Increased risk of cholecystectomy in users of supplemental estrogen

Relationship of triglyceride-glucose index to gallstone prevalence and age at first gallstone surgery in American adults

The triglyceride-glucose (TyG) index is a novel marker of insulin resistance that has been strongly associated with many diseases related to metabolic disorders, such as diabetes, coronary heart disease, myocardial infarction, obesity, nonalcoholic fatty liver disease, and stroke. However, whether the TyG index is associated with the prevalence of gallstones has not been determined. Therefore, the purpose of this study was to evaluate the relationship between the TyG index and the prevalence of gallstones in American adults, as well as the age at which adults in America undergo their first gallstone surgery. We selected individuals from the National Health and Nutrition Examination Survey (NHANES) database from 2017 to March 2020. Based on the goal of our study, comprehensive inclusion and exclusion criteria were created. A logistic regression analysis, dose-response curve, and subgroup analysis were computed to assess the relationship between the TyG index and gallstone prevalence and age at first surgery for gallstone. A total of 3905 participants aged > 20 years were included in our study, of whom 421 had a self-reported history of gallstones. A total of 1884 (48.2%) males and 2021 (51.8%) females were included. After confounders adjustment, it was found single-unit increases in the TyG index were linked with a 25.0% increase in gallstone prevalence (odds ratio [OR] = 1.25, 95% confidence interval [95%CI]: 1.04, 1.51). After conversion of the TyG index values from continuous to categorical variables with tertiles, a marked 48% increase in gallstone incidence was found in tertile 3 relative to tertile 1 (OR = 1.48, 95% CI: 1.09, 1.99). The dose-response curve results indicated positive associations between gallstone prevalence and the TyG index, while the latter was negatively associated with age at first gallstone surgery. Based on subgroup analysis, the positive association between TyG index and high-incidence of gallstones was more significant in females (OR = 1.39, 95% CI: 1.09, 1.77), age < 40 years (OR = 2.02, 95% CI: 1.23, 3.29), and other race (OR = 1.46, 95% CI: 1.06, 2.02). A higher TyG index is associated with a higher incidence of gallstones and may lead to an earlier age of first gallstone surgery. However, a causal relationship between TyG and gallstones cannot be established.

Individual and joint associations of per- and polyfluoroalkyl substances (PFAS) with gallstone disease in adults: A cross-sectional study

Disturbances in the enterohepatic circulation are important biological mechanisms for causing gallstones and also have important effects on the metabolism of Per- and polyfluoroalkyl substances (PFAS). Moreover, PFAS is associated with sex hormone disorder which is another important cause of gallstones. However, it remains unclear whether PFAS is associated with gallstones. In this study, we used logistic regression, restricted cubic spline (RCS), quantile g-computation (qg-comp), Bayesian kernel machine regression (BKMR), and subgroup analysis to assess the individual and joint associations of PFAS with gallstones and effect modifiers. We observed that the individual associations of perfluorodecanoic acid (PFDeA) (OR: 0.600, 95% CI: 0.444 to 0.811), perfluoroundecanoic acid (PFUA) (OR: 0.630, 95% CI: 0.453 to 0.877), n-perfluorooctane sulfonic acid (n-PFOS) (OR: 0.719, 95% CI: 0.571 to 0.906), and perfluoromethylheptane sulfonic acid isomers (Sm-PFOS) (OR: 0.768, 95% CI: 0.602 to 0.981) with gallstones were linearly negative. Qg-comp showed that the PFAS mixture (OR: 0.777, 95% CI: 0.514 to 1.175) was negatively associated with gallstones, but the difference was not statistically significant, and PFDeA had the highest negative association. Moreover, smoking modified the association of perfluorononanoic acid (PFNA) with gallstones. BKMR showed that PFDeA, PFNA, and PFUA had the highest groupPIP (groupPIP = 0.93); PFDeA (condPIP = 0.82), n-perfluorooctanoic acid (n-PFOA) (condPIP = 0.68), and n-PFOS (condPIP = 0.56) also had high condPIPs. Compared with the median level, the joint association of the PFAS mixture with gallstones showed a negative trend; when the PFAS mixture level was at the 70th percentile or higher, they were negatively associated with gallstones. Meanwhile, when other PFAS were fixed at the 25th, 50th, and 75th percentiles, PFDeA had negative associations with gallstones. Our evidence emphasizes that PFAS is negatively associated with gallstones, and more studies are needed in the future to definite the associations of PFAS with gallstones and explore the underlying biological mechanisms.

