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Biomedical subjects

H G Burger

Publications and source records attributed to H G Burger.

At least 19 recordsLinked to original sources
PubMed2002

Inhibins/activins as diagnostic markers for ovarian cancer.

It is widely recognised that the early detection and subsequent assessment of recurrence of ovarian cancers are key steps for successful treatment. Available serum markers (e.g. CA125) are sensitive for some epithelial carcinomas (e.g. serous, endometrioid, clear cell), however, these markers are less sensitive for granulosa cell tumours and mucinous carcinomas. Serum inhibin is an ovarian product which decreases to non detectable levels after menopause, however, certain ovarian cancers (mucinous carcinomas and sex cord stromal tumours such as granulosa cell tumours) continue to produce inhibin which provides a basis for a serum diagnostic test. Studies from this and other laboratories have investigated the suitability of inhibin as a diagnostic marker by identifying which inhibin (inhibin A (alphabetaA), inhibin B (alphabetaB), free alpha subunit) or activin (betaAbetaA) form is associated with these cancers. Available data show that inhibin assays which detect all inhibin forms, i.e. assays which detect the alpha subunit both as the free form and as an alphabeta subunit dimer provide the highest sensitivity/specificity characteristics as an ovarian cancer diagnostic test. This review will discuss the data supporting these observations and show recent studies in which a new alpha subunit monoclonal antibody-based ELISA is used as a potential diagnostic test. Furthermore, based on the high sensitivity/specificity characteristics of the respective assays for the various types of ovarian cancer, the combination of the inhibin assay with CA125 detects the majority of all ovarian cancers.

Activins↗
PubMed2002

Surgical or medical treatment of polycystic ovary syndrome: a cost-benefit analysis.

With the availability of laparoscopic ovarian cautery, there has been a resurgence in interest in the surgical treatment of clomiphene citrate-resistant polycystic ovary syndrome (PCOS). Comparison of ovulation and pregnancy rates has found no difference in success rates between ovarian cautery and gonadotropin ovulation induction for such women. We have therefore compared the cost of laparoscopic ovarian cautery with that of a typical cycle of gonadotropin ovulation induction, and also found that there is little difference. Because of the potential advantages of ovarian cautery, we recommend this surgery as the next line of treatment if clomiphene citrate fails to induce ovulation in PCOS patients, before gonadotropins are introduced.

Cautery↗
PubMed2002

FSH-regulated gene expression profiles in ovarian tumours and normal ovaries.

Development, growth and function of the ovary are controlled by endocrine and paracrine signals. These may also influence the development of ovarian cancer. The aim of this study was to identify the key molecular markers of the unregulated growth and hormone synthesis seen in ovarian tumours, particularly in granulosa cell tumours (GCT). Genes used in this study were chosen on the basis of our understanding of growth and differentiation in the normal ovary. We sought to define the patterns of gene expression in a panel of epithelial and stromal ovarian tumours. Expression was determined by RT-PCR using gene-specific primers for the FSH receptor (FSHR); the FSH early response genes: regulatory subunit of protein kinase A (RII-beta), cyclin D2 (cycD2) and sgk; and late response markers: cyclooxygenase-2 (COX-2) and the LH receptor (LHR). The GCT had high expression of FSHR compared with normal ovaries and the other tumours. cycD2 and RII-beta and COX-2 genes were also highly expressed in the GCT. sgk and LHR expression was lower in all of the tumours than in normal ovaries. Serous cystadenocarcinomas also had an unexpectedly high expression of COX-2. Comparison of the gene expression profiles between each tumour group suggests a molecular phenotype for GCT that is similar to that reported for FSH stimulated pre-ovulatory granulosa cells.

Adult↗
PubMed2002

Characterization of inhibin forms and their measurement by an inhibin alpha-subunit ELISA in serum from postmenopausal women with ovarian cancer.

