The effect of a low fat diet on estrogen metabolism

Sex, Gender, and Sex Hormones in Pulmonary Hypertension and Right Ventricular Failure

Pulmonary hypertension (PH) encompasses a syndrome of diseases that are characterized by elevated pulmonary artery pressure and pulmonary vascular remodeling and that frequently lead to right ventricular (RV) failure and death. Several types of PH exhibit sexually dimorphic features in disease penetrance, presentation, and progression. Most sexually dimorphic features in PH have been described in pulmonary arterial hypertension (PAH), a devastating and progressive pulmonary vasculopathy with a 3-year survival rate <60%. While patient registries show that women are more susceptible to development of PAH, female PAH patients display better RV function and increased survival compared to their male counterparts, a phenomenon referred to as the "estrogen paradox" or "estrogen puzzle" of PAH. Recent advances in the field have demonstrated that multiple sex hormones, receptors, and metabolites play a role in the estrogen puzzle and that the effects of hormone signaling may be time and compartment specific. While the underlying physiological mechanisms are complex, unraveling the estrogen puzzle may reveal novel therapeutic strategies to treat and reverse the effects of PAH/PH. In this article, we (i) review PH classification and pathophysiology; (ii) discuss sex/gender differences observed in patients and animal models; (iii) review sex hormone synthesis and metabolism; (iv) review in detail the scientific literature of sex hormone signaling in PAH/PH, particularly estrogen-, testosterone-, progesterone-, and dehydroepiandrosterone (DHEA)-mediated effects in the pulmonary vasculature and RV; (v) discuss hormone-independent variables contributing to sexually dimorphic disease presentation; and (vi) identify knowledge gaps and pathways forward. © 2020 American Physiological Society. Compr Physiol 10:125-170, 2020.

Efflux transport of estrogen glucuronides by human MRP2, MRP3, MRP4 and BCRP

Estrone, estradiol and estriol are endogenous human estrogens that are rapidly conjugated with glucuronic acid in both intestinal and hepatic epithelial cells. The resulting glucuronides, estrone-3-glucuronide (E₁-G), estradiol-3- and 17-glucuronides (E₂-3G and E₂-17G), as well as estriol-3- and 16-glucuronides (E₃-3G and E₃-16G) are found in human plasma and urine. Unlike E₂-17G, the efflux transport of other estrogen glucuronides by human transporters has not yet been investigated comprehensively. We have studied the transport of E₁-G, E₂-3G, E₃-3G, E₃-16G and estrone-3-sulfate (E₁-S), another important estrogen conjugate, using the vesicular transport assay with recombinant human MRP2, MRP3, MRP4, MDR1 and BCRP that were expressed in insect cells. The transport screening assays revealed that whereas E₁-S was a good and specific substrate for BCRP, the less transporter-specific conjugates, E₁-G and E₂-3G, were still transported by BCRP at 10-fold higher rates than E₁-S. BCRP also transported E₃-16G at higher rates than the studied MRPs, while it transported E₃-3G at lower rates than MRP3. MRP2 exhibited lower or equal transport rates of E₁-G, E₂-3G, E₃-3G and E₃-16G in comparison to MRP3 and BCRP in the screening assays, mainly due to its high K_m values, between 180 and 790 μM. MRP3 transported all the tested glucuronides at rather similar rates, at K_m values below 20 μM, but lower V_max values than other transporters. In the case of E₃-3G, MRP3 was the most active transporter in the screening assay. MRP4 transported only E₃-16G at considerable rates, while none of the tested estrogen conjugates was transported by MDR1 at higher rates than control vesicles. These new results, in combination with previously reported in vivo human data, stimulate our understanding on the substrate specificity and role of efflux transporters in disposition of estrogen glucuronides in humans.

Pharmacokinetics and bioavailability of plant lignan 7-hydroxymatairesinol and effects on serum enterolactone and clinical symptoms in postmenopausal women: a single-blinded, parallel, dose-comparison study

Objective

7-Hydroxymaitairesinol (7-HMR) is a naturally occurring plant lignan found in whole grains and the Norway spruce (Piciea abies). The purpose of this study was to evaluate the bioavailability of a proprietary 7-HMR product (HMRlignan, Linnea SA, Locarno, Switzerland) through measurement of lignan metabolites and metabolic precursors.

Methods

A single-blind, parallel, pharmacokinetic and dose-comparison study was conducted on 22 post-menopausal females not receiving hormone replacement therapy. Subjects were enrolled in either a 36 mg/d (low-dose) or 72 mg/d dose (high-dose) regimen for 8 weeks. Primary measured outcomes included plasma levels of 7-HMR and enterolactone (ENL), and single-dose pharmacokinetic analysis was performed on a subset of subjects in the low-dose group. Safety data and adverse event reports were collected as well as data on hot flash frequency and severity.

Results

Pharmacokinetic studies demonstrated 7-HMR C_max = 757.08 ng/ml at 1 hour and ENL C_max = 4.8 ng/ml at 24 hours. From baseline to week 8, plasma 7-HMR levels increased by 191% in the low-dose group (p < 0.01) and by 1238% in the high-dose group (p < 0.05). Plasma ENL levels consistently increased as much as 157% from baseline in the low-dose group and 137% in the high-dose group. Additionally, the mean number of weekly hot flashes decreased by 50%, from 28.0/week to 14.3/week (p < 0.05) in the high-dose group. No significant safety issues were identified in this study.

Conclusion

The results demonstrate that HMRlignan is quickly absorbed into the plasma and is metabolized to ENL in healthy postmenopausal women. Clinically, the data demonstrate a statistically significant improvement in hot flash frequency. Doses up to 72 mg/d HMRlignan for 8 weeks were safe and well tolerated in this population.

Progress in solving the sex hormone paradox in pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a devastating and progressive disease with marked morbidity and mortality. Even though being female represents one of the most powerful risk factors for PAH, multiple questions about the underlying mechanisms remain, and two "estrogen paradoxes" in PAH exist. First, it is puzzling why estrogens have been found to be protective in various animal models of PAH, whereas PAH registries uniformly demonstrate a female susceptibility to the disease. Second, despite the pronounced tendency for the disease to develop in women, female PAH patients exhibit better survival than men. Recent mechanistic studies in classical and in novel animal models of PAH, as well as recent studies in PAH patients, have significantly advanced the field. In particular, it is now accepted that estrogen metabolism and receptor signaling, as well as estrogen interactions with key pathways in PAH development, appear to be potent disease modifiers. A better understanding of these interactions may lead to novel PAH therapies. It is the purpose of this review to 1) review sex hormone synthesis, metabolism, and receptor physiology; 2) assess the context in which sex hormones affect PAH pathogenesis; 3) provide a potential explanation for the observed estrogen paradoxes and gender differences in PAH; and 4) identify knowledge gaps and future research opportunities. Because the majority of published studies investigated 17β-estradiol and/or its metabolites, this review will primarily focus on pulmonary vascular and right ventricular effects of estrogens. Data for other sex hormones will be discussed very briefly.

