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Publication
Journal: Journal of Clinical Endocrinology and Metabolism
January/9/2006
Abstract
BACKGROUND
The polycystic ovary syndrome (PCOS) is frequently associated with obesity. However, there are very few data about PCOS in morbid obesity, especially with regard to its evolution after bariatric surgery.
OBJECTIVE
The objective of this study was to evaluate the response of PCOS to the sustained and marked weight loss achieved by bariatric surgery in morbidly obese women.
METHODS
This was a longitudinal prospective nonrandomized evaluation.
METHODS
The study was performed at an academic hospital.
METHODS
Thirty-six consecutive premenopausal women submitted to bariatric surgery were screened for PCOS, which was present in 17.
METHODS
Bariatric surgery was performed.
METHODS
Hyperandrogenism, menstrual function, and insulin resistance were estimated before and at least 6 months after bariatric surgery in 12 patients with PCOS.
RESULTS
Weight loss (41 +/- 9 kg after 12 +/- 5 months) was paralleled by decreases in the hirsutism score (from 9.5 +/- 6.8 to 4.9 +/- 4.2; P = 0.001), total (69 +/- 32 to 42 +/- 19 ng/dl; P < 0.02) and free testosterone (from 1.6 +/- 0.7 to 0.6 +/- 0.3 ng/dl; P < 0.005), androstenedione (from 4.1 +/- 1.5 to 3.0 +/- 0.9 ng/ml; P < 0.02), and dehydroepiandrosterone sulfate (from 2000 +/- 1125 to 1353 +/- 759 ng/ml; P < 0.005); amelioration of insulin resistance estimated by homeostasis model assessment (from 6.0 +/- 3.0 to 1.6 +/- 1.0; P < 0.001); and restoration of regular menstrual cycles and/or ovulation in all patients.
CONCLUSIONS
The PCOS is a frequent finding in women with morbid obesity and may resolve after weight loss induced by bariatric surgery.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
January/6/2010
Abstract
BACKGROUND
In postmenopausal women, endogenous bioavailable testosterone (T) and estradiol (E2) have been positively associated, and SHBG has been negatively associated, with incident type 2 diabetes (T2DM). Previous studies have not explored possible factors explaining these relationships.
OBJECTIVE
Our objective was to examine the association of endogenous sex hormones with incident T2DM in postmenopausal women and possible explanatory factors.
METHODS
The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective study that included 1612 postmenopausal women aged 45-84 yr, followed between the years 2000-2006, who were not taking hormone replacement therapy, had no prevalent cardiovascular disease or diabetes, and had complete ascertainment of sex hormones.
METHODS
T2DM was defined based on fasting glucose and/or treatment for diabetes.
RESULTS
There were 116 incident cases of diabetes during follow-up. Across higher quartiles of bioavailable T and E2 and lower quartiles of SHBG, we found significantly greater hazards of developing incident T2DM (all P for trend <or=0.001). After adjustment for body mass index and insulin resistance estimated by homeostasis model assessment of insulin resistance, bioavailable T was no longer associated with incident T2DM. The associations of E2 and SHBG with incident T2DM were partially explained by body mass index and insulin resistance but persisted in fully adjusted models (both P for trend <0.02). <em>Dehydroepiandrosterone</em> had no relationship with incident T2DM.
CONCLUSIONS
Adiposity and insulin resistance explained most of the association of bioavailable T but only partially explained the associations of E2 and SHBG with incident T2DM among postmenopausal women.
Publication
Journal: Biochemical Journal
July/2/2003
Abstract
Human multidrug-resistance protein (MRP) 4 transports cyclic nucleotides and when overproduced in mammalian cells mediates resistance to some nucleoside analogues. Recently, it has been shown that Mrp4 is induced in the livers of Fxr ((-/-)) mice, which have increased levels of serum bile acids. Since MRP4, like MRP1-3, also mediates transport of a model steroid conjugate substrate, oestradiol 17-beta-D-glucuronide (E(2)17betaG), we tested whether MRP4 may be involved in the transport of steroid and bile acid conjugates. Bile salts, especially sulphated derivatives, and cholestatic oestrogens inhibited the MRP4-mediated transport of E(2)17betaG. Inhibition by oestradiol 3,17-disulphate and taurolithocholate 3-sulphate was competitive, suggesting that these compounds are MRP4 substrates. Furthermore, we found that MRP4 transports dehydroepiandrosterone 3-sulphate (DHEAS), the most abundant circulating steroid in humans, which is made in the adrenal gland. The ATP-dependent transport of DHEAS by MRP4 showed saturable kinetics with K (m) and V (max) values of 2 microM and 45 pmol/mg per min, respectively (at 27 degrees C). We further studied the possible involvement of other members of the MRP family of transporters in the transport of DHEAS. We found that MRP1 transports DHEAS in a glutathione-dependent manner and exhibits K (m) and V (max) values of 5 microM and 73 pmol/mg per min, respectively (at 27 degrees C). No transport of DHEAS was observed in membrane vesicles containing MRP2 or MRP3. Our findings suggest a physiological role for MRP1 and MRP4 in DHEAS transport and an involvement of MRP4 in transport of conjugated steroids and bile acids.