The aim of this study was to characterize the molecular wt forms of inhibins A and B and its free alpha-subunit present in serum from women with ovarian cancer as a basis for developing improved monoclonal antibody-based inhibin assays for monitoring ovarian cancer. Three new inhibin alpha-subunit (alphaC) ELISAs were developed using monoclonal antibodies directed to three nonoverlapping peptide regions of the alphaC region of the inhibin alpha-subunit. To characterize serum inhibin molecular wt forms present in women with ovarian cancer, existing inhibin immunoassays (inhibin A, inhibin B, and pro-alphaC) and the new alphaC ELISAs were applied to sera from women with granulosa cell tumors and mucinous carcinomas previously fractionated using a combined immunoaffinity chromatography, preparative SDS-PAGE, and electroelution procedure. The distribution and molecular size of dimeric inhibins and alpha-subunit detected were consistent with known mol wt forms of inhibins A and B and inhibin alpha-subunit and their precursor forms present in serum and follicular fluid from healthy women. The alphaC ELISAs recognized all known forms of inhibin and the free inhibin alpha-subunit, although differences between alphaC ELISAs were observed in their ability to detect high mol wt forms. To assess which of the alphaC ELISAs was preferred in application to ovarian cancer, the alphaC ELISAs were applied to serum from a range of normal postmenopausal women (n = 61) and postmenopausal women (n = 152) with ovarian (serous, mucinous, endometrioid, clear cell carcinomas, and granulosa cell tumors) and nonovarian (breast and colon) cancers. Despite differences in their ability to detect high mol wt forms of inhibin, the alphaC ELISAs showed similar sensitivity (i.e. proportion of cancer patients correctly detected) and specificity (proportion of controls correctly detected) indexes in the detection of mucinous carcinomas (84% and 95%) and granulosa cell tumors (100% and 95%) compared with earlier inhibin RIA or polyclonal antibody-based immunofluorometric assays. A combination of the alphaC ELISAs with the CA125 assay, an ovarian tumor marker that has a high sensitivity and specificity for other ovarian cancers (serous, clear cell, and endometrioid), resulted in an increase in sensitivity/specificity indexes (95% and 95%) for the all ovarian cancer group. These new monoclonal antibody-based inhibin alphaC ELISAs now provide practical and sensitive assays suitable for evaluation as diagnostic tests for monitoring ovarian cancers.

Adenocarcinoma, Mucinous↗
PubMed2001

The inhibins and ovarian cancer.

Interest in inhibin as a marker of ovarian malignancy was stimulated by the description of elevated immunoreactive inhibin levels in the sera of patients with granulosa cell tumours. Several groups have confirmed the value of serum inhibin in the diagnosis and follow-up of patients with this uncommon malignancy. Immunoreactive inhibin levels are also frequently elevated in patients with mucinous cystadenocarcinoma and less frequently in other forms of ovarian tumour. Assay of sera using the specific dimeric inhibin assays has shown that ovarian tumours are able to secrete dimeric inhibin particularly inhibin B. The less specific alpha-subunit directed assays, however, most frequently show elevated concentrations. Used in combination with CA125 as a dual tumour marker, it appears in principle that inhibin can be a useful diagnostic agent. Immunohistochemistry for the inhibin subunits has been reported with increasing frequency as a helpful method to assess suspected ovarian stromal cell tumours. Its diagnostic accuracy for other types of ovarian adenocarcinoma appears less reliable. Expression of the inhibin subunit mRNAs has been demonstrated in a variety of ovarian malignancies. The observation that inhibin levels are elevated in ovarian cancer has stimulated studies of their relevance to the molecular pathogenesis of these malignancies. Findings to date have been largely negative with no evidence for activating mutations of the FSH receptor or of the post-receptor signalling pathway proteins.

Biomarkers, Tumor↗
PubMed2001

The effects of Chinese medicinal herbs on postmenopausal vasomotor symptoms of Australian women. A randomised controlled trial.