Association with menopausal hormone therapy and asymptomatic gallstones in US women in the third National Health and Nutrition Examination Study

15% of US adults have gallstones, most of which are clinically "silent". Several studies show that menopausal hormone therapy (MHT) increases symptomatic gallstones and cholecystectomy risk. MHT use may be contraindicated in women with gallstones and population studies may be biased by "confounding by contraindication" while the true association between MHT and gallstones remains underestimated. We sought to examine whether MHT use was associated with asymptomatic gallstones using instrumental variable (IV) analysis to account for confounding by contraindication. We used 2018 postmenopausal women from the Third National Health and Nutrition Examination Survey to estimate associations of MHT use with asymptomatic gallstones. A traditional logistic regression analysis was compared to instrumental variable (IV) analysis to account for confounding by contraindication. 12% of women with asymptomatic gallstones and 25% of women without gallstones were current MHT users (P < 0.001). The traditional analysis suggested a decreased odds of asymptomatic gallstones in current versus never users (OR 0.58, 95% CI 0.37, 0.89), but increased odds (OR 1.51, 95% CI 0.44, 5.16) in the IV analysis. The traditional analysis consistently underestimated the odds of asymptomatic gallstones with MHT use compared to the IV analysis. Accounting for confounding by contraindication, we found a suggestive, though imprecise, positive association between MHT use and asymptomatic gallstones among postmenopausal women. Failure to consider contraindication can produce incorrect results.

Factors Influencing Gallstone Formation: A Review of the Literature

Gallstone disease is a common pathology of the digestive system with nearly a 10–20% incidence rate among adults. The mainstay of treatment is cholecystectomy, which is commonly associated with physical pain and may also seriously affect a patient’s quality of life. Clinical research suggests that cholelithiasis is closely related to the age, gender, body mass index, and other basic physical characteristics of patients. Clinical research further suggests that the occurrence of cholelithiasis is related to obesity, diabetes, non-alcoholic fatty liver, and other diseases. For this reason, we reviewed the following: genetic factors; excessive liver cholesterol secretion (causing cholesterol supersaturation in gallbladder bile); accelerated growth of cholesterol crystals and solid cholesterol crystals; gallbladder motility impairment; and cardiovascular factors. Herein, we summarize and analyze the causes and mechanisms of cholelithiasis, discuss its correlation with the pathogenesis of related diseases, and discuss possible mechanisms.

Estrogen and its role in gastrointestinal health and disease

INTRODUCTION

While the concept of a role of estrogen in gastrointestinal (in particular, colonic) malignancy has generated excitement in recent years, no review has examined the role of this potent and omnipresent steroid hormone in physiological states or its contribution to the development of benign pathological processes. Understanding these effects (and mechanisms therein) may provide a platform for a deeper understanding of more complex disease processes.

METHODS

A literature search was conducted using the PubMed database and the search terms were "estrogen," "estrogen AND gastrointestinal tract," "estrogen AND colon," "estrogen AND esophagus," "estrogen AND small intestine," "estrogen AND stomach," "estrogen AND gallbladder," and "estrogen AND motility." Bibliographies of extracted studies were further cross-referenced. In all, 136 full-text articles were selected for review. A logical organ-based approach was taken to enable extraction of data of clinical relevance and meaningful interpretation thereof. Insight is provided into the hypotheses, theories, controversies, and contradictions generated over the last five decades by extensive investigation of estrogen in human, animal, and cell models using techniques as diverse as autoradiographic studies of baboons to human population analysis.

CONCLUSIONS

Effects from esophagus through to the colon and rectum are summarized in this first concise collection of data pertaining to estrogenic actions in gastrointestinal health and disease. Mechanisms of these actions are discussed where possible. Undoubtedly, this hormone exerts many actions yet to be elucidated, and its potential therapeutic applications remain, as yet, largely unexplored.

The prevalence and risk factors for gallstone disease

Gallstone disease is one of the most prevalent gastrointestinal disorders. In addition, the costs associated with the diagnosis and treatment of gallstone disease have been rapidly increasing. The etiology and pathogenesis of gallstone disease remains incompletely understood. Gallstone formation may result from a complex interaction of genetic and environmental factors. This article reviews the prevalence and risk factors associated with gallstone disease. Understanding the pathogenesis of gallstone disease could lead to the development of better therapeutic and preventive strategies for dealing with this disease.

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.

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.

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.

Cholecystectomy and endometrial cancer: a marker of long-term elevated estrogen exposure?