Publication
Journal: Cancer Research
October/27/1997
Abstract
This study investigates the significance of the glucose-6-phosphate dehydrogenase (G6PD) catalyzed oxidative and the transketolase (TK) catalyzed nonoxidative pentose cycle (PC) reactions in the tumor proliferation process by characterizing tumor growth patterns and synthesis of the RNA ribose moiety in the presence of respective inhibitors of G6PD and TK. Mass spectra analysis of 13C-labeled carbons revealed that these PC reactions contribute to over 85% of de novo ribose synthesis in RNA from [1,2-(13)C]glucose in cultured Mia pancreatic adenocarcinoma cells, with the fraction synthesized through the TK pathway predominating (85%). Five days of treatment with the TK inhibitor oxythiamine (OT) and the G6PD inhibitor dehydroepiandrosterone-sulfate (0.5 microM each) exerted a 39 and a 23% maximum inhibitory effect on cell proliferation in culture, which was increased to 60% when the two drugs were administered in combination. In vivo testing of 400 mg/kg OT or dehydroepiandrosterone-sulfate in C57BL/6 mice hosting Ehrlich's ascitic tumor cells revealed a 90.4 and a 46% decrease in the final tumor mass after 3 days of treatment. RNA ribose fractional synthesis through the TK reaction using metabolites directly from glycolysis declined by 9.1 and 23.9% after OT or the combined treatment, respectively. Nonoxidative PC reactions play a central regulating role in the carbon-recruiting process toward de novo nucleic acid ribose synthesis and cell proliferation in vitro and in vivo. Therefore, enzymes or substrates regulating the nonoxidative synthesis of ribose could also be the sites to preferentially target tumor cell proliferation by new anticancer drugs.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
April/6/1992
Abstract
Immediate post-training intracerebroventricular administration to male mice of pregnenolone (P), pregnenolone sulfate (PS), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), androstenedione, testosterone, dihydrotestosterone, or aldosterone caused improvement of retention for footshock active avoidance training, while estrone, estradiol, progesterone, or 16 beta-bromoepiandrosterone did not. Dose-response curves were obtained for P, PS, DHEA, and testosterone. P and PS were the most potent, PS showing significant effects at 3.5 fmol per mouse. The active steroids did not show discernible structural features or known membrane or biochemical effects that correlated with their memory-enhancing capacity. The above, together with the findings that DHEA acted even when given at 1 hr after training and that P, PS, and DHEA improved retention over a much wider dose range than do excitatory memory enhancers, led to the suggestion that the effects of the active steroids converge at the facilitation of transcription of immediate-early genes. P and PS, for which receptors have not yet been demonstrated, may exert their effects by serving as precursors for the formation of a panoply of different steroids, ensuring near-optimal modulation of transcription of immediate-early genes required for achieving the plastic changes of memory processes. Low serum levels of P in aging and the increases of cancer and behavioral disorders in individuals receiving drugs that block synthesis of cholesterol, the immediate precursor of P, suggest possible clinical utility for P.
Publication
Journal: International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity
December/26/1996
Abstract
BACKGROUND
Obesity is considered a protective factor for osteoporosis improving bone mass and maintaining higher levels of estrogen during menopause.
OBJECTIVE
To determine the association of obesity with bone mineral density (BMD), and its relationship with sex hormone levels.
METHODS
A case-control study in Caucasian obese and non obese postmenopausal women.
METHODS
113 obese and 50 non-obese postmenopausal women.
METHODS
BMD (dual-photon X-ray absorptiometry) at cervical femur. Ward's triangle, proximal radius and lumbar spine. Plasma levels of glucose, insulin, total estrogen, follicle stimulating hormone (FSH), sex hormone binding globulin (SHBG), dehydroepiandrosterone sulfate (DHA-S) and testosterone.
RESULTS
Mean BMD at femoral sites were significantly higher in obese women (femoral neck: 0.849 +/- 0.124 g/cm2 vs 0.753 +/- 0.095 g/cm2, P < 0.001; Ward's triangle: 0.634 +/- 0.134 g/cm2 vs. 0.553 +/- 0.100 g/cm2, P < 0.001). Mean BMD at lumbar spine was 0.906 +/- 0.138 g/cm2 in obese women and 0.849 +/- 0.137 g/cm2 in non obese, P < 0.017. A decreased risk of osteopenia in femoral neck (Age adjusted OR = 0.36, 95%CI 0.17-0.75) and in lumbar spine (Age adjusted OR = 0.43, 95%CI 0.20-0.91) in obese women was observed. Although total estrogen were similar in both groups, in obese women, SHBG was lower (68.6 +/- 26.84 nmol/l vs. 85.1 +/- 31.18 nmol/l, P < 0.001), and postglucose load insulin levels were higher, than in non obese (77.2 +/- 50.4 Ul/ml vs. 49.4 +/- 24.1 Ul/ml, P < 0.0005).