OBJECTIVE: To evaluate the effects of a defined formula of Chinese medicinal herbs (CMH) on menopausal symptoms. DESIGN: A double-blind randomised placebo-controlled trial. METHODS: Between August 1998 and April 1999, 55 postmenopausal Australian women recruited from an urban population completed 12 weeks of intervention with either a defined formula of CMH (n = 28) or placebo (n = 27) taken twice daily as a beverage. MAIN OUTCOME MEASURES: The primary end-point was change in frequency of vasomotor events (hot flushes and night sweats). The secondary end-points were changes in score for the domains measured in the Menopause Specific Quality of Life (MENQOL) Questionnaire. RESULTS: There was a reduction in average weekly frequency of vasomotor events with CMH (-15%; 95% CI, -31% to +1%) and with placebo (-31%; 95% CI, -42% to -21%). The difference between groups favoured the use of placebo; however, this was not significant (P=0.09). Although significant reductions in scores for the various domains of the MENQOL Questionnaire were observed for both CMH and placebo, there were no significant differences between the two treatment groups for any domain. There was evidence for effect modification by previous use of natural therapies for the vasomotor, physical and sexual domains of the MENQOL Questionnaire: women with no prior use of natural therapies for their menopausal symptoms responded to therapy, whereas prior users did not. CONCLUSIONS: The defined formula of CMH was no more effective than placebo in reducing vasomotor episodes in Australian postmenopausal women, or in improving any of the four symptom domains in the MENQOL Questionnaire. Three of the MENQOL Questionnaire domains were modified by prior use of natural therapies. This finding has implications for future studies.

Aged↗
PubMed2001

Impaired fasting glycaemia in middle-aged women: a prospective study.

OBJECTIVES: To investigate: (i) the incidence of impaired fasting glycaemia (IFG) developed over 5 y in a population-based sample of Australian-born women; (ii) prospectively the factors which are associated with the development of IFG; (iii) the association of the menopausal transition with the onset of IFG and an increase in serum insulin concentrations. DESIGN AND METHODS: A total of 265 women (110 pre-, 138 peri-, 17 postmenopausal) participants in the longitudinal phase of the Melbourne Women's Midlife Health Project, aged 46-57 and with normal fasting plasma glucose concentrations at the time of the initial measure, were interviewed, had physical measurements and blood taken annually over a 5 y follow-up period. RESULTS: During the study period 43 women (16%) recorded a fasting glucose concentration of > or =6.1 mmol/l (IFG). Women who recorded IFG prospectively had, at the time of the initial measure when fasting glucose concentrations were normal: higher body mass index (BMI), trunk skinfold thicknesses, waist and hip circumferences (P<0.005), lower SHBG, higher free androgen index and serum insulin concentrations (P<0.05), higher systolic blood pressure, serum triglyceride and lower HDL-cholesterol concentrations (P<0.05) than women whose fasting glucose concentrations remained normal. The onset of IFG was not triggered by the menopausal transition or hormone use. Changes in insulin concentration were associated with changes in BMI (P<0.05). CONCLUSION: Women who developed IFG during the menopausal transition exhibited significantly higher levels of body fatness and dyslipidemia, premenopausally, compared with the women who did not develop IFG. The menopausal transition did not have an effect on the development of IFG, but weight gain during this period was associated with an increase in insulin concentration.

Australia↗
PubMed2001

Physiological principles of endocrine replacement: estrogen.

The major biologically active circulating estrogen in both males and females is estradiol (E(2)). Circulating E(2) is a product of the ovarian granulosa cell and the testicular Leydig cell. Its gonadal formation is dependent on A-ring aromatization of its immediate precursor, testosterone, by a particular isoform of the enzyme aromatase, which also catalyses the conversion of the much weaker androgen, androstenedione, to the weak estrogen, estrone. E(2) is also formed in non-gonadal tissues, such as adipose tissue, liver, muscle and brain. Only adipose tissue makes significant extra-gonadal contributions to circulating estrogen. Loss of ovarian function during reproductive life, as a result of loss of gonadotropin secretion (secondary hypogonadism) or as a result of premature ovarian failure (generally defined as cessation of ovarian function prior to age 40), results in loss of the majority of circulating E(2) and of luteal progesterone. Loss of ovarian function at the menopause likewise results in a 90% loss of circulating E(2). The consequences of loss of ovarian function during reproductive life may be severe. Symptoms include hot flushes, night sweats, vaginal dryness and dyspareunia, loss of libido, loss of bone mass with subsequent osteoporosis and abnormalities of cardiovascular function, including a substantial increase in the risk of ischemic heart disease. Various regimens of estrogen replacement have been employed, aiming to eliminate symptoms, restore well-being and avert the consequences of estrogen depletion. The commonly adopted form of replacement is with the low-dose oral contraceptive pill for reasons of convenience, cost, efficacy, general freedom from side effects and the psychological advantage that many of the patient's peer group are also "taking the pill". An often neglected aspect of hormone therapy in the reproductive age group is the therapeutic use of testosterone. The application of such principles to the postmenopausal period is more problematic, as there is a common perception that the menopause is a normal physiological occurrence and that it is therefore not physiological to offer hormone therapy at that time. The pragmatic approach is to recommend standard therapy with estrogen and progestogen for the management of menopausal symptoms and to recommend longer term hormone replacement in the light of the individual's needs and current data with regard to efficacy for protection from osteoporosis and cardiovascular disease.

