Fruit and vegetable consumption and risk of cholecystectomy in women

Ultraprocessed food consumption and risk of gallstone disease: analysis of 3 prospective cohorts

BACKGROUND

Majority of dietary intake in United States adults comes from ultraprocessed foods (UPFs), which have been linked to several adverse health outcomes. Gallstone disease is highly prevalent and constitutes a significant burden to the United States health system but remains understudied.

OBJECTIVES

This study aimed to investigate the association between UPF consumption and incident gallstone disease risk.

METHODS

In this analysis, 44,149 males in the Health Professionals' Follow-up Study (HPFS: 1986-2022), 71,145 females in the Nurses' Health Study (NHS: 1986-2021), and 90,932 females in the NHS II (1991-2021) were prospectively followed. Dietary intake was quadrennially assessed with semiquantitative food frequency questionnaires and used to identify UPFs. The primary outcome was defined as cholecystectomy. Cox proportional hazards model was used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

Baseline median age was 54 y in HPFS, 53 y in NHS, and 36 y in NHS II. We identified 32,374 incident gallstone disease cases over 5,077,059 person-years. Participants in the highest UPF quintile had a higher incidence of gallstone disease than those in the lowest quintile (aHR: 1.29; 95% CI: 1.24, 1.36; P < 0.001). Incremental risk of incident gallstone disease was 2.8% per daily serving (95% CI: 2.4%, 3.2%; P < 0.001). This risk was driven by sugar-sweetened beverages and artificially sweetened beverages on UPF subgroup analyses. The proportion of risk mediated by obesity was 12.8% (95% CI: 7.7%, 20.5%; P < 0.001) in HPFS, 14.3% (95% CI: 10.4%, 19.4%; P < 0.001) in NHS, and 39.4% (95% CI: 31.2%, 48.1%; P < 0.001) in NHS II. The partial population attributable risk was estimated at 15.9% (95% CI: 13.4%, 18.3%).

CONCLUSIONS

UPF consumption is associated with a higher risk of gallstone disease, particularly consumption of sugar-sweetened beverages and artificially sweetened beverages. A substantial proportion of this risk is potentially mediated by obesity in younger females.

Characterizing the relationships between dietary indices, gallstone prevalence and the need for gallbladder surgery in the general US population

Background

The dietary inflammatory index (DII) and composite dietary antioxidant index (CDAI) were developed as tools for use when seeking to assess the potential inflammatory and antioxidant activity of a given diet, respectively. The associations between these indices and gallstone incidence remain largely unexplored.

Objective

The present study sought to clarify how both the DII and the CDAI are related to gallstone incidence and age at first gallbladder surgery among adults in the USA.

Methods

Cross-sectional data from the 2017-2020 cycles of the National Health and Nutrition Examination Survey (NHANES) pertaining to 12,426 individuals were used to conduct the present study. Data from 2 days with 24-h dietary recall were employed when calculating DII and CDAI scores. Relationships between dietary indices and the incidence of gallstones were assessed through logistic regression analyses, while linear regression analyses were employed to characterize how these indices are associated with the age at first gallbladder surgery.

Results

Higher DII scores and lower CDAI scores, which, respectively, denote diets with greater inflammatory potential and reduced antioxidant potential, were found to be associated with higher gallstone incidence even following adjustment for potential confounding factors. Smooth curve fitting suggested that the association between DII and gallstones was nearly linear, whereas that between CDAI and gallstone incidence was nonlinear. Higher DII values were also related to first gallbladder surgery at an earlier age (β = -0.64, 95% CI: -1.26, -0.02).

Conclusion

These results emphasize the benefits of anti-inflammatory diets rich in antioxidants, which may help reduce gallstone incidence among adults in the USA. Higher DII scores may also predict the need for gallbladder surgery at a younger age.

Dietary Total Antioxidant Capacity and Risk of Gall Stone: A Case-Control Study

Background

Since the relation between dietary total antioxidant capacity (DTAC) and the occurrence of gallstone disease (GSD) remains unclear, we conducted, for the first time, a case-control study to clarify this association in the Iranian population.

Methods

In the present case-control study, convenience Sampling was performed. A total of 600 participants (300 case and 300 control) were included. Anthropometric, demographic, physical activity, and nutrient intakes data were obtained from each subject. DTAC was calculated using the US Department of Agriculture's database. The odds ratio (OR) and 95% confidence intervals were assessed using unconditional logistic regression.

Results

The participants in the highest quartile of DTAC had a significantly lower OR for gallstone than the lowest quartile, which remained significant after further adjustment for age, sex, and education (model 2: OR, 0.34; 95% CI, 0.16-0.71). In addition, after adjustment for age, sex, education, BMI, physical activity, and energy, the results revealed that participants with the highest quartile of DTAC had 71% lower odds of gallstone than those with the lowest quartile (model 3: OR, 0.29; 95% CI, 0.11-0.78).

Conclusions

The results of the present study demonstrated that the DTAC had an inverse association with GSD incident. However, interventional approaches are needed to confirm the relation between DTAC and GSD prevention.

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.

A healthy lifestyle pattern and the risk of symptomatic gallstone disease: results from 2 prospective cohort studies

BACKGROUND

Symptomatic gallstones cause high financial and disease burden for public health systems. The combined role of diet and other lifestyle factors has not been studied so far.

OBJECTIVES

We aimed to investigate the association between an a priori defined healthy lifestyle score (HLS, including healthy diet, moderate alcohol and regular coffee intakes, never smoking, physical activity, and normal weight) and the risk of symptomatic gallstone disease, and to estimate the proportion of cases potentially preventable by lifestyle modification.

