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Risk of coronary heart disease is higher in African-American than in Caucasian women.The aim of this study was to evaluate the contribution of sex hormone levels, race, and measures of body fat to the variation in plasma lipid levels, a well-established risk factor for coronary heart disease.This was a cross-sectional study.The study was conducted in the general community.Sixty Caucasian and 117 African-American premenopausal women participated.Body weight, body mass index (BMI), and waist to hip circumference ratio (WHR), as well as plasma lipid and serum sex hormone levels, were assessed.Relative to Caucasian women, African-American women had significantly higher mean BMI (23.92 +/- 3.87 vs. 26.99 +/- 5.87 kg/m2, respectively; P0.001), and WHR (0.733 +/- 0.052 vs. 0.757 +/- 0.068; P0.03). Also, plasma triglyceride (TG) levels were significantly lower in African-American women (81 +/- 61 vs. 55 +/- 24 mg/dl; P0.0001). Serum estrone sulfate (556 +/- 323 vs. 442 +/- 332 pg/ml, Caucasian vs. African-American; P0.001), estradiol (E2) (55.1 +/- 43.6 vs. 35.8 +/- 17.7 pg/ml; P0.0001), androstenedione (2.6 +/- 0.9 vs. 1.6 +/- 0.7 ng/ml; P0.0001), and testosterone (0.36 +/- 0.12 vs. 0.31 +/- 0.19 ng/ml; P0.002) levels were significantly lower in African-American women than in Caucasian women. After correction for the effects of age, BMI, and WHR, serum E2 levels were significantly and positively associated with plasma high-density lipoprotein cholesterol levels in all women, and serum estrone sulfate levels with plasma total cholesterol and TG levels in African-American women.Our results indicate that race is an important determinant of plasma TG and serum sex hormone levels, even after adjustment for differences in body size. A significant association between endogenous E2 and high-density lipoprotein cholesterol levels exists in premenopausal women, independent of their race.

Little is known about the descriptive epidemiology of androgen deficiency. In this study, we sought to address this issue by providing estimates of the crude and age-specific prevalence and incidence rates of androgen deficiency in a randomly sampled population-based cohort of middle-aged and older men. Data on androgen deficiency (defined using both signs/symptoms plus total and calculated free testosterone) were available for n = 1691 (baseline) and n = 1087 (follow-up) men from the Massachusetts Male Aging Study. Crude and age-specific prevalence and incidence rates were calculated. Based on these estimates, projections for the number of cases of androgen deficiency in the 40- to 69-yr-old U.S. male population were computed. Estimates of the crude prevalence of androgen deficiency at baseline and follow-up were 6.0 and 12.3%, respectively. Prevalence increased significantly with age. From baseline age-specific prevalence data, it is estimated that there are approximately 2.4 million 40- to 69-yr-old U.S. males with androgen deficiency. The crude incidence rate of androgen deficiency was 12.3 per 1,000 person-years, and the rate increased significantly (P < 0.0001) with age. Based on these incidence data, we can expect approximately 481,000 new cases of androgen deficiency per year in U.S. men 40–69 yr old.

As men age, serum testosterone levels decrease, a factor that may contribute to some aspects of age-related physiological deterioration. Although androgen replacement has been shown to have beneficial effects in frankly hypogonadal men, its use in elderly men with borderline hypogonadism is controversial. Furthermore, current testosterone replacement methods have important limitations.We investigated the ability of the orally administered aromatase inhibitor, anastrozole, to increase endogenous testosterone production in 37 elderly men (aged 62–74 yr) with screening serum testosterone levels less than 350 ng/dl. Subjects were randomized in a double-blind fashion to the following 12-wk oral regimens: group 1: anastrozole 1 mg daily (n = 12); group 2: anastrozole 1 mg twice weekly (n = 11); and group 3: placebo daily (n = 14). Hormone levels, quality of life (MOS Short-Form Health Survey), sexual function (International Index of Erectile Function), benign prostate hyperplasia severity (American Urological Association Symptom Index Score), prostate-specific antigen, and measures of safety were compared among groups.Mean ± sd bioavailable testosterone increased from 99 ± 31 to 207 ± 65 ng/dl in group 1 and from 115 ± 37 to 178 ± 55 ng/dl in group 2 (P < 0.001 vs. placebo for both groups and P = 0.054 group 1 vs. group 2). Total testosterone levels increased from 343 ± 61 to 572 ± 139 ng/dl in group 1 and from 397 ± 106 to 520 ± 91 ng/dl in group 2 (P < 0.001 vs. placebo for both groups and P = 0.012 group 1 vs. group 2). Serum estradiol levels decreased from 26 ± 8 to 17 ± 6 pg/ml in group 1 and from 27 ± 8 to 17 ± 5 pg/ml in group 2 (P < 0.001 vs. placebo for both groups and P = NS group 1 vs. group 2). Serum LH levels increased from 5.1 ± 4.8 to 7.9 ± 6.5 U/liter and from 4.1 ± 1.6 to 7.2 ± 2.8 U/liter in groups 1 and 2, respectively (P = 0.007 group 1 vs. placebo, P = 0.003 group 2 vs. placebo, and P = NS group 1 vs. group 2). Scores for hematocrit, MOS Short-Form Health Survey, International Index of Erectile Function, and American Urological Association Symptom Index Score did not change. Serum prostate-specific antigen levels increased in group 2 only (1.7 ± 1.0 to 2.2 ± 1.5 ng/ml, P = 0.031, compared with placebo).These data demonstrate that aromatase inhibition increases serum bioavailable and total testosterone levels to the youthful normal range in older men with mild hypogonadism. Serum estradiol levels decrease modestly but remain within the normal male range. The physiological consequences of these changes remain to be determined.