CONCLUSIONS
The findings confirm a higher BMD in obese women and suggest that obesity exerts protection due to a decreased SHBG thus increasing free sex steroids. Besides, hyperinsulinemia may produce a decline in the production of IGFBG-1, leading to an increase of IGF-1, that may stimulate the proliferation of osteoblasts.
Publication
Journal: Endocrine Reviews
October/6/2003
Abstract
Serum androgens as well as their precursors and metabolites decrease from the age of 30-40 yr in women, thus suggesting that a more physiological hormone replacement therapy at menopause should contain an androgenic compound. It is important to consider, however, that most of the androgens in women, especially after menopause, are synthesized in peripheral intracrine tissues from the inactive precursors dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) of adrenal origin. Much progress in this new area of endocrine physiology called intracrinology has followed the cloning and characterization of most of the enzymes responsible for the transformation of DHEA and DHEA-S into androgens and estrogens in peripheral target tissues, where the locally produced sex steroids are exerting their action in the same cells in which their synthesis takes place without significant diffusion into the circulation, thus seriously limiting the interpretation of serum levels of active sex steroids. The sex steroids made in peripheral tissues are then inactivated locally into more water-soluble compounds that diffuse into the general circulation where they can be measured. In a series of animal models, androgens and DHEA have been found to inhibit breast cancer development and growth and to stimulate bone formation. In clinical studies, DHEA has been found to increase bone mineral density and to stimulate vaginal maturation without affecting the endometrium, while improving well-being and libido with no significant side effects. The advantage of DHEA over other androgenic compounds is that DHEA, at physiological doses, is converted into androgens and/or estrogens only in the specific intracrine target tissues that possess the appropriate physiological enzymatic machinery, thus limiting the action of the sex steroids to those tissues possessing the tissue-specific profile of expression of the genes responsible for their formation, while leaving the other tissues unaffected and thus minimizing the potential side effects observed with androgens or estrogens administered systemically.
Publication
Journal: Archives of general psychiatry
June/14/2010
Abstract
BACKGROUND
The contribution of reproductive hormones to mood has been the focus of considerable research. Results from clinical and epidemiological studies have been inconsistent. It remains unclear whether alterations in serum hormone levels across the menopausal transition are linked to depressive symptoms.
OBJECTIVE
To evaluate the relationship between serum hormone levels and high depressive symptoms and whether hormone levels or their change might explain the association of menopausal status with depressive symptoms previously reported in a national sample of midlife women.
METHODS
A longitudinal, community-based, multisite study of menopause. Data were collected at baseline and annually from December 1995 to January 2008 on a range of factors. Early follicular phase serum samples were assayed for levels of estradiol, follicle-stimulating hormone, testosterone, and dehydroepiandrosterone sulfate.
METHODS
Seven communities nationwide.
METHODS
A community-based sample of 3302 multiethnic women, aged 42 to 52 years, still menstruating and not using exogenous reproductive hormones. Main Outcome Measure Depressive symptoms assessed with the Center for Epidemiological Studies Depression Scale (CES-D). The primary outcome was a CES-D score of 16 or higher.
RESULTS
In multivariable random-effects logistic regression models, log-transformed testosterone level was significantly positively associated with higher odds of a CES-D score of 16 or higher (odds ratio = 1.15; 95% confidence interval, 1.01-1.31) across 8 years, and a larger increase in log-transformed testosterone from baseline to each annual visit was significantly associated with increased odds of a CES-D score of 16 or higher (odds ratio = 1.23; 95% confidence interval, 1.04-1.45). Less education, being Hispanic, and vasomotor symptoms, stressful life events, and low social support at each visit were each independently associated with a CES-D score of 16 or higher. No other hormones were associated with a CES-D score of 16 or higher. Being perimenopausal or postmenopausal compared with being premenopausal remained significantly associated with a CES-D score of 16 or higher in all analyses.
CONCLUSIONS
Higher testosterone levels may contribute to higher depressive symptoms during the menopausal transition. This association is independent of menopausal status, which remains an independent predictor of higher depressive symptoms.
Publication
Journal: International Review of Neurobiology
February/28/2002
Abstract
Neurosteroids are synthetisized in the central and the peripheral nervous system, in glial cells, and also in neurons, from cholesterol or steroidal precursors imported from peripheral sources. They include 3 beta-hydroxy-delta 5-compounds, such as pregnenolone (PREG) and dehydroepiandrosterone, their sulfate esters, and compounds known as reduced metabolites of steroid hormones, such as the tetrahydroderivative of progesterone 3 alpha-hydroxy-5 alpha-pregnan-20-one. These neurosteroids can act as modulators of neurotransmitter receptors, such as GABAA, NMDA, and sigma 1 receptors. Progesterone itself is also a neurosteroid, and a progesterone receptor has been detected in peripheral and central glial cells. At different sites in the brain, neurosteroid concentrations vary according to environmental and behavioral circumstances, such as stress, sex recognition, or aggressiveness. A physiological function of neurosteroids in the central nervous system is strongly suggested by the role of hippocampal PREGS with respect to memory performance, observed in aging rats. In the peripheral nervous system, a role for PROG synthesized in Schwann cells has been demonstrated in remyelination after cryolesion of the sciatic nerve in vivo and in cultures of dorsal root ganglia. A new mechanism of PREG action discovered in the brain involves specific steroid binding to microtubule associated protein and increased tubulin polymerization for assembling microtubules. It may be important to study the effects of abnormal neurosteroid concentration/metabolism in view of the possible treatment of functional and trophic disturbances of the nervous system.
