Estrogen replacement therapy and gallbladder disease in postmenopausal women

Menopausal hormone therapy increases the risk of gallstones: Health Insurance Database in South Korea (HISK)-based cohort study

OBJECTIVE

To determine whether menopausal hormone therapy (MHT) increases the risk of gallstones and gallbladder cancer.

DESIGN

A retrospective cohort study.

PATIENTS OR OTHER PARTICIPANTS

Data from the Korea National Health Insurance Corporation was obtained between January 1, 2002, and December 31, 2019.

INTERVENTIONS

Participants were divided into MHT and non-MHT groups; the MHT group was analyzed in detail by dividing participants into tibolone, combined estrogen plus progestin by the manufacturer (CEPM) or physician (CEPP), oral estrogen alone, and topical estrogen subgroups.

MAIN OUTCOME MEASURES

The incidence of gallstones and gallbladder cancer was compared between the two groups.

RESULTS

This study enrolled 1,004,034 and 381,711 patients in the non-MHT and the MHT groups, respectively. The incidence of gallstones was 2.6% in the non-MHT group and 3.4%, 2.6%, 3.4%, 3.2%, and 4.4% in the tibolone, CEPM, oral estrogen alone, CEPP, and topical estrogen groups, respectively. Cox proportional hazard analysis revealed that all hormones increased the risk of gallstones ([tibolone] hazard ratio [HR]: 1.347, 95% confidence interval [CI]: 1.309-1.387, [CEPM] HR: 1.146, 95% CI: 1.1-1.19, [oral estrogen alone] HR: 1.241, 95% CI: 1.18-1.305, [CEPP] HR: 1.164, 95% CI: 1.01-1.341, [topical estrogen] HR: 1.602, 95% CI: 1.295-1.983). However, the risk of gallbladder cancer did not change with any hormone therapy.

CONCLUSIONS

All types of MHT including tibolone, increased the risk of gallstones. This risk was the highest with topical estrogen, which may be a result of selection bias due to concerns regarding the adverse effects of CEE and MPA.

Risk of Gynecological Cancers in Cholecystectomized Women: A Large Nationwide Cohort Study

Background: Gallstones affect women more frequently than men, and symptomatic gallstones are increasingly treated with surgical removal of the gallbladder (cholecystectomy). Breast, endometrial, and ovarian cancer share several risk factors with gallstones, including overweight, obesity, and exposure to female sex hormones. We intended to assess the association between cholecystectomy and female cancer risk, which has not been comprehensively investigated. Methods: We investigated the risk of female cancers after cholecystectomy leveraging the Swedish Cancer, Population, Patient, and Death registries. Standardized incidence ratios (SIRs) adjusted for age, calendar period, socioeconomic status, and residential area were used to compare cancer risk in cholecystectomized and non-cholecystectomized women. Results: During a median follow-up of 11 years, 325,106 cholecystectomized women developed 10,431 primary breast, 2888 endometrial, 1577 ovarian, and 705 cervical cancers. The risk of ovarian cancer was increased by 35% (95% confidence interval (CI) 2% to 77%) in the first 6 months after cholecystectomy. The exclusion of cancers diagnosed in the first 6 months still resulted in an increased risk of endometrial (19%, 95%CI 14% to 23%) and breast (5%, 95%CI 3% to 7%) cancer, especially in women cholecystectomized after age 50 years. By contrast, cholecystectomized women showed decreased risks of cervical (-13%, 95%CI -20% to -7%) and ovarian (-6%, 95%CI -10% to -1%) cancer. Conclusions: The risk of ovarian cancer increased by 35% in a just short period of time (6 months) following the surgery. Therefore, it is worth ruling out ovarian cancer before cholecystectomy. Women undergoing cholecystectomy showed an increased risk of breast and endometrial cancer up to 30 years after surgery. Further evaluation of the association between gallstones or gallbladder removal on female cancer risk would allow for the assessment of the need to intensify cancer screening in cholecystectomized women.

G Protein-Coupled Estrogen Receptor, GPER1, Offers a Novel Target for the Treatment of Digestive Diseases

There are gender differences between men and women in many physiological functions and diseases, which indicates that female sex hormones may be important. Traditionally, estrogen exerts its biological activities by activating two classical nuclear estrogen receptors, ESR1 and ESR2. However, the roles of estrogen in the regulation of physiological functions and the pathogenesis of diseases become more complicated with the identification of the G protein-coupled estrogen receptor (GPER1). Although many GPER1-specific ligands have been developed, the therapeutic mechanisms of exclusively targeting GPER1 are not yet well understood. Translational applications and clinical trial efforts for the identified GPER1 ligands have been focused primarily on the reproductive, cardiovascular, nervous, endocrine, and immune systems. More recently, research found that GPER1 may play an important role in regulating the digestive system. Cholesterol gallstone disease, a major biliary disease, has a higher prevalence in women than in men worldwide. Emerging evidence implies that GPER1 could play an important role, independent of the classical ESR1, in the pathophysiology of cholesterol gallstones in women. This review discusses the complex signaling pathways of three estrogen receptors, highlights the development of GPER1-specific ligands, and summarizes the latest advances in the role of GPER1 in the pathogenesis of gallstone formation.