Fruit intake associated with urinary estrogen metabolites in healthy premenopausal women

Urinary concentrations of 2:16-hydroxyestrone (2:16-OHE₁) approximate concentrations of 2-OHE₁ and 16α -OHE₁ in breast tissue. As estrogens are purported to be involved in breast cancer development, the 2:16-OHE₁ ratio can provide an indication of estrogen metabolite exposure in the breast. With prior studies observing associations between urinary estrogen metabolites and dietary intake of fruits, vegetables, and fiber ascertained from food questionnaires, we examined associations between dietary factors ascertained through 3-day food records and urinary 2:16-OHE₁ in 191 pre-menopausal healthy women. Fruit consumption was positively associated with 2:16-OHE₁ after adjustment for total energy, ethnicity, body mass index, parity, smoking history, and serum estradiol (p= 0.003). Fruit consumption was positively associated with 2- OHE₁ concentrations (p=0.006), but was not associated with 16α-OHE₁ (p=0.92). The Musaceae botanical grouping (comprised primarily of bananas) was positively associated with the 2:16-OHE₁ ratio, and Rosaceae (comprised of citrus fruits) and Musaceae botanical groupings were positively associated with 2-OHE₁ (but not 16α-OHE₁) concentrations, after adjustment for confounders. Our data suggest that dietary fruit intake is associated with urinary 2- OHE₁ and the 2:16-OHE₁ ratio and that breast tissue exposure to estrogen metabolites may thus be influenced by diet.

Diets and hormonal levels in postmenopausal women with or without breast cancer

The role of diet in breast cancer (BC) risk is unclear. Fiber could reduce BC risk, through the enterohepatic circulation of estrogens. We examined the relationship between diet and sex hormones in postmenopausal women with or without BC. Thirty-one postmenopausal women (10 omnivores, 11 vegetarians, and 10 BC omnivores) were recruited. Dietary records (5 days) and hormone levels (3 days) were evaluated on 4 occasions over 1 yr. Vegetarians showed a lower fat/fiber ratio, a higher intake of total and cereal fiber (g/d)/body weight (kg), a significantly lower level of plasma estrone-sulfate, estradiol, free-estradiol, free-testosterone, and ring D oxygenated estrogens, and a significantly higher level of sex-hormone-binding-globulin than BC subjects. Fiber was consumed in slightly larger amounts by omnivores than by BC subjects. Omnivores had significantly lower plasma testosterone and estrone-sulfate but higher sex-hormone-binding-globulin than BC subjects. No difference was found for the urinary 16-oxygenated estrogens. However, the 2-MeO-E1/2-OH-E1 ratio was significantly lower in omnivores than in BC group. This ratio is positively associated with the fat/fiber ratio. In conclusion, testosterone may contribute to causing alterations in the levels of catechol estrogens and 16-oxygenated estrogens. The fat/fiber ratio appears to be useful in evaluating dietary effects on estrogen metabolism.

Urinary 2/16 estrogen metabolite ratio levels in healthy women: a review of the literature

This is a summary of the published literature on the urinary 2/16 estrogen metabolite ratio in human populations, and a report the observed range of normal values in healthy women. Original research studies that included the measurement of urinary estrogen metabolites in human subjects were identified through an extensive Medline search; 43 distinct studies were identified, including a total of 6802 healthy women. The range of mean values of the 2/16 ratio measured with the ELISA method varied from 0.98 to 1.74; in studies of pre-menopausal women the range of mean values was 1.5-2.74, in studies of post-menopausal women mean values ranged from 1.15 to 2.25. The heterogeneity across studies was highly significant (p-value Q-test: <0.0001). In multivariable analyses, only race confirmed its role as an independent predictor of 2/16 ratio (F-value: 7.95; p-value: 0.009), after adjustment for age and menopausal status. There appears to be a large body of data on the 2/16 urinary ratio in healthy women. However, summary estimates are difficult to perform due to the high variability of the published study-specific values. The data suggests that race may be a contributor to 2/16 urinary ratio levels.

Diet and risk of endometriosis in a population-based case-control study

Diet plausibly has a role in the aetiology of endometriosis through effects on steroid hormone levels; however, few published studies have examined the diet and endometriosis risk. We evaluated dietary risk factors for endometriosis in a population-based case-control study. Cases were 284 Group Health (GH) enrollees aged 18-49 years with newly diagnosed, surgically confirmed endometriosis between 1996 and 2001. Controls were 660 randomly selected age-matched female GH enrollees without a history of endometriosis. Nutrients and selected food groups were assessed using the Women's Health Initiative FFQ. OR of endometriosis risk associated with dietary exposures were estimated using unconditional logistic regression and adjusted for identified covariates. Increased total fat consumption was associated with decreased endometriosis risk (fourth quartile v. lowest: OR 0·5, 95% CI 0·2, 1·0, P-trend = 0·12). Increased β-carotene consumption and servings/d of fruit were associated with increased risk (β-carotene third quartile v. lowest: OR 1·7, 95% CI 1·1, 2·6; fourth quartile v. lowest: OR 1·6, 95% CI 1·0, 2·5, P-trend 0·16; fruit >2 servings/d v. < 1: OR 1·5, 95% CI 1·0, 2·3, P-trend = 0·04). We also found a suggestion of decreased endometriosis risk associated with the consumption of dairy products (2 servings/d v. ≤ 1: OR 0·6, >2 servings/d v. ≤ 1: OR 0·7), but this association was not statistically significant for the highest tertile. The present study suggests that specific dietary components may be associated with endometriosis risk.

Diet, physical activity and energy balance and their impact on breast and prostate cancers

Obesity, physical activity status and circulating levels of sex steroid hormones and growth factor proteins are intrinsically linked to energy balance. Epidemiological studies have previously reported associations between these factors and the risk of hormone-related cancers such as prostate and breast cancer in men and postmenopausal women. An increasing number of intervention studies in 'at-risk' populations and cancer survivors are now investigating the effects of lifestyle interventions that promote negative energy balance on circulating levels of sex hormones and growth factor proteins as surrogate markers of cancer risk. Evidence from these studies suggests that lifestyle interventions can improve insulin sensitivity, alter the balance of circulating sex steroid hormones and insulin-like growth factor (IGF) axis proteins (including IGF-1 and the IGF binding proteins 1 and 3) and change the functioning of immune cells in peripheral blood. Such changes could influence the risk of developing hormone-related cancers, as well as having the potential to improve disease-free survival in patients recovering from cancer treatment. However, despite promising results, the methodological quality of most intervention studies has been limited due to small subject numbers, lack of adequate control groups or non-randomised designs and the absence of long-term follow-up measures. More intervention studies with randomised controlled designs, higher numbers of subjects and longer-term follow-up measures are needed to establish which combination of specific dietary and physical activity interventions work best for reducing risk in 'at-risk' populations and survivors, optimal dose-response relationships and the magnitude of change in surrogate markers of cancer risk that is required to induce a protective effect.