Publication
Journal: Recent progress in hormone research
June/3/2002
Abstract
The menopause is the permanent cessation of menstruation resulting from the loss of ovarian follicular activity. It is heralded by the menopausal transition, a period when the endocrine, biological, and clinical features of approaching menopause begin. A common initial marker is the onset of menstrual irregularity. The biology underlying the transition to menopause includes central neuroendocrine changes as well as changes within the ovary, the most striking of which is a profound decline in follicle numbers. Follicle-stimulating hormone (FSH) is an established indirect marker of follicular activity. In studies of groups of women, its concentration, particularly in the early follicular phase of the menstrual cycle, begins to increase some years before there are any clinical indications of approaching menopause. The rise in FSH is the result of declining levels of inhibin B (INH-B), a dimeric protein that reflects the fall in ovarian follicle numbers, with or without any change in the ability of the lining granulosa cells to secrete INH-B. Estradiol levels remain relatively unchanged or tend to rise with age until the onset of the transition and are usually well preserved until the late perimenopause, presumably in response to the elevated FSH levels. During the transition, hormone levels frequently vary markedly - hence, measures of FSH and estradiol are unreliable guides to menopausal status. Concentrations of testosterone have been reported to fall by about 50% during reproductive life, between the ages of 20 and 40. They change little during the transition and, after menopause, may even rise. Dehydroepiandrosterone (DHEA) and DHEAS, its sulphate, on the other hand, decline with age, without any specific influence of the menopause. Symptoms of the menopause can be interpreted as resulting primarily from the profound fall in estradiol, occurring over a 3- to 4-year period around final menses, a fall that presumably contributes importantly to the beginning, in the late perimenopause, of loss of bone mineral density.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
November/12/1992
Abstract
Dehydroepiandrosterone sulfate (DS) was measured by direct tritium RIA in longitudinal plasma specimens from 97 normal healthy male participants in the Baltimore Longitudinal Study of Aging. Fasting blood was collected at regular visits (approximately 1.5 yr apart) over an average 13 yr of adulthood (cumulative age range: 32-83 yr). DS was measured in 3-4 widely spaced specimens from each subject. A decline in DS was found in 65 (67%) subjects, 13 subjects (13%) showed no change, and increases were found in the 19 remaining subjects during the study period. A plot of individual data points revealed the same pattern we had obtained previously from a cross-sectional study of a different normal male population. A plot of DS values vs. age among subjects whose DS increased during the study also revealed an age-related decline. Thus, the longitudinal decrease in circulating DS, long inferred from cross-sectional data, is confirmed for normal men in the present study. A more detailed study of every specimen collected during the study period from 12 of the Baltimore Longitudinal Study of Aging subjects (4 whose values tended to be low, 4 whose values tended to be high, and 4 whose values were near the mean) failed to reveal any patterns of variation that could be correlated with changes in life circumstances, health status, or any other discernible factors. Hence, the wide variability seen in DS among individuals within normal populations remains unexplained.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
November/28/1994
Abstract
It is well recognized that aging in men is accompanied by a decline in the serum levels of some adrenal and testicular steroids, but little or no attention has focused on the multiple steroid metabolites that are formed by steroid-converting enzymes in target tissues. In the present study, we have examined in detail the serum concentrations of a large series of adrenal and testicular steroids and their most significant metabolites produced in intracrine peripheral tissues. The serum concentrations of 26 conjugated and unconjugated C21-, C19-, and C18-steroids were measured in 2423 men aged 40-80 yr. The serum concentrations of the major circulating adrenal C19-steroids, namely dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S), androst-5-ene-3 beta, 17 beta-diol and its sulfate, and androstenedione, decreased by about 60% between the ages of 40-80 yr. The small decrease in the serum concentrations of progesterone and pregnenolone in the presence of increased levels of cortisol and markedly decreased levels of DHEA, androst-5-ene-3 beta, 17 beta-diol, and their polar metabolites suggests that adrenal 17,20-lyase is particularly affected by aging. In addition to a marked decline in the serum concentrations of adrenal C19-steroids, a smaller, but significant, decrease occurred in serum testosterone. However, serum dihydrotestosterone levels remained constant, but the glucuronidated derivatives of dihydrotestosterone metabolites (androstane-3 alpha, 17 beta-diol glucuronide, androstane-3 beta, 17 beta-diol glucuronide, and androsterone glucuronide) were reduced by 45-50%, suggesting that 5 alpha-reductase activity in peripheral tissues may show a compensatory increase during aging. Analysis of the fatty acid esters of DHEA (DHEA-FA) also revealed that these nonpolar steroids markedly decrease between 40-80 yr of age, although such a decrease in DHEA-FA levels was smaller than that in DHEA and DHEA-S, suggesting that the formation of DHEA-FA may be specifically increased during aging. In summary, the present study suggests that in contrast to the marked decline in activity of steroidogenic enzymes in the adrenals and the small decrease in the testis, the activity of the steroid-converting enzymes present in peripheral tissues does not decrease during aging. In fact, the marked decrease in DHEA formation by the adrenals leads to a decrease of about 50% in total androgens in men between the ages of 40-80 yr. Such a decrease probably affects many physiological processes during aging.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