Frequency of symptoms associated with gallstone disease: a hospital-based cross sectional study

This study investigated the likely outcomes of gallstone disease and frequency of symptoms associated with this. This cross sectional study was performed at the Aliebn Abitaleb hospital in Rafsanjan over a period of twelve months from 2000 to 2001. A total sample of 70 individuals were included in the study, interviewing them using of a questionnaire covering data in terms of demographic features and medical history.The majority of patients belonged to the age group of 41 to 60 years (44.3% of all patients), while the lowest frequency was in the age group of 20 years or less. Frequency of females was higher than males. The frequency of female patients increased with the number of child birth, the highest being in women who had more than 5 child births. The most common complaint of pain was revealed as upper right abdominal quadrant (RUQ), which accounted for 95.7% of cases. Vomiting was observed in 52.9% of patients. In addition, the frequency of patients with chronic pain initiation was more than those with acute pain initiation. Among women, 17.5% had oral contraceptive pill constipation. It is worth noting that ultrasonography was the best diagnostic tool for evaluating patients. It is noteworthy that the most common symptom was right upper quadrant tenderness. Our data indicate that diabetes was the most common illness associated with gallstone disease and that 8.6% of patients had a family history of gallstone disease.

The association between gallstones and metabolic syndrome in urban Han Chinese: a longitudinal cohort study

The precise association between metabolic syndrome (MetS) and gallstone disease remains unclear in China. This study aimed to clarify the relationship between MetS and gallstone and evaluate whether counts of metabolic abnormalities had influence on gallstone disease. We fitted gender-specific generalized estimating equation (GEE) regression models with data from a large-scale longitudinal study over 6-year follow-up to elucidate the real association. This study included 18291 participants with 3 times repeated measures at least who were free from a prior history of gallstone disease and cholecystectomy. A total of 873 cases of gallstones occurred during 6-year follow-up. The incidence density of gallstone in the group of subjects with MetS was higher than the group without MetS (10.27 vs 5.79). The GEE analyses confirmed and clarified the association between MetS and gallstone disease in males (RR = 1.33, P = 0.0020), while this association was not significant in females (RR = 1.15, P = 0.4962). With numbers of metabolic syndrome components increasing, the risk of gallstone disease showed corresponding increasing in males. In conclusion, the associations of MetS and gallstone are different in males and in females. And the risk of gallstone disease increases with the number of components of MetS for males but not for females.

Osteoporosis increases subsequent risk of gallstone: a nationwide population-based cohort study in Taiwan

BACKGROUND

Osteopontin (OPN) is a pro-inflammatory cytokine which is expressed in various tissues. It participates in the bone remodeling process and stimulates bone resorption by osteoclasts. It is also a core protein of cholesterol gallstones. We hypothesized osteoporotic patients might have higher risk in developing gallstones and conducted a population-based study to examine the risk of developing gallstone in osteoporotic patients in Taiwan.

METHODS

A total of 1,638 patients diagnosed with osteoporosis between 2003 and 2005 were identified in the National Health Insurance Research Database. A comparison cohort without osteoporosis (n =6,552) was randomly matched to each osteoporosis patient at a ratio of 4: 1 based on age and sex. A Cox proportional-hazards regression analysis was performed to evaluate the 5-year gallstone-free survival rates for the 2 cohorts.

RESULTS

During the 5-year follow-up period, 114 and 311 cases of gallstone occurred in the osteoporosis and comparison cohorts, respectively. After adjusting for the confounders, the Cox regression analysis of the risk of gallstone in the osteoporosis and comparison cohorts yielded a hazard ratio of 1.35 (95% confidence interval: 1.07 - 1.69; p < 0 .01).

CONCLUSION

Patients with osteoporosis in Taiwan have a higher risk of developing gallstone than the general population.

Postmenopausal estrogen therapy and risk of gallstone disease: a population-based case-control study

BACKGROUND

Female gender and increasing age are key risk factors for gallstone disease; therefore, postmenopausal women are at high risk. Estrogen increases cholesterol saturation of bile and may further increase gallstone risk, but population-based evidence is sparse.

OBJECTIVE

Our objective was to examine the association between postmenopausal estrogen therapy and risk of gallstone disease and the impact of duration of treatment and use of opposing progestin.

STUDY DESIGN

We conducted a population-based case-control study. Cases were postmenopausal women (defined as aged ≥45 years) with gallstone disease identified in the period 1996-2010. For each case, we selected ten population controls matched to cases by age and sex. We defined exposure as any use of estrogen (opposed and unopposed by progestin). Cases/controls were categorized as current estrogen users if their last prescription was redeemed <90 days before gallstone diagnosis (or corresponding date for controls); all other users were categorized as former users. The reference group consisted of cases/controls with no/rare estrogen use.

SETTING

Medical databases covering the population of Northern Denmark (2.4 million inhabitants through the period 1996-2010).

MAIN OUTCOME MEASURE

We used conditional logistic regression to compute adjusted odds ratios (ORs) and 95 % confidence intervals (CIs) of gallstone disease in women treated with estrogen. The ORs were adjusted for relevant comorbidity, other drugs known to influence gallstone risk, and parity.

RESULTS

We identified 16,386 cases with gallstone disease and 163,860 controls. A total of 1,425 cases (8.7 %) and 8,930 controls (5.4 %) were current estrogen users, yielding an adjusted OR for gallstone disease of 1.74 (95 % CI 1.64-1.85) compared with non-users. The corresponding adjusted OR for former users was 1.35 (95 % CI 1.28-1.42). The results suggested a duration response for current users. Use of unopposed estrogen was associated with higher adjusted ORs than estrogen opposed by progestin.