Cytochrome P450 1B1 Val432Leu polymorphism and breast cancer risk in Nigerian women: a case control study

Background

Cytochrome P450 1B1 (CYP1B1) is active in the metabolism of estrogens to reactive catechols and of different procarcinogens. Several studies have investigated the relationship between genetic polymorphisms of CYP1B1 and breast cancer risk with inconsistent results. A G → C transversion polymorphism in the heme-binding region in codon 432 of the gene results in amino acid change (Val → Leu); the Leu allele display increased catalytic efficiency for 4-hydroxylation of estradiol in some experimental systems.

Methods

In this study, we utilized a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay to assess the relationship between this polymorphism and breast cancer risk in a case control study including 250 women with breast cancer and 250 controls from four University Teaching Hospitals in Southern Nigeria.

Results

Heterozygosity for the CYP1B1 M1 genotype (CYP1B1 M1 [Val/Leu]) was associated with a significant 59% increased risk of breast cancer (OR = 1.59, 95% CI 1.01–2.58) while homozygosity for the genotype (CYP1B1 M1 [Leu/Leu]) conferred a non-significant 51% increased risk of breast cancer. These risk profiles were modified in subgroup analysis. In premenopausal women, harboring at least one CYP1B1 (Leu) allele conferred a significant two-fold increased risk of breast cancer (OR = 2.04, 95% CI 1.10–3.78). No significant association was observed in postmenopausal women (OR = 1.08, 95% CI 0.57–2.04).

Conclusion

Our results suggest that the codon 432 polymorphism of the CYP1B1 gene is associated with increased risk of breast cancer and is particularly involved in breast cancer risk in premenopausal women of African descent.

Fat/fiber intakes and sex hormones in healthy premenopausal women in USA

The mechanisms by which diet affects breast cancer (BC) risk are poorly understood but a positive relationship between fat and a negative association with fiber intake and BC risk have been demonstrated. Here we study the association between dietary fat/fiber ratio and estrogen metabolism. Fifty women were recruited, 22 were included in the low fat/high fiber and 22 were in the high fat/low fiber group and 6 did not meet our criteria. Estrogens (determined in plasma, urine and feces) and dietary records were collected during 3 following days. All data were collected in winter and in summer. The high fat/low fiber group had significantly higher urinary total estrogens, estriol-3-glucuronide, 2-hydroxyestradiol, 16alpha-hydroxyestrone, and a higher 2-hydroxyestrone/4-hydroxyestrone ratio. Total fat intake correlated significantly with plasma estrone, estradiol, urinary 2-hydroxyestrone, 2-hydroxyestradiol, 2-hydroxyestrone/4-hydroxyestrone ratio, and total urinary estrogens, even after adjustment for total fiber intake. The high fat/low fiber diet was associated with high values both for catechol and 16alpha-hydroxylated estrogens and a high 2-hydroxyestrone/4-hydroxyestrone ratio, but 2-hydroxyestrone/16alpha-hydroxyestrone ratio was not different between the groups. Our results suggest that fat affects estrogen metabolism more than does fiber and that one mechanism resulting in high estrogen values is an increased reabsorption of biliary estrogens.

Isoflavonas en mujeres menopáusicas

Phytoestrogens are composed derivatives of vegetables. The 2 main classes of interest to human health are lignans and isoflavones. Isoflavones exist in at least 15 different chemical forms and their effect on human health has been investigated to some extent (particularly, genistein and daidzein as high levels of these compounds are present in soybean). Isoflavones have similar structure to oestrogen and have the capacity to exert both oestrogenic and anti oestrogenic effects. They may block the effects of oestrogen in some tissues (e. g., the breast and endometrium), but act like an oestrogen in providing possible protection against bone loss and heart disease. Lignans are much more widespread in plant foods but investigation has been limited due to the complexity of measurement. The increasing interest in the use of the soybean and the phytoestrogens derived from the soybean is due to the results published on experimental animal actions, and in human case-control studies. There are many observational and epidemiologists studies that suggest the potential benefit of isoflavones on the menopause symptoms, the cardiovascular system, the osteoporosis and the estrogen dependent cancers, but many open questions exist. We must be very strict with certain observational studies by the possible influences of collateral factors to the isoflavones (exercise, type of diet, etc.), and attribute the beneficial effects may be due to own treatment.

Short-term soy and probiotic supplementation does not markedly affect concentrations of reproductive hormones in postmenopausal women with and without histories of breast cancer

BACKGROUND

Observational studies suggest that dietary isoflavones reduce breast cancer risk, and this may be caused in part by effects on endogenous hormone concentrations. Because intestinal bacteria metabolize isoflavones, it was hypothesized that consumption of probiotic bacteria would enhance the biologic effects of isoflavones, including effects on endogenous hormones.

DESIGN

Twenty (20) postmenopausal breast cancer survivors and 20 healthy postmenopausal women completed four 42-day diet periods in a randomized, crossover design. They received one of the following: isolated soy protein; isolated milk protein; soy + probiotic capsules; or milk + probiotic capsules. Each protein supplement provided 0.38 g protein/(kg body weight/day) (26.6 +/- 4.5 g protein/day) and soy protein provided 0.64 mg isoflavones/(kg body weight/day) (44.4 +/- 7.5 mg isoflavones/day). Probiotic capsules provided 10(9) colony-forming units Lactobacillus acidophilus (strain DDS-1), Bifidobacterium longum, and 15-20 mg fructo-oligosaccharide.

MEASURES

Plasma samples were collected at baseline and after each diet for analysis of estrogens, follicle-stimulating hormone (FSH), androgens, and sex hormone?binding globulin (SHBG).

RESULTS

Hormone levels were not affected by soy, probiotic supplements, or equol producer status, and neither cancer status nor equol producer status altered the effects of soy or probiotics. Furthermore probiotics did not alter the effects of soy consumption. Soy protein tended to decrease SHBG compared to milk protein diets (p = 0.05), although both proteins significantly decreased SHBG relative to baseline (p = 0.0001 and p = 0.03).

CONCLUSIONS

These data suggest that short-term, moderate consumption of isoflavone-containing soy protein and consumption of these particular probiotic capsules do not significantly alter reproductive hormone concentrations in breast cancer survivors or controls, regardless of equol producer status.