Estrogen levels are higher during the luteal compared with the follicular phase of the menstrual cycle. It was hypothesized that the luteal compared with the follicular phase has a lipid and lipoprotein profile associated with decreased coronary heart disease (CHD) risk. This was tested using well-defined data from healthy, well-characterized premenopausal Caucasian women under very controlled metabolic conditions. The percent differences in lipid, lipoprotein, and sex hormone levels between the follicular and luteal phases were estimated using generalized estimating equations after adjusting for age, body mass index, calendar time, and season. The low-density lipoprotein cholesterol (LDL-C) level was 6.2% lower (P = 0.015), and the total cholesterol/high-density lipoprotein cholesterol (HDL-C) and LDL-C/HDL-C ratios were 5.1% (P = 0.0006) and 8.4% (P = 0.002) lower, respectively, during the luteal phase. Levels of estradiol and other estrogens were significantly higher (by100% each; P0.0001 in all cases) in the luteal phase. These findings support the study hypothesis. Fluctuations in levels of LDL-C and the total cholesterol/HDL-C and LDL-C/HDL-C ratios between menstrual cycle phases need to be considered in the screening and medical monitoring of premenopausal women, especially those with borderline levels. Although small, such fluctuations may prove to be clinically significant in the long run. Studies involving premenopausal women need to more clearly define and validate menstrual cycle phase in the design and interpretation of study results.

This study measured bone mineral content (BMC), bone mineral density (BMD), and bone area at the spine and hip to learn whether bone loss takes place premenopausally. Participants were 130 non-Hispanic white women 31 to 50 years of age who were in good general health and had taken no drugs that affect bone metabolism. Measurements were made by dual-energy x-ray absorptiometry at the L2-4 segment of the lumbar spine, in the femoral neck, and in the total hip. The studies were repeated at least twice over 1 to 9 years. Both BMC and bone area increased significantly over time in the spine, as did BMD. If, however, BMC was normalized by bone volume, there was no age-related change in volumetric density. Measurements of the total hip showed no significant change with age. BMD in the femoral neck declined at a rate of about 0.0036 g/cm2 per year. BMC was lost as well, so the drop in BMD was not an artifact of bone expansion. Changes in BMD correlated positively with weight change and estradiol levels and negatively with gonadotropin levels. Somewhat less bone loss was noted in subjects who gained more weight during the study. Higher levels of LH and FSH were documented in women who lost more than 1% of BMD per year. Estrogen levels were highest in women who manifested no bone loss. Declining BMD was more a result of a loss of BMC in women with high FSH levels, but due more to an expansion in bone area in those with relatively low FSH levels. The positive association between body weight change and BMD was not entirely mediated by higher estrogen. Premenopausal women more than 30 years of age in this study lost BMD at the femoral neck at an average annual rate of 0.4%. Bone loss was less in women who gained more weight but greater in those with reduced estrogen levels even in the absence of symptoms. Early bone loss might be preventable if premenopausal women with suboptimal sex hormone levels are detected at an early stage.

Androstenedione is a steroid hormone and the major precursor to testosterone. It is available without prescription and taken with the expectation that it will be converted to testosterone endogenously and increase strength and athletic performance. The metabolism of orally administered testosterone has not been well studied.We randomly assigned 37 healthy men to receive 0, 100, or 300 mg oral androstenedione in a single daily dose for 7 d. Single 8-h urine collections were performed on the day before the start of the androstenedione administration and on d 1 and 7 to assess excretion rates of free and glucuronide- conjugated testosterone, androsterone, etiocholanolone, and dihydrotestosterone. Serum testosterone glucuronide concentrations were measured by frequent blood sampling over 8 h on d 1 in 16 subjects (5 each in the 0 and 100 mg group and 6 in the 300 mg group).In the control group, mean (±se) d 1 and 7 excretion rates for testosterone, androsterone, etiocholanolone, and dihydrotestosterone were 3 ± 1, 215 ± 26, 175 ± 26, and 0.4 ± 0.1 μg/h, respectively. In the 100 mg group, mean d 1 and 7 excretion rates for testosterone, androsterone, etiocholanolone, and dihydrotestosterone were 47 ± 11, 3,836 ± 458, 4,306 ± 458, and 1.6 ± 0.2 μg/h, respectively. In the 300 mg group, mean d 1 and 7 excretion rates for testosterone, androsterone, etiocholanolone, and dihydrotestosterone were 115 ± 39, 8,142 ± 1,362, 10,070 ± 1,999, and 7.7 ± 1.5μ g/h, respectively. Urinary excretion rates of all metabolites were greater in both the 100 and 300 mg groups than in controls (P < 0.0001). Urinary excretion rates of testosterone (P = 0.007), androsterone (P = 0.009), etiocholanolone (P= 0.0005), and dihydrotestosterone (P < 0.0001) were greater in the subjects who received 300 mg androstenedione than in those who received 100 mg. In the treated groups, excretion of free testosterone accounted for less than 0.1% of the total excreted testosterone measured. Serum testosterone glucuronide levels increased significantly during frequent blood sampling in both the 100 and 300 mg groups compared with controls (P = 0.0005 for the 100 mg group; P < 0.0001 for the 300 mg group). The net mean changes in area under the curve for serum testosterone glucuