstones, we suggest adhering to a regular eating routine and avoiding overly casual and frequent food consumption. If the main EO routine occurs in the morning, this time should not exceed 9:00 a.m. Additionally, reducing carbohydrate intake and maintaining a moderate level of fat intake is believed to contribute to a lower risk of gallstones.

Cholelithiasis, Gut Microbiota and Bile Acids after Bariatric Surgery-Can Cholelithiasis Be Prevented by Modulating the Microbiota? A Literature Review

BACKGROUND

Cholelithiasis is one of the more common complications following bariatric surgery. This may be related to the rapid weight loss during this period, although the exact mechanism of gallstone formation after bariatric surgery has not been fully elucidated.

METHODS

The present literature review focuses on risk factors, prevention options and the impact of the gut microbiota on the development of gallbladder stones after bariatric surgery.

RESULTS

A potential risk factor for the development of cholelithiasis after bariatric surgery may be changes in the composition of the intestinal microbiota and bile acids. One of the bile acids-ursodeoxycholic acid-is considered to reduce the concentration of mucin proteins and thus contribute to reducing the formation of cholesterol crystals in patients with cholelithiasis. Additionally, it reduces the risk of both asymptomatic and symptomatic gallstones after bariatric surgery. Patients who developed gallstones after bariatric surgery had a higher abundance of Ruminococcus gnavus and those who did not develop cholelithiasis had a higher abundance of Lactobacillaceae and Enterobacteriaceae.

CONCLUSION

The exact mechanism of gallstone formation after bariatric surgery has not yet been clarified. Research suggests that the intestinal microbiota and bile acids may have an important role in this.

Novel insights into the pathogenic impact of diabetes on the gastrointestinal tract

Type 2 and type 1 diabetes are common endocrine disorders with a progressively increasing incidence worldwide. These chronic, systemic diseases have multiorgan implications, and the whole gastrointestinal (GI) tract represents a frequent target in terms of symptom appearance and interdependent pathophysiological mechanisms. Metabolic alterations linked with diabetic complications, neuropathy and disrupted hormone homeostasis can lead to upper and/or lower GI symptoms in up to 75% of diabetic patients, with multifactorial involvement of the oesophagus, stomach, upper and lower intestine, and of the gallbladder. On the other hand, altered gastrointestinal motility and/or secretions are able to affect glucose and lipid homeostasis in the short and long term. Finally, diabetes has been linked with increased cancer risk at different levels of the GI tract. The presence of GI symptoms and a comprehensive assessment of GI function should be carefully considered in the management of diabetic patients to avoid further complications and to ameliorate the quality of life. Additionally, the presence of gastrointestinal dysfunction should be adequately managed to improve metabolic homeostasis, the efficacy of antidiabetic treatments and secondary prevention strategies.

Excess Body Weight and Gallstone Disease

Background

Approximately one fifth of adults are diagnosed with gallstones worldwide. Of these, around 25% develop gallstone disease (indicated by the presence of symptoms) and undergo cholecystectomy.

Summary

The risk of gallstones is influenced by a combination of genetic and lifestyle factors, such as excess body weight. In fact, body mass has been demonstrated to be a major risk factor for symptomatic gallstones. Rapid weight loss can also initiate a prolithogenic state and further increase the likelihood of either gallstone formation or existing gallstones becoming symptomatic; however, sensible weight loss strategies can mitigate this risk. This review discusses the role of excess body weight and the risk of gallstone disease, as well as the options available for the prevention of symptomatic gallstones.

Key Messages

Healthy weight loss diets combined with regular physical activity can promote successful weight loss and weight maintenance and reduce the risk of gallstones. Should rapid weight loss be required for health reasons or be expected, e.g., after bariatric surgery, prophylactic ursodeoxycholic acid during the period of weight reduction has been demonstrated to reduce the incidence of gallstones formation or symptomatic gallstone occurrence. The recent German guidelines on gallstones recommend simultaneous cholecystectomy during bariatric surgery but only for those with preexisting symptomatic stones.

Gallstone Disease, Obesity and the Firmicutes/Bacteroidetes Ratio as a Possible Biomarker of Gut Dysbiosis

Obesity is a major risk factor for developing gallstone disease (GSD). Previous studies have shown that obesity is associated with an elevated Firmicutes/Bacteroidetes ratio in the gut microbiota. These findings suggest that the development of GSD may be related to gut dysbiosis. This review presents and summarizes the recent findings of studies on the gut microbiota in patients with GSD. Most of the studies on the gut microbiota in patients with GSD have shown a significant increase in the phyla Firmicutes (Lactobacillaceae family, genera Clostridium, Ruminococcus, Veillonella, Blautia, Dorea, Anaerostipes, and Oscillospira), Actinobacteria (Bifidobacterium genus), Proteobacteria, Bacteroidetes (genera Bacteroides, Prevotella, and Fusobacterium) and a significant decrease in the phyla Bacteroidetes (family Muribaculaceae, and genera Bacteroides, Prevotella, Alistipes, Paludibacter, Barnesiella), Firmicutes (genera Faecalibacterium, Eubacterium, Lachnospira, and Roseburia), Actinobacteria (Bifidobacterium genus), and Proteobacteria (Desulfovibrio genus). The influence of GSD on microbial diversity is not clear. Some studies report that GSD reduces microbial diversity in the bile, whereas others suggest the increase in microbial diversity in the bile of patients with GSD. The phyla Proteobacteria (especially family Enterobacteriaceae) and Firmicutes (Enterococcus genus) are most commonly detected in the bile of patients with GSD. On the other hand, the composition of bile microbiota in patients with GSD shows considerable inter-individual variability. The impact of GSD on the Firmicutes/Bacteroidetes ratio is unclear and reports are contradictory. For this reason, it should be stated that the results of reviewed studies do not allow for drawing unequivocal conclusions regarding the relationship between GSD and the Firmicutes/Bacteroidetes ratio in the microbiota.