Selected diet and lifestyle factors are associated with estrogen metabolites in a multiracial/ethnic population of women

Diet and lifestyle factors, body size, and smoking behavior may influence estrogen metabolism, but the nature of these relations may vary according to race/ethnic groups. We evaluated the association of lifestyle factors with estrogen metabolites 2-hydroxyestrone (2-OHE1) and 16alpha-hydroxyestrone (16alpha-OHE1) in a racially diverse population. With a cross-sectional study design, urine samples from 1881 African-American, Caucasian, Chinese, Japanese, and Hispanic women, aged 42-52 y, from the Study of Women's Health Across the Nation (SWAN) were assayed by EIA for 2-OHE1 and 16alpha-OHE1. Dietary factors and beverages were measured using a modified Block FFQ. Dietary fiber, vegetable and fruit servings, Brassica vegetables, polyphenols, coffee, caffeine, green and black tea, and total alcohol and wine were related to metabolite values using multiple variable regression analyses. In adjusted analyses, 2-OHE1 concentrations were significantly associated with race/ethnicity, weight, smoking, and consumption of hydroxybenzoic acid, anthocyanidins, wine, and caffeine (P < 0.05). Regression models incorporating these variables explained 19-20% of the variation in 2-OHE1 concentrations. Regression models for 16alpha-OHE1, which explained 16-17% of the variability, included race/ethnicity, smoking, caffeine, total dietary fiber, and fiber from fruits and vegetables as variables. These associations may reflect why increased consumption of polyphenol-containing foods and fruit as well as decreased smoking, caffeine intake, and body size would be consistent with hypothesized benefits and risks for selected health outcomes.

Inflammation and Endometrial Cancer: A Hypothesis

Endometrial cancer is the most common gynecologic malignancy in the United States. Substantial epidemiologic data implicate an imbalance of estrogens and progestogens in the etiology of this disease. We propose that inflammation also plays a role in endometrial cancer development. Emerging laboratory data suggest that elevated levels of prostaglandin E(2) may underlie the transformation of normal endometrium to neoplastic tissue and that in vitro nonsteroidal anti-inflammatory drugs may inhibit endometrial cancer cell growth. In this review, we suggest that the risk factors for endometrial cancer--unopposed estrogens, anovulation, polycystic ovary syndrome, excessive menstruation, early menarche, and late menopause--may be viewed as factors increasing the exposure of the endometrium to inflammation, whereas pregnancy and smoking, two likely protective factors, have the opposite effect. Chronic inflammation can induce rapid cell division, increasing the possibility for replication error, ineffective DNA repair, and subsequent mutations. A proinflammatory milieu can also directly increase estrogen production. Hence, inflammation may work in conjunction with or in addition to estrogen exposure in the development of endometrial cancer.

Isoflavones and postmenopausal women: a critical review

Isoflavonic phytoestrogens, or isoflavones, constitute a class of phytoestrogens that have properties similar to selective estrogen receptor modulators, and have attracted a substantial degree of attention in recent years, particularly as a possible alternative to the conventional hormone replacement therapy regimens used by postmenopausal women. Despite great promise, it is difficult to make many specific recommendations about their use at the current time, in light of the many outstanding questions that hopefully will be answered in the future by focused interventional studies involving humans. Studies to date indicate that the use of isoflavones to address vasomotor symptoms provides at most small benefits beyond a placebo effect, and no benefit for genital atrophy. As for postmenopausal women whose primary concern is cardiovascular disease, the recommendation of the American Heart Association to include soy protein foods as part of an otherwise healthy diet is well justified, and similarly the substitution of supplements containing soy protein for animal protein can also be recommended. The use of purified isoflavone supplements not containing soy protein may have some cardiovascular benefits, but these appear to be less substantial in degree than those provided by soy protein with isoflavones. In particular, more research is needed to assess the effects of isoflavones on osteoporosis, for which no recommendation regarding isoflavones can be made based on the current data. Also, isoflavones should not be taken by postmenopausal women for the specific purpose of decreasing their risk of breast or endometrial cancer, although, at least for those without pre-existing disease or at high risk, it seems quite unlikely that isoflavone use is harmful in this regard.

Fitoestrogênios: posicionamento do Departamento de Endocrinologia Feminina da Sociedade Brasileira de Endocrinologia e Metabologia (SBEM)

Para avaliar a utilidade dos fitoestrogênios (FE) na terapia de reposição hormonal da menopausa (TRHM), o Departamento de Endocrinologia Feminina da SBEM reuniu um grupo de especialistas para fazer uma revisão bibliográfica e selecionar trabalhos nos quais a metodologia adotada demonstrasse rigor científico. Os FE têm ações estrogênicas e antiestrogênicas, predominantemente sobre os receptores de estrogênios (E) beta, com potência estrogênica muito inferior à do estradiol. O conteúdo de FE nas suas fontes vegetais é variável, dependendo da forma de cultivo, safra, armazenamento e industrialização. Também a conversão dos precursores em fitormônios ativos no organismo humano tem grande variabilidade individual. A maior parte das pesquisas com FE é realizada in vitro ou com animais de laboratório, nem sempre podendo ser extrapoladas para humanos. Com relação à síndrome do climatério, alguns estudos sugerem discreta melhora dos fogachos, sem modificação do ressecamento vaginal ou das alterações do humor. No metabolismo lipídico, alimentação rica em soja, mas não isoflavonas isoladamente, promove redução do colesterol total, do LDL-col e dos triglicerídeos, mas não elevam o HDL-col, como os E, e podem causar aumento da lipoproteína (a), que os E contribuem para diminuir. Embora alguns estudos de curta duração sugiram aumento da densidade mineral óssea com uso de isoflavonas, não há demonstração de redução de fraturas. Conclui-se que não há evidências convincentes que justifiquem o uso de FE ou alimentação rica em soja como alternativa para a TRHM.

Tissue specificity: the clinical importance of steroid metabolites in hormone replacement therapy

Metabolic activations or inactivations of estrogens, progesterone and androgens are important steps towards the understanding of the physiological and the pathological effects of these hormones in the female organism. Analysis of the tissue specific metabolic pathways of sex steroids will result in a better understanding of successful hormone replacement therapy on the one hand and of the occurrence of steroid hormone related side effects on the other hand. In this contribution we analyse the different mechanisms involved in the synthesis of tissue specific metabolites and discuss the therapeutical importance of these metabolites in hormone replacement therapy.

Macronutrient intake and estrogen metabolism in healthy postmenopausal women

The purpose of this study was to determine if dietary factors could bias estimates of the relationships between estrogen metabolites and breast cancer risk factors. A lower ratio of urinary 2-hydroxyestrone/16alpha-hydroxyestrone (2/16) has been associated with breast cancer diagnosis. However, both estrogen metabolism and breast cancer risk have been associated with dietary intake, and breast cancer patients may have different dietary patterns than healthy controls. An association between urinary 2/16 levels and breast cancer risk may be due to transitory dietary change after diagnosis, or due to other breast cancer risk factors which have been associated to steroid hormone metabolism. Thirty-seven healthy postmenopausal women provided two 24-h urine samples at a two-week interval. Six 24-h diet recalls were administered in this same time period. In linear regression analysis, dietary fat-to-fiber ratio (fat/fiber) and the saturated fat/soluble fiber ratio was inversely associated with urinary 2/16 values (b = -0.22, 95% CI (-0.43, -0.01); b= -0.26, 95% CI (-0.43, -0.09), respectively). The effects of these dietary factors on 2/16 were independent of body mass index or other breast cancer risk factors. These study results suggest that some of the variation in estrogen metabolite levels among postmenopausal Caucasian women may be due to dietary intake, and that dietary factors should be carefully measured and evaluated when investigating the relationship between estrogen metabolites and breast cancer risk.