Excess hormones, both endogenous and exogenous, are implicated in the etiology of endometrial cancer. We considered whether having had gallstones or a cholecystectomy (surgery to remove the gallbladder), which are more common in women who are obese and who use exogenous hormones, might be a marker for high lifetime levels of estrogen. We conducted a population-based study of endometrial cancer cases and community controls in women aged 40-79 years. Participants completed an interviewer-administered questionnaire that elicited exposures prior to diagnosis or reference date, including history of gallstones and cholecystectomy, as well as reproductive history, lifetime body mass, smoking, postmenopausal hormone (PMH) use, and other risk factors. Compared to controls, cholecystectomy was associated with a 50% increased risk of developing endometrial cancer (odds ratio = 1.5 [1.1-2.0]). The relationship appeared to depend upon PMH user status; the association was observed only among never hormone users. Body mass index did not appear to modify this relationship. Having a diagnosis of gallstones was also associated with endometrial cancer, although to a lesser magnitude. Although other etiologic factors may play a role in the relation between cholecystectomy and endometrial cancer, the current analysis suggests that this association is attributable, at least in part, to the sharing of hormonal risk factors.

Is there a link between oestrogen therapy and gallbladder disease?

Cholelithiasis is the most common form of benign gallbladder disease that results in major heath expenditure. Female sex hormones are causally related to cholesterol gallstone disease, which are more common in women than in men. The risk of development of cholelithiasis is further enhanced by the use of exogenous female sex hormones and by pregnancy. Oestrogens are used in oral contraceptives and in hormone replacement therapy (HRT). Oral contraceptives do not pose a greater risk for gallbladder disease. The findings from two randomised, controlled trials, the Heart and Oestrogen/Progestin Replacement Study and the Women's Health Initiative postmenopausal hormone trial, unequivocally confirm that oral oestrogen use in postmenopausal women is causally associated with gallbladder disease, and the magnitude of the effect is not influenced greatly by the presence or absence of progestins. A cautious approach should be observed when prescribing HRT. Women must be informed about the effect of oestrogen use on increased risk of benign gallbladder disease. HRT should be used in the lowest possible dose for the shortest possible time. Women harbouring asymptomatic gallstones should not receive oestrogens because of the possibility of developing cholecystitis.

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.

Hormone replacement therapy in postmenopausal women

BACKGROUND

For many years, hormone replacement therapy (HRT) was considered an effective method of restoring the relative protection from coronary artery disease enjoyed by premenopausal women compared with men of similar age. This view has been supported by a substantial number of basic science and observational studies.

DATA SOURCES

Results of recent randomized controlled trials have seriously challenged the concept of the protective value of HRT by showing that rather than decreasing the risk of coronary artery disease, HRT actually appears to increase it. In addition, it increases the risk for breast cancer, stroke, venous thromboembolism, and cholecystitis.

RESULTS

Despite some benefits such as increased bone mineral density and decreased risk of fracture and colorectal cancer, these data suggest that the risks of HRT outweigh the benefits.

CONCLUSIONS

HRT is no longer routinely recommended for prevention of chronic disease. We present the current scientific data, benefits, risks, and consequent clinical recommendations regarding HRT use in postmenopausal women.

The medicalization of menopause: critique and consequences

Menopause is in the process of becoming medicalized. Midlife and older women are being told that natural menopause is actually a deficiency condition requiring replacement hormones to maintain health and increase longevity. The three major diseases that are being linked with the lower estrogen levels of midlife and older women are heart disease, osteoporosis and, most recently, Alzheimer's disease. Primary prevention of these diseases is the rationale used for urging healthy women to take long-term hormones. Although there have been many challenges to these links and warnings against the widespread use of hormones, they have been either ignored or trivialized. In this article, the author examines mortality and morbidity statistics across and within nations and over time, critiques the major arguments used to support the notion that menopause places women at an increased risk of disease and that exogenous hormones reduce this risk, and discusses the adverse consequences of defining all midlife and older women as hormonally deficient and in need of medical intervention.

Estrogens, selective estrogen receptor modulators, and dementia: what is the evidence?

At least 10% of people aged 65 or older have some form of cognitive impairment, increasing to around 50% by age 85. Several studies have suggested that estrogen may improve cognitive function or prevent the development of dementia, but other studies have not shown a benefit, and results from large randomized trials are lacking. Fortunately, further trials are currently being conducted. With the recognition that selective estrogen receptor modulators (SERMs) have differential tissue-dependent effects on estrogen receptor function, there is recent interest in the effects of raloxifene, tamoxifen, and other SERMs on cognition. In this paper, the current state of knowledge of the role of estrogen for preventing dementia in postmenopausal women will be reviewed. In addition, the status of ongoing and recently completed trials of estrogen and SERMs on cognitive function or on Alzheimer's disease severity will be summarized.