Dietary Restrictions and Nutrition in the Prevention and Treatment of Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of death in many developed countries and remains one of the major diseases strongly affected by the diet. Nutrition can affect CVD directly by contributing to the accumulation of vascular plaques and also indirectly by regulating the rate of aging. This review summarizes research on nutrition and CVD incidence based on a multipillar system that includes basic research focused on aging, epidemiological studies, clinical studies, and studies of centenarians. The relevant research linking nutrition and CVD with focus on macronutrients and aging will be highlighted. We will review some of the most relevant studies on nutrition and CVD treatment, also focusing on interventions known to delay aging. We will discuss both everyday dietary compositions, as well as intermittent and periodic fasting interventions with the potential to prevent and treat CVD.

The Role of Diet in the Pathogenesis of Cholesterol Gallstones

Cholesterol gallstone disease is a major health problem in Westernized countries and depends on a complex interplay between genetic factors, lifestyle and diet, acting on specific pathogenic mechanisms. Overweigh, obesity, dyslipidemia, insulin resistance and altered cholesterol homeostasis have been linked to increased gallstone occurrence, and several studies point to a number of specific nutrients as risk- or protective factors with respect to gallstone formation in humans. There is a rising interest in the identification of common and modifiable dietetic factors that put the patients at risk of gallstones or that are able to prevent gallstone formation and growth. In particular, dietary models characterized by increased energy intake with highly refined sugars and sweet foods, high fructose intake, low fiber contents, high fat, consumption of fast food and low vitamin C intake increase the risk of gallstone formation. On the other hand, high intake of monounsaturated fats and fiber, olive oil and fish (ω-3 fatty acids) consumption, vegetable protein intake, fruit, coffee, moderate alcohol consumption and vitamin C supplementation exert a protective role. The effect of some confounding factors (e.g., physical activity) cannot be ruled out, but general recommendations about the multiple beneficial effects of diet on cholesterol gallstones must be kept in mind, in particular in groups at high risk of gallstone formation.

Diet: Cause or Consequence of the Microbial Profile of Cholelithiasis Disease?

Recent dietary habits and lifestyle could explain the shaping of the gut microbiota composition and, in consequence, the increasing prevalence of certain pathologies. However, little attention has been paid to the influence of diet on microbiotas, other than the gut microbiota. This is important in cholelithiasis, given that changes in the production of bile acids may affect gallbladder microbial communities. Our aim was to assess the association between regular dietary intake and gallbladder microbial composition. Fourteen adults with cholelithiasis and 14 controls, sex‒age-matched and without gastrointestinal pathology, were included. Diet was assessed through a food frequency questionnaire and quantification of gallbladder microbiota sequences by Illumina 16S rRNA gene-based analysis. The cholelithiasic patients showed greater intake of potatoes and lower consumption of vegetables, non-alcoholic drinks, and sauces, which resulted in a lower intake of energy, lipids, digestible polysaccharides, folate, calcium, magnesium, vitamin C, and some phenolic compounds. Regarding the altered bile microorganisms in cholelithiasic patients, dairy product intake was negatively associated with the proportions of Bacteroidaceae and Bacteroides, and several types of fiber, phenolics, and fatty acids were linked to the abundance of Bacteroidaceae, Chitinophagaceae, Propionibacteraceae, Bacteroides, and Escherichia‒Shigella. These results support a link between diet, biliary microbiota, and cholelithiasis.

Sex and ethnic/racial-specific risk factors for gallbladder disease

BACKGROUND

Gallbladder disease (GBD) is a highly prevalent condition; however, little is known about potential differences in risk factors by sex and ethnicity/race. Our aim was to evaluate dietary, reproductive and obesity-related factors and GBD in multiethnic populations.

METHODS

We performed a prospective analysis from the Multiethnic Cohort study who self-identified as non-Hispanic White (n = 32,103), African American (n = 30,209), Japanese (n = 35,987), Native Hawaiian (n = 6942) and Latino (n = 39,168). GBD cases were identified using Medicare and California hospital discharge files (1993-2012) and self-completed questionnaires. We used exposure information on the baseline questionnaire to identify exposures of interest. Associations were estimated by hazard ratios and 95% confidence intervals using Cox models adjusted for confounders.

RESULT

After a median 10.7 years of follow-up, there were 13,437 GBD cases. BMI over 25 kg/m2, diabetes, past and current smoking, red meat consumption, saturated fat and cholesterol were significant risk factors across ethnic/racial populations (p-trends < 0.01). Protective factors included vigorous physical activity, alcohol use, fruits, vegetables and foods rich in dietary fiber (p-trends < 0.01). Carbohydrates were inversely associated with GBD risk only among women and Latinos born in South America/Mexico (p-trend < 0.003). Parity was a significant risk factor among women; post-menopausal hormones use was only associated with an increased risk among White women (estrogen-only: HR = 1.24; 95% CI = 1.07-1.43 and estrogen + progesterone: HR = 1.23; 95% CI = 1.06-1.42).

CONCLUSION

Overall, dietary, reproductive and obesity-related factors are strong risk factors for GBD affecting men and women of different ethnicities/races; however some risk factors appear stronger in women and certain ethnic groups.

Alcohol consumption and risk of gallstone disease: a meta-analysis

Epidemiology studies have been carried out to investigate the association between alcohol consumption and the risk of gallstone disease, but the results remain controversial. We carried out a meta-analysis to quantitatively summarize the evidences from observational studies on alcohol consumption and the risk of gallstone disease. Eligible studies published in English were identified by searching PubMed, Web of Science, and Embase databases. The random-effect model was used to calculate the pooled relative risks (RRs) with 95% confidence intervals (CIs). Restricted cubic splines were used to assess the dose-response relationship. Eight cohort studies and 10 case-control studies were included in our meta-analysis. The pooled RR of gallstone disease for the highest versus the lowest alcohol consumption was 0.62 (95% CI: 0.49-0.78). Statistically significant associations were also found in stratified analysis by study design (cohort studies: RR=0.66, 95% CI: 0.48-0.91 and case-control studies: RR=0.58, 95% CI: 0.45-0.73). With respect to sex, both men (RR=0.57, 95% CI: 0.4-0.8) and women (RR=0.64, 95% CI: 0.53-0.77) showed statistically significant associations between alcohol consumption and the risk of gallstone disease. A linear dose-response relationship was found between alcohol consumption and gallstone disease risk and the risk of gallstone disease decreased by 12% (RR=0.88, 95% CI: 0.84-0.92; Pnonlinearity=0.079) for each 10 g/day increment in alcohol consumption. This meta-analysis suggests that alcohol consumption is associated with significantly decreased risk of gallstone disease.