CONCLUSION

Postmenopausal estrogen therapy was associated with increased risk of gallstone disease in current and former estrogen users. Use of unopposed estrogen was associated with higher risk than use of estrogen opposed by progestin; this finding needs to be confirmed and explored further in future studies.

Menopausal hormone therapy and risk of cholecystectomy: a prospective study based on the French E3N cohort

BACKGROUND

Studies in the United States and the United Kingdom have reported an increased risk of cholecystectomy among women exposed to menopausal hormone therapy, but with substantial heterogeneity between types of hormone treatments. We evaluated the risk of cholecystectomy associated with different regimens of menopausal hormone therapy in a large prospective cohort study.

METHODS

Between 1992 and 2008, 70 928 menopausal women from the French E3N study cohort were sent questionnaires assessing their use of menopausal hormone therapy, medical history and lifestyle characteristics. The primary outcome was cholecystectomy. We analyzed the risk of cholecystectomy associated with use of menopausal hormone therapy using Cox proportional models, with age as time-scale.

RESULTS

During follow-up, 45 984 (64.8%) of the participants were exposed to menopausal hormone therapy, and 2819 cholecystectomies were recorded. The use of menopausal hormone therapy was associated with an increased risk of cholecystectomy (adjusted hazard ratio [HR] 1.10, 95% confidence interval [CI] 1.01-1.20) compared with women who were not exposed to menopausal hormone therapy. The association was restricted to unopposed oral estrogen therapy (adjusted HR 1.38, 95% CI 1.14-1.67). Over 5 years, about 1 cholecystectomy in excess would be expected in every 150 women using oral estrogen therapy without progestogens, compared with women not exposed to menopausal hormone therapy.

INTERPRETATION

The risk of cholecystectomy was increased among women exposed to oral estrogen menopausal hormone therapy, especially oral regimens without a progestagen. Complicated gallstone disease should be added to the list of potential adverse events to be considered when balancing the benefits and risks associated with menopausal hormone therapy.

Molecular Mechanisms Underlying the Link between Nuclear Receptor Function and Cholesterol Gallstone Formation

Cholesterol gallstone disease is highly prevalent in western countries, particularly in women and some specific ethnic groups. The formation of water-insoluble cholesterol crystals is due to a misbalance between the three major lipids present in the bile: cholesterol, bile salts, and phospholipids. Many proteins implicated in biliary lipid secretion in the liver are regulated by several transcription factors, including nuclear receptors LXR and FXR. Human and murine genetic, physiological, pathophysiological, and pharmacological evidence is consistent with the relevance of these nuclear receptors in gallstone formation. In addition, there is emerging data that also suggests a role for estrogen receptor ESR1 in abnormal cholesterol metabolism leading to gallstone disease. A better comprehension of the role of nuclear receptor function in gallstone formation may help to design new and more effective therapeutic strategies for this highly prevalent disease condition.

The effect of retinoic acid receptor agonist acitretin on the production of bile and concentrations of some serum components in ovariectomized rats

OBJECTIVE

Acitretin is an oral retinoid that is approved for the treatment of psoriasis and in the chemoprevention of nonmelanoma skin cancer. The metabolism of acitretin occurs in the liver and may affect other metabolic processes in the liver, such as metabolism of bilirubin, bile acids, and lipids. These processes may be also affected by physiologic loss of estrogens in postmenopausal women. Therefore, the aim of this study was to examine the effect of acitretin on the secretion and composition of bile and the turnover of cholesterol in a model of estrogen deficiency in ovariectomized rats.

METHODS

The study was carried out on female Wistar rats divided into three groups: sham-operated control, ovariectomized control, and ovariectomized rats receiving acitretin. The studied group was administered acitretin (Neotigason capsules 25 mg, Roche; 7.1 mg/kg body weight per 24 h) for 28 days. Bile fractions and blood were collected for determinations of concentration of bile acids, total cholesterol, calcium ions, chloride ions, and direct bilirubin. In addition, low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol were assayed.

RESULTS

It was found that ovariectomy produced alterations in the process of secretion of bile and its principal components: cholesterol, bile acids, chloride ions, and bilirubin. The administration of acitretin decreased the secretion of bile and bile cholesterol, as well as serum levels of total, LDL, and HDL cholesterol, and moreover increased the proportion of bile acids to total cholesterol.

CONCLUSIONS

Acitretin may influence the hepatic metabolism of bile, bile acids, and lipids. This action is associated with a decrease in factors influencing the lithogenicity of bile, with reductions in the serum levels of total, LDL, and HDL cholesterol.

Reproductive factors and risks of biliary tract cancers and stones: a population-based study in Shanghai, China

BACKGROUND

Parity has been linked to gallbladder cancer and gallstones, but the effects of other reproductive factors are less clear.

METHODS

We examined 361 incident biliary tract cancer cases, 647 biliary stone cases, and 586 healthy women in a population-based study in Shanghai.

RESULTS

The effects of parity (odds ratios, OR(> or =3 vs 1 child)=2.0, 95% confidence interval (CI) 0.7-5.1), younger age at first birth (OR(per 1-year decrease)=1.2, 95% CI 0.99-1.6), and older age at menarche (OR(per 1-year increase)=1.4, 95% CI 1.1-1.8) on gallbladder cancer risk were more pronounced among women with stones, but the interactions were not significant.