Petrochemical exposure and menstrual disturbances

BACKGROUND

An exploratory, cross-sectional retrospective study was conducted to examine the effects of benzene exposure on menstrual problems.

METHODS

The study was based on a survey administered to over 3,000 women who worked in a large petrochemical company in Beijing, China. An abnormal menstrual cycle length (AMCL), defined as an average menstrual cycle length of greater than 35 days or less than 21 days, is the major outcome of interest.

RESULTS

After 7 years of benzene exposure, the adjusted odds ratio of having AMCL for each additional 5 years of exposure was 1.71 (95% CI 1.27-2.31). Feeling stressed at work was also an important predictor.

CONCLUSIONS

This study suggests a significant association of benzene exposure and perceived stress with menstrual disturbance. A prospective study is needed to confirm this finding.

Vitamin D, calcium and prevention of breast cancer: a review

Several recent epidemiologic and experimental studies have suggested that decreased calcium and vitamin D intake and high dietary fat are associated with mammary gland carcinogenesis. Complete reduction or elimination of human exposure to environmental factors such as high-fat diets is inherently difficult to implement. Recent studies have begun to evaluate a possible role for increased dietary calcium and vitamin D in reducing the risk of colonic and mammary cancers, even in the presence of a high-fat diet. Studies from our laboratory recently found that decreased dietary calcium and vitamin D in a high-fat diet induced adverse changes in the mammary gland and several other organs, which were reversed by increasing dietary calcium and vitamin D; the findings further suggest a possible role for increased dietary calcium and vitamin D in the chemoprevention of these cancers.

Dietary fat and carcinogenesis

Epidemiologic investigations have suggested a relationship between dietary fat intake and various types of cancer incidences. Furthermore, epidemiologic studies as well as studies with animal models have demonstrated that not only the amount but also the type of fat consumed is important. At present, the mechanism by which dietary fat modulates carcinogenesis has not been elucidated. The effects of dietary fat on the development of tumours have been summarized in the present review with emphasis on colorectal, pancreas, breast and prostate cancer. It is concluded that influence on synthesis of prostaglandins and leukotrienes may be the universal mechanism by which dietary fats modulate carcinogenesis.

Effect of flaxseed consumption on urinary estrogen metabolites in postmenopausal women

Flaxseed, the richest known source of plant lignans, has been shown to have chemoprotective effects in animal and cell studies. Some of its effects may be mediated through its influence on endogenous hormone production and metabolism. Two competing pathways in estrogen metabolism involve production of the 2-hydroxylated and 16 alpha-hydroxylated metabolites. Because of the proposed differences in biological activities of these metabolites, the balance of the two pathways has been used as a biomarker for breast cancer risk. We examined the effects of flaxseed consumption on urinary estrogen metabolite excretion in postmenopausal women. Twenty-eight postmenopausal women were studied for three seven-week feeding periods in a randomized crossover design. During the feeding periods, subjects consumed their usual diets plus ground flaxseed (0, 5, or 10 g/day). Urinary excretion of the estrogen metabolites 2-hydroxyestrogen (2-OHEstrogen) and 16 alpha-hydroxyestrone (16 alpha-OHE1) as well as their ratio, 2/16 alpha-OHE1, was measured by enzyme immunoassay. Flaxseed supplementation significantly increased urinary 2-OHEstrogen excretion (p < 0.0005) and the urinary 2/16 alpha-OHE1 ratio (p < 0.05) in a linear, dose-response fashion. There were no significant differences in urinary 16 alpha-OHE1 excretion. These results suggest that flaxseed may have chemoprotective effects in postmenopausal women.

Health psychology: mapping biobehavioral contributions to health and illness

Our evolving understanding of how psychosocial and behavioral factors affect health and disease processes has been marked by investigation of specific relationships and mechanisms underlying them. Stress and other emotional responses are components of complex interactions of genetic, physiological, behavioral, and environmental factors that affect the body's ability to remain or become healthy or to resist or overcome disease. Regulated by nervous, endocrine, and immune systems, and exerting powerful influence on other bodily systems and key health-relevant behaviors, stress and emotion appear to have important implications for the initiation or progression of cancer, HIV, cardiovascular disease, and other illnesses. Health-enhancing and health-impairing behaviors, including diet, exercise, tobacco use, and protection from the sun, can compromise or benefit health and are directed by a number of influences as well. Finally, health behaviors related to being ill or trying to avoid disease or its severest consequences are important. Seeking care and adhering to medical regimens and recommendations for disease surveillance allow for earlier identification of health threats and more effective treatment. Evidence that biobehavioral factors are linked to health in integrated, complex ways continues to mount, and knowledge of these influences has implications for medical outcomes and health care practice.

Influence of dietary calcium and vitamin D on diet-induced epithelial cell hyperproliferation in mice

BACKGROUND

Previous epidemiologic and laboratory studies, including some from our own laboratory, have suggested that a high-fat diet increases risk of cancer development in the pancreas, prostate, colon, and breast and that carcinogenesis in some of these organs may be influenced by alterations in dietary calcium and vitamin D. In this study, we sought to investigate the effect of added dietary calcium or vitamin D on the development of epithelial cell hyperproliferation induced by a Western-style diet in the exocrine pancreas, prostate, and mammary gland of mice.

METHODS

Four-week-old C57BL/6J mice were given either a control diet (American Institute of Nutrition [AIN]-76A), a Western-style diet (containing reduced calcium and vitamin D and the fat level of the average human Western diet), or a putative chemopreventive diet (a Western-style diet with the addition of dietary calcium and vitamin D). Nine weeks after dietary intervention, osmotic pumps were implanted in the mice to provide 3 days of bromodeoxyuridine (BrdU) infusion. All P values are two-sided.

RESULTS

Mice on the Western-style diet had statistically significant increases in BrdU-labeling indices of epithelial cells in the interlobular (P = .015) and intralobular (P = .012) ducts and centroacinar cells (P = .001) of the pancreatic duct system, the dorsal lobe of the prostate (P = .045), and the terminal ducts of the mammary gland (P = .032), compared with mice in the respective control diet groups. Adding dietary calcium and vitamin D markedly suppressed the Western-style diet-induced hyperproliferation of epithelial cells in those tissues (P = .001-.033).

CONCLUSIONS

This study confirms previous findings that a Western-style diet produces hyperproliferation of epithelial cells in several organs and that the changes can be prevented by increasing dietary calcium and vitamin D alone.

