首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Estrogens are involved in the etiology of breast cancer. Their blastomogenic influence may be partly realized through their conversion into catecholestrogens, rate of which may be modified by smoking. The risk of having breast cancer diagnosed can increase in women using estrogen replacement therapy (ERT). The principal aim of this investigation was to compare the excretion of classical estrogens and catecholestrogens in smoking and non-smoking postmenopausal women receiving Progynova (estradiol valerate, 2 mg/day, 1 month). Total 16 women were studied before and after treatment. Urinary estrogen profile method based on isotope dilution capillary gas chromatography-mass spectrometry was used. Before ERT, significantly lower excretion of 16-epiestriol and 4-hydroxyestrone (4-OHE1) and lower ratio of 4-OHE1/E1 were revealed in smokers. After ERT, much higher excretion of 2-OHE1, and 4-hydroxyestradiol (4-OHE2), higher ratios of 2-OHE1/E1 and 4-OHE1/E1 and lower ratio of 2-methoxyestrone/2-OHE1 were discovered in smokers as compared to non-smoking women. In conclusion only combination of ERT + smoking and not smoking itself leads to the specific prevalence of catecholestrogens (2-OH- and carcinogenic and DNA-damaging 4-OH-metabolites) that may increase risk of genotoxic variant of hormone-induced breast carcinogenesis without influence on the total morbidity.  相似文献   

3.
Concerns exist about the cardiovascular effects of hormone replacement therapy (HRT) in postmenopausal women because results from the Women's Health Initiative (WHI) and the Heart and Estrogen/Progestin Replacement Study (HERS) are contradictory. In both of these studies, postmenopausal conjugated equine estrogens + medroxyprogesterone acetate did not reduce risk, and somewhat increased the risk of myocardial infarction in both primary (WHI) and secondary (HERS) prevention. These results appear to contradict numerous observational clinical trials and animal studies, which reported profound beneficial effects of HRT on cardiovascular disease risk. Results of both human and monkey studies indicate that estrogen replacement therapy (ERT)/HRT is effective in inhibiting progression of early stage (fatty streak) atherosclerosis but that ERT/HRT is much less effective in inhibiting progression of more advanced (established plaque) atherosclerosis. Results of these monkey studies are consistent with those of studies in women wherein ERT/HRT was initiated in postmenopausal women with different initial amounts of atherosclerosis. Based on these findings, it is speculated that ERT/HRT may be more cardioprotective in younger postmenopausal women with less coronary artery disease, and less effective in women with established coronary artery disease. Researchers are challenged to define the relative cardiovascular risk/benefit in different populations of postmenopausal women based on differences in age, amounts of pre-existing atherosclerosis, and risk factors.  相似文献   

4.
Objective To assess the risk of venous thromboembolism in women using hormone replacement therapy by study design, characteristics of the therapy and venous thromboembolism, and clinical background.Design Systematic review and meta-analysis.Data sources Medline.Studies reviewed Eight observational studies and nine randomised controlled trials.Inclusion criteria Studies on hormone replacement therapy that reported venous thromboembolism.Review measures Homogeneity between studies was analysed using χ2 and I2 statistics. Overall risk of venous thromboembolism was assessed from a fixed effects or random effects model.Results Meta-analysis of observational studies showed that oral oestrogen but not transdermal oestrogen increased the risk of venous thromboembolism. Compared with non-users of oestrogen, the odds ratio of first time venous thromboembolism in current users of oral oestrogen was 2.5 (95% confidence interval 1.9 to 3.4) and in current users of transdermal oestrogen was 1.2 (0.9 to 1.7). Past users of oral oestrogen had a similar risk of venous thromboembolism to never users. The risk of venous thromboembolism in women using oral oestrogen was higher in the first year of treatment (4.0, 2.9 to 5.7) compared with treatment for more than one year (2.1, 1.3 to 3.8; P<0.05). No noticeable difference in the risk of venous thromboembolism was observed between unopposed oral oestrogen (2.2, 1.6 to 3.0) and opposed oral oestrogen (2.6, 2.0 to 3.2). Results from nine randomised controlled trials confirmed the increased risk of venous thromboembolism among women using oral oestrogen (2.1, 1.4 to 3.1). The combination of oral oestrogen and thrombogenic mutations or obesity further enhanced the risk of venous thromboembolism, whereas transdermal oestrogen did not seem to confer additional risk in women at high risk of venous thromboembolism.Conclusion Oral oestrogen increases the risk of venous thromboembolism, especially during the first year of treatment. Transdermal oestrogen may be safer with respect to thrombotic risk. More data are required to investigate differences in risk across the wide variety of hormone regimens, especially the different types of progestogens.  相似文献   