The use of hormone replacement therapy in postmenopausal women with type 2 diabetes

In healthy postmenopausal women, estrogen or hormone replacement therapy (ERT or HRT) can alleviate menopausal symptoms and prevent osteoporosis and may also protect against cardiovascular disease (CVD). In addition to improving lipid metabolism, there are reports that estrogen also improves parameters regulating carbohydrate metabolism, including insulin resistance, in healthy women. Therefore, it is likely that ERT or HRT would also benefit women with type 2 diabetes, not only in relieving menopausal symptoms but also in improving the metabolic abnormalities associated with diabetes and in preventing cardiovascular disease.

Role of estrogens in the management of postmenopausal bone loss

It is well known that estrogen deficiency is the major determinant of bone loss in postmenopausal women. Estrogen is important to the bone remodeling process through direct and indirect actions on bone cells. The largest clinical experience exists with estrogen therapy, demonstrating its successful prevention of osteoporosis as well as its positive influence on oral bone health, vasomotor and urogenital symptoms, and cardiovascular risk factors, which may not occur with other nonestrogen-based treatments. Compliance with HRT, however, is typically poor because of the potential side effects and possible increased risk of breast or endometrial cancer. Nevertheless, there is now evidence that lower doses of estrogens in elderly women may prevent bone loss while minimizing the side effects seen with higher doses of estrogen. Additionally, when adequate calcium, vitamin D, and exercise are used in combination with estrogen-based treatments, more positive increases occur in bone density. The benefits and risks of HRT must be assessed on a case-by-case basis, and the decision to use HRT is a matter for each patient in consultation with her physician. Estrogen-based therapy remains the treatment of choice for the prevention of osteoporosis in most postmenopausal women, and there may be a role for estrogen to play in the prevention of corticosteroid osteoporosis. Combination therapies using estrogen should probably be reserved for patients who continue to fracture on single therapy or should be used in patients who present initially with severe osteoporosis.

Cardioprotective benefits of hormone replacement therapy

PURPOSE

To examine the effect of hormone replacement therapy (HRT) on adverse cardiac events in postmenopausal women.

DATA SOURCES

A systematic review of all available scientific literature (513 articles) on the cardioprotective benefits of HRT, including research reports, meta-analyses, and commentaries.

CONCLUSIONS

Epidemiological studies have consistently suggested that HRT administered to postmenopausal women significantly lowers the risks of cardiovascular events. However, the claimed benefits might have been exaggerated. The results of the only large randomized clinical trial did not show similar benefits as those reported from observational studies. Research findings about cardiovascular protection of HRT remain inconclusive.

IMPLICATIONS FOR PRACTICE

While waiting for more definitive data, it is appropriate to consider other options that have been proven safe and effective in the prevention of cardiovascular disease.

Myocardial infarction and acute cholecystitis: an application of sequence symmetry analysis

Using a statewide hospital discharge database and a novel epidemiology method, sequence symmetry analysis (Epidemiology. 1996;7:478-84), I examined the relative risk for hospital admission for acute cholecystitis after admission for myocardial infarction. In sequence symmetry analysis, the ratio of the number of subjects in a fixed population who experienced two events in a "causal" vs "noncausal" temporal sequence estimates the incidence rate ratio (IRR). Of 514 patients admitted for both myocardial infarction and acute cholecystitis during a 3-year window period, 295 were admitted for myocardial infarction first and 219 for acute cholecystitis first, yielding a null sequence-adjusted IRR of 1.45 [95% confidence interval (CI) = 1.28-1.64]. A similar analysis for a known relation (myocardial infarction-->congestive heart failure, N = 27,850) showed the expected association [adjusted IRR = 1.92 (95% CI = 1.88-1.95)], whereas an analysis for a relation hypothesized not to be strong (congestive heart failure-->acute cholecystitis, N = 775) showed only a small association [adjusted IRR = 1.16 (95% CI = 1.05-1.28)]. Subgroup analysis revealed time courses that supported each relation as causal. Hospitalization for myocardial infarction may increase the risk for subsequent hospitalization for acute cholecystitis.

Prescribing hormone replacement therapy for menopausal symptoms

This paper addresses the clinical presentation of menopause, pretreatment assessment for hormone replacement therapy, benefits and risks of this treatment, common hormone replacement regimens and their side effects, and patient management. The case-based discussion focuses on the clinical management of a patient who is considering hormone replacement therapy for menopausal symptoms.