Do urinary oestrogen metabolites predict breast cancer? Guernsey III cohort follow-up

This is the first prospective study of urinary measures of the two major competing pathways of oestrogen metabolism, 16alpha-hydroxyoestrone (16alpha-OHE1) and 2-hydroxyoestrone (2-OHE1), in relation to incident breast cancer risk. Experimental and case-control study results suggest that metabolism favouring the more oestrogenic 16alpha-OHE1 pathway may be linked to higher breast cancer risk. Women aged 35 and older from Guernsey (n = 5104) were surveyed in 1977-85 and have been continuously monitored for breast cancer and mortality up to the present (Guernsey III, Imperial Cancer Research Fund). Incident cases of breast cancer were matched to three control subjects for comparison of urinary oestrogen metabolite levels measured by enzyme immunoassay (EIA) in spot urine samples collected at baseline and stored frozen for up to 19 years. Consistent with case-control study results, post-menopausal (but not premenopausal) women at baseline who went on to develop breast cancer showed about a 15% lower 2:16alpha-OHE1 ratio than matched control subjects. Further, subjects with metabolite ratios in the highest tertile of 2:16alpha-OHE1 had about a 30% lower risk than women with ratios in the lowest two-thirds, although results were not statistically significant (OR = 0.71, 95% CI = 0.29-1.75). It is of potential importance that, in contrast to most risk factors for breast cancer, such as late age at first birth, oestrogen metabolism appears to be modifiable via diet and exercise, offering women the possibility of lowering breast cancer risk through non-pharmacological measures, although this remains to be tested.

Effects at two years of a low-fat, high-carbohydrate diet on radiologic features of the breast: results from a randomized trial. Canadian Diet and Breast Cancer Prevention Study Group

BACKGROUND

The appearance of breast tissue on mammography varies according to its composition. Fat is radiolucent and appears dark on mammography, while stromal and epithelial tissue has greater optical density and appears light. Extensive areas of radiologically dense breast tissue seen on mammography are associated with an increased risk of breast cancer.

PURPOSE

The purpose of the present study was to determine whether the adoption of a low-fat, high-carbohydrate diet for 2 years would reduce breast density.

METHODS

Women with radiologic densities in more than 50% of the breast area on mammography were recruited and randomly allocated to an intervention group taught to reduce intake of dietary fat (mean, 21% of calories) and increase complex carbohydrate (mean, 61% of calories) or to a control group (mean, 32% of calories from fat and 50% of calories from carbohydrates). Mammographic images from 817 subjects were taken at baseline and compared with those taken 2 years after random allocation by use of a quantitative image analysis system, without knowledge of the dietary group of the subjects or of the sequence in which pairs of images had been taken. The effects of the intervention on the mammographic features of breast area, area of dense tissues in the breast, and the percent of the breast occupied by dense tissue were examined using t tests. Multiple regression was used to examine these effects while accounting for age at trial entry, weight change, and menopausal status.

RESULTS

After 2 years, the total area of the breast was reduced by an average of 233.7 mm2 (2.4%) (95% confidence interval [CI] = 106.9-360.6) in the intervention group compared with an average increase of 26.3 mm2 (0.3%) (95% CI = -108.0-160.5) in the control group (P = .01). The area of density was reduced by 374.4 mm2 (6.1%) (95% CI = 235.1-513.8) in the intervention group compared with an average of 127.7 mm2 (2.1%) (95% CI = 8.6-246.7) in the control group (P = .01). Weight loss was associated with a reduction in breast area. The effect of the intervention on breast area was only marginally statistically significant after weight change, menopausal status, and age at trial entry were taken into account (P = .06). Greater weight loss and becoming postmenopausal were associated with statistically significant reductions in the area of density on the mammographic image at 2 years (P = .04 and P<.001, respectively). Age at entry into the trial was marginally significant in the same direction (P = .06). The effect of the intervention on area of density remained statistically significant after controlling for weight loss, age at entry, and menopausal status (P = .03). The change in the percentage of dense tissue in the mammographic image was not significantly different between the two groups (P = .71).

CONCLUSIONS AND IMPLICATIONS

These results show that after 2 years, a low-fat, high-carbohydrate diet reduced the area of mammographic density, a radiographic feature of the breast that is a risk factor for breast cancer. Longer observation of a larger number of subjects will be required to determine whether these effects are associated with changes in risk of breast cancer.

Fat and fiber intakes in relation to serum estrogen concentration in premenopausal Japanese women

It has been implied that fat and fiber intakes influence breast cancer risk. The effects of these dietary factors may be mediated by hormonal changes. We evaluated the relationships between fat or fiber intake and serum concentration of estradiol (E2) or sex hormone-binding globulin in premenopausal women. In 1994 blood samples were collected from each of 50 premenopausal healthy Japanese women on Days 11 and 22 of the menstrual cycle. Nutrient intakes were assessed by food frequency questionnaire in which the subjects were asked about their diets during one year before the study. Each nutrient intake was categorized into tertile after adjustment for total energy. Linear regression models, including age and cycle length as covariates, were utilized to evaluate the association between the nutrient intakes and the hormone concentrations. A statistically significant trend was observed between increasing fat intake and increasing E2 on Day 11 of the cycle (p = 0.05). The positive trend for increasing sex hormone-binding globulin on Day 22 with fat intake was of borderline significance (p = 0.06). There was a statistically significant inverse trend for E2 on Day 11 of the cycle with fiber intake (p = 0.05). It was suggested that fat as well as fiber intake should affect the hormone status.

Urinary markers of estrogen metabolism 2- and 16 alpha-hydroxylation in premenopausal women

There is considerable scientific interest in whether measurement of the major estrogen metabolites 2- and 16 alpha-hydroxyestrone will shed light on the role of estrogen in the risk of breast cancer. These have been difficult to measure in large numbers because of the need for radiolabeled tracers, but a new assay is able to utilize spot urine samples. The main objective of this study was to assess the reliability of a newly developed enzyme immunoassay (EIA) for the measurement of 2- and 16 alpha-hydroxyestrone in urine samples collected from a large group of healthy premenopausal women enrolled in a clinical trial A secondary objective was to assess the impact of several factors such as body weight on the urinary estrogen metabolite ratios. The study cohort included 174 women aged 44-50, who were enrolled in the Cardiovascular Risk Factors and Menopause Trial, also referred to as the Women's Healthy Lifestyle Project (WHLP), an ongoing 5-year clinical trial of 535 premenopausal women randomized either to an intensive dietary life-style intervention group or to an assessment-only control group. Measurements of 2- and 16 alpha-hydroxyestrone showed a high intraclass correlation for blind duplicate urine samples (R = 0.94 and R = 0.80), cross-sectionally and over time (R = 0.79 and R = 0.62), in this population of healthy premenopausal women. The intervention diet (of 25% of total calories from fat) did not appear to influence the estrogen metabolite ratio. This new estrogen metabolite EIA demonstrates good reliability and thus may be appropriate for use in large epidemiologic studies of estrogen-related diseases. There was no relation between dietary fat reduction, weight loss, and increased exercise and change in the ratio among premenopausal women in this study.