5.
6.
Randomized clinical trials have not shown long-term benefit of postmenopausal hormone replacement therapy (PHT) nor have they shown conclusively that the harmful consequences outweighs the benefits of the treatment. Rather, it is possible that an individualized hormone replacement therapy in questionably clinically healthy postmenopausal women may lead to different results than randomized trials. DESIGN: In this cross-sectional study we evaluated anthropometric parameters, body composition, serum lipids, blood pressure, heart rate variability (HRV) and neurocognitive functions in 39 healthy postmenopausal women PHT users or not users (n=13, age 53.0+/-3.3 and n=26, age=53.3+/-5.0 SD, respectively) as well as in 27 younger controls (ages=33.3+/-7.1). RESULTS: Demographic parameters were similar in women PHT users and not users. Postmenopausal women showed a significantly increase of body mass index (BMI) as well as of waist circumference, compared to younger controls, but in PHT users the values of fat free mass were intermediate between the ones of not treated and younger women. The study of HRV showed a reduction in low frequency (LF) component (sympathetic modulation) during the day, and a reduction in high frequency (HF) component (parasympathetic modulation), particularly in postmenopausal women without PHT. PHT users were characterized by autonomic parameters intermediate between younger controls and age-matched women without PHT. CONCLUSIONS: The impact of PHT on the age-dependent changes of anthropometric features and body composition seems to be modest but positive. Furthermore, PHT seems to play a positive role on the autonomic modulation of cardiac function, through a shift of LF/HF ratio values towards those of young controls.  相似文献   

7.
Evidence exists that the functional differences between the left and right cerebral hemispheres are affected by age. One prominent hypothesis proposes that frontal activity during cognitive task performance tends to be less lateralized in older than in younger adults, a pattern that has also been reported for motor functioning. Moreover, functional cerebral asymmetries (FCAs) have been shown to be affected by sex hormonal manipulations via hormone therapy (HT) in older women. Here, we investigate whether FCAs in fine motor coordination, as reflected by manual asymmetries (MAs), are susceptible to HT in older women. Therefore, sixty-two postmenopausal women who received hormone therapy either with estrogen (E) alone (n = 15), an E-gestagen combination (n = 21) or without HT (control group, n = 26) were tested. Saliva levels of free estradiol and progesterone (P) were analyzed using chemiluminescence assays. MAs were measured with a finger tapping paradigm consisting of two different tapping conditions. As expected, postmenopausal controls without HT showed reduced MAs in simple (repetitive) finger tapping. In a more demanding sequential condition involving four fingers, however, they revealed enhanced MAs in favour of the dominant hand. This finding suggests an insufficient recruitment of critical motor brain areas (especially when the nondominant hand is used), probably as a result of age-related changes in corticocortical connectivity between motor areas. In contrast, both HT groups revealed reduced MAs in sequential finger tapping but an asymmetrical tapping performance related to estradiol levels in simple finger tapping. A similar pattern has previously been found in younger participants. The results suggest that, HT, and E exposure in particular, exerts positive effects on the motor system thereby counteracting an age-related reorganization.  相似文献   