May/16/2000
Abstract
The secretion and the blood levels of the adrenal steroid dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) decrease profoundly with age, and the question is posed whether administration of the steroid to compensate for the decline counteracts defects associated with aging. The commercial availability of DHEA outside the regular pharmaceutical-medical network in the United States creates a real public health problem that may be resolved only by appropriate long-term clinical trials in elderly men and women. Two hundred and eighty healthy individuals (women and men 60-79 years old) were given DHEA, 50 mg, or placebo, orally, daily for a year in a double-blind, placebo-controlled study. No potentially harmful accumulation of DHEAS and active steroids was recorded. Besides the reestablishment of a "young" concentration of DHEAS, a small increase of testosterone and estradiol was noted, particularly in women, and may be involved in the significantly demonstrated physiological-clinical manifestations here reported. Bone turnover improved selectively in women >70 years old, as assessed by the dual-energy x-ray absorptiometry (DEXA) technique and the decrease of osteoclastic activity. A significant increase in most libido parameters was also found in these older women. Improvement of the skin status was observed, particularly in women, in terms of hydration, epidermal thickness, sebum production, and pigmentation. A number of biological indices confirmed the lack of harmful consequences of this 50 mg/day DHEA administration over one year, also indicating that this kind of replacement therapy normalized some effects of aging, but does not create "supermen/women" (doping).
Publication
Journal: Circulation
November/7/2006
Abstract
BACKGROUND
The age-related decline of circulating anabolic hormones in men is associated with increased morbidity and mortality. We studied the prevalence and prognostic consequences of deficiencies in circulating total testosterone (TT) and free testosterone, dehydroepiandrosterone sulfate (DHEAS), and insulin-like growth factor-1 (IGF-1) in men with chronic heart failure (CHF).
RESULTS
Serum levels of TT, DHEAS, and IGF-1 were measured with immunoassays in 208 men with CHF (median age 63 years; median left ventricular ejection fraction 33%; New York Heart Association class I/II/III/IV, 19/102/70/17) and in 366 healthy men. Serum levels of free testosterone were estimated (eFT) from levels of TT and sex hormone binding globulin. Deficiencies in DHEAS, TT, eFT, and IGF-1, defined as serum levels at or below the 10th percentile of healthy peers, were seen across all age categories in men with CHF. DHEAS, TT, and eFT were inversely related to New York Heart Association class irrespective of cause (all P<0.01). DHEAS correlated positively with left ventricular ejection fraction and inversely with N-terminal pro-brain natriuretic peptide (both P<0.01). Circulating TT, eFT, DHEAS, and IGF-1 levels were prognostic markers in multivariable models when adjusted for established prognostic factors (all P<0.05). Men with CHF and normal levels of all anabolic hormones had the best 3-year survival rate (83%, 95% CI 67% to 98%) compared with those with deficiencies in 1 (74% survival rate, 95% CI 65% to 84%), 2 (55% survival rate, 95% CI 45% to 66%), or all 3 (27% survival rate, 95% CI 5% to 49%) anabolic endocrine axes (P<0.0001).
CONCLUSIONS
In male CHF patients, anabolic hormone depletion is common, and a deficiency of each anabolic hormone is an independent marker of poor prognosis. Deficiency of >1 anabolic hormone identifies groups with a higher mortality.
Publication
Journal: The Lancet Oncology
November/3/2013
Abstract
BACKGROUND
Associations between circulating concentrations of oestrogens, progesterone, and androgens with breast cancer and related risk factors in premenopausal women are not well understood. We aimed to characterise these associations with a pooled analysis of data from seven studies.
METHODS
Individual participant data for prediagnostic sex hormone and sex hormone-binding globulin (SHBG) concentrations were contributed from seven prospective studies. We restricted analyses to women who were premenopausal and younger than 50 years at blood collection, and to women with breast cancer diagnosed before age 50 years. We estimated odds ratios (ORs) with 95% CIs for breast cancer associated with hormone concentrations by conditional logistic regression in cases and controls matched for age, date of blood collection, and day of cycle, with stratification by study and further adjustment for cycle phase. We examined associations of hormones with risk factors for breast cancer in control women by comparing geometric mean hormone concentrations in categories of these risk factors, adjusted for study, age, phase of menstrual cycle, and body-mass index (BMI). All statistical tests were two-sided.