Nutritional aspects of amenorrhea in the female athlete triad

Female athletes experience a high incidence of menstrual abnormalities. This has critical health consequences because amenorrheic athletes are at greater risk of developing osteopenia and bone injury compared to normally menstruating athletes or nonathletic normally cycling females. Female performers and athletes are also at risk for developing disordered eating behaviors. There appears to be a connection between menstrual dysfunction, athletic training, and disordered eating, but how they relate is not fully understood. In this paper we explore how low calorie intakes, nutritional inadequacies, vegetarianism, low body fat stores, and specific training behaviors may contribute to the abnormal menstrual patterns seen in this population. Recommendations for the detection and prevention of eating and training problems and consequent menstrual abnormalities are included.

Physical activity and dietary constituents as predictors of forearm cortical and trabecular bone gain in healthy children and adolescents: a prospective study

We have prospectively studied forearm trabecular and cortical bone mineral density gain (delta BMD) in relation to nutrient intake, weight-bearing physical activity (WPA) and daylight exposure (DE) in 470 healthy boys and girls aged 8.2-16.5 years at the baseline. BMD was assessed using single photon absorptiometry (SPA). Cortical delta BMD peaked at the age of 14.0 +/- 0.3 and 16.0 +/- 0.3 (SD) years in girls and boys, respectively. Girls had achieved adult premenopausal values of trabecular BMD by the age of 15 years and cortical BMD values by the age of 16.5 years. WPA, BMD, body height, height gain, weight, weight gain, dietary polyunsaturated fat and sodium were correlated with delta BMD. WPA, predicting cortical as well as trabecular delta BMD, had the greatest effect on trabecular delta BMD in the presence of a high calcium intake in children below 11 years of age. In conclusion, our results indicate that physical activity and calcium intake should be encouraged at a prepubertal age in order to increase bone density.

Model of mouse mammary gland hyperproliferation and hyperplasia induced by a western-style diet

Mammary glands of female C57BL/6J mice were analyzed after they were fed a Western-style diet or control AIN-76A diet. The Western-style diet contained several risk factors found in human diets in geographic regions having increased risk for breast cancer: high fat and phosphate and low calcium and vitamin D. After they were fed these diets for 8, 14, and 20 weeks, mice were sacrificed, and mammary glands were removed for morphometric and radioautographic measurements. Although after the animals were fed the Western-style diet for 8 weeks the number of terminal ducts per mouse mammary gland (NTDMG) was similar in the Western-style and control diet groups, after they were fed the Western-style diet for 14 weeks (p < 0.05) and 20 weeks (p < 0.01) the NTDMG significantly increased compared with the control group. Moreover, there was a significant increase (p < 0.01) in the tritiated thymidine labeling index of mammary terminal ductal epithelial cells after 14 and 20 weeks of Western-style diet administration. Thus the Western-style diet induced increased epithelial cell proliferation and increased NTDMG in female mice when fed during young adult growth and development. The findings raise the possibility that the ingestion of a diet with Western-style fat and phosphate content and with low calcium and vitamin D may induce similar changes during the early development of the human mammary gland.

Nutrition and endometrial cancer

Epidemiologic evidence on the relation between nutrition and endometrial cancer (EC) is reviewed. Obesity is an important determinant of EC, probably because of its effect on the hormonal milieu of both pre- and postmenopausal women. However, epidemiologic studies of body fat distribution and EC are inconsistent, as are the data pertaining to the relation between body fat distribution and sex hormones. Randomized and observational studies of diet and sex hormones indicate that low fat diets may be associated weakly with decreased estrogen levels, and thus a lowering of EC risk. Only ecologic and case-control studies of diet and EC have been reported. These findings as well as the methodologic limitations of these study designs are discussed. Both types of studies implicate fat as a potential risk factor, while the case-control studies suggest that carotene may lower risk of EC. Epidemiologic studies of alcohol and EC also are inconsistent, but generally indicate no association, or a weak protective effect. The role of diet in the etiology of EC is unresolved. The conduct of cohort and intervention studies, which can avoid many of the methodologic shortcomings of ecologic and case-control studies, would improve our understanding of diet and EC.

Relations between sex hormones, sex hormone binding globulin, insulin-like growth factor-I and insulin-like growth factor binding protein-1 in post-menopausal breast cancer patients

OBJECTIVE

Oestrogens, androgens and anti-endocrine drugs such as tamoxifen and aminoglutethimide influence plasma insulin-like growth factor-I (IGF-I). IGF-I, in turn, has been found to stimulate the peripheral aromatase in vitro. The aim of this study was to examine relations between sex hormones, IGF-I and insulin-like growth factor binding protein-1 (IGFBP-1) in post-menopausal women with breast cancer.

DESIGN

To measure plasma sex steroids, sex hormone binding globulin (SHBG), IGF-I, IGFBP-1, insulin and urinary oestrogen metabolites in post-menopausal women with breast cancer not receiving any endocrine therapy.

PATIENTS

Thirty-two patients had fasting blood samples obtained between 0800 and 1000 h. A sub-group of 10 patients had 24-hour urine oestrogen metabolites determined.

MEASUREMENTS

Plasma steroids and proteins were measured by radioimmunoassays. Urinary oestrogens were measured by GC-MS.

RESULTS

SHBG correlated negatively with plasma androstenedione (P < 0.001), insulin (P < 0.001), IGF-I, height and plasma oestrone sulphate (P < 0.025 for all), but positively with plasma IGFBP-1 (P < 0.025). IGFBP-1 correlated negatively with IGF-I (P < 0.001) and the testosterone/SHBG ratio (P < 0.05). Neither IGF-I nor IGFBP-1 correlated with any of the plasma or urinary sex hormones or with the oestrone/androstenedione and oestradiol/testosterone ratios. Multivariate analysis revealed plasma SHBG to correlate positively with IGFBP-1 (P = 0.029) and negatively with insulin (P = 0.031). Plasma IGFBP-1 correlated negatively with IGF-I (P < 0.0001) but not with insulin.

CONCLUSION

Our results do not suggest any influence of plasma sex steroids in physiological concentrations on IGF-I or IGFBP-1 in post-menopausal breast cancer patients, nor do they indicate IGF-I at physiological concentrations influences the ratios between plasma oestrogens and their androgen precursors.

Factors associated with onset of menopause in women aged 45-49

This paper uses a cross-sectional sample of women aged 45-49 to investigate factors that might be associated with an early menopause. Using logistic regression analysis we found that age, smoking, age of maternal menopause, parity, social class, meat and alcohol consumption were all independently associated with an early natural menopause. Meat, alcohol consumption and maternal menopausal age do not seem to have been previously noted as associated with the timing of the menopause. These associations would merit further study, preferably using prospective data. However, this study in line with much previous work shows that smoking is associated with a reduction in menopausal age.