Gallstones: A Worldwide Multifaceted Disease and Its Correlations with Gallbladder Carcinoma

Background

Gallstones (GS) associated diseases are among the most recurrent and frequent diseases delineated in India and United Arab Emirates. Several reports suggest that the association of GS with gallbladder cancer (GBC) is very high in Northern part of India; however, its occurrence in UAE and Southern part of India is notably low. Therefore, in the present study, we aimed to perform compositional analysis of GS in three different geographical areas by Solid State Nuclear Magnetic Resonance and Fourier Transformed Infrared spectroscopy.

Methods

Natural abundance ¹³C cross polarization magic angle spinning Nuclear Magnetic Resonance and Fourier Transform Infrared spectroscopy is employed for the analysis of human gallstone.

Results

Cholesterol, bilirubin and calcium carbonate were present in variant concentrations in GS obtained from three different geographical regions. Cholesterol was present predominantly in gallstones from North India. Bilirubin was found to be a main constituent in gallstones pertaining to South India. Whereas GS from UAE showed both cholesterol and bilirubin as their major constituents. Calcium carbonate was found in varying concentrations in gallstones acquired from different regions.

Conclusion

Variation in environmental condition and dietary habits may contribute and affect the GS formation. Alterations in bile composition influence the GB and augment the crystallization of cholesterol. Analysis of different geographical regions GS could be an important stride to understand the etiology of GS diseases.

Increased Risk of Clinically Significant Gallstones following an Appendectomy: A Five-Year Follow-Up Study

Although the vermiform appendix is commonly considered a vestigial organ, adverse health consequences after an appendectomy have garnered increasing attention. In this study, we investigated the risks of gallstone occurrence during a 5-year follow-up period after an appendectomy, using a population-based dataset. We used data from the Taiwan Longitudinal Health Insurance Database 2005. The exposed cohort included 4916 patients who underwent an appendectomy. The unexposed cohort was retrieved by randomly selecting 4916 patients matched with the exposed cohort in terms of sex, age, and year. We individually tracked each patient for a 5-year period to identify those who received a diagnosis of gallstones during the follow-up period. Cox proportional hazard regressions were performed for the analysis. During the 5-year follow-up period, the incidence rate per 1000 person-years was 4.71 for patients who had undergone an appendectomy, compared to a rate of 2.59 for patients in the unexposed cohort (p<0.001). Patients who had undergone an appendectomy were independently associated with a 1.79 (95% CI = 1.29~2.48)-fold increased risk of being diagnosed with gallstones during the 5-year follow-up period. We found that among female patients, the adjusted hazard ratio of gallstones was 2.25 (95% CI = 1.41~3.59) for patients who underwent an appendectomy compared to unexposed patients. However, for male patients, we failed to observe an increased hazard for gallstones among patients who underwent an appendectomy compared to unexposed patients. We found an increased risk of a subsequent gallstone diagnosis within 5 years after an appendectomy.

Vegetable protein intake is associated with lower gallbladder disease risk: Findings from the Women's Health Initiative prospective cohort

OBJECTIVE

This study aimed to measure associations between gallbladder disease and protein intake patterns, separated by quantity and type (vegetable vs. animal), among postmenopausal women.

METHODS

Analyses were based on 130,859 postmenopausal women enrolled from 1993 to 1998 at 40 U.S. clinical centers in the Women's Health Initiative clinical trials and observational study. Women were excluded if they reported a history of gallbladder disease prior to baseline. Cox proportional hazards regression models, adjusted for gallbladder disease risk factors, were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between energy-adjusted protein intake and gallbladder disease.

RESULTS

In this study sample, 8.1% of postmenopausal women self-reported incident gallbladder disease. In multivariate analysis, women in the highest quintile of energy-adjusted vegetable protein intake (>24.0g/d) had a lower risk of gallbladder disease (HR, 0.87; 95% CI, 0.81-0.93) as compared to women in the lowest quintile (<16.3g/d) (Ptrend<0.001). Total protein intake was modestly protective against gallbladder disease (Ptrend<0.021). Animal protein intake was not associated with gallbladder disease risk. The protective effect of vegetable protein held stable only for women without history of diabetes (HR, 0.86; 95% CI, 0.80-0.92) and without recent weight loss (HR, 0.88; 95% CI, 0.80-0.97).

CONCLUSIONS

Vegetable protein intake is inversely associated with gallbladder disease risk in our sample of postmenopausal women. In addition to weight management, healthcare providers could emphasize vegetable protein as an additional dietary modality to promote lower risk for gallbladder disease.

Beyond Ischemic Heart Disease: Are There other Health Benefits from Drinking Alcohol?

Evidence is growing that alcohol consumption confers health benefits beyond protection from ischemic heart disease. We review this evidence with regard to cerebrovascular disease, peripheral vascular disease, diabetes, cholelithiasis (gallstones), cognitive functioning, and stress reduction and subjective psychosocial benefits. Other possible benefits are briefly considered. The weight of evidence suggests that low-level alcohol consumption offers some protection against ischemic stroke. The evidence that moderate alcohol consumption protects against diabetes and gallstones is also fairly strong. The possibility of other health benefits cannot be dismissed. For all the conditions considered, more research is indicated. The application of more appropriate statistical techniques, studies of patterns of drinking, and experimental approaches to delineating underlying mechanisms should enable firmer conclusions to be drawn. A better understanding of both the benefits and the risks of alcohol use for individuals and populations will facilitate the development of appropriate program and policy interventions to promote health.