RESULTS
We included data for up to 767 women with breast cancer and 1699 controls in the risk analyses. Breast cancer risk was associated with a doubling in concentrations of oestradiol (OR 1·19, 95% CI 1·06-1·35), calculated free oestradiol (1·17, 1·03-1·33), oestrone (1·27, 1·05-1·54), androstenedione (1·30, 1·10-1·55), dehydroepiandrosterone sulphate (1·17, 1·04-1·32), testosterone (1·18, 1·03-1·35), and calculated free testosterone (1·08, 0·97-1·21). Breast cancer risk was not associated with luteal phase progesterone (doubling in concentration OR 1·00, 95% CI 0·92-1·09), and adjustment for other factors had little effect on any of these ORs. Cross-sectional analyses in control women showed several associations of sex hormones with breast cancer risk factors.
CONCLUSIONS
Circulating oestrogens and androgens are positively associated with the risk for breast cancer in premenopausal women.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
December/23/1996
Abstract
Fluoxetine administered intraperitoneally to sham-operated or adrenalectomized/castrated (ADX/CX) male rats dose-dependently (2.9-58 mumol/kg i.p.) increased the brain content of the neurosteroid 3 alpha-hydroxy-5 alpha-pregnan-20-one (allopregnanolone, 3 alpha, 5 alpha-TH PROG). The increase of brain 3 alpha, 5 alpha-TH PROG content elicited by 58 mumol/kg fluoxetine lasted more than 2 hr and the range of its extent was comparable in sham-operated (approximately 3-10 pmol/g) and ADX/CX rats (2-9 pmol/g) and was associated with a decrease (from 2.8 to 1.1 pmol/g) in the 5 alpha-pregnan-3,20-dione (5 alpha-dihydroprogesterone, 5 alpha-DH PROG) content. The pregnenolone, progesterone, and dehydroepiandrosterone content failed to change in rats receiving fluoxetine. The extent of 3 alpha, 5 alpha-TH PROG accumulation elicited by fluoxetine treatment differed in various brain regions, with the highest increase occurring in the olfactory bulb. Importantly, fluoxetine failed to change the 3 alpha, 5 alpha-TH PROG levels in plasma, which in ADX/CX rats were at least two orders of magnitude lower than in the brain. Two other serotonin re-uptake inhibitors, paroxetine and imipramine, in doses equipotent to those of fluoxetine in inhibiting brain serotonin uptake, were either significantly less potent than fluoxetine (paroxetine) or failed to increase (imipramine) 3 alpha, 5 alpha-TH PROG brain content. The addition of 10 microM of 5 alpha-DH PROG to brain slices of ADX/CX rats preincubated with fluoxetine (10 microM, 15 min) elicited an accumulation of 3 alpha, 5 alpha-TH PROG greater than in slices preincubated with vehicle. A fluoxetine stimulation of brain 3 alpha, 5 alpha-TH PROG biosynthesis might be operative in the anxiolytic and antidysphoric actions of this drug.
Publication
Journal: British Journal of Cancer
February/23/2004
Abstract
We assessed the association of sex hormone levels with breast cancer risk in a case-control study nested within the cohort of 7054 New York University (NYU) Women's Health Study participants who were postmenopausal at entry. The study includes 297 cases diagnosed between 6 months and 12.7 years after enrollment and 563 controls. Multivariate odds ratios (ORs) (95% confidence interval (CI)) for breast cancer for the highest quintile of each hormone and sex-hormone binding globulin (SHBG) relative to the lowest were as follows: 2.49 (1.47-4.21), P(trend)=0.003 for oestradiol; 3.24 (1.87-5.58), P(trend)<0.001 for oestrone; 2.37 (1.39-4.04), P(trend)=0.002 for testosterone; 2.07 (1.28-3.33), P(trend)<0.001 for androstenedione; 1.74 (1.05-2.89), P(trend)<0.001 for dehydroepiandrosterone sulphate (DHEAS); and 0.51 (0.31-0.82), P(trend)<0.001 for SHBG. Analyses limited to the 191 cases who had donated blood five to 12.7 years prior to diagnosis showed results in the same direction as overall analyses, although the tests for trend did not reach statistical significance for DHEAS and SHBG. The rates of change per year in hormone and SHBG levels, calculated for 95 cases and their matched controls who had given a second blood donation within 5 years of diagnosis, were of small magnitude and overall not different in cases and controls. The association of androgens with risk did not persist after adjustment for oestrone (1.08, 95% CI=0.92-1.26 for testosterone; 1.15, 95% CI=0.95-1.39 for androstenedione and 1.06, 95% CI=0.90-1.26 for DHEAS), the oestrogen most strongly associated with risk in our study. Our results support the hypothesis that the associations of circulating oestrogens with breast cancer risk are more likely due to an effect of circulating hormones on the development of cancer than to elevations induced by the tumour. They also suggest that the contribution of androgens to risk is largely through their role as substrates for oestrogen production.