METHODS

We followed 60,768 women from the Nurses' Health Study (NHS) and 40,744 men from the Health Professionals Follow-up Study (HPFS), both ongoing prospective cohort studies, from baseline (1986) until 2012. Symptomatic gallstone disease was self-reported and validated by review of medical records. The association between the HLS and the risk of symptomatic gallstone disease was investigated using Cox proportional hazards regression.

RESULTS

During 1,156,079 and 769,287 person-years of follow-up, respectively, 6946 women and 2513 men reported symptomatic gallstone disease. Comparing 6 with 0 points of the HLS, the multivariable HR of symptomatic gallstone disease was 0.26 (95% CI: 0.15, 0.45) for women, and 0.17 (95% CI: 0.07, 0.43) for men. For individual lifestyle factors, multivariable and mutually adjusted partial population attributable risks (women and men) were 33% and 23% for BMI <25 kg/m2, 10% and 18% for ≥2 cups of coffee per day, 13% and 7% for moderate alcohol intake, 8% and 11% for a high Alternate Healthy Eating Index 2010, 9% and 5% for being physically active, and 1% and 5% for never smoking. The full population attributable risk percentage for all factors combined was 62% and 74%, respectively.

CONCLUSIONS

Findings from these large prospective studies indicate that adopting a healthy lifestyle, especially maintaining a healthy weight, can help to prevent a considerable proportion of symptomatic gallstone diseases.

Fruits and vegetables consumption and the risk of gallstone diasease: A systematic review and meta-analysis

BACKGROUND

The role of fruit and vegetables (FVs) consumption in decreasing gallstone disease risk remains contradictory. We performed a meta-analysis to analyze this potential correlation, followed by investigation of dose-response relationship of FVs consumption with gallstone disease.

MATERIALS AND METHODS

PubMed, Embase, as well as Web of Science were searched to determine all published researches about the connection of FVs consumption with gallstone disease before March 2018. Relative risks (RRs) or odds ratios (ORs) along with corresponding 95% confidence intervals (CIs) was pooled utilizing random effect models, aiming at examining the correlation of FVs consumption with gallstone disease risk.

RESULTS

One cross-sectional study, our case-control studies as well as nine cohort studies were enrolled, covering approximately 33,983 patients with gallstone disease and 1,53,3752 participants. In a pooled analysis, vegetables consumption was significantly related to a decreased gallstone disease risk, (RR = 0.83, 95% CI, 0.74-0.94, I = 91.1%), and for fruits consumption, RR was similar (RR = 0.88, 95%CI, 0.83-0.92, I = 0.01%). This inverse correlation of FVs consumption with gallstone disease risk was solid in most subgroup analysis. The nonlinear dose-response correlation indicated that gallstone risk was reduced by 4% (RR = 0.96, 95%CI, 0.93-0.98) and 3% (RR = 0.97, 95%CI, 0.96-0.98) for every 200 g per day increment in vegetables consumption (P = .001) and fruits consumption (P = .001), respectively.

CONCLUSION

This study suggests vegetables and fruits consumption is correlated with a significantly reduced risk of gallstone disease.

Cholesterol cholelithiasis: part of a systemic metabolic disease, prone to primary prevention

Cholesterol gallstone disease have relationships with various conditions linked with insulin resistance, but also with heart disease, atherosclerosis, and cancer. These associations derive from mechanisms active at a local (i.e. gallbladder, bile) and a systemic level and are involved in inflammation, hormones, nuclear receptors, signaling molecules, epigenetic modulation of gene expression, and gut microbiota. Despite advanced knowledge of these pathways, the available therapeutic options for symptomatic gallstone patients remain limited. Therapy includes oral litholysis by the bile acid ursodeoxycholic acid (UDCA) in a small subgroup of patients at high risk of postdissolution recurrence, or laparoscopic cholecystectomy, which is the therapeutic radical gold standard treatment. Cholecystectomy, however, may not be a neutral event, and potentially generates health problems, including the metabolic syndrome. Areas covered: Several studies on risk factors and pathogenesis of cholesterol gallstone disease, acting at a systemic level have been reviewed through a PubMed search. Authors have focused on primary prevention and novel potential therapeutic strategies. Expert commentary: The ultimate goal appears to target the manageable systemic mechanisms responsible for gallstone occurrence, pointing to primary prevention measures. Changes must target lifestyles, as well as experimenting innovative pharmacological tools in subgroups of patients at high risk of developing gallstones.

Fruit and vegetable consumption and risk of endometriosis

STUDY QUESTION

Is there an association between intake of fruits and vegetables and risk of laparoscopically confirmed endometriosis?

SUMMARY ANSWER

Higher intake of fruits, particularly citrus fruits, is associated with a lower risk of endometriosis.

WHAT IS KNOWN ALREADY

Two case-control studies have examined the associations between fruit and vegetable intake and endometriosis risk with contrasting results. Diets rich in fruits and vegetables include higher levels of pro-vitamin A nutrients (alpha-carotene, beta-carotene, beta-cryptoxanthin) and women with endometriosis have been reported to have lower intake of vitamin A than women without endometriosis.

STUDY DESIGN SIZE, DURATION

A prospective cohort study using data collected from 70 835 premenopausal women from 1991 to 2013 as part of the Nurses' Health Study II cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Diet was assessed with a validated food frequency questionnaire (FFQ) every 4 years. Cases were restricted to laparoscopically confirmed endometriosis. Cox proportional hazards models were used to calculate rate ratios (RR) and 95% CI.