CONCLUSION

Our results provide support for high parity, younger age at first birth, and late age at menarche in the development of gallbladder cancer, particularly among women with biliary stones.

New insights into the molecular mechanisms underlying effects of estrogen on cholesterol gallstone formation

Epidemiological and clinical studies have found that at all ages women are twice as likely as men to form cholesterol gallstones, and this gender difference begins since puberty and continues through the childbearing years, which highlight the importance of female sex hormones. Estrogen is a crucial hormone in human physiology and regulates a multitude of biological processes. The actions of estrogen have traditionally been ascribed to two closely related classical nuclear hormone receptors, estrogen receptor 1 (ESR1) and ESR2. Recent studies have revealed that the increased risk for cholesterol gallstones in women vs. men is related to differences in how the liver metabolizes cholesterol in response to estrogen. A large number of human and animal studies have proposed that estrogen increases the risk of developing cholesterol gallstones by increasing the hepatic secretion of biliary cholesterol, which, in turn, leads to an increase in cholesterol saturation of bile. Furthermore, it has been identified that hepatic ESR1, but not ESR2, plays a major role in cholesterol gallstone formation in mice in response to high doses of 17beta-estradiol. The mechanisms mediating estrogen's action have become more complicated with the recent identification of a novel estrogen receptor, G protein-coupled receptor 30 (GPR30), a member of the seven-transmembrane G protein-coupled receptor superfamily. In this review, we provide an overview of the evidence for the lithogenic actions of estrogen through ESR1 and discuss the cellular and physiological actions of GPR30 in estrogen-dependent processes and the relationship between GPR30 and classical ESR1 on gallstone formation.

Variants in hormone-related genes and the risk of biliary tract cancers and stones: a population-based study in China

Biliary tract cancers, encompassing gallbladder, extrahepatic bile duct and ampulla of Vater cancers, are uncommon but often fatal malignancies. Hormone-related factors, including parity, oral contraceptive use, obesity, and gallstones, have been implicated in the etiology of these cancers. To further clarify the role of hormones in biliary tract cancers and biliary stones, we genotyped 18 single-nucleotide polymorphisms (SNPs) in nine genes involved in steroid hormone biosynthesis, metabolism and transport in a population-based case-control study in Shanghai, China. This study included subjects who completed an interview and provided blood, which totaled 411 biliary tract cancer and 893 biliary stone patients and 786 healthy Shanghai residents. The CYP1A1 IVS1 + 606 (rs2606345) T allele was associated with gallbladder [odds ratio (OR) = 2.0, 95% confidence interval (CI), 1.3-3.0] and bile duct cancers (OR = 1.8, 95% CI = 1.1-3.1), whereas the CYP1A1 Ex7 + 131 (rs1048943) G allele was associated with ampulla of Vater cancer (OR = 2.9, 95% CI = 1.5-5.4). After taking into account multiple comparisons for SNPs within each gene, CYP1A1 was significantly associated with gallbladder (P = 0.004) and ampulla of Vater cancers (P = 0.01), but borderline with bile duct cancer (P = 0.06). The effect of CYP1A1 IVS1 + 606 on gallbladder cancer was more pronounced among non-obese (body mass index < 23) (OR = 3.3, 95% CI = 1.8-6.1; P interaction = 0.001). Among women taking oral contraceptives, the effect of SHBG Ex8 + 6 (rs6259) on gallbladder cancer (OR = 6.7, 95% CI = 2.2-20.5; P interaction = 0.001) and stones (OR = 2.3, 95% CI = 1.1-4.9; P-interaction = 0.05) was statistically significant. Our findings suggest that common variants in hormone-related genes contribute to the risk of biliary tract cancers and stones, possibly by modulating hormone metabolism.

Known risk factors do not explain disparities in gallstone prevalence between Denmark and northeast Germany

OBJECTIVES

Gallstones are a common disease worldwide, with disparities in the prevalence of the disease in different settings. The aim of the present study was to assess if different distributions of risk factors could explain the disparities in the prevalence of gallstone disease between Denmark and northeast Germany.

METHODS

Data of 5,559 subjects from the Danish MONICA survey and of 3,647 subjects of the German Study of Health in Pomerania were investigated. Gallstone disease was defined as a prior history of cholecystectomy or the presence of sonographically diagnosed gallstones. Logistic regression models were performed to assess the confounding effect of selected risk factors on regional disparities in gallstone disease.

RESULTS

After adjustment for age and vocational training, German subjects (women: Odds ratio, OR, 2.46 (95% confidence interval, CI: 2.07-2.91); men: OR, 1.89 (95% CI: 1.52-2.36)) had approximatively twice the odds of gallstones than Danes. Inclusion of lifestyle factors (smoking, alcohol intake, coffee use) did not affect this result, whereas adjustment for body mass index (BMI), lipids, diabetes, and use of oral contraceptives, menopausal hormone therapy (MHT) and parity (women only) changed the estimates considerable, but still Germans (women: OR, 1.65 (95% CI: 1.36-2.00); men: OR, 1.61 (95% CI: 1.27-2.04)) had higher odds than Danes.