Publication
Journal: Brain Research
September/22/1983
Abstract
Pregnenolone (P) and its sulfate ester (PS) have been characterized in the brain of adult male rats. The concentration of P (38.4 +/- 6.9 and 22.1 +/- 2.9 ng/g, mean +/- S.D., in anterior and posterior brain, respectively) exceeded that of PS in brain (15.8 +/- 3.0 and 5.7 +/- 2.1 ng/g in the same fractions) and largely those of P and PS in plasma (1.3 +/- 0.2 and 1.4 +/- 0.3 ng/g, respectively). The level of P in brain was much larger than that of dehydroepiandrosterone sulfate (DS), characterized and measured previously (Corpéchot et al.). Brain P and PS levels did not seem to depend on steroidogenic gland secretion: no meaningful difference occurred in brain 15 days after adrenalectomy plus orchiectomy, compared with sham-operated controls. It is proposed that, as that of DS (ref. 5) P and PS formation or accumulation (or both) in the rat brain depend on in situ mechanisms unrelated to the peripheral endocrine gland system.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
May/31/1995
Abstract
N-Methyl-D-aspartate (NMDA, 200 microM) evokes the release of [3H]norepinephrine ([3H]NE) from preloaded hippocampal slices. This effect is potentiated by dehydroepiandrosterone sulfate (DHEA S), whereas it is inhibited by pregnenolone sulfate (PREG S) and the high-affinity sigma inverse agonist 1,3-di(2-tolyl)guanidine, at concentrations of>> or = 100 nM. Neither 3 alpha-hydroxy-5 alpha-pregnan-20-one nor its sulfate ester modified NMDA-evoked [3H]NE overflow. The sigma antagonists haloperidol and 1-[2-(3,4-dichlorophenyl)-ethyl]-4-methylpiperazine, although inactive by themselves, completely prevented the effects of DHEA S, PREG S, and 1,3-di(2-tolyl)guanidine on NMDA-evoked [3H]NE release. Progesterone (100 nM) mimicked the antagonistic effect of haloperidol and 1-[2-(3,4-dichlorophenyl)ethyl]-4-methyl-piperazine. These results indicate that the tested steroid sulfate esters differentially affected the NMDA response in vitro and suggest that DHEA S acts as a sigma agonist, that PREG S acts as a sigma inverse agonist, and that progesterone may act as a sigma antagonist. Pertussis toxin, which inactivates the Gi/o types of guanine nucleotide-binding protein (Gi/o protein) function, suppresses both effects of DHEA S and PREG S. Since sigma 1 but not sigma 2 receptors are coupled to Gi/o proteins, the present results suggest that DHEA S and PREG S control the NMDA response via sigma 1 receptors.
Publication
Journal: Neuroscience
May/17/2006
Abstract
This review briefly summarizes recent developments in our understanding of the role of androgens in maintaining normal hippocampal structure. Studies in rats and vervet monkeys have demonstrated that removal of the testes reduces the density of synaptic contacts on dendritic spines of cornu ammonis 1 (CA1) pyramidal neurons. This effect is rapidly reversed by treatment with either testosterone or the non-aromatizable androgen dihydrotestosterone, suggesting that maintenance of normal synaptic density is androgen-dependent, via a mechanism that does not require intermediate estrogen biosynthesis. Similar effects of these androgens are observed in ovariectomized female rats, except that in the female the actions of testosterone include a substantial contribution from estrogen formation. The ability to stimulate hippocampal spine synapse density is not directly related to systemic androgenic potency: thus, weak androgens such as dehydroepiandrosterone exert effects that are comparable to those of dihydrotestosterone; while partial agonist responses are observed after injection of the synthetic antiandrogen, flutamide. These data provide a morphological counterpart to observations that androgens enhance cognitive function and mood state, suggesting that these effects may result at least in part from hippocampal neurotrophic responses. The unusual specificity of these responses raises the possibility that effects of androgens on the brain may be mediated via different mechanisms than the masculinizing actions of these steroids in non-neural androgen target organs.
Publication
Journal: Dialogues in Clinical Neuroscience
May/11/2011
Abstract
Major depressive disorder (MDD) is associated with a high rate of developing serious medical comorbidities such as cardiovascular disease, stroke, dementia, osteoporosis, diabetes, and the metabolic syndrome. These are conditions that typically occur late in life, and it has been suggested that MDD may be associated with "accelerated aging." We review several moderators and mediators that may accompany MDD and that may give rise to these comorbid medical conditions. We first review the moderating effects of psychological styles of coping, genetic predisposition, and epigenetic modifications (eg, secondary to childhood adversity). We then focus on several interlinked mediators occurring in MDD (or at least in subtypes of MDD) that may contribute to the medical comorbidity burden and to accelerated aging: limbic-hypothalamic-pituitary-adrenal axis alterations, diminution in glucocorticoid receptor function, altered glucose tolerance and insulin sensitivity, excitotoxicity, increases in intracellular calcium, oxidative stress, a proinflammatory milieu, lowered levels of "counter-regulatory" neurosteroids (such as allopregnanolone and dehydroepiandrosterone), diminished neurotrophic activity, and accelerated cell aging, manifest as alterations in telomerase activity and as shortening of telomeres, which can lead to apoptosis and cell death. In this model, MDD is characterized by a surfeit of potentially destructive mediators and an insufficiency of protective or restorative ones. These factors interact in increasing the likelihood of physical disease and of accelerated aging at the cellular level. We conclude with suggestions for novel mechanism-based therapeutics based on these mediators.