MAIN RESULTS AND THE ROLE OF CHANCE

During 840 012 person-years of follow-up, 2609 incident cases of laparoscopically confirmed endometriosis were reported (incidence rate = 311 per 100 000 person-years). We observed a non-linear inverse association between higher fruit consumption and risk of laparoscopically confirmed endometriosis (Psignificance of the curve = 0.005). This inverse association was particularly evident for citrus fruits. Women consuming ≥1 servings of citrus fruits/day had a 22% lower endometriosis risk (95% CI = 0.69-0.89; Ptrend = 0.004) compared to those consuming <1 serving/week. No association was observed between total vegetable intake and endometriosis risk. However, women consuming ≥1 servings/day cruciferous vegetables had a 13% higher risk of endometriosis (95% CI = 0.95-1.34; Ptrend = 0.03) compared to those consuming <1 serving/week. Of the nutrients examined, only beta-cryptoxanthin intake was significantly associated with lower endometriosis risk (RR fifth quintile = 0.88; 95% CI = 0.78-1.00; Ptrend = 0.02).

LIMITATIONS REASONS FOR CAUTION

Some error in the self-reporting of dietary intake is expected, however, use of a validated FFQ and examining diet prospectively across multiple time points, make it unlikely that this non-differential misclassification strongly influenced the results.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that a higher intake of fruits, particularly citrus fruits, is associated with a lower risk of endometriosis, and beta-cryptoxanthin in these foods may partially explain this association. In contrast to what we hypothesized, consumption of some vegetables increased endometriosis risk which may indicate a role of gastrointestinal symptoms in both the presentation and exacerbation of endometriosis-related pain; however, it is not clear what components of these foods might underlie the observed associations. Future studies examining dietary patterns that consider different combinations of food intake may help clarify these associations.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by research grants HD4854, HD52473 and HD57210 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and grant P30 DK046200 from the National Institute of Diabetes and Digestive and Kidney Diseases. The Nurses' Health Study II is supported by the Public Health Service grant UM1 CA176726 from the National Cancer Institute, National Institutes of Health. HRH is supported by the National Cancer Institute, National Institutes of Health (K22 CA193860). No competing interests.

TRIAL REGISTRATION NUMBER

n/a.

Hesperidin, a major flavonoid in orange juice, might not affect lipid profile and blood pressure: A systematic review and meta-analysis of randomized controlled clinical trials

Previous studies have led to conflicting results regarding the effect of hesperidin supplementation on cardiometabolic markers. This study aimed to evaluate the efficacy of hesperidin supplementation on lipid profile and blood pressure through a systematic review and meta-analysis of randomized controlled trials (RCTs). PubMed, Web of Science, Scopus, and Google Scholar, as well as the reference lists of the identified relevant RCTs, were searched up to May 2018. Effect sizes were pooled by using the random effects model. Ten RCTs (577 participants) were eligible to be included in the systematic review. The meta-analysis revealed that hesperidin supplementation had no effect on serum total cholesterol (weighted mean difference [WMD] = -1.04 mg/dl; 95% confidence interval [CI]: -5.65, 3.57), low-density lipoprotein cholesterol (WMD = -1.96 mg/dl; 95% CI [-7.56, 3.64]), high-density lipoprotein cholesterol (WMD = 0.16 mg/dl; 95% CI [-1.94, 2.28]), and triglyceride (WMD = 0.69 mg/dl; 95% CI [-5.91, 7.30]), with no significant between-study heterogeneity. Hesperidin supplement also had no effect on systolic (WMD = -0.85 mmHg; 95% CI [-3.07, 1.36]) and diastolic blood pressure (WMD = -0.48 mmHg; 95% CI [-2.39, 1.42]). Hesperidin supplementation might not improve lipid profile and blood pressure. Future well-designed trials are still needed to confirm these results.

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-quality scores and the risk of symptomatic gallstone disease: a prospective cohort study of male US health professionals

OBJECTIVE

To investigate the association between three diet-quality scores corresponding to adherence to healthy dietary patterns [alternate Mediterranean (aMed), Alternate Healthy Eating Index (AHEI-2010), Dietary Approaches to Stop Hypertension (DASH)] and the risk of symptomatic gallstone disease.

METHODS

The study comprised 43 635 men of the Health Professionals Follow-up Study-an ongoing prospective cohort study of US health professionals. Participants were free of symptomatic gallstone disease and diabetes and provided dietary information every 4 years from 1986 (baseline) until 2012. The aMed, AHEI-2010 and DASH scores were generated and associated with the risk of symptomatic gallstone disease using Cox proportional hazards regression.

RESULTS

During 716 904 person-years of follow-up, 2382 incident cases of symptomatic gallstone disease were identified. All three scores were inversely associated with risk of symptomatic gallstone disease after adjustment for potential confounders including age, smoking, physical activity, energy and coffee intake [hazard ratios (HRs) and 95% confidence intervals (CIs)] comparing the highest with the lowest quintiles: aMed: 0.66 (0.57-0.77), AHEI-2010: 0.64 (0.56-0.74) and DASH: 0.66 (0.58-0.76)]. Findings were similar after additional adjustment for body mass index and after inclusion of asymptomatic cases. Associations were stronger when analysis was restricted to cases who had undergone cholecystectomy.

CONCLUSIONS

In this prospective cohort of male US health professionals, higher adherence to the aMed, AHEI-2010 and DASH diets was associated with lower risk of symptomatic gallstone disease. Dietary recommendations focusing on high-quality diets targeting symptomatic gallstone disease may lower the incidence of this prevalent disease.

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.