A nested case-control study on dietary fat consumption and the risk for gallstone disease

BACKGROUND

Gallstone disease (GD) incidence and prevalence rates differ between populations. Diet and lifestyle may be involved in GD development. To our knowledge, no study to date has evaluated quantitative data on diet when studying the relationship between fat consumption levels and GD in an Argentinean population. The present study aimed to assess the association between dietary fat intake and GD.

METHODS

A nested case-control study design was applied. Data were taken from subjects who participated in a previous cross-sectional study carried out in a random sample of asymptomatic people in Rosario, Argentina. Participants underwent a personal interview, and current weight and height, ancestor's ethnicity, and socio-economic status were recorded. Applying a food-frequency questionnaire and a food photography atlas, quantitative dietary data were estimated by combining the intake frequency, portion size and food composition. Logistic regression analysis was used to compute odds ratios and 95% confidence intervals adjusted by age, sex, ancestor's ethnicity, body mass index and daily total energy intake as potential confounders.

RESULTS

In total, 114 patients were studied (49 cases and 65 controls), without any statistically significant differences for age, sex, socio-economic status, body mass index and ancestry. The mean energy intake was higher in cases than in controls, and significant differences were found for dietary fat consumption. Obese or overweight people have a higher GD risk than subjects with normal weight. Increased GD risks were associated with high intakes of energy, total fat, and saturated and monounsaturated fatty acids.

CONCLUSIONS

According to our results, total fat, saturated and monounsaturated fatty acids high intakes are associated with increased GD risk.

Black bile of melancholy or gallstones of biliary colics: historical perspectives on cholelithiasis

Barely 130 years after its first description, cholecystectomies are among the most commonly performed surgeries in the USA. The success of this operation with subsequent technical improvements, such as laparoscopic approaches, caused a paradigm shift in the management of gallstone disease. However, symptoms persist in 10-40 % of successfully operated patients. Reviewing monographs, textbooks, and articles published during the last 300 years, several important factors emerge as likely contributors to limited or poor treatment responses. Early on, clinicians recognized that cholelithiasis is quite common and thus often an incidental finding, especially if patients present with vague or atypical symptoms. Consistent with these observations, patients with such atypical symptoms are less likely to benefit from cholecystectomy. Similarly, lasting improvements are more reliably seen in patients with symptoms of presumed biliary origin and documented gallstones compared to individuals without stones, an important point in view of increasing rates of surgery for biliary dyskinesia. While cholelithiasis can cause serious complications, the overall incidence of clinically relevant problems is so low that prophylactic cholecystectomy cannot be justified. This conclusion corresponds to epidemiologic data showing that the rise in elective cholecystectomies decreased hospitalizations due to gallstone disease, but was associated with a higher volume of postoperative complications, ultimately resulting in stable combined mortality due to gallstone disease and its treatment. These trends highlight the tremendous gains in managing gallstone disease, while at the same time reminding us that the tightening rather than expanding indications for cholecystectomy may improve outcomes.

Moderate to severe, but not mild, nonalcoholic fatty liver disease associated with increased risk of gallstone disease

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) and gallstone disease (GSD) share some of the same risk factors. The association between NAFLD and GSD was inconsistent. Moreover, there are no studies on the association between GSD and the severity of NAFLD in the literature. The aim of this study was to determine the relationship between the severity of NAFLD and GSD in a Taiwanese population.

MATERIALS AND METHODS

A total of 12,033 subjects were enrolled. The diagnoses of GSD and NAFLD were based on the finding of abdominal ultrasonography. The severity of NAFLD was divided into mild, moderate, and severe.

RESULTS

Compared with the non-GSD group, the GSD one was older and had a higher BMI, blood pressure, fasting plasma glucose, cholesterol, triglyceride, and higher prevalence of diabetes and hypertension, but they had a lower eGFR and HDL-C level and less prevalence of current smoking and alcohol drinking. There was a significant difference in the severity of NAFLD between subjects with and without GSD. Based on logistic regression, age ≥65 versus <40 years, 40-64.9 versus <40 years, female, current alcohol drinking, diabetes, hypertension, HDL-C level and moderate to severe NAFLD, but not mild NAFLD, were the independently associated risk factors of GSD.

CONCLUSION

Moderate to severe, but not mild, NAFLD was associated with an increased risk of GSD, independent of the traditional cardio-metabolic risk factor. Age, female, diabetes, and hypertension were also related to a higher risk of GSD, but HDL-C level and moderate alcohol drinking showed a lower risk.

Gallstones

Gallstone disease is a worldwide medical problem, but the incidence rates show substantial geographical variation, with the lowest rates reported in African populations. Publications in English language on gallstones which were obtained from reprint requests and PubMed database formed the basis for this paper. Data extracted from these sources included authors, country, year of publication, age and sex of patients, pathogenesis, risk factors for development of gallstones, racial distribution, presenting symptoms, complications and treatment. Gallstones occur worldwide, however it is commonest among North American Indians and Hispanics but low in Asian and African populations. High biliary protein and lipid concentrations are risk factors for the formation of gallstones, while gallbladder sludge is thought to be the usual precursor of gallstones. Biliary calcium concentration plays a part in bilirubin precipitation and gallstone calcification. Treatment of gallstones should be reserved for those with symptomatic disease, while prophylactic cholecystectomy is recommended for specific groups like children, those with sickle cell disease and those undergoing weight-loss surgical treatments. Treatment should be undertaken for a little percentage of patients with gallstones, as majority of those who harbor them never develop symptoms. The group that should undergo cholecystectomy include those with symptomatic gallstones, sickle cell disease patients with gall stones, and patients with morbid obesity who are undergoing laparotomy for other reasons.

Dietary fat and protein intake are not associated with incident biliary sludge and stones during pregnancy

BACKGROUND

Dietary composition can cause insulin resistance, elevated serum lipid levels, and obesity, all of which predispose to gallstone formation. The effects of dietary fat (including individual fatty acids) and protein on gallstone formation are controversial. The aim of this study was to examine the effects of dietary fat and protein intake on incident gallstone disease during pregnancy, a high-risk time for stone formation.