Publication
Journal: Progress in Neurobiology
November/23/2009
Abstract
Neuroactive steroids refer to steroids that are capable of regulating neuronal activities. Neuroactive steroids, synthesized either de novo in the nervous tissue or in the peripheral endocrine glands or as synthetic steroids, have exhibited numerous important modulatory effects on brain functions and brain diseases. At the cellular level, in addition to the effect on postsynaptic receptors, most neuroactive steroids, including pregnenolone, pregnenolone sulfate, progesterone, allopregnanolone, dehydroepiandrosterone, dehydroepiandrosterone sulfate, testosterone and estradiol, have modulatory effects on the release of multiple neurotransmitters like glutamate, GABA, acetylcholine, norepinephrine, dopamine and 5-HT. Many of these effects occur in the brain regions involved in learning and memory, emotion, motivation, motor and cognition. Moreover, the effects are rather complicated, maybe depending on many factors such as types of neuroactive steroids, brain regions and presynaptic functional states. The mechanisms are also complicated. Many of them involve rapid non-genomic effects on presynaptic receptors and ion channels like sigma-1 receptor, alpha(1) receptor, nicotine receptor, D1 receptor, NMDA receptor, GABA(A) receptor and L-type Ca(2+) channels. These effects have made neuroactive steroids important regulators of synaptic transmission in the central nervous system and constitute the major basis for many important actions of neuroactive steroids on brain functions and brain diseases.
Authors
Publication
Journal: Journal of Immunology
July/19/1993
Abstract
Normal aging in humans has been recently shown to be accompanied by reduced control over production of the multifunctional cytokine IL-6. This cytokine was reported to be quantitatively elevated in most serum samples obtained from "normal" elderly humans. In the present investigation, we report that IL-6 levels are elevated in serum samples obtained from aged mice, and its spontaneous production could also be easily detected in culture supernatants of unstimulated lymphoid cells obtained from aged, but not mature, adult donors. Spontaneous production of IL-6 was consistently observed in culture supernatants of lymphoid cells from both the spleen and mesenteric lymph nodes from aged donors, but was absent from supernatants derived from their peripheral lymph nodes. In aged mice, the reduced regulation of IL-6 production could be effectively prevented and/or reversed by supplementing aging animals with dehydroepiandrosterone sulfate, a steroid hormone whose endogenous production is known to decline with advancing age in all species tested. It was also established that serum obtained from old dehydroepiandrosterone sulfate-treated mice contained lower (normal) levels of serum amyloid P substance (an acute phase reactant), reduced levels of serum Ig (all classes and isotypes) and lower titers of tissue-specific autoantibodies than untreated aged controls. Therefore, a number of well described, age-related conditions, some of which could be contributing to the pathologic phenotype of old age, may actually represent secondary effects to this age-associated change in IL-6 production.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
October/15/1996
Abstract
We performed this study to investigate the hypothesis that insulin resistance plays a role in the pathogenesis of reproductive abnormalities in women with the polycystic ovary syndrome (PCOS). Twenty-five women with PCOS were enrolled in a double-blind randomized 3-month trial of two doses of the insulin-sensitizing agent, troglitazone, 21 of whom completed the study: 200 mg, n = 10; 400 mg, n = 11. Baseline hormonal parameters and glucose tolerance were compared with 12 age- and weight-matched ovulatory control women. There were no significant changes in body mass index during the study. Fasting (P < 0.01) and 2-h post-75-g glucose load insulin levels (P < 0.05), as well as integrated insulin responses to the glucose load, decreased (P < 0.05), and insulin sensitivity assessed by a frequently sampled iv glucose tolerance test increased significantly (P < 0.001) during troglitazone treatment. This was accompanied by significant decreases in the levels of nonsex hormone-binding globulin-bound testosterone (P < 0.01), dehydroepiandrosterone sulfate (P < 0.001), estradiol (P < 0.01), and estrone (P < 0.001). Stepwise regression analysis indicated that decreases in nonsex hormone-binding globulin testosterone levels were significantly correlated with decreases in integrated insulin responses to the glucose load (r2 0.44, P < 0.01). The only significant changes at the 200-mg troglitazone dose were an increase in insulin sensitivity (P < 0.05) and decreases in dehydro-epiandrosterone sulfate (P < 0.01) and estrone (P < 0.05) levels. At the 400-mg dose, in addition to the changes noted in the entire troglitazone treatment group, increases in the disposition index (the product of insulin sensitivity and secretion) achieved significance, as did decreases in androstenedione (P < 0.01) and LH (P < 0.05) levels and increases in sex hormone-binding globulin levels (P < 0.01). Two PCOS women had ovulatory menses. We conclude that 1) troglitazone improves total body insulin action in PCOS, resulting in lower circulating insulin levels; 2) insulin resistance, probably via hyperinsulinemia, results in a general augmentation of steroidogenesis and LH release in PCOS; and 3) insulin-sensitizing agents, such as troglitazone, may provide a novel therapy for PCOS.
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