Association between diet and gallstones of cholesterol and pigment among patients with cholecystectomy: a case-control study in Korea

BACKGROUND

The prevalence of cholesterol gallstones is high in Western populations, while pigment gallstones are common in Asian populations. Dietary factors are suggested to be associated with gallstone risk, but their relationship with gallstone type has not been evaluated. This study investigated the association between diet and risk of cholesterol gallstone or pigment gallstone in a Korean population whose dietary pattern and type of gallstone were changed during the last 30 years.

METHODS

Patients with cholesterol (n = 40) and pigment (n = 59) gallstones were recruited after laparoscopic cholecystectomy and were compared with those of age- and sex-matched controls without gallstones (n = 99). Dietary intakes were assessed by trained dietitians using a semi-quantitative food frequency questionnaire. Multinomial logistic regression analysis was performed to calculate odds ratios and 95% confidence intervals to examine the associations between diet and risk for type of gallstones adjusted by potential confounders.

RESULTS

Patients with cholesterol gallstone consumed more lipid, animal lipid, beef, pork, and fried food than those with pigment gallstones and control, while patients with pigment gallstone consumed more carbohydrate and noodles than patients with cholesterol gallstone and control. In multinomial logistic regression analysis using control as reference group, dietary pattern with high consumption of beef, pork, and fried food was associated with risk of cholesterol gallstones, while there was no association between the risk of pigment gallstone and dietary pattern. In addition, control consumed more alcohol than patients with cholesterol and pigment gallstones.

CONCLUSIONS

The present study suggested consumption of fat from meat and fried foods increased the risk of cholesterol gallstone, and intake of carbohydrate from noodles increased the risk of pigment gallstone.

Diet and Risk of Cholecystectomy: A Prospective Study Based on the French E3N Cohort

OBJECTIVES

This study aimed to examine the relationship between diet and cholecystectomy risk, using three approaches, in a large French cohort.

METHODS

In a prospective cohort study in French women who completed a food-frequency questionnaire at baseline, we analyzed diet with three approaches: food groups, dietary patterns obtained by factor analysis, and the Mediterranean diet score. The primary outcome was cholecystectomy. We used Cox proportional hazards regression to assess the relationship between diet and cholecystectomy risk, adjusting for the main potential confounders.

RESULTS

During 1,033,955 person years of follow-up, we identified 2,778 incident cases of cholecystectomy. Higher intakes of legumes, fruit, vegetable oil, and wholemeal bread were associated with decreased cholecystectomy risk. Two dietary patterns were identified by factor analysis: "Western" (essentially processed meat, pizza, pies, high-alcohol beverages, French fries, sandwiches…) and "Mediterranean" (essentially fruits, vegetables, seafood, and olive oil). The "Mediterranean" pattern was inversely associated with cholecystectomy risk in the subgroup of postmenopausal women who ever used menopausal hormone therapy (hazard ratio for quartile 4 vs. 1=0.79, 95% confidence interval (CI): 0.65-0.95; P for linear trend=0.008). High adherence to the Mediterranean diet was associated with decreased risk of cholecystectomy (hazard ratio for a 6-9 score vs. 0-3=0.89, 95% CI: 0.80-0.99; P for linear trend=0.02).

CONCLUSIONS

Adherence to a diet rich in fruit, vegetables, legumes, and olive oil was associated with a reduction in cholecystectomy risk in French women. Further studies in different settings are requested.

Risk Factors for Cholelithiasis

Gallstone disease is one of the most common public health problems in the United States. Approximately 10%-20% of the national adult populations currently carry gallstones, and gallstone prevalence is rising. In addition, nearly 750,000 cholecystectomies are performed annually in the United States; direct and indirect costs of gallbladder surgery are estimated to be $6.5 billion. Cholelithiasis is also strongly associated with gallbladder, pancreatic, and colorectal cancer occurrence. Moreover, the National Institutes of Health estimates that almost 3,000 deaths (0.12% of all deaths) per year are attributed to complications of cholelithiasis and gallbladder disease. Although extensive research has tried to identify risk factors for cholelithiasis, several studies indicate that definitive findings still remain elusive. In this review, predisposing factors for cholelithiasis are identified, the pathophysiology of gallstone disease is described, and nonsurgical preventive options are discussed. Understanding the risk factors for cholelithiasis may not only be useful in assisting nurses to provide resources and education for patients who are diagnosed with gallstones, but also in developing novel preventive measures for the disease.

Vegetarian diet as a risk factor for symptomatic gallstone disease

BACKGROUND/OBJECTIVES

Previous small studies have shown either no difference or a lower risk of symptomatic gallstone disease in vegetarians than in non-vegetarians. This study examined the incidence of symptomatic gallstone disease in a cohort of British vegetarians and non-vegetarians, and investigated the associations between nutrient intake and risk of symptomatic gallstone disease.

SUBJECTS/METHODS

The data were analysed from 49 652 adults enroled in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Oxford study, one-third of whom were vegetarian. The linked databases of hospital records were used to identify incident cases. Risk by diet group was estimated using Cox proportional hazards models. Further analysis quantified risk by intakes of selected macronutrients.

RESULTS

There were 1182 cases of symptomatic gallstone disease during 687 822 person-years of follow-up (mean=13.85 years). There was a large significant association between increasing body mass index (BMI) and risk of developing symptomatic gallstone disease (overall trend P<0.001). After adjustment for BMI and other risk factors, vegetarians had a moderately increased risk compared with non-vegetarians (HR: 1.22; 95% CI: 1.06-1.41; P=0.006). Although starch consumption was positively associated with gallstones risk (P=0.002 for trend), it did not explain the increased risk in vegetarians.