METHODS

We prospectively studied 3070 pregnant women who underwent serial gallbladder ultrasound examinations during pregnancy and at 4-6 weeks postpartum. All women had at least 2 study ultrasounds for comparison. A semi-quantitative food frequency questionnaire was completed by subjects in the early third trimester. Multivariate logistic regression was performed to assess the risk of incident gallbladder disease across quartiles of intake of total fat, individual fatty acids (polyunsaturated, monounsaturated, saturated, and total trans-fatty acids, as well as cholesterol), protein, and protein subtype (animal or vegetable based).

RESULTS

The cumulative incidence of new biliary sludge/stones or progression of baseline sludge to stones was 10.2% by 4-6 weeks postpartum. There was no association between total dietary fat (odds ratio [OR], 1.18; 95% confidence interval [CI], 0.64-2.18 comparing lowest and highest quartiles) or protein intake (OR, 0.83; 95% CI, 0.44-1.22 comparing lowest and highest quartiles) and incident gallbladder disease. There was also no association between individual fatty acids or protein subtype and gallbladder disease.

CONCLUSIONS

Neither total nor subtype of dietary fat or protein was associated with incident biliary stone or sludge formation in this cohort of pregnant women.

Carbohydrate intake as a risk factor for biliary sludge and stones during pregnancy

BACKGROUND

High carbohydrate intake has been linked to insulin resistance, obesity, and abnormal serum lipid profiles-conditions which favor gallstone formation.

GOALS

The aim of this study was to evaluate the effect of dietary carbohydrate intake on incident gallbladder disease, defined as biliary sludge and stones, during pregnancy.

STUDY

We prospectively studied 3070 pregnant women who underwent serial gallbladder ultrasound during pregnancy and at 4 to 6 weeks postpartum. All women had at least 2 study ultrasounds for comparison. A semiquantitative food frequency questionnaire was completed by subjects in the early third trimester. Multivariate logistic regression was performed to assess the risk of incident gallbladder disease across quartiles total and individual carbohydrate and individual carbohydrates (starch, sucrose, galactose, fructose, and lactose) intake.

RESULTS

The cumulative incidence of gallbladder disease was 10.2% by 4 to 6 weeks postpartum. The risk of incident gallbladder disease during pregnancy was significantly higher among women in the highest quartile of total carbohydrate intake versus those in the lowest quartile (odds ratio 2.09, 95% confidence interval 1.02-4.27). High intake of fructose was associated with increased risk even after additional adjustment for total carbohydrate intake (odds ratio 2.18, 95% confidence interval 1.23-3.86, comparing highest with lowest quartile). No association was found between the intake of starch, sucrose, lactose, or galactose and the risk of incident gallbladder disease.

CONCLUSIONS

High consumption of total carbohydrate and fructose may increase the risk of developing gallbladder disease during pregnancy. Dietary modification during pregnancy might reduce gallstone incidence during this time period.

Lifestyle and gallstone disease: scope for primary prevention

OBJECTIVE

To study the antecedent risk factors in the causation of gallstone disease in a hospital-based case control study.

MATERIALS AND METHODS

Cases (n = 150) from all age groups and both sexes with sonographically proven gallstones were recruited over a duration of 3 months from the surgical wards of a tertiary care teaching hospital. Modes of presentation were also noted among cases. Age- and sex-matched controls (n = 150) were chosen from among ward inmates admitted for other reasons. Univariate and multivariate logistic regression analyses were performed for selected sociodemographic, dietary, and lifestyle-related variables.

RESULTS

Females had a higher prevalence of gallstone disease than males (P < 0.01). Among males, the geriatric age group (<60 years) was relatively more susceptible (28%). Prepubertal age group was least afflicted (3.3%). Univariate analysis revealed multiparity, high fat, refined sugar, and low fiber intakes to be significantly associated with gallstones. Sedentary habits, recent stress, and hypertension were also among the significant lifestyle-related factors. High body mass index and waist hip ratios, again representing unhealthy lifestyles, were the significant anthropometric covariates. However, only three of these, viz., physical inactivity, high saturated fats, and high waist hip ratio emerged as significant predictors on stepwise logistic regression analysis (P < 0.05).

CONCLUSION

Gallstone disease is frequent among females and elderly males. Significant predictor variables are abdominal adiposity, inadequate physical activity, and high intake of saturated fats; thus representing high risk lifestyles and yet amenable to primary prevention.

Epidemiology of gallbladder disease: cholelithiasis and cancer

Diseases of the gallbladder are common and costly. The best epidemiological screening method to accurately determine point prevalence of gallstone disease is ultrasonography. Many risk factors for cholesterol gallstone formation are not modifiable such as ethnic background, increasing age, female gender and family history or genetics. Conversely, the modifiable risks for cholesterol gallstones are obesity, rapid weight loss and a sedentary lifestyle. The rising epidemic of obesity and the metabolic syndrome predicts an escalation of cholesterol gallstone frequency. Risk factors for biliary sludge include pregnancy, drugs like ceftiaxone, octreotide and thiazide diuretics, and total parenteral nutrition or fasting. Diseases like cirrhosis, chronic hemolysis and ileal Crohn's disease are risk factors for black pigment stones. Gallstone disease in childhood, once considered rare, has become increasingly recognized with similar risk factors as those in adults, particularly obesity. Gallbladder cancer is uncommon in developed countries. In the U.S., it accounts for only ~ 5,000 cases per year. Elsewhere, high incidence rates occur in North and South American Indians. Other than ethnicity and female gender, additional risk factors for gallbladder cancer include cholelithiasis, advancing age, chronic inflammatory conditions affecting the gallbladder, congenital biliary abnormalities, and diagnostic confusion over gallbladder polyps.

Could gastrointestinal disorders differ in two close but divergent social environments?

BACKGROUND

Many public health problems in modern society affect the gastrointestinal area. Knowledge of the disease occurrence in populations is better understood if viewed in a psychosocial context including indicators of the social environment where people spend their lives. The general aim of this study was to estimate the occurrence in the population and between sexes of common gastrointestinal conditions in two neighborhood cities representing two different social environments defined as a "white-collar" and a "blue-collar" city.