8.
OBJECTS: To investigate the effect of combined estrogen and progesterone therapy on insulin resistance (IR) and carbohydrate and lipid metabolism in postmenopausal women (PMW) with impaired (IGT) and normal glucose tolerance (NGT). METHODS: Sixteen Japanese PMW with IGT and 33 with NGT received daily oral hormone replacement therapy (HRT; 0.625 mg of conjugated equine estrogen plus 2.5 mg of medroxyprogesterone acetate) for 12 months. As controls, 13 Japanese PMW with IGT and 31 with NGT were enrolled and not treated by HRT. Fasting plasma glucose (FPG), fasting immunoreactive insulin (IRI), and IR were measured in each subject at study initiation and 12 months later. We used homeostasis model assessment (HOMA) to determine IR. RESULTS: FPG and HOMA IR were decreased in both HRT groups, and fasting IRI was reduced in the HRT-NGT group. In controls, FPG, fasting IRI, and HOMA IR were unaltered. Total and low-density lipoprotein cholesterol were decreased and high-density lipoprotein cholesterol was increased in both HRT groups, but triglyceride was unchanged. In controls, lipid metabolism was unaltered. CONCLUSION: HRT decreased IR and improved carbohydrate and lipid metabolism in Japanese PMW with IGT and NGT. These beneficial effects argue for the use of HRT in PMW with IGT as well as NGT.  相似文献   

9.
10.
Hormone replacement therapy is increasingly being used for purposes unrelated to the alleviation of menopausal symptoms, such as the prevention of osteoporosis and cardiovascular disease. Clinical trials, however, suggest that the one drug/many purposes concept may be too optimistic. The availability of new estrogen-like compounds and the discovery of a second estrogen receptor have opened new possibilities for more specific drug development.  相似文献   

11.
12.
13.
Two groups of postmenopausal women were seen at monthly intervals during a three-month trial of continuous therapy with oral unconjugated oestrogens. Ten women in the first group were administered daily Hormonin No. 1 containing oestriol (E3) 0.135 mg, oestradiol (E2) 0.3 mg and oestrone (E1) 0.7 mg. Eight women in the second group received Hormonin No. 2 containing E3 0.27 mg, E2 0.6 mg and E1 1.4 mg. E1, E2, E3 and dehydroepiandrosterone (DHA) as well as follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured by radioimmunoassay. Maturation index of vaginal smears and clinical effects were also evaluated. Oral replacement therapy with these unconjugated oestrogens produced a significant elevation of E1 (p less than 0.05) and E2 (p less than 0.05) to values corresponding well with the premenopausal range measured in our laboratory. Postmenopausal levels of FSH and LH showed only a moderate but significant decrease (p less than 0.05). There was consistent relief of vasomotor symptoms. One case of endometrial focal adenomatous hyperplasia uncovered during the period of treatment was transformed to functional secretory endometrium after an appropriate course with progestogens. Oral administration of unconjugated oestrogens and periodic withdrawal bleeding induced with a progestational agent seems to be an effective method of replacement therapy in postmenopausal women.  相似文献   

14.
Brooks, E. M., A. L. Morgan, J. M. Pierzga, S. L. Wladkowski, J. T. O'Gorman, J. A. Derr, and W. L. Kenney. Chronic hormone replacement therapy alters thermoregulatory and vasomotor function in postmenopausal women. J. Appl.Physiol. 83(2): 477-484, 1997.This investigationexamined effects of chronic (2 yr) hormone replacement therapy (HRT),both estrogen replacement therapy (ERT) and estrogen plus progesteronetherapy (E+P), on core temperature and skin blood flow responses ofpostmenopausal women. Twenty-five postmenopausal women [9 not onHRT (NO), 8 on ERT, 8 on E+P] exercised on a cycle ergometer for1 h at an ambient temperature of 36°C. Cutaneous vascularconductance (CVC) was monitored by laser-Doppler flowmetry, and forearmvascular conductance (FVC) was measured by using venous occlusionplethysmography. Iontophoresis of bretylium tosylate was performedbefore exercise to block local vasoconstrictor (VC) activity at oneskin site on the forearm. Rectal temperature (Tre) was ~0.5°C lower forthe ERT group (P < 0.01) comparedwith E+P and NO groups at rest and throughout exercise. FVC: mean body temperature (Tb) and CVC:Tb curves were shifted~0.5°C leftward for the ERT group(P < 0.0001). Baseline CVC wassignificantly higher in the ERT group(P < 0.05), but there was nointeraction between bretylium treatment and groups once exercise wasinitiated. These results suggest that1) chronic ERT likely acts centrally to decrease Tre,2) ERT lowers theTre at which heat-loss effector mechanisms are initiated, primarily by actions on active cutaneous vasodilation, and 3) addition ofexogenous progestins in HRT effectively blocks these effects.