CONCLUSIONS

There is a highly significant association of increased BMI with risk of symptomatic gallstone disease. After adjusting for BMI, there is a small but statistically significant positive association between vegetarian diet and symptomatic gallstone disease.

Dietary Factors Reduce Risk of Acute Pancreatitis in a Large Multiethnic Cohort

BACKGROUND & AIMS

Pancreatitis is a source of substantial morbidity and health cost in the United States. Little is known about how diet might contribute to its pathogenesis. To characterize dietary factors that are associated with risk of pancreatitis by disease subtype, we conducted a prospective analysis of 145,886 African Americans, Native Hawaiians, Japanese Americans, Latinos, and whites in the Multiethnic Cohort.

METHODS

In the Multiethnic Cohort (age at baseline, 45-75 y), we identified cases of pancreatitis using hospitalization claim files from 1993 through 2012. Patients were categorized as having gallstone-related acute pancreatitis (AP) (n = 1210), AP not related to gallstones (n = 1222), or recurrent AP or suspected chronic pancreatitis (n = 378). Diet information was obtained from a questionnaire administered when the study began. Associations were estimated by hazard ratios and 95% confidence intervals using Cox proportional hazard models adjusted for confounders.

RESULTS

Dietary intakes of saturated fat (P trend = .0011) and cholesterol (P trend = .0008) and their food sources, including red meat (P trend < .0001) and eggs (P trend = .0052), were associated positively with gallstone-related AP. Fiber intake, however, was associated inversely with gallstone-related AP (P trend = .0005) and AP not related to gallstones (P trend = .0035). Vitamin D, mainly from milk, was associated inversely with gallstone-related AP (P trend = .0015), whereas coffee consumption protected against AP not related to gallstones (P trend < .0001). With the exception of red meat, no other dietary factors were associated with recurrent acute or suspected chronic pancreatitis.

CONCLUSIONS

Associations between dietary factors and pancreatitis were observed mainly for gallstone-related AP. Interestingly, dietary fiber protected against AP related and unrelated to gallstones. Coffee drinking protected against AP not associated with gallstones. Further studies are warranted to confirm our findings.

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.

Fruit and vegetable consumption and risk of cholecystectomy: a prospective cohort study of women and men

Purpose

Epidemiologic data on whether consumption of fruit and vegetables (FVs) decreases the risk of gallstone disease are sparse. Therefore, we examined the association between FV consumption and the 14-year risk of symptomatic gallstone disease (defined as occurrence of cholecystectomy) in a large group of middle-aged and elderly persons.

Methods

Data from two population-based cohorts were used, which included 74,554 men and women (born 1914–1952). Participants filled in a food frequency questionnaire in the late fall of 1997 and were followed up for cholecystectomy between 1998 and 2011 via linkage to the Swedish Patient Register. Cox regression models were used to obtain hazard ratios (HRs).

Results

During 939,715 person-years of follow-up, 2120 participants underwent a cholecystectomy (1120 women and 1000 men). An inverse association between FV consumption and risk of cholecystectomy was observed in age- and sex-adjusted analyses (P_trend = .036) but not in confounder-adjusted analyses (P_trend = .43). The multivariable-adjusted HR was 0.95 (95 % CI 0.83–1.08) for the highest compared with the lowest sex-specific quartile of FV consumption. There was no evidence of interactions with age (P = .25) or sex (P = .72) in analyses pooled by sex. However, an age-by-FV consumption interaction was observed in separate analyses of women (P = .010), with decreased HRs of cholecystectomy for ages up to 60 years.

Conclusions

This study supports an inverse association between FV consumption and risk cholecystectomy in women, although the association was restricted to women aged 48–60 years. In contrast, the study does not support an association in men.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-016-1298-6) contains supplementary material, which is available to authorized users.

Preventing a Mass Disease: The Case of Gallstones Disease: Role and Competence for Family Physicians

Gallstone formation is the result of a complex interaction between genetic and nongenetic factors. We searched and reviewed the available literature to define how the primary prevention of gallstones (cholesterol gallstones in particular) could be applied in general practice. Electronic bibliographical databases were searched. Prospective and retrospective cohort studies and case-controlled studies were analyzed and graded for evidence quality. The epidemiological data confirmed that genetic factors are estimated to account for only approximately 25% of the overall risk of gallstones, while metabolic/environmental factors are at least partially modifiable in stone-free risk groups, and are thus modifiable by primary prevention measures related to diet, lifestyle, and environmental factors (i.e., rapid weight loss, bariatric surgery, somatostatin or analogues therapy, transient gallbladder stasis, and hormone therapy). There is no specific recommendation for the secondary prevention of recurrent gallstones. Family physicians can contribute to preventing gallstones due to their capability to identify and effectively manage several risk factors discussed in this study. Although further studies are needed to better elucidate the involvement of epigenetic factors that may regulate the effect of environment and lifestyle on gene expression in the primary prevention of gallstone formation, preventive interventions are feasible and advisable in the general practice setting.