CONCLUSIONS

German individuals had a higher prevalence of gallstones than Danes. This difference was partly explained by a higher BMI, unfavorable lipid levels, higher prevalence of diabetes, and a more frequent use of OR and MHT in German subjects. Further research is needed to evaluate the impact of unmeasured predictors, including genetic components, on the population-related risk of gallstones.

Capsule endoscopy: in search of the ideal image

Capsule studies can be reviewed by varying rates and speeds; however, the presence of significant debris is frustrating to the reviewer much like the excessive stool that tends to hinder the progress of a colonoscopist. Numerous studies have been published in regards to the advantages of an ideal preparation in the setting of capsule endoscopy. This most recent study by Wei et al. is another study that has demonstrated that a colonic preparation, in this situation, combined with simethicone given just prior to the capsule study results in improved visibility of the mucosa. In theory, this will lead to an improved diagnostic ability to limit excessive reading duration.

Menopausal hormone therapy and gallbladder disease: the Study of Health in Pomerania (SHIP)

OBJECTIVE

Several studies suggest that oral menopausal hormone therapy (MHT) is associated with an increased risk of gallbladder disease. It has been hypothesized that nonoral MHT may reduce the risk of cholelithiasis. The objective of the present study was to analyse the association between (1) use of life-time MHT (ever use) and gallbladder disease and (2) nonoral use of MHT and gallbladder disease.

DESIGN

Cross-sectional study using population-based data from the Study of Health in Pomerania (SHIP).

POPULATION

The study population included 994 postmenopausal women, aged 40-79 years. The subgroup of current oral and nonoral MHT users comprised 139 women.

METHODS AND MEASUREMENTS

Sociodemographic, medical and reproductive characteristics were based on computer-assisted personal interviews, and selected laboratory parameters were analysed. Gallbladder disease was defined by either a prior history of cholecystectomy or the presence of current sonographically diagnosed gallstones. Data analyses consisted of descriptive, bivariable and multivariable procedures. We performed Poisson regression with Huber/White standard errors to investigate the association between ever use, current nonoral use of MHT and gallbladder disease.

RESULTS

We found no significant association between ever use of MHT and gallbladder disease and sonographically diagnosed gallstones in fully adjusted analyses. Women who used MHT had a significantly higher risk for cholecystectomy compared to nonusers. There was no association between nonoral use of MHT and gallbladder disease.

CONCLUSIONS

Our analyses do not lend support to the hypothesis that use of MHT is associated with gallbladder disease.

Gender and gallstone disease

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

Physicians’ views and practices concerning menopausal hormone therapy

OBJECTIVE

To examine physicians' views and practices concerning estrogen+progestogen therapy (EPT).

DESIGN

Questionnaires were mailed to a random sample of physicians in the United States (US) in 2003. A total of 1614 (53.8%) surveys were returned (633 obstetricians and gynecologists (Ob/Gyns), 571 family practitioners, and 410 internists).

RESULTS

Only a minority of the physicians (16%) would offer EPT to menopausal women in the absence of menopausal symptoms (26% Ob/Gyn, 11% family practitioners, 6% internists, p<0.0001). However, many physicians (62%) believed that EPT could be offered "short term" to menopausal women with menopausal symptoms assuming no contraindications (82% Ob/Gyn, 54% family practitioners, 42% internists; p<0.0001). Irrespective of specialty, the strongest contraindications to EPT use reported by these physicians were personal history of breast cancer (93%), thrombosis (92%), cerebrovascular disease (84%), ischemic heart disease (74%), uterine cancer (73%), as well as women's subjective "concern" about breast cancer (57%). Procedures reported as always required by physicians for continuing women on EPT were breast examination (97%), mammogram (96%), blood pressure measurement (94%), and pelvic examination (91%).

CONCLUSIONS

Internists and family practitioners address more contraindications to EPT use than Ob-Gyns. Although many physicians appear to be accepting of short-term use of EPT for menopausal indications in the absence of contraindications, the majority would not prescribe it for prophylactic purposes.

CYP17 MspA1 polymorphism and risk of biliary tract cancers and gallstones: a population-based study in Shanghai, China

Biliary tract cancers, encompassing cancers of the gallbladder, extrahepatic bile duct and ampulla of Vater, are rare but highly fatal malignancies. Other than gallstones, little is known about the risk factors for biliary tract cancers. Endogenous estrogens are thought to play a role in the etiology of gallstones and gallbladder cancer, since both conditions predominate in females and are associated with parity and obesity. In view of reports linking the CYP17 MspA1 polymorphism to high circulating levels of estrogens and a predisposition to other hormonally related cancers, we examined the relationship between CYP17 MspA1 variants and risk of biliary disease in a population-based case-control study in Shanghai. The study included 446 cancer cases (254 gallbladder, 139 extrahepatic bile duct, 53 ampullary cancers), 929 biliary stone cases (691 gallbladder, 238 bile duct) and 818 population controls. Genomic DNA from peripheral blood lymphocytes was used for genotyping. Relative to those with the A2/A2 genotype, A1 carriers (A1/A1 and A1/A2 genotypes) had an increased risk of gallbladder cancer (odds ratio (OR) = 1.5, 95% confidence interval (CI) = 1.1-2.1). In addition, women with the A1 allele and high parity (> or =3) had a 3-fold risk of gallbladder cancer (OR = 3.3, 95% CI = 1.6-6.9), compared to those with the A2/A2 genotype and lower parity, with the highest risk seen for those also having biliary stones (OR = 4.6, 95% CI = 1.8-11.7, P(interaction) = 0.04). The A1 allele was not associated with a higher risk of gallstones except among those with body mass index (BMI) greater than 25 kg/m2 (OR = 3.1, 95% CI = 2.0-4.8, P(interaction) = 0.02) and among those with a history of diabetes (OR = 2.5, 95% CI = 1.4-4.3, P interaction = 0.09). No clear relation was seen between the CYP17 polymorphism and cancers of the bile duct or ampulla of Vater. The association of the CYP17 MspA1 polymorphism with an increased risk of gallbladder cancer, as well as biliary stones among overweight and diabetic individuals, suggests an interplay between genetic and hormonal risk factors in gallbladder disease.