Hormone and nonhormone therapy for the maintenance of postmenopausal health: the need for randomized controlled trials of estrogen and raloxifene

Multiple health benefits have been postulated for the long-term use of hormone therapy in postmenopausal women, most notably for prevention of osteoporotic fractures and coronary heart disease, as well as several risks, including cancer of the breast and uterus and venous thromboembolism. Cardiovascular disease is the most common cause of death among postmenopausal women. If real, the reduction in risk of coronary heart disease by hormone use suggested by observational studies would likely outweigh the risks. The decision to initiate and maintain hormone therapy is complicated by uncertainties about estrogen's true benefits and risks. Raloxifene, a selective estrogen receptor modulator (SERM), appears to have many of the benefits of estrogen without the cancer risks. It is not known if SERMs can provide significant cardiovascular protection. This article reviews the relation of use of postmenopausal hormones and raloxifene to women's health and addresses the need for large randomized trials to quantify the effect of both postmenopausal estrogen and raloxifene on cardiovascular health.

Hormone replacement therapy, heart disease, and other considerations

Multiple observational studies suggest a marked reduction in risk of coronary heart disease (CHD) associated with postmenopausal estrogen use. A new meta-analysis presented here extends these results to estrogen plus progestin regimens. Although the findings from observational studies are strong and consistent, and there are several plausible mechanisms by which estrogen might reduce risk for CHD, most of the known biases would tend to exaggerate estrogen's benefit. Further, estrogen therapy clearly increases risk for endometrial hyperplasia and cancer, venous thromboembolic events and gallbladder disease, and long-term use probably also increases the risk of breast cancer. Therefore, until findings from randomized trials confirm and quantitate the benefit of estrogen therapy for prevention of CHD, we believe it should not be recommended to all postmenopausal women.

New developments in topical estrogen therapy

OBJECTIVE

To review new developments in transdermal E2 therapy in postmenopausal women.

DESIGN

A bibliographic search (Medline) of the medical literature from 1966 through 1995 was used to identify new studies evaluating transdermal E2.

PATIENT(S)

Menopausal and postmenopausal women.

RESULT(S)

Like oral estrogen, transdermal E2 relieves menopausal symptoms, reverses urogenital atrophy, and conserves bone economy. Initial studies have demonstrated beneficial effects of transdermal E2 on cardiovascular function. Quality of life, patient satisfaction, and compliance also improve with transdermal E2. Advances in transdermal delivery continue to emerge, including low-dose systems and patches that maintain serum E2 levels for a full 7-day period.

CONCLUSION(S)

New developments in transdermal administration have the potential to increase the number of postmenopausal women who accept and are compliant with long-term estrogen replacement therapy.

Menorest: technical development and pharmacokinetic profile

Transdermal application of oestradiol enables the use of lower doses than with the oral drug and avoids first-pass metabolism in the liver. First-generation transdermal delivery systems were of reservoir design. Menorest is one of a new generation of patches, in which oestradiol is dispersed in a micronized suspension throughout the adhesive matrix. This design results in a very thin patch with good cosmetic acceptability. Pharmacokinetic studies indicate that Menorest allows transdermal release of oestradiol at a constant and reproducible rate at doses from 25-100 micrograms/day. There is a linear relationship between the dose of oestradiol administered (which is determined by the surface area of the patch) and the plasma concentration of oestradiol. In contrast to the standard reference reservoir patch, Estraderm, Menorest maintains plasma oestradiol concentrations at or above the target level of 40 pg/ml throughout the 84-h dosing interval.

Relative value of transdermal and oral estrogen therapy in various clinical situations

OBJECTIVE

In this study, we reviewed the comparative effectiveness of transdermal and oral estrogen therapy in various groups of women.

DESIGN

On the basis of published data and personal clinical experience, we compiled recommendations for use of the various modes of estrogen replacement therapy.

MATERIAL AND METHODS

The use of injectable estrogen or implantable estrogen pellets can no longer be recommended because of their expense, inconvenience, and unphysiologic pattern of serum estrogen response. The two main estrogen preparations currently used in the United States--orally administered conjugated estrogens and transdermally administered estradiol--undergo different metabolism, and these processes are reflected in differing levels of circulating hormones and hepatic by-products, including blood clotting factors, binding proteins, renin substrate, and apolipoproteins, and in varied composition of the bile.