Gallstones

Gallstones grow inside the gallbladder or biliary tract. These stones can be asymptomatic or symptomatic; only gallstones with symptoms or complications are defined as gallstone disease. Based on their composition, gallstones are classified into cholesterol gallstones, which represent the predominant entity, and bilirubin ('pigment') stones. Black pigment stones can be caused by chronic haemolysis; brown pigment stones typically develop in obstructed and infected bile ducts. For treatment, localization of the gallstones in the biliary tract is more relevant than composition. Overall, up to 20% of adults develop gallstones and >20% of those develop symptoms or complications. Risk factors for gallstones are female sex, age, pregnancy, physical inactivity, obesity and overnutrition. Factors involved in metabolic syndrome increase the risk of developing gallstones and form the basis of primary prevention by lifestyle changes. Common mutations in the hepatic cholesterol transporter ABCG8 confer most of the genetic risk of developing gallstones, which accounts for ∼25% of the total risk. Diagnosis is mainly based on clinical symptoms, abdominal ultrasonography and liver biochemistry tests. Symptoms often precede the onset of the three common and potentially life-threatening complications of gallstones (acute cholecystitis, acute cholangitis and biliary pancreatitis). Although our knowledge on the genetics and pathophysiology of gallstones has expanded recently, current treatment algorithms remain predominantly invasive and are based on surgery. Hence, our future efforts should focus on novel preventive strategies to overcome the onset of gallstones in at-risk patients in particular, but also in the population in general.

Diabetes mellitus and the risk of gallbladder disease: A systematic review and meta-analysis of prospective studies

BACKGROUND

Diabetes has been hypothesized to increase the risk of gallbladder disease based on the observation that obesity and insulin resistance are associated with gallbladder disease. Although several studies have investigated the association between a diabetes diagnosis and risk of gallbladder disease, the results have not been entirely consistent. For this reason we conducted a systematic review and meta-analysis of the available cohort studies.

MATERIALS AND METHODS

We searched the PubMed and Embase databases for studies of diabetes and gallbladder disease (defined as gallstones, cholecystectomy, or cholecystitis) up to January 9th 2015. Prospective studies were included if they reported relative risk estimates and 95% confidence intervals of gallbladder disease associated with a diabetes diagnosis. Summary relative risks were estimated by use of a random effects model.

RESULTS

We identified 10 prospective studies that could be included in the meta-analysis which included 223,651 cases among 7,365,198 participants. The summary RR for diabetes patients was 1.56 (95% CI: 1.26-1.93, I(2)=99.4%, pheterogeneity<0.0001). The results persisted when stratified by gender, and in most subgroup analyses and there was no heterogeneity among studies with more than 10 years duration of follow-up. There was no evidence of publication bias.

CONCLUSIONS

Our analysis provides further support for an increased risk of gallbladder disease among diabetes patients.

Statin use and risk of gallstone disease: A meta-analysis

AIM

There is emerging evidence from animal and human studies that current statins can decrease the formation of gallbladder cholesterol gallstones and subsequently decrease the risk of gallstone disease, but consistent results have not been reported. We performed a meta-analysis to provide an overview of the relevant studies.

METHODS

Relevant studies published between January 1980 and February 2014 were identified by searching Medline, Embase and the Cochrane Library. Studies were selected using a priori defined criteria. The strength of the relationship between statin use and risk of gallstone disease was assessed by adjusted odds ratio (OR).

RESULTS

A total of 622 868 participants from six studies (four case-control studies, one cohort study and one cross-sectional study) were identified in this meta-analysis. The studies provided adjusted overall OR estimates for current statin use versus non-use, leading to a pooled OR of 0.86 (95% confidence interval [CI], 0.77-0.97; P < 0.001). The overall OR of population-based case-control studies and cholecystectomy due to gallstone disease were 0.83 (95% CI, 0.73-0.95; P = 0.0131) and 0.78 (95% CI, 0.74-0.82; P = 0.615), respectively.

CONCLUSION

There is evidence that current statin use lowers the risk of gallstone disease compared with non-use, especially for cholecystectomy due to gallstone disease. Low statin use (1-4 prescriptions) did not decrease the risk of gallstone disease, but moderate and high statin use significantly decreased the risk. Further multicenter and better controlled studies are needed to confirm these findings.

The prevalence and risk factors for gallstone disease in taiwanese vegetarians

Introduction

Gallstone disease (GSD) and its complications are major public health issues globally. Although many community-based studies had addressed the risk factors for GSD, little is known about GSD prevalence and risk factors among Taiwanese vegetarians.

Methods

This study included 1721 vegetarians who completed a questionnaire detailing their demographics, medical history, and life-styles. GSD was ascertained by ultrasonography or surgical history of cholecystectomy for GSD. The predictive probability of GSD for male and female vegetarians was estimated from the fitted model.

Results

The prevalence of GSD was 8.2% for both male and female vegetarians. The risk of GSD is similar in men and women across all age groups, and increases steadily with increasing age. For male vegetarians, age (OR: 1.04; 95% CI: 1.00–1.08) and serum total bilirubin level (OR: 2.35; 95% CI: 1.31–4.22) predict risk for GSD. For female vegetarians, age (OR: 1.03; 95% CI: 1.01–1.05), BMI (OR: 1.07; 95% CI: 1.01–1.13), and alcohol consumption (OR: 7.85; 95% CI: 1.83–33.73) are associated with GSD. GSD is not associated with type of vegetarian diet, duration of vegetarianism, low education level, physical inactivity, diabetes, coronary artery disease, cerebral vascular accident, chronic renal failure, hepatitis C virus infection, and lipid abnormalities. GSD is also not associated with age at menarche, postmenopausal status, and multiparity in female vegetarians.

Conclusions

Risk factors useful for predicting GSD in vegetarians are (1) age and total bilirubin level in men, and (2) age, BMI, and alcohol consumption in women. Many previously identified risk factors for general population does not seem to apply to Taiwanese vegetarians.