Estrogen Replacement Therapy↗
PubMed2000

Longitudinal study of risk factors for coronary heart disease across the menopausal transition.

The patterns of change in blood lipids, diastolic blood pressure, body mass index, smoking and drinking behaviors, and exercise were examined in an ongoing longitudinal study from 1991 to 1995 of 150 middle-aged Melbourne, Australia, women as they passed through menopause. Changes in risk factors over time were examined with reference to time of the final menstrual period (FMP). Random effects models were fitted with adjustments for repeated measures and other covariates, including age. There were overall net increases between 3 years before and the 3 years after menopause of 0.25 mmol/liter for low density lipoprotein cholesterol, 0.05 mmol/liter for high density lipoprotein cholesterol (HDL cholesterol), 0.34 mmol/liter for triglycerides, 0.12 kg/m2 for body mass index, and 0.48 mmHg for diastolic pressure. The proportion of drinkers decreased by 13%, that of smokers increased by 17%, and that of women who exercised at least once a week increased by 6%. The only change dependent on the FMP was a significant decrease in HDL cholesterol (counterbalanced by a similar rise in HDL cholesterol in the year before the FMP), and the rate of decrease was maximal around 9 months after menses ceased, with an instantaneous estimate of slope of 0.55 mmol/liter per year.

Blood Pressure↗
PubMed2000

A prospective population-based study of menopausal symptoms.

OBJECTIVE: To identify symptoms that change in prevalence and severity during midlife and evaluate their relationships to menopausal status, hormonal levels, and other factors. METHODS: In a longitudinal, population-based study of 438 Australian-born women observed for 7 years with an 89% retention rate, 172 advanced from premenopause to perimenopause or postmenopause. Annual measures included a 33-item symptom check list; psychosocial, lifestyle, and health-related factors; menstrual status; hormone usage; and blood levels of follicle-stimulating hormone and estradiol (E2). RESULTS: Increasing from early to late perimenopause were the number of women who reported five or more symptoms (+14%), hot flushes (+27%), night sweats (+17%) and vaginal dryness (+17%) (all P <.05). Breast soreness-tenderness decreased with the menopausal transition (-21%). Trouble sleeping increased by +6%. The major change in prevalence was from early to late perimenopause, except for insomnia, which showed a gradual increase. Those variables most related to onset of hot flushes were number of symptoms at early perimenopause (P <.05), having an unskilled or no occupation (P <.05), more than 10 pack-years of smoking (P <.01), and decreased E2 (P <.01). The onset of night sweats increased with the change in E2 (P <.05). The onset of vaginal dryness decreased with more years of education (P <.05). Trouble sleeping was predicted by prior lower well-being (P <.01), belief at baseline that women with many interests hardly notice menopause (P <.01), and hot flushes (P <.01). CONCLUSION: Although middle-aged women are highly symptomatic, the symptoms that appear to be specifically related to hormonal changes of menopausal transition are vasomotor symptoms, vaginal dryness, and breast tenderness. Insomnia reflected bothersome hot flushes and psychosocial factors.

Adult↗
PubMed2000

Inhibins A and B are regulated differentially in the early post-partum period.