METHODS

We conducted a retrospective register study using data of diagnosed gastrointestinal disorders (cumulative incidence rates) derived from an administrative health care register based on medical records assigned by the physicians at hospitals and primary care.

RESULTS

Functional gastrointestinal diseases and peptic ulcers were more frequent in the white-collar city, while diagnoses in the gallbladder area were significantly more frequent in the blue-collar city. Functional dyspepsia, irritable bowel syndrome, and unspecified functional bowel diseases, and celiac disease, were more frequent among women while esophageal reflux, peptic ulcers, gastric and rectal cancers were more frequent among men regardless of social environment.

CONCLUSIONS

Knowledge of the occurrence of gastrointestinal problems in populations is better understood if viewed in a context were the social environment is included. Indicators of the social environment should therefore also be considered in future studies of the occurrence of gastrointestinal problems.

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.

Food-frequency questionnaires: a review of their design, validation and utilisation

A review of the literature concerning the design, utilisation and validation of food-frequency questionnaires (FFQ) has been carried out using a semi-systematic approach to obtaining, reviewing and extracting data from articles. Databases were searched from 1980 to 1999. The present review identified 227 validation (from 1980 to September 1999) and 164 utilisation (for 1998 only) studies. A number of design issues have been evaluated through the present review. These include: the need to consider how portion sizes have been described, self-defined giving higher mean correlations; how an FFQ was administered, interviewer-administered giving higher mean correlations for some nutrients; how many items to include on an FFQ, those with the largest number of items having higher correlations. Validation techniques were described. Most validation studies involved comparing an FFQ against another dietary assessment method; only 19 % compared an FFQ to a biomarker. Measurement differences were most commonly assessed by correlation coefficients as opposed to other more appropriate methods. Mean correlation coefficients were highest for Ca and fat, and lowest for vitamin A and vegetables. The utilisation studies showed that FFQ were most commonly used in cross-sectional surveys, with ninety-three of the FFQ being designed to be disease-specific. The present review results were presented to a group of experts and a consensus arrived at concerning the development, validation and use of FFQ. Recommendations derived from the consensus arising from the literature review are presented as an appendix to the present paper.

Macronutrients and insulin resistance in cholesterol gallstone disease

Cholelithiasis is a major source of digestive morbidity worldwide. Cholesterol stones account for the majority of gallstones in the United States and other Western countries. The pathogenesis of cholesterol gallstone disease is multifactorial with key factors including cholesterol supersaturation of bile, altered biliary motility, and nucleation and growth of cholesterol crystals. Increasing evidence suggests that many, but not all, causative factors of cholesterol gallstones are related to insulin resistance which, in association with obesity, has reached an epidemic level worldwide. Experimental studies show that hyperinsulinemia, a key feature of insulin resistance, may cause increased hepatic cholesterol secretion and cholesterol supersaturation of bile and gallbladder dysmotility, and thereby may enhance gallstone formation. Insulin resistance syndrome can be modified by environmental factors, including dietary factors. The impact of diet on insulin sensitivity is mediated by both dietary composition and its energy content. The contribution of specific dietary elements to the prevalence and incidence of cholesterol gallstone disease has been explored in animal and human studies. There is considerable evidence to suggest that different types of fatty acids, independent of the total amount of fat consumption, affect insulin sensitivity and cholesterol gallstone disease differently. The effects of salt intake, consumption of protein and carbohydrates, and alcohol drinking on insulin resistance are controversial. Additional intervention trials and controlled experimental feeding studies are needed to further clarify these relationships and to provide useful prophylactic and therapeutic strategies.

Role of diet in cholesterol gallstone formation

BACKGROUND

There is a high prevalence of gallstone disease in Western countries as a consequence of genetic, biochemical, and environmental factors. Animal and clinical studies have explored the importance of dietary elements. Overwhelming but conflicting information has been reported about the relationship between specific dietary components and gallstone disease. Although the detailed biochemical pathways have been described in experimental models, human studies are mainly epidemiological.

METHODS

We performed a Medline search with the terms "diet", "gallstones", "cholesterol", "risk factors", including results from 1965 to 2006 and the author's personal library to review the relationship between dietary factors and cholesterol gallstone disease.

RESULTS

We identified over 150 references and present their results with respect to the author's criteria.

CONCLUSIONS

The best delineated relationship between cholesterol gallstones and diet was found in the studies that analyzed total calorie intake, refined sugars and fiber. The possible mechanisms are discussed in base of experimental studies.

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.

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.

Diet as a risk factor for cholesterol gallstone disease

Cholesterol gallstone disease is a common condition in western populations. The etiology is multifactorial with interaction of genetic and environmental factors. Obesity, aging, estrogen treatment, pregnancy and diabetes are consistently associated to a higher risk. A number of dietary factors have been involved in the pathogenesis of cholelithiasis. In this article we summarize several studies that have evaluated the role of diet as a potential risk factor for gallstone formation, including energy intake, cholesterol, fatty acids, fiber, carbohydrates, vitamins and minerals, and alcohol intake. Consumption of simple sugars and saturated fat has been mostly associated to a higher risk, while fiber intake and moderate consumption of alcohol, consistently reduce the risk. The association between cholesterol intake and gallstone disease has been variable in different studies. The effects of other dietary factors are less conclusive; additional studies are therefore necessary to clarify their relevance in the pathogenesis of gallstone disease. Recent discoveries of the role of orphan nuclear receptors in the regulation of fatty acid and hepatic cholesterol metabolism and excretion open new perspectives for a better understanding of the role of dietary constituents on cholesterol gallstone formation. KEY TEACHING POINTS: The etiology of cholesterol gallstone disease is multifactorial with interaction between genome and environment. It has been postulated that dietary constituents are important determinants for the formation of lithogenic bile. Intake of high energy, simple sugar and saturated fat favors gallstone formation. Fiber and moderate consumption of alcohol reduce the risk. The role of orphan nuclear receptors in the regulation of hepatic cholesterol metabolism and excretion open new leads for understanding the role of dietary constituents on cholesterol gallstone formation.