Effect of fresh orange juice intake on physiological characteristics in healthy volunteers

Background. Impaired endothelial function is a predictor of cardiovascular events. Orange juice (OJ) is rich in dietary flavonoids and could inhibit oxidative stress and inflammatory responses. We examined the effects of commercial (COJ) and fresh orange juice (FOJ) on endothelial function and physiological characteristics in healthy humans. Materials and Methods. Twenty-two healthy volunteers years were enrolled in a single blind randomized crossover controlled trial. The two groups consumed either COJ for the first 4 weeks and then FOJ (CFOJ, 4 weeks), or FOJ for the first 4 weeks and then COJ (FCOJ, 4 weeks). We assessed endothelial function by measuring flow-mediated dilation, serum concentrations of lipids, apolipoproteins A and B (apo A-1 and apo B), and inflammatory markers such as vascular endothelial adhesion molecule 1 (VCAM-1), E-selectin, high-sensitivity C-reactive protein (hs-CRP), and interleukin-6. Results. Consumption of both juices decreased VCAM, hs-CRP, and E-selectin but increased apo A-1. A decline in LDL occurred in the FOJ group. There were no differences between the characteristics of two groups, with the exception of apo A-1 levels that were increased with both forms of OJ. The largest variations occurred with hs-CRP, VCAM in both groups. Conclusion. Consumption of COJ and FOJ produced beneficial effects on the physiological characteristics of healthy volunteers. Although these results could encourage the consumption of OJ, intervention studies are needed to determine the long-term effects of these types of OJ on metabolic and cardiovascular endpoints.

Natural and anthropogenic lead in soils and vegetables around Guiyang city, southwest China: a Pb isotopic approach

Soils, vegetables and rainwaters from three vegetable production bases in the Guiyang area, southwest China, were analyzed for Pb concentrations and isotope compositions to trace its sources in the vegetables and soils. Lead isotopic compositions were not distinguishable between yellow soils and calcareous soils, but distinguishable among sampling sites. The highest (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios were found for rainwaters (0.8547-0.8593 and 2.098-2.109, respectively), and the lowest for soils (0.7173-0.8246 and 1.766-2.048, respectively). The (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios increased in vegetables in the order of roots<stems<leaves<fruits. Plots of the (207)Pb/(206)Pb ratios versus the (208)Pb/(206)Pb ratios from all samples formed a straight line and supported a binary end-member mixing model for Pb in vegetables. Using deep soils and rainwaters as geogenic and anthropogenic end members in the mixing model, it was estimated that atmospheric Pb contributed 30-77% to total Pb for vegetable roots, 43-71% for stems, 72-85% for leaves, and 90% for capsicum fruits, whereas 10-70% of Pb in all vegetable parts was derived from soils. This research supports that heavy metal contamination in vegetables can result mainly from atmospheric deposition, and Pb isotope technique is useful for tracing the sources of Pb contamination in vegetables.

Health Implications of a Vegetarian Diet

There is now a significant amount of research that demonstrates the health benefits of vegetarian and plant-based diets, which have been associated with a reduced risk of obesity, diabetes, heart disease, and some types of cancer as well as increased longevity. Vegetarian diets are typically lower in fat, particularly saturated fat, and higher in dietary fiber. They are also likely to include more whole grains, legumes, nuts, and soy protein, and together with the absence of red meat, this type of eating plan may provide many benefits for the prevention and treatment of obesity and chronic health problems, including diabetes and cardiovascular disease. Although a well-planned vegetarian or vegan diet can meet all the nutritional needs of an individual, it may be necessary to pay particular attention to some nutrients to ensure an adequate intake, particularly if the person is on a vegan diet. This article will review the evidence for the health benefits of a vegetarian diet and also discuss strategies for meeting the nutritional needs of those following a vegetarian or plant-based eating pattern.

Cholelithiasis and the risk of nephrolithiasis

PURPOSE

Existing data on the relation between gallstones and kidney stones are provocative but limited. Therefore, we determined whether symptomatic radiographically confirmed gallstones (and/or cholecystectomy) and symptomatic kidney stone disease are independently associated.

MATERIALS AND METHODS

We conducted cross-sectional and prospective analyses in the Nurses' Health Studies I and II (older and younger women, respectively) and the Health Professionals Follow-Up Study (men) that included more than 240,000 participants followed for 14 to 24 years. Regression models adjusted for age, body size, thiazide use, diet and other factors.

RESULTS

At baseline the multivariate odds ratio of kidney stone history in individuals with gallstone history compared to those without was 1.65 (95% CI 1.46-1.86) in older women, 1.85 (95% CI 1.65-2.07) in younger women and 1.61 (95% CI 1.41-1.85) in men. Prospectively, the multivariate relative risk of incident kidney stones in participants with gallstone history compared to those without was 1.26 (95% CI 1.09-1.44) in older women, 1.32 (95% CI 1.14-1.52) in younger women and 1.28 (95% CI 1.03-1.57) in men. The multivariate relative risk of incident gallstones in participants with kidney stone history compared to those without was 1.17 (95% CI 1.06-1.29) in older women, 1.31 (95% CI 1.19-1.45) in younger women and 1.51 (95% CI 1.35-1.68) in men. Prospective lag analyses instituting a delay of 4 years between the diagnoses of gallstones and kidney stones yielded similar results.

CONCLUSIONS

Gallstones and kidney stones are independently associated. Additional studies are needed to identify shared mechanisms underlying both diseases.

Diabetes mellitus and the risk of cholecystectomy

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Targets for current pharmacologic therapy in cholesterol gallstone disease

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

Vitamin C supplement use may protect against gallstones: an observational study on a randomly selected population

BACKGROUND

Animal experiments have shown a protective effect of vitamin C on the formation of gallstones. Few data in humans suggest an association between reduced vitamin C intake and increased prevalence of gallstone disease. The aim of this study was to assess the possible association of regular vitamin C supplementation with gallstone prevalence.