BACKGROUND: The early postpartum period is characterized endocrinologically by a rapid fall in the levels of oestradiol (E2) and immunoreactive inhibin, and a delayed rise in serum follicle stimulating hormone (FSH). No description is currently available of changes in serum inhibins A and B. OBJECTIVES: The present study aimed to examine the levels of inhibin A and B during the early weeks of postpartum lactational amenorrhoea, to determine whether there was evidence for differential regulation of the two hormones at a time when no dominant follicle was developing in the ovary. SUBJECTS AND METHODS: Serum samples were available from 12 subjects aged 29-38 in whom postpartum levels of FSH, immunoreactive inhibin, E2 and prolactin had been examined previously. Samples for hormone assays had been obtained prior to delivery, daily for the 3-5 days postpartum, and weekly thereafter. Inhibins A and B were measured by specific ELISA assays, and results were calculated as 10 day averages for samples obtained on days 1-10, 11-20, 21-30, etc. postpartum. Normal hormone concentrations for reference were obtained from volunteers, also aged 29-38, sampled on days 3-5 of a normal menstrual cycle. RESULTS: Inhibin A in the predelivery sample ranged from 62 to 1243 ng/l, geometric mean 592. Concentrations fell rapidly postpartum and reached a nadir in the low follicular phase range between days 5 and 37 postdelivery, mean 13.6 days. The concentrations of both inhibin B and FSH rose 14-27 days postpartum from their initially low postdelivery levels, to reach the normal follicular phase range. These increases in concentration were significantly correlated in all individual subjects. CONCLUSIONS: The secretion of inhibin A and B is regulated differentially during the early stages of lactational amenorrhoea, just as it is in the late luteal phase of the normal menstrual cycle. Whilst inhibin A falls postpartum, reflecting cessation of placental function, and remains low until ovulatory cycles are resumed, FSH and inhibin B rise after a delay of two weeks or more. It is postulated that the rise of inhibin B is the result of secretion from a cohort of small follicles stimulated by rising FSH levels.

Adult↗
PubMed2000

Selective oestrogen receptor modulators.

Selective oestrogen receptor modulators (SERMs) are compounds which act like oestrogens in some target tissues but which antagonise their effects in others. The first example of a SERM (referred to as a first-generation compound) was tamoxifen, for which oestrogen-like agonist activity on bone was seen to occur simultaneously with oestrogen antagonist activity on the breast. An unwanted effect of tamoxifen was its oestrogen-like action on the endometrium. Second-generation compounds have since been developed, most notably raloxifene, which has oestrogen-like actions on bone, lipids and the coagulation system, and oestrogen antagonist effects on the breast and uterus. Raloxifene has undergone very extensive, prospective, placebo-controlled, randomised trial evaluation, in which anti-fracture efficacy (to date only for vertebral fracture) has been accompanied by a major reduction in the incidence of new breast cancer. The compound is similar to placebo in its uterine effects, and similar to oestrogen in causing a two- to threefold increase in the risk of venous thromboembolism. Its lipid effects are similar to those of oestrogen, except for a relatively small effect on high-density lipoprotein cholesterol, and no significant effect on triglycerides. Data on cardiovascular event rates are not yet available; data on cognitive function are preliminary and, to date, reassuring. The mechanisms by which the same compound can exert oestrogen agonist effects on one target and antagonist effects on another are still being clarified. Important aspects include the fact that the oestrogen receptor undergoes different conformational changes according to the ligand. Thus the crystal structure of oestradiol bound to the oestrogen receptor differs from that of raloxifene bound to the same receptor. The existence of two oestrogen receptor subtypes may also be relevant. Mechanisms include differing interactions with various domains of the oestrogen receptor, and tissue-specific recruitment of steroid receptor co-activators and co-repressors may underlie some of the tissue-specific effects. The SERMs may be the prototype for other selective steroid receptor modulators, for example the androgen and progesterone receptors. The development of tissue target-specific agents is an exciting advance in endocrine pharmacology and can be extended to agents, such as tibolone, which exert some of their tissue specificity through their metabolites.

Animals↗
PubMed2000

Estrogen receptor isoform gene expression in ovarian stromal and epithelial tumors.