  相似文献   

15.
Stevenson, Edith T., Kevin P. Davy, Pamela P. Jones,Christopher A. Desouza, and Douglas R. Seals. Blood pressure risk factors in healthy postmenopausal women: physical activity and hormonereplacement. J. Appl. Physiol. 82(2):652-660, 1997.The prevalence of cardiovascular disease (CVD)increases with advancing age in women, particularly after menopause.CVD risk is lower in physically active women relative to theirsedentary peers, but the responsible mechanisms are not wellunderstood. The aims of this study were to test the hypotheses that1) physically active postmenopausalwomen demonstrate more favorable blood pressure (BP)-related riskfactors for CVD than do sedentary healthy women and2) women on hormone replacementtherapy (HRT) also have more favorable levels of these CVD riskfactors. BP-related CVD risk factors were measured in physically activewomen (n = 18; age 55 ± 1 yr;n = 8 on HRT) and in healthyless-active controls (n = 34; age 59 ± 1 yr; n = 17 on HRT). Maximaloxygen consumption was higher in the active group, whereas waist-to-hipratio and waist circumference were lower (allP < 0.005). The activewomen demonstrated marginally lower (5-8 mmHg;P  0.10) levels of casual, 24-h, anddaytime systolic BP (SBP). They also tended to have lower(P = 0.11) daytime SBP loads(percentage of BP recordings >140/90 mmHg) and lower daytime andnighttime BP variabilities (P = 0.04)and a reduced (P < 0.007) SBPresponse to submaximal exercise. Women on HRT tended to have lower(3-4 mmHg; P = 0.07) levels of24-h and nighttime diastolic BP (DBP) relative to the nonusers andsmaller (P < 0.04) daytime and 24-hDBP loads. Stepwise multiple regression indicated that waistcircumference was the primary predictor of most of the SBP-related CVDrisk factors while HRT use was the best predictor for DBP loads. Thesefindings indicate that, in general, physically active postmenopausalwomen demonstrate more favorable SBP-related CVD risk factors relative to their less-active healthy peers, which may be mediated, in part, bytheir lower levels of abdominal adiposity. In addition, HRT use tendsto be associated with lower levels of DBP-related CVD risk factors.

  相似文献   

16.
17.
Postmenopausal women receiving estrogen-replacement therapy (ERT) regulate body temperature (T(b)) at a lower level than women not receiving hormone replacement therapy (untreated) and women using estrogen plus progesterone therapy (E + P), but it is not clear if reproductive hormones alter T(b) by directly acting on central thermoregulatory centers or indirectly via a secondary mediator(s). The purpose of the present investigation was to examine the possible involvement of pyrogenic cytokines and cyclooxygenase (COX) products (e.g., prostaglandins) in the regulation of T(b) in three groups of postmenopausal women (8 ERT, 7 E + P, and 8 untreated). We measured ex vivo secretion of cytokine agonists [tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta and -6] and modifiers (IL-2 soluble receptor, IL-1 receptor antagonist, soluble TNF receptor type I, soluble TNF receptor type II, soluble IL-6 receptor, and soluble glycoprotein 130) from peripheral blood mononuclear cells and thermoregulatory responses at rest and during 1 h of passive whole body heating in the postmenopausal women before and after 3 days of placebo or aspirin (50 mg. day(-1). kg(-1)). With and without aspirin, the ERT group had a lower baseline rectal temperature (T(re); 0.44 degrees C, P < 0.004) and a reduced T(b) threshold for cutaneous vasodilation (0.29 degrees C and 0.38 degrees C, P < 0.01) compared with the untreated and E + P groups, respectively. In the placebo condition, waking morning oral temperature (T(or)) correlated with ex vivo secretion of the proteins associated with IL-6 bioactivity. Aspirin caused significant reductions in waking T(or) in the E + P group and in baseline T(re) in the untreated group. However, the difference in thermoregulation brought about by steroid hormone treatment could not be explained by these relatively modest apparent influences by cytokines and COX products. Therefore, the altered thermoregulation induced by reproductive steroid therapy appears to occur via a mechanism distinct from a classic infection-induced fever.  相似文献   