RESULTS

At least theoretically, transdermal estrogen therapy might be more beneficial than oral estrogen therapy for women who smoke cigarettes or who have migraine headaches, hypertriglyceridemia, hepatobiliary disorders, fibrocystic breast disease, or a history of thromboembolism. In contrast, women with hypercholesterolemia might respond better to oral than to transdermal estrogen therapy.

CONCLUSION

Additional properly designed clinical studies are necessary before these recommendations for estrogen replacement therapy can be validated or refuted.

Postmenopausal hormone replacement therapy--clinical implications

The menopause is defined as cessation of menstruation, ending the fertile period. The hormonal changes are a decrease in progesterone level, followed by a marked decrease in estrogen production. Symptoms associated with these hormonal changes may advocate for hormonal replacement therapy. This review is based on the English-language literature on the effect of estrogen therapy and estrogen plus progestin therapy on postmenopausal women. The advantages of hormone replacement therapy are regulation of dysfunctional uterine bleeding, relief of hot flushes, and prevention of atrophic changes in the urogenital tract. Women at risk of osteoporosis will benefit from hormone replacement therapy. The treatment should start as soon after menopause as possible and it is possible that it should be maintained for life. The treatment may be supplemented with extra calcium intake, vitamin D, and maybe calcitonin. Physical activity should be promoted, and cigarette smoking reduced if possible. Women at risk of cardiovascular disease will also benefit from hormone replacement therapy. There is overwhelming evidence that hormone therapy will protect against both coronary heart disease and stroke, and there is no increased risk of venous thrombosis or hypertension. A disadvantage of hormone replacement therapy is an increased risk of forming gall-bladder stones and undergoing cholecystectomy. Unopposed estrogen therapy gives a higher incidence of endometrial cancer in women with an intact uterus, but the contribution of progestins for about 10 days every month excludes this risk. Breast cancer in relation to estrogen-progestogen therapy has been given much concern, and the problem is still not fully solved. If there is a risk, it is small, and only after prolonged use of estrogen (15-20 years). The decision whether or not to use hormone replacement therapy should, of course, be taken by the individual woman in question, but her decision should be based on the available scientific information. It is the opinion of the authors that the advantages of hormone replacement therapy far exceed the disadvantages. We suggest that every woman showing any signs of hormone deprivation should be treated with hormone replacement therapy. This includes women with subjective or objective vaso-motor symptoms, genito-urinary symptoms, women at risk of osteoporosis (fast bone losers), and women at risk of cardiovascular diseases.

Long-term hormone replacement treatment in menopause: new choices, old apprehensions, recent findings

In recent years there has been an increase in the use of parenteral oestradiol as an alternative to the conventional oral preparations used in hormone replacement treatment (HRT) in menopause, such as conjugated equine oestrogens (CEE). The latter have been subject in the past to apprehensions, partly due to misunderstanding and oversimplification but also in relation to problems that have arisen during the history of HRT, for example the increase in endometrial cancer risk deriving from the use of non-progestogen-opposed treatment. However, confidence in long-term HRT comes from the epidemiological findings, which refer mainly to the use of oral CEE unopposed by progestogen: a reduced risk of osteoporotic fractures and of cardiovascular disease, and a very limited risk of breast cancer. Oral oestrogens produce marked hepatocellular effects. These effects are, on the whole, favourable from the point of view of cardiovascular risk. In addition, it cannot be excluded that some hepatocellular effects of oral oestrogen, for example increased sex hormone binding globulin levels and reduced circulating insulin-like growth factor I activity, offer protection to the breast. As progestogen supplementation is needed in non-hysterectomized women, priority should be given to preparations, such as progesterone or dydrogesterone, that feature good endometrial activity without opposing oestrogen hepatocellular effects.

Influence of oral contraceptives on fasting gallbladder volume

A total of 615 healthy fertile women (518 pill users and 97 non-users) were examined by real-time ultrasonography for fasting gallbladder volume, gallstones and biliary dysmorphism. None of the six examined combinations of oral contraceptives appeared to influence fasting gallbladder volume significantly. When fasting gallbladder volumes were reanalyzed according to the presence or absence of recognized biliary risk factors, significant modifications were detected, in both pill users and non-users. These changes related only to age and parity. Relative risks of cholelithiasis and biliary dysmorphism were not affected by contraceptive treatment.

A meta-analysis of cholecystectomy and risk of colorectal cancer

BACKGROUND

Over 60 studies have addressed the hypothesis that the risk of colorectal cancer is increased following cholecystectomy; these studies have yielded inconsistent findings. The aim of the present study was to quantitatively summarize the results from the collective studies.