Derivation of tolerable upper alcohol intake levels in Germany: a systematic review of risks and benefits of moderate alcohol consumption

BACKGROUND

The objective of this study is to weigh the risks of moderate alcohol consumption against its benefits and, as a result, to derive tolerable upper alcohol intake levels (TUALs) for the German adult population.

METHODS

Human studies assessing the effects of moderate alcohol consumption (< or = 40 g/day) on coronary heart disease, stroke, blood pressure, diseases of the liver, gallbladder, bile duct, and pancreas, cancer of the mouth/pharynx/larynx/oesophagus, stomach, colon/rectum, and breast, foetal alcohol syndrome/foetal alcohol effects, as well as all-cause mortality, published in the 10-15 years before 1999, have been systematically reviewed. The quality of studies has been evaluated using a self-constructed evaluation scheme. As a result of comparing the critical endpoints of alcohol intake related to morbidity and mortality, the TUALs have been derived.

RESULTS

The TUALs have been set at 10-12 g/day for healthy women and 20-24 g/day for healthy men of the adult population (18 years and older). Additional guidelines on alcohol use have been defined, taking into account further important aspects like alcohol consumption patterns and high-risk groups.

CONCLUSIONS

The TUALs are not intended to be recommended intake levels. However, if the TUALs and the additional guidelines are followed, a relation of alcohol consumption to an increased risk of alcohol-associated diseases is unlikely for the majority of the population.

Development of symptoms and complications in individuals with asymptomatic gallstones

BACKGROUND

Gallbladder stones are common in the developed world. Complications of gallstones contribute substantially to healthcare costs and may be life threatening. The identification of individuals likely to develop complications would be of benefit in clinical practice as elective cholecystectomy could then be performed.

METHODS

Seven hundred and thirty-nine subjects aged 35-85 years from the general population were screened for gallbladder problems by ultrasonography and questionnaire assessment of putative risk factors and digestive symptoms. Gallstones, cholesterolosis or sludge in the gallbladder were diagnosed in 123 (16.3 per cent) of 739 subjects, 120 of whom were followed for a median of 87 (range 3-146) months to May 2003 or until treatment was required.

RESULTS

Fourteen patients were admitted to hospital and treated for gallstone-related complications or symptoms. The cumulative risk of being treated during the first 5 years after detection of asymptomatic gallstones was 7.6 per cent and there was no indication of this risk levelling off. There were no significant differences between treated and untreated subjects with regard to digestive symptoms or any of the risk factors monitored at the initial screening, although treated subjects were significantly younger than those who were not treated.

CONCLUSION

Nearly one in ten individuals with asymptomatic gallbladder stones in the general population may be expected to develop symptoms or complications that require treatment within 5 years. Age may be inversely related to the incidence of complications.

Lipase inhibition by orlistat: effects on gall-bladder kinetics and cholecystokinin release in obesity

BACKGROUND

Obese subjects are at risk of developing gallstones as a result of the obese state and during weight reduction.

AIM

To study whether orlistat, by lipase inhibition, impairs gall-bladder emptying, thus further predisposing weight-losing obese subjects to gallstone formation.

METHODS

Patients entering a randomized clinical trial of 1 month of diet, followed by treatment with placebo, 3 x 60 mg orlistat or 3 x 120 mg orlistat, underwent gall-bladder emptying studies measured by ultrasound. Meal-induced cholecystokinin release and gall-bladder emptying were investigated at the start, at randomization and after 1 and 12 months.

RESULTS

One month of dieting did not change gall-bladder emptying and cholecystokinin release. After 1 month, placebo treatment resulted in a decreased fasting volume of 11%, compared with increases of 26% and 47% with 60 and 120 mg orlistat, respectively. Gall-bladder emptying increased by 9% with placebo and decreased by 15% and 53% with 60 and 120 mg orlistat, respectively. Fasting cholecystokinin values and cholecystokinin release decreased significantly in the orlistat group. After 1 year, a persistent but attenuated effect of orlistat on gall-bladder emptying and cholecystokinin release remained. Three of 40 patients developed gallstones, two on placebo with major weight loss and one on 60 mg orlistat.

CONCLUSIONS

One month of lipase inhibition by orlistat significantly impaired gall-bladder motility, which persisted to some extent after 1 year. Obese subjects with diabetes or hyperlipidaemia, who are more at risk of gallstones, should be followed carefully.

Alcohol consumption in relation to risk of cholecystectomy in women

BACKGROUND

Alcohol consumption has been linked to a lower risk of gallstone disease. However, the magnitude of the association is uncertain, and little is known about the relation of alcohol consumption patterns and individual types of alcoholic beverages to gallstone disease risk.

OBJECTIVE

We prospectively examined the association between alcohol intake and cholecystectomy, a surrogate for symptomatic gallstone disease, in a large cohort of women.

DESIGN

Women from the Nurses' Health Study who had no history of gallstone disease in 1980 (n = 80,898) were followed for 20 y. Alcohol consumption, which was measured every 2-4 y by food-frequency questionnaires, was used to predict subsequent cholecystectomy through multivariate analysis.

RESULTS

We ascertained 7831 cases of cholecystectomy. Relative to subjects who had no alcohol intake, subjects who had alcohol intakes of 0.1-4.9, 5.0-14.9, 15.0-29.9, 30.0-49.9, and >/=50.0 g/d had multivariate relative risks of cholecystectomy of 0.95, 0.86, 0.80, 0.67, and 0.62 (95% CI: 0.49, 0.79), respectively. Relative to subjects who never consumed alcohol, subjects who consumed alcohol 1-2, 3-4, 5-6, and 7 d/wk had multivariate relative risks of cholecystectomy of 0.94, 0.88, 0.87, and 0.73 (0.63, 0.84), respectively. All alcoholic beverage types were inversely associated with cholecystectomy risk, independent of consumption patterns (for quantity of alcohol consumed, P = 0.04, 0.001, and 0.003 for wine, beer, and liquor, respectively; for frequency of alcohol consumption, P = 0.01, 0.07, and <0.0001 for wine, beer, and liquor, respectively).