METHODS

An observational, population-based study of 2129 subjects aged 18-65 years randomly selected from the general population in southern Germany was conducted. Abdominal ultrasound examination, completion of a standardized questionnaire, compilation of anthropometric data and blood tests were used. Data were collected in November and December 2002. Data analysis was conducted between December 2005 and January 2006.

RESULTS

Prevalence of gallstones in the study population was 7.8% (167/2129). Subjects reporting vitamin C supplementation showed a prevalence of 4.7% (11/232), whereas in subjects not reporting regular vitamin C supplementation, the prevalence was 8.2% (156/1897). Female gender, hereditary predisposition, increasing age and body-mass index (BMI) were associated with increased prevalence of gallstones. Logistic regression with backward elimination adjusted for these factors showed reduced gallstone prevalence for vitamin C supplementation (odds ratio, OR 0.34; 95% confidence interval, CI 0.14 to 0.81; P = 0.01), increased physical activity (OR 0.62; 95% CI, 0.42 to 0.94; P = 0.02), and higher total cholesterol (OR 0.65; 95% CI, 0.52 to 0.79; P < 0.001).

CONCLUSION

Regular vitamin C supplementation and, to a lesser extent, increased physical activity and total cholesterol levels are associated with a reduced prevalence of gallstones. Regular vitamin C supplementation might exert a protective effect on the development of gallstones.

Nationwide epidemiological study of severe gallstone disease in Taiwan

Background

Our study aimed to assess the nationwide trends in the incidence of severe gallstone disease in Taiwan among adults aged ≥20.

Methods

A retrospective longitudinal study was conducted using Taiwan National Health Insurance Research Database collected during 1997–2005. Patients with incident severe gallstone disease (acute cholecystitis, biliary pancreatitis, acute cholangitis) and gallstone-related procedures (elective and non-elective cholecystectomy, endoscopic retrograde cholangiopancreatography [ERCP]) that led to hospital admission were identified using ICD-9-CM diagnostic and procedure codes. Annual incidence rates of gallstone-related complications and procedures were calculated and their 95% confidence intervals (CI) were estimated assuming a Poisson distribution.

Results

The hospital admission rate for severe gallstone disease increased with advancing age and the age-standardized rate (95% CI) per 1000 population was 0.60 (0.59–0.60) for men and 0.59 (0.59–0.60) for women. Men had a higher rate of acute cholecystitis, probably due to the substantially lower rate of elective cholecystectomy among men than women. For those aged 20–39, hospital admissions for all gallstone-related complications and procedures increased significantly. For those aged ≥60, incidences of biliary pancreatitis, acute cholangitis, and hospital admission for gallstone receiving ERCP increased significantly without substantial change in the incidence of acute cholecystitis and despite a decreased rate of elective cholecystectomy.

Conclusion

This population-based study found a substantial increase in the rate of admission for severe gallstone disease among those aged 20–39. Concurrently, the incidences of biliary pancreatitis and acute cholangitis have risen among those aged ≥60.

Gallbladder disease and use of transdermal versus oral hormone replacement therapy in postmenopausal women: prospective cohort study

OBJECTIVE

To determine whether transdermal compared with oral use of hormone replacement therapy reduces the risk of gallbladder disease in postmenopausal women.

DESIGN

Prospective cohort study (Million Women Study).

SETTING

Women registered with the National Health Service (NHS) in England and Scotland.

PARTICIPANTS

1,001,391 postmenopausal women (mean age 56) recruited between 1996 and 2001 from NHS breast screening centres and followed by record linkage to routinely collected NHS hospital admission data for gallbladder disease.

MAIN OUTCOME MEASURES

Adjusted relative risk and standardised incidence rates of hospital admission for gallbladder disease or cholecystectomy according to use of hormone replacement therapy.

RESULTS

During follow-up 19 889 women were admitted for gallbladder disease; 17 190 (86%) had a cholecystectomy. Compared with never users of hormone replacement therapy, current users were more likely to be admitted for gallbladder disease (relative risk 1.64, 95% confidence interval 1.58 to 1.69) but risks were substantially lower with transdermal therapy than with oral therapy (relative risk 1.17, 1.10 to 1.24 v 1.74, 1.68 to 1.80; heterogeneity P<0.001). Among women using oral therapy, equine oestrogens were associated with a slightly greater risk of gallbladder disease than estradiol (relative risk 1.79, 1.72 to 1.87 v 1.62, 1.54 to 1.70; heterogeneity P<0.001) and higher doses of oestrogen increased the risk more than lower doses: for equine oestrogens >0.625 mg, 1.91 (1.78 to 2.04) v <or=0.625 mg, 1.76 (1.68 to 1.84); heterogeneity P=0.02; estradiol >1 mg, 1.68 (1.59 to 1.77) v <or=1 mg, 1.44 (1.31 to 1.59); heterogeneity P=0.003. The risk of gallbladder disease decreased with time since stopping therapy (trend P=0.004). Results were similar taking cholecystectomy as the outcome. Standardised hospital admission rates per 100 women over five years for cholecystectomy were 1.1 in never users, 1.3 with transdermal therapy, and 2.0 with oral therapy.

CONCLUSION

Gallbladder disease is common in postmenopausal women and use of hormone replacement therapy increases the risk. Use of transdermal therapy rather than oral therapy over a five year period could avoid one cholecystectomy in every 140 users.