Overexpression of estrogen receptor alpha increases hepatic cholesterogenesis, leading to biliary hypersecretion in mice

We explored whether there is an "estrogen-ERalpha-SREBP-2" (for estrogen-estrogen receptor subtype alpha-sterol-regulatory element binding protein-2) pathway for regulating hepatic cholesterol biosynthesis in ovariectomized AKR mice treated with 17beta-estradial (E2) at 6 microg/day or E2 plus the antiestrogenic agent ICI 182,780 at 125 microg/day and on chow or fed a high-cholesterol (1%) diet for 14 days. To monitor changes in cholesterol biosynthesis and newly synthesized cholesterol secreted into bile, incorporation into digitonin-precipitable sterols in mice treated with 25 mCi of [3H]water was measured in extracts of liver and extrahepatic organs 1 h later and in hepatic biles 6 h later. ERalpha upregulated SREBP-2, with resulting activation of SREBP-2-responsive genes in the cholesterol biosynthetic pathway. The E2-treated mice continued to synthesize cholesterol in spite of its excess availability from high dietary cholesterol, which reflects a loss in controlling the negative feedback regulation of cholesterol synthesis. These alterations augmented biliary cholesterol secretion and enhanced the lithogenicity of bile. However, these lithogenic effects of E2 were fully blocked by ICI 182,780. We conclude that during estrogen treatment, more newly synthesized cholesterol determined by the estrogen-ERalpha-SREBP-2 pathway is secreted into bile, leading to biliary cholesterol hypersecretion. These studies provide insights into therapeutic approaches to cholesterol gallstones in high-risk subjects, especially those exposed to high levels of estrogen.

Effect of tibolone on turnover of cholesterol to bile acids in ovariectomized rats

OBJECTIVE

Tibolone is used in breast cancer therapy in women. The most important aspect of this therapy concerns its influence on bone and lipid metabolism. Several studies have reported the effect of tibolone on plasma lipids. Approximately 40% of total cholesterol removal occurs by its conversion to bile acids, a process that takes place in the liver. The aim of the study was to evaluate the influence of tibolone on the conversion of cholesterol to bile acids in estrogen-deficient rats.

DESIGN

Thirty female Wistar rats were divided into three groups: sham-operated controls, ovariectomized controls, and ovariectomized rats treated with tibolone. After 42 days of drug administration, bile was collected under anesthesia after administration of radioactive 4-C cholesterol. Bile was assayed for total C radioactivity; C bile acids were determined after thin-layer chromatography separation by using the isotopic technique.

RESULTS

The ovariectomy decreased the concentrations of C-radioactive bile, taurocholic acid, and cholic acid. The administration of tibolone significantly increased the excretion of C-radioactive bile and C-radioactive bile acids as compared with ovariectomized controls. Moreover, the therapy with tibolone significantly increased the concentrations of C taurocholic acid, C glycocholic acid, cholic acid, and taurochenodeoxycholic plus taurodeoxycholic acids.

CONCLUSION

The results of the present study suggest that tibolone may increase the concentrations of cholesterol and trihydroxy bile acids in bile. These changes may be associated with an increased risk of gallstone generation.

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

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

Effect of tamoxifen, raloxifen and tibolon on bile components in ovariectomized rats

The aim of the study was to investigate the effect of ovariectomy on the bile composition in order to estimate the ability of selective estrogen receptor modulators (SERMS) (tibolon, tamoxifen, raloxifen) to modify the ovariectomy-induced disorders. The study was carried out on the ovariectomized female Wistar rats. Tibolon (1 mg kg(-1) 24 h(-1)), tamoxifen (5 mg kg(-1) 24 h(-1)) and raloxifen (10 mg kg(-1) 24 h(-1)) were administered for 42 days. Under anesthesia bile was collected during 6h period. The ovariectomy increased significantly the excretion of biliary acids and calcium in bile and decreased the excretion of cholesterol and chloride. In rats treated with tamoxifen and raloxifen the excretion and concentration of cholesterol in bile were significantly reduced in comparison with ovariectomized rats. In rats treated with tibolon these values were increased. Moreover in rats treated with tamoxifen and raloxifen the concentrations of calcium in bile were significantly reduced. Tibolon had no significant effect on bile calcium concentrations. The therapy with tamoxifen, raloxifen and tibolon decreased the serum cholesterol concentrations, whereas the bile acid concentrations were increased in comparison with ovariectomized control. The drugs studied had no significant effect on calcium and chloride serum concentrations. Our results suggest that the therapy with tamoxifen and raloxifen may have the positive effect on bile composition in ovariectomized rats and probably may prevent the gallstone formation.