The factors involved in the pathogenesis of ovarian cancers remain unclear, and the response of these tumors to hormonal therapy is limited. The identification of a second estrogen receptor gene (ERbeta), expressed predominantly in ovarian granulosa cells, led us to explore its possible role in ovarian cancer, particularly in granulosa cell tumors (GCT). Several isoforms of ERbeta have been identified. We sought to define the patterns of both ERalpha and ERbeta gene expression in a panel of ovarian tumors consisting of GCT and serous and mucinous cystadenocarcinomas as well as in normal ovary. Expression was determined by RT-PCR using gene- and isoform-specific primers and probes combined with Southern blot analysis of the PCR products. Widespread expression of ERalpha was observed in all tumor types, but at relatively low levels. ERbeta is expressed predominantly in GCT, with lower levels in mucinous tumors and very low levels in serous tumors. The ERbeta2 splice variant previously reported in rodents was not observed. Only very low levels of the exon 5, exon 6, and exon 5/6 deletion variants were detected. The C-terminal truncation variant ERbeta(cx), however, exhibited widespread expression across all the tumor types. As ERbeta(cx) has been shown to be a ligand-independent antagonist of ERalpha action, the relative ratios of ERbeta(cx), ERalpha, and ERbeta may influence the response of a tumor to antiestrogen therapy.

Adult↗
PubMed2000

A prospective longitudinal study of serum testosterone, dehydroepiandrosterone sulfate, and sex hormone-binding globulin levels through the menopause transition.

The aims of this study were to describe, in relation to date of final menses, the average androgen levels of women in the years before and after this date, and to determine the extent to which these average levels were dependent on age and body mass index (BMI) and the degree of tracking in residual androgen levels, or the extent to which individuals above (below) the mean for their age or time relative to final menstrual period (FMP) and BMI remain above (below) the mean as time progresses. Serial levels of serum sex hormone-binding globulin (SHBG), testosterone (T), and dehydroepiandrosterone sulfate (DHEAS) were measured annually in 172 women from the Melbourne Women's Midlife Health Project who experienced a natural menopause during 7 yr of follow-up. Fasting blood samples were drawn between days 4-8 if women were still menstruating or after 3 months of amenorrhea. The free androgen index (FAI) was calculated as the ratio ofT to SHBG x 100. Means of the log-transformed androgen levels were analyzed as a double logistic function of time relative to FMP as well as age and BMI, and correlations between repeated androgen levels were measured. Mean SHBG levels decreased by 43% from 4 yr before to 2 yr after the FMP. The time of most change was 2 yr before FMP [95% confidence interval (CI), 0.8-3.2]. SHBG levels were, on the average, 5% lower for each halving of estradiol (E2) levels and 4% lower for each kilogram per m2 of BMI (P < 0.0001). About one third of the decline in SHBG was explained by E2 and BMI. After adjusting for all variables, SHBG showed strong tracking. Mean T levels did not vary with time relative to FMP and were independent of age and BMI. Residual values of T showed weak tracking. The FAI increased by 80% from 4 yr before FMP to 2 yr after FMP, and changed maximally 2.2 yr before FMP (95% CI, 1.2-3.2). The FAI was not related to age or E2, but was, on the average, 4% higher for each kilogram per m2 of BMI (P < 0.0001). Residual values of FAI showed moderate tracking. Mean DHEAS levels were not related to the FMP, but were 1.5% lower for each year of age (P < 0.01) and 3.8% lower for each kilogram per m2 of BMI (P < 0.0001). Residual values of DHEAS showed strong tracking. It is concluded that SHBG and FAI levels change at the time of the menopause, at least partially due to the decline in E2. DHEAS decreases as a function of age, not time relative to FMP, and T remains unchanged during the menopausal years. SHBG and DHEAS show a high degree of stability within an individual over time.

Adult↗
PubMed2000

Early follicular phase serum FSH as a function of age: the roles of inhibin B, inhibin A and estradiol.