CONCLUSIONS

The intake of all alcoholic beverage types is inversely associated with the risk of cholecystectomy. Recommendations regarding the benefit of consuming moderate quantities of alcohol should be weighed against the potential health hazards.

Defining alcohol-related fatal medical conditions for social-cost studies in western societies: an update of the epidemiological evidence

OBJECTIVES

To elaborate a state-of-the-art list of alcohol-related fatal medical conditions for future social-cost studies in Western societies.

METHODS

Three major social-cost studies were compared with regard to their respective section on fatal health effects attributable to long-term as well as short-term use of alcohol. On discordant conditions, a systematic literature search was conducted in the Medline and ETOH databases.

RESULTS

There is no consensus between social-cost studies with respect to alcohol-related causes of mortality. Based on the recent epidemiological evidence on alcohol and health, this paper suggests an up-to-date list of fatal medical conditions for which the causal relationship has been established with sufficient scientific evidence. A further investigation is needed, however, to reestimate relative risks by meta-analysis.

CONCLUSIONS

Evaluating new epidemiological evidence regularly is necessary for the purpose of up-to-date social-cost studies.

Gallstones

Gallstones are estimated to affect over 20 million people in the United States. Recent studies have clarified the role of various dietary components in gallstone disease. Also, insulin resistance has been demonstrated to be a risk factor for gallstones. Other research has focused on the pathophysiology of gallstones and on clarifying the underlying mechanisms of previously noted risk factors for gallstones. New techniques for the noninvasive diagnosis of bile duct stones continue to be developed and tested. These techniques include computed tomography and magnetic resonance cholangiography. The impact and appropriateness of laparoscopic cholecystectomy continue to debated, and studies point to both overuse and underuse of this operation in the management of the disease.

Review article: epidemiology of gall-bladder disease--role of intestinal transit

Recent epidemiological studies have suggested that hyperinsulinaemia may be a central factor in the pathogenesis of cholesterol gallstones, explaining a probable link with physical inactivity as well as abdominal adiposity. There is also increasing evidence for the hypothesis that enrichment of bile with DCA. 'the colonic bile acid', leads to enrichment of bile with cholesterol. Biliary DCA can be raised and lowered by slowing down and speeding up colonic transit, respectively. Slow transit is characteristic of non-obese British women with gallstones and of non-obese peasants in a gallstone-prone mountain community. High biliary DCA predicts recurrence of gallstones and so does laxative usage, a pointer to constipation and therefore to slow transit. In some studies, at least, a high fibre intake is protective against gallstones. Much else besides fibre influences colonic function. Future studies of gallstone aetiology should include measurements of colonic function. Measures that speed up colonic transit should be tested for their ability to prevent gallstone formation in high-risk individuals.

Moderate alcohol consumption: the gentle face of Janus

OBJECTIVES

The regular consumption of alcohol in moderate amounts (defined in North America as up to 2 drinks per day for men and 1 drink per day for females) has been recognized in the last decade as a negative risk factor for atherosclerosis and its clinical sequelae: coronary heart disease (CHD), ischemic stroke, and peripheral vascular disease. Mortality and morbidity attributable to CHD are 40-60% lower in moderate drinkers than among abstainers. Among the mechanisms accounting for these reductions, increased circulating concentrations of HDL-cholesterol and inhibition of blood coagulation appear to be paramount. Additional benefits are, in certain beverages, conferred by the presence of constituents other than alcohol (e.g., flavonoids and hydroxystilbenes), which prevent oxidative damage, free radical formation, and elements of the inflammatory response.

CONCLUSIONS

A number of other diseases appear to be beneficially modulated by moderate alcohol consumption based on epidemiologic surveys and, in some instances, experimental evidence. These include duodenal ulcer, gallstones, enteric infections, rheumatoid arthritis, osteoporosis, and diabetes mellitus (type II). Compared with abstainers, moderate drinkers exhibit improved mental status characterized by decreased stress and depression, lower absenteeism from work, and decreased incidence of dementia (including Alzheimer's disease). Although limits of safe drinking have been conservatively defined, it is regrettable that political considerations are hampering the clinical application of this knowledge and its dissemination to the lay public.

Gallstones

This review summarizes the main advances made in the epidemiology, pathogenesis, and medical treatment of gallstone disease in the past year. Whether rapid weight reduction can precipitate gallstone formation is still debated. Phospholipase A(2)-II seems to play an interesting role in the pathogenesis of multiple cholesterol stone formation, and ursodeoxycholic acid may partially halt the formation of multiple cholesterol stones by mediating an anti-inflammatory effect on the gallbladder. Bacterial infections may contribute to gallstone formation, perhaps through secretion of biofilm. The combination of ursodeoxycholic acid and simvastatin for the resolution and prevention of gallstones is promising, but larger studies are needed.

Prevalence and ethnic differences in gallbladder disease in the United States

BACKGROUND & AIMS

Gallbladder disease is one of the most common conditions in the United States, but its true prevalence is unknown. A national population-based survey was performed to determine the age, sex, and ethnic distribution of gallbladder disease in the United States.

METHODS

The third National Health and Nutrition Examination Survey (NHANES III) conducted gallbladder ultrasonography among a representative U.S. sample of more than 14, 000 persons. The diagnosis of gallbladder disease by detection of gallstones or cholecystectomy was made with excellent reproducibility.

RESULTS

An estimated 6.3 million men and 14.2 million women aged 20-74 years had gallbladder disease. Age-standardized prevalence was similar for non-Hispanic white (8. 6%) and Mexican American (8.9%) men, and both were higher than non-Hispanic black men (5.3%). These relationships persisted with multivariate adjustment. Among women, age-adjusted prevalence was highest for Mexican Americans (26.7%) followed by non-Hispanic whites (16.6%) and non-Hispanic blacks (13.9%). Among women, multivariate adjustment reduced the risk of gallbladder disease for both Mexican Americans and non-Hispanic blacks compared with non-Hispanic whites.

CONCLUSIONS

More than 20 million persons have gallbladder disease in the United States. Ethnic differences in gallbladder disease prevalence differed according to sex and were only partly explained by known risk factors.