Safety and adverse effects associated with raloxifene: multiple outcomes of raloxifene evaluation

OBJECTIVE

To examine the effect of raloxifene on major adverse events that occur with postmenopausal estrogen therapy or tamoxifen.

METHODS

The Multiple Outcomes of Raloxifene Evaluation, a multicenter, randomized, double-blind trial, enrolled 7,705 postmenopausal women with osteoporosis. Women were randomly assigned to raloxifene 60 mg/d or 120 mg/d or placebo. Outcomes included venous thromboembolism, cataracts, gallbladder disease, and endometrial hyperplasia or cancer.

RESULTS

During a mean follow-up of 3.3 years, raloxifene was associated with an increased risk for venous thromboembolism (relative risk [RR] 2.1; 95% confidence interval [CI] 1.2-3.8). The excess event rate was 1.8 per 1,000 woman-years (95% CI -0.5-4.1), and the number needed to treat to cause 1 event was 170 (95% CI 100-582) over 3.3 years. Risk in the raloxifene group was higher than in the placebo group for the first 2 years, but decreased to about the same rate as in the placebo group thereafter. Raloxifene did not increase risk for cataracts (RR 0.9; 95% CI 0.8-1.1), gallbladder disease (RR 1.0; 95% CI 0.7-1.3), endometrial hyperplasia (RR 1.3; 95% CI 0.4-5.1), or endometrial cancer (RR 0.9; 95% CI 0.3-2.7).

CONCLUSION

Raloxifene was associated with an increased risk for venous thromboembolism, but there was no increased risk for cataracts, gallbladder disease, endometrial hyperplasia, or endometrial cancer.

LEVEL OF EVIDENCE

I

Estrogen receptor alpha, but not beta, plays a major role in 17beta-estradiol-induced murine cholesterol gallstones

BACKGROUND & AIMS

Cholesterol gallstones are more common in women than men, and exposure to oral contraceptive steroids and conjugated estrogens increases the risk for gallstones. It is hypothesized that estrogen enhances cholesterol cholelithogenesis by augmenting functions of hepatic estrogen receptors (ERs).

METHODS

To investigate molecular mechanisms of how estrogen influences cholesterol gallstones, we studied gonadectomized AKR/J mice of both genders that were implanted subcutaneously with pellets releasing 17beta-estradiol at 0, 3, or 6 microg/day and that were fed a lithogenic diet for 12 weeks. To test the hypothesis that ERs play a pivotal role in mediating lithogenic actions of estrogen and to dissect the potential pathophysiologic roles of each receptor subtype, ERalpha and ERbeta, in the formation of gallstones, we investigated gonadectomized mice treated with synthetic ER subtype-selective agonists or antagonists.

RESULTS

17beta-estradiol promoted gallstone formation by up-regulating hepatic expression of ERalpha but not ERbeta, and the lithogenic actions of estrogen can be blocked completely by the antiestrogenic ICI 182,780. The ERalpha-selective agonist propylpyrazole, but not the ERbeta-selective agonist diarylpropionitrile, augmented hepatic cholesterol output that resulted in cholesterol supersaturated bile and gallstones. Similar to the 17beta-estradiol treatment, tamoxifen significantly increased biliary cholesterol secretion and gallstone prevalence in both gonadectomized females and males.

CONCLUSIONS

The hepatic ERalpha, but not ERbeta, plays a critical role in 17beta-estradiol-induced cholesterol gallstones. Our findings may offer a new approach to treat gallstones by inhibiting hepatic ER activity with a liver-specific, ERalpha-selective antagonist.

Benefits and harms associated with hormone replacement therapy: clinical decision analysis

OBJECTIVE

To evaluate harms and benefits associated with use of combined hormone replacement therapy (HRT) for five years in women with different baseline risks for breast cancer.

DESIGN

Probabilistic clinical decision analysis.

SETTING

Hypothetical population of white UK women aged 50 years with different baseline risks for breast cancer.

MAIN OUTCOME MEASURE

Gain or loss in quality adjusted life years (QALYs).

RESULTS

Women free of menopausal symptoms showed a net harm from HRT use, which increased for increasing baseline risk of breast cancer. Those with a baseline risk of 1.2% would expect a loss in QALYs of 0.4 months (- 0.03 QALYs, 95% credibility interval - 0.05 to - 0.01). The main analysis showed HRT to be on average beneficial in women with symptoms, with benefit decreasing with increasing baseline risk of breast cancer. The results were sensitive to the assumed value of quality of life with menopausal symptoms, therefore a contour plot was developed to show the probability of net harm for a range of different values and baseline risks.

CONCLUSIONS

HRT for primary prevention of chronic diseases in women without menopausal symptoms is unjustified. Perceived quality of life in women with symptoms should be taken into account when deciding on HRT. Thus, a decision analysis tailored to an individual woman is more appropriate in clinical practice than a population based approach.