Eating fat or being fat and risk of cardiovascular disease and cancer among women

This article first reviews the relationship between intake of saturated fat and cholesterol and atherosclerosis; then the relationship between fat intake, obesity, and disease; and finally, some of the determinants of obesity and weight gain. The percentage of saturated fat and cholesterol in the diet is the major determinant of atherosclerosis and coronary heart disease among populations. In addition, fat intake is directly related to obesity. The degree of obesity is a major determinant of blood glucose and insulin, high-density-lipoprotein cholesterol, and triglycerides. Weight gain, especially after adolescence, and high fat intake may contribute, to a greater extent, to metabolically active intra-abdominal fat and risk of disease. Fat in diet, weight gain, or obesity may play an important role in sex-steroid hormone metabolism. Hormonal changes may contribute to an increased risk of breast cancer. The risks associated with eating fat may be related to the time of development of obesity (i.e., weight gain) and the balance between effects on sex-steroid hormone metabolism and insulin-glucose metabolism.

Dietary habits and mammographic patterns in patients with breast cancer

Between 1983 and 1986, dietary history interviews were conducted with 238 women aged 50-65 years who had surgery for stage I-II breast cancer. Diagnostic mammograms were coded in line with Wolfe's criteria in N1, P1, P2, and Dy patterns. Women with Dy pattern reported significantly higher intake of total fat, monounsaturated fatty acids (FA), polyunsaturated FA, n-3 FA, n-6 FA in per cent of energy (E%), and alpha-tocopherol in mg/10 MJ. Fat intake was lowest in women with N1 pattern and highest in those having Dy pattern. Patients having ER-rich cancers and Dy pattern reported significantly higher intake of total fat, monounsaturated FA, polyunsaturated FA, n-6 FA (E%), and alpha-tocopherol (mg/10 MJ), as well as significantly lower intake of carbohydrate (E%) and calcium (g/10 MJ). In the stepwise multivariate analysis, the multivariate-odds ratio (OR) for having P2 + Dy patterns was 1.06 (95% confidence interval (CI), 1.02-1.12) for each increment in E% of total fat. In women with ER-rich tumors this OR was 1.09 (95% CI, 1.02-1.16). The highest self-reported body mass index (BMI) was observed in women with N1 + P1 patterns. OR for having P2 + Dy patterns was 0.91 (95% CI, 0.83-0.98) for each increment in 1 kg/m2 of BMI. The results suggest that dietary habits affect the mammographic parenchymal pattern in women with breast cancer and that a high fat intake is associated with a higher proportion of mammograms with Dy pattern in such patients.

Weight loss and menstrual cycle: clinical and endocrinological evaluation

This study explores the clinical and endocrine implications of weight loss. The frequency of menstrual abnormalities was found to be greatly influenced by reduction in body weight. The occurrence of amenorrhea appeared to be proportional to the rate of weight loss, while regular cycles and luteal phase deficiency were inversely correlated to weight loss. Endocrine variations were noted. Significant decreases in luteinizing hormone and follicle stimulating hormone levels occurred only in amenorrheic patients with a weight loss higher than 20%. The estradiol level decreased in proportion to the reduction in body weight. Cortisolemia increased in all patients, with higher values apparent in amenorrheic women presenting with a weight loss higher than 20%. The prolactin values were normal except in amenorrheic patients who had lower levels. A reduction of insulin levels occurred in all groups, with a significant difference found only in amenorrheic women in Group C (weight loss higher than 20%). The data suggest that weight loss in young women causes alterations in the menstrual cycle mainly through two mechanisms involving both the hypothalamic-pituitary-adrenal axis and ovarian steroidogenesis together with estrogen catabolism.

The metabolism of 2,4-dibromo [6,7-3H]17 beta-oestradiol in the rat: ring-A dibromination blocks male-specific 15 alpha-hydroxylation and catechol formation

The metabolism in the rat of 2,4-dibromo-17 beta-oestradiol (2,4-DBE2), a compound of potential use for tumour imaging and assessment, has been studied. 2,4-DB[6,7-3H]E2 was synthesized by bromination of [6,7-3H]E2 with N-bromosuccinimide, and administered (40 micrograms/kg, i.v.) to anaesthetized male and female rats. Metabolites were rapidly and extensively excreted in bile (60 and 82% of the dose over 1 and 6 h, respectively). No unchanged compound was excreted. 2,4-DBE2 was almost entirely oxidized to 2,4-DB-oestrone; which was largely eliminated as its glucuronide but partly (approx. 30%) metabolized to 2,4-DB-16 alpha-hhydroxyoesterone and, to a minor extent, 2,4-DB-oestriol. No products of either oxidative or reductive debromination were detected. Neither of the two oxidative transformations of 2,4-DBE2 in the rat, in contrast with those of exogenous E2, was sex-selective, and 2,4-DB-oestrone underwent less extensive hydroxylation than oestrone formed from E2. In female rats, the substituents selectively redirected the principal site of hydroxylation from C-2 to C-16, whereas in males they had no significant effect on the existing 16 alpha-hydroxylation but did block the major pathway, 15 alpha-hydroxylation. Thus the sexual differentiation of E2 oxidative metabolism was abolished by direct blockage causing metabolic switching to a latent reaction in the female rat and long-range inhibition of the vicinal hydroxylation in the male rat.

Effect of wheat bran on excretion of radioactively labeled estradiol-17 beta and estrone-glucuronide injected intravenously in male rats

Urinary and fecal estrogen excretion were studied in male rats fed a non-fiber wheat starch diet (dietary fiber less than 1%; NF group; n = 4), a low-fiber wheat flour diet (dietary fiber 2%; LF group; n = 4) or a high-fiber wheat bran diet (dietary fiber 11.6%; HF group; n = 3). Short-term effects of the experimental diet on estrogen excretion were studied after i.v. injection of 5 microCi (0.185 MBq) of [14C]estradiol-17 beta (E2) into the tail vein of the rats fed the diets for 2 days. After 3 weeks on the experimental diets, the long-term effects were studied after injection of 5 microCi of [14C]E2 and 10 microCi of [3H]estrone-3-glucuronide (E1-gluc). The diet was found to affect estrogen excretion. The short-term effect indicated that rats fed the HF diet excreted a relatively large amount of labeled compounds in the feces during the first day after injection, while rats fed the NF or the LF diets excreted about half that amount over the same period. On the other hand, urinary excretion of labeled compounds was significantly higher in the NF and LF rats. The long-term effect resulted in steeper slopes (P less than 0.05) of the fecal excretion profiles of rats fed the HF diet as compared with rats fed the NF and LF diets, indicating an accelerated fecal excretion of labeled compounds in the HF rats. The kinetic profiles of 14C and 3H radioactivity in blood plasma indicated a fast decrease (t1/2 of less than 2 min) for both [14C]E2 and [3H]E1-gluc. It was concluded that, owing to the short-term effect of wheat bran intake, during the first 24 h after i.v. administration relatively large amounts of radioactively labeled compounds are excreted in feces of rats fed the HF diet. In contrast, excretion is lower in urine of these rats. When the microflora is adapted to the experimental diet the wheat bran diet still results in an accelerated fecal excretion of labeled compounds, which might be attributed to an interruption of the enterohepatic circulation of estrogens. This might result in lowered plasma and/or tissue estrogen levels and hence a decreased exposure of estrogen-sensitive tissue to estrogens, which might decrease risk on mammary (breast) cancer development.