METHODS

A meta-analysis of the published studies addressing the relation between cholecystectomy and colorectal cancer was conducted.

RESULTS

The combined results from 33 case-control studies showed an association between cholecystectomy and risk of colorectal cancer (pooled relative risk [RR] = 1.34; 95% confidence interval [CI] = 1.14-1.57), particularly when limited to the proximal colon (RR = 1.88; 95% CI = 1.54-2.30). In most studies, the risk was stronger when the first 5-15 years following the surgery were excluded. The results from 6 cohort studies, with follow-up to approximately 15 years postcholecystectomy, were generally null (RR = 0.97; 95% CI = 0.82-1.14). A more limited body of evidence suggests that cholelithiasis is related to an elevated risk of proximal colon cancer.

CONCLUSIONS

Because the risks varied substantially by study design and because time since cholecystectomy or potentially confounding factors were often not considered, we could not firmly quantitate this risk. However, the findings are consistent with other evidence that suggests some characteristic of bile acid metabolism increases the risk of cancer of the proximal colon.

Physicians' views on hormone therapy around and after menopause

Estrogens and progestins are commonly and increasingly used during and after menopause. We studied Finnish physicians' views of this hormone therapy based on their specialty. A questionnaire was sent to a stratified random sample of gynecologists, internists, general practitioners and nonspecialists (n = 500; response rate 74%). Reported prescription habits and opinions concerning benefits and harms of hormones were asked and compared to current literature. Combined therapy was much more popular than was estrogen alone. One fourth of the physicians said hormones should be preventively given to all or to all those at risk for osteoporosis. Long therapies were accepted by many and for our patient cases hormones were recommended much more commonly than were other medical therapies. Most considered prevention of osteoporosis to be a benefit of combined therapy, but opinions of other benefits and harms varied. Gynecologists had the most favourable opinions and most of them considered hormone therapy very useful; the other physicians' opinions were characterized by uncertainties about hormone therapy and its long term effects.

Different hepatobiliary effects of oral and transdermal estradiol in postmenopausal women

Estrogen-replacement therapy is important for the prevention of postmenopausal osteoporosis. However, oral synthetic and conjugated estrogens increase biliary cholesterol saturation index and risk of gallstone disease. To examine whether transdermal estrogen administration could avoid these adverse effects, 17 postmenopausal women were treated with transdermal estradiol (Estraderm TTS; Ciba-Geigy, Arnhem, The Netherlands), 100 micrograms/day for 4 weeks, and after 1 month without therapy, with oral estradiol (Progynova; Schering, Weesp, The Netherlands), 2 mg/day for 4 weeks. The increase in the serum estradiol level was much higher during transdermal than oral estradiol administration. On the contrary, the increase in the serum estrone level was much more pronounced during oral treatment. Both modes of treatment led to a similar reduction of urinary calcium excretion. A highly significant decrease in serum phosphate levels was found during transdermal therapy. Biliary cholesterol saturation index did not change during transdermal therapy (mean +/- SEM, 1.25 +/- 0.06 before and 1.22 +/- 0.07 at the end of transdermal therapy; P = NS). A slight increase in cholesterol saturation index that did not reach statistical significance was found during oral therapy (1.28 +/- 0.09 before and 1.36 +/- 0.09 during oral treatment). However, the subgroup of women with strong increases in serum estrone levels during oral estradiol therapy (greater than 0.5 pmol/mL; n = 8) generally had increased biliary cholesterol saturation index, a decrease in relative percentage chenodeoxycholic acid in bile, and increased serum sex hormone-binding globulin levels during oral treatment. Cholesterol monohydrate crystals were never found in duodenal biles during either treatment. This study indicates that transdermal estradiol does not induce lithogenic bile. On the contrary, oral estradiol leads to lithogenic bile in a subgroup of women with strong increases in serum estrone levels during oral treatment.

Visceral perception in health and functional dyspepsia. Crossover study of gastric distension with placebo and domperidone