Postmenopausal hormone therapy: a concise guide to therapeutic uses, formulations, risks, and alternatives

Postmenopausal hormone replacement therapy is helpful in relieving menopausal vasomotor symptoms and vaginal atrophy and can prevent osteoporosis; however, attendant risks include breast cancer, thromboembolism, gallbladder disease, stroke, CHD, dementia, and hypertriglyceridemia. Decision making must weigh these risks and benefits and also include potential benefits on mood, colorectal cancer prevention, and hip fracture reduction. Some areas, such as ovarian cancer risk and the impact of combination estrogen-progestin versus unopposed estrogen on risk, remain unclear. The physician and patient need to carefully assess, discuss, and monitor the individual's symptoms and risks when considering HT use. For those with contraindications or concerns about HT, there are alternative therapies of variable efficacy for vasomotor symptoms and vaginal atrophy.

Hormone replacement therapy and cancer risk: a systematic analysis from a network of case-control studies

To provide comprehensive and quantitative information on the benefits and risks of hormone replacement therapy (HRT) on several cancer sites, we systematically examined the relation between HRT use and the risk of various cancers in women aged 45-79 by using data from a framework of case-control studies conducted in Italy between 1983 and 1999. The overall data set included the following incident, histologically confirmed neoplasms: oral cavity, pharynx, larynx and esophagus (n = 253), stomach (n = 258), colon (n = 886), rectum (n = 488), liver (n = 105), gallbladder (n = 31), pancreas (n = 122), breast (n = 4,713), endometrium (n = 704), ovary (n = 1,614), urinary bladder (n = 106), kidney (n = 102), thyroid (n = 65), Hodgkin's disease (n = 26), non-Hodgkin's lymphomas (n = 145), multiple myeloma (n = 65) and sarcomas (n = 78). The control group comprised 6,976 women aged 45-79 years, admitted for a wide spectrum of acute, nonneoplastic conditions. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) for use of HRT were derived from multiple logistic regression equations. There was an inverse association between ever use of HRT and colon (OR = 0.7), rectum (OR = 0.5) and liver cancer (OR = 0.2), with a consistent pattern of protection for duration of use. An excess risk was found for gallbladder (OR = 3.2), breast (OR = 1.1), endometrial (OR = 3.0) and urinary bladder cancer (OR = 2.0). These data from a southern European population add some useful information on the risk-benefit assessment of HRT among postmenopausal women.

Estradiol and norgestimate: a review of their combined use as hormone replacement therapy in postmenopausal women

The focus of this review is hormone replacement therapy (HRT) with continuous administration of micronised, oral 17beta-estradiol 1 mg/day (herein referred to as continuous estradiol) plus micronised, oral norgestimate 90 microg/day administered for 3 days then withdrawn for 3 days in a 6-day repeating sequence (herein referred to as intermittent norgestimate). According to data from randomised, comparative trials of 1 year's duration, continuous estradiol 1 mg/day plus intermittent norgestimate 90 microg/day relieves climacteric symptoms (vasomotor symptoms and vulvovaginal atrophy) in postmenopausal women. Continuous estradiol 1 mg/day plus intermittent norgestimate 90 microg/day appeared as effective as estradiol 1 mg/day alone or continuous estradiol 2 mg/day plus continuous norethisterone acetate 1 mg/day in the treatment of postmenopausal women with vasomotor symptoms. Continuous estradiol 1 mg/day plus intermittent norgestimate 90 microg/day was as effective as continuous estradiol 1 mg/day in causing the maturation of vaginal epithelial cells. In a randomised, double-blind study, bone mineral density (BMD) increased to a significantly greater extent and the rate of bone turnover was slower in postmenopausal women treated with continuous oral estradiol 1 mg/day plus intermittent norgestimate 90 microg/day than in placebo-treated patients. Two randomised, double-blind studies indicated that the addition of norgestimate 90 microg/day to continuous estradiol 1 mg/day did not attenuate the beneficial effects of estradiol on lipid parameters. Continuous estradiol 1 mg/day plus intermittent norgestimate 90 microg/day was associated with increases in mean serum high density lipoprotein (HDL)-cholesterol levels and decreases in total cholesterol, low density lipoprotein (LDL)-cholesterol and lipoprotein (a) levels, compared with baseline. There was no statistically significant increase in triglyceride levels. In comparative trials, continuous oral estradiol 1 mg/day plus intermittent oral norgestimate 90 microg/day was well tolerated. Headache, breast pain or discomfort, abdominal pain or discomfort, uterine bleeding, dysmenorrhoea, oedema, nausea and depression were the most commonly reported adverse events. Continuous estradiol 1 mg/day plus intermittent oral norgestimate 90 microg/day was associated with a favourable uterine bleeding profile that improved over time. In a randomised trial, 80% of women were free from bleeding (irrespective of spotting) during month 12 of treatment. Norgestimate 90 microg/day was effective in protecting postmenopausal women against induction of endometrial hyperplasia by continuous estradiol 1 mg/day. In conclusion, data from a limited number of randomised studies indicate that HRT with continuous estradiol 1 mg/day plus intermittent norgestimate 90 microg/day is effective in relieving climacteric symptoms, increasing BMD and slowing the rate of bone turnover in postmenopausal women. This HRT regimen is well tolerated and is associated with a similar incidence of adverse events to that reported in recipients of continuous estradiol 1 mg/day. The norgestimate component of the regimen provides good endometrial protection and is associated with a favourable bleeding profile. Long-term studies investigating the associated risk of breast cancer and thromboembolic events in recipients of continuous estradiol plus intermittent norgestimate are needed. In the meantime, continuous oral estradiol plus intermittent oral norgestimate can be regarded as an effective new option for HRT in postmenopausal women.