18.
Urogenital infections in postmenopausal women remain problematic. The use of estrogen replacement therapy has been shown to lower these infection rates, corresponding to increasing colonization by Lactobacillus species. Despite the gut's 500 microbial species and the proximity of the anus to the vagina, only a relatively few microbial strains appear to be able to colonize the urogenital area. In the present study, the sparsity of microbes in the vagina was confirmed by denaturing gradient gel electrophoresis analysis of swabs taken at time zero and monthly for 3 months from 40 postmenopausal subjects receiving Premarin (conjugated equine estrogen in combination with progesterone) hormone replacement therapy (HRT) and 20 who were not on HRT. Lactobacilli were recovered from the vagina of 95% or more women in both groups, but in the HRT group, Lactobacillus were more often the dominant and only colonizers and significantly fewer bacteria with pathogenic potential were found. The incidence of bacterial vaginosis was significantly lower in the HRT group than in the non-HRT-treated women (5.6% versus 31%). The use of HRTs has recently come under criticism. The ability of drugs such as Premarin to help recover the lactobacilli vaginal microbiota appears to be at least one benefit of HRT use. In women not using HRTs, use of probiotics may be the only way to restore a nonpathogen-dominated flora.  相似文献   

19.
The purpose of this study was to investigate the effect of norepinephrine and vasopressin on urinary kallikrein excretion in the rat. Two studies were undertaken: (a) acute experiments in which the rats were infused with 30% dextrose in water with the addition of norepinephrine or vasopressin, (b) chronic experiments in which the drugs were infused during seven days through an osmotic minipump. In acute experiments, urinary kallikrein excretion increased without modification in urinary flow and glomerular filtration rate. In chronic experiments, urinary kallikrein excretion was not modified in norepinephrine-treated rats and decreased in vasopressin-infused animals. This decrease followed the modifications of the urine flow. In chronic experiments the dextrose infusion increased urinary kallikrein excretion. In all the groups studied a positive correlation between urine flow and urinary kallikrein excretion was observed. It is concluded that norepinephrine and vasopressin are important stimulators of the urinary kallikrein excretion only in those circumstances where it is necessary to eliminate an excess of water.  相似文献   

20.
Epidemiological studies have revealed that postmenopausal estrogen replacement therapy results in a marked reduction in the risk for cardiovascular diseases. In the present study, we evaluated plasma lipoprotein profile as well as homocysteine levels in 145 postmenopausal and premenopausal Chinese women living in Hong Kong. We also investigated the effect of hormonereplacement therapy (HRT) with estrogen or estrogen combined with progestin on plasma lipoprotein profile and homocysteine concentrations in those individuals. Postmenopausal women displayed significantly higher plasma levels of total cholesterol, LDLcholesterol and apoB as well as higher plasma homocysteine levels than that of premenopausal women. HRT with either estrogen (17-estradiol or conjugated equine estrogen) alone or estrogen combined with progestin for 3.5–4.5 years significantly improved the lipoprotein profile in postmenopausal women by decreasing the levels of total cholesterol (12–20% reduction), LDL-cholesterol (26–29% reduction) and apoB (21–25% reduction). In women treated with 17estradiol or conjugated equine estrogens their plasma levels of apoAI were significantly elevated (18% elevation) as compared to non-users. HRT also reduced plasma concentrations of homocysteine (13–15% reduction). In conclusion, we found that long-term HRT was associated with improvement in plasma lipoprotein profile and a reduction in homocysteine concentration in postmenopausal women. These results support the notion that the improvement of lipoprotein profile and a reduction in homocysteine concentration may contribute to the beneficial effect of HRT on cardiovascular risk.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号