The symptoms of functional dyspepsia are still unexplained. To evaluate the possible role of abnormal visceral perception, we studied the symptomatic responses and the pressure variations during progressive gastric distension in 10 female healthy control subjects (mean age 33.6 years) and in 10 female patients with functional dyspepsia (mean age 35.2 years). A rubber balloon was positioned 4 cm below the lower esophageal sphincter (LES) and inflated with progressively larger volumes of air by steps of 50 ml; pressures at the gastric fundus and at the LES were continuously recorded by perfused manometric catheters. Each subject was studied on two separate occasions after randomized double-blind administration of either placebo or 20 mg of domperidone. Symptomatic responses and the manometric data were analyzed at the time of the initial recognition of distension (bloating step) and at the time of reporting pain or up to a maximum of 700 ml of balloon inflation (pain or 700-ml step). On placebo, the volumes of gastric distension were more than two times lower in patients than in control subjects at the bloating step (185 +/- 32 ml vs 470 +/- 40 ml, P = 0.001) and at the pain or 700-ml step (265 +/- 54 ml vs 600 +/- 34 ml, P less than 0.005), while the pressure gradients (pressure at inflation steps minus baseline pressure before beginning inflation) were not statistically different between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Biliary-tract cancer in Chile

This epidemiological study in Chile shows a marked increase in biliary-tract cancer based on mortality data, from an age-adjusted rate (1970 world population) of 5.1 per 100,000 in 1970 to 12.0 per 100,000 in 1988. There is an increased risk of this cancer in all age groups but especially in young adults (15-44 years). The female ratio of 3:1 persists. The increase in biliary-tract cancer in 1970-1985 was particularly important for young women but occurred in all female age groups whereas in men it was mostly in the elderly (65 years and more) and less in the middle-aged (45-64 years); no changes were observed in young men. Regional differences have begun to be appreciated. One of the factors which may account for this impressive and unexpected increase is the remarkable decrease in cholecystectomy rates. Less than 20% of the 154% increase in biliary-tract cancer mortality in the period 1970-1985 could be attributed to population aging. Improvements in diagnostic methods did not appear to be an important contributing factor. Other factors that could affect this increase in the incidence to epidemic levels include: an increase in the prevalence of cholelithiasis, an increase in the number of typhoid carriers and possible environmental carcinogens.

Immunohistochemical analysis of estrogen receptors in human gallbladder

Estrogen receptors (ER) in human gallbladders were examined immunohistochemically using a specific monoclonal antibody against human ER. ER immunoreactivity was positive in 6 (19.4%) of 31 cases of cholelithiasis, 6 (33.3%) of 18 cases of epithelial polyp, 14 (53.8%) of 26 cases of adenoma, and 26 (22.8%) of 114 cases of adenocarcinoma. ER immunoreactivity was located at the nucleus of the epithelium of both non-neoplastic and neoplastic tissues, although the number of ER-immunoreactive cells was small. There was no sex difference in the incidence of ER immunoreactivity. No significant difference in survival rates could be demonstrated between ER-positive and ER-negative carcinomas. Epithelial polyps, adenomas and carcinomas were divided into metaplastic type and non-metaplastic type based on the presence or absence of metaplastic changes for comparison of the incidence of ER immunoreactivity. The incidence of ER immunoreactivity in the metaplastic type was significantly higher than that in the non-metaplastic type. We conclude that ER are present in the gallbladder mucosa in various disease states and suggest that the presence of ER is related to metaplasia of the gallbladder mucosa.

Oral calcium promotes pigment gallstone formation

Dietary calcium supplementation has been recommended for prevention of osteoporosis and has become a standard component of most "health food" diets. Biliary calcium has been recognized to play a central role in the formation of pigment gallstones. We have recently demonstrated that 5 days of oral calcium supplementation significantly increases biliary calcium in the prairie dog (K. D. Lillemoe, T. H. Magnuson, G. E. Peoples, et al., Gastroenterology 94: A563, 1988). We hypothesized, therefore, that long-term oral calcium supplementation would promote pigment gallstone formation. Sixteen adult male prairie dogs were maintained on a standard nonlithogenic diet. Eight animals received calcium supplementation (2.5 x control levels) in their water, while the remaining eight animals served as controls. After 8 weeks, cholecystectomy was performed, and the common bile duct was cannulated. Bile was examined microscopically and analyzed for ionized calcium, bilirubin, glycoprotein, and biliary lipids. The cholesterol saturation index (CSI) was calculated. Pigment stones and calcium bilirubinate sludge were present in all animals receiving calcium supplementation. Only one control animal had evidence of pigment stones (P less than 0.001). Biochemical analysis of gallbladder bile demonstrated a significant increase in total bilirubin and bilirubin monoglucuronide (P less than 0.01) as well as bile glycoprotein content (P less than 0.05) after oral calcium supplementation. Gallbladder bile ionized calcium was also increased although not significantly. These data suggest that oral calcium supplementation promotes gallbladder sludge and pigment gallstone formation in the prairie dog. This observation raises concern that oral calcium supplementation, especially in the older female population, may enhance gallstone formation.