OBJECTIVE: Reproductive aging in regularly cycling normal women is characterized by a gradual decline in ovarian follicle number and a progressive increase in serum follicle stimulating hormone (FSH), particularly over the age of 40 years. The lack of any consistent decrease in circulating estradiol and progesterone has led to the hypothesis that the FSH increase results from decreasing ovarian inhibin production. The aim of this study was to investigate the relationship between serum inhibins A and B, FSH and estradiol in normal women between the ages of 20 and 50 years. DESIGN AND PATIENTS: Serum from 66 regularly cycling subjects, aged 20-50 years, was collected on days 3-5 of the menstrual cycle for this cross-sectional study. MEASUREMENTS: Serum inhibin A and inhibin B levels were measured by specific enzyme-linked immunosorbent assays (ELISAs). Alpha subunit forms were determined by an immunofluorometric assay which detects all known monomeric and dimeric forms of inhibin A and inhibin B and free alpha subunit. FSH and estradiol levels were measured by immunoassay. Data were log transformed before analysis. RESULTS: Serum FSH, inhibin A and estradiol, but not inhibin B, were positively correlated (p < 0.05-p < 0.001) with age between years 20 and 50. Between 40 and 50 years, serum FSH was negatively correlated with inhibin B (r = -0.61, p < 0.001) and alpha subunit forms (r = -0.47, p < 0.05) and with estradiol (r = -0.39, p < 0.05), but not with inhibin A (r = -0.21, not significant). When log(FSH) was modelled as a function of log(inhibin B) and log(estradiol) with age fitted as a covariate, inhibin B only was a significant independent predictor of FSH (beta = -0.30, p < 0.01). Using purified inhibin A and B standards for the three assays, which were calibrated in terms of their alpha subunit content, serum inhibin A levels were 10-15% of those of inhibin B, with inhibin A + B levels being 22% of total alpha subunit levels. No significant correlation was observed between total inhibin alpha subunit and its dimers. The free alpha subunit, as determined from the difference in levels of total alpha subunit and inhibin A + B, remained relatively unchanged with age, suggesting that it is not differentially regulated. CONCLUSIONS: This study shows that, during the early follicular phase, FSH, inhibin A and estradiol but not inhibin B increase with age. Some of the increase in inhibin A and estradiol may be the result of accelerated follicular development with increasing age. Serum inhibin B and estradiol but not inhibin A are inversely correlated with FSH between ages 40 and 50, but only inhibin B is a significant independent predictor of FSH. This supports the postulate that inhibin B is the main form of inhibin regulating FSH at this stage of the menstrual cycle. During the early follicular phase, serum levels of inhibin A are presumably too low to play a significant physiological role or are less active.

Adult↗
PubMed1999

Hormone therapy use in Australian-born women: a longitudinal study.

OBJECTIVES: To describe the pattern of use of hormone therapy (HT) among Australian women, and its side-effects and benefits, and to compare baseline characteristics of HT users with never users. DESIGN: Longitudinal community-based study with annual interviews. SETTING: Melbourne, May 1991-October 1997. PARTICIPANTS: 357 Australian-born women aged 45-55 years who were pre- or perimenopausal and not using HT at baseline. MAIN OUTCOME MEASURES: Rates of HT use; baseline characteristics of users and non-users; side effects and benefits of HT use. RESULTS: 151 women (42%) used HT over the six years and 93 (26%) were current users at six-year follow-up. HT users did not differ significantly from non-users in lifestyle, sociodemographic and cardiovascular risk factors or in most health status factors at baseline. However, HT users were significantly more likely to have had a breast examination by a health professional (odds ratio [OR], 2.60; 95% CI, 1.62-4.17), to have had a tubal ligation (OR, 1.73; 95% CI, 1.09-2.74), to report a history of premenstrual complaints (OR, 1.72; 95% CI, 1.08-2.74), to agree that women "regret when their period stops for the last time" (OR, 1.69; 95% CI, 1.04-2.74), and to report that they took non-prescription medications (OR, 1.62; 95% CI, 1.02-2.59). Most (84%) HT users described benefits (most commonly relief of hot flushes and improved wellbeing), while 53% complained of side effects (most commonly weight gain and breast tenderness). CONCLUSIONS: HT users did not differ significantly from non-users at baseline in most characteristics. Long-term follow-up of this cohort is now required to assess any difference in cardiovascular events or other health outcomes between HT users and non-users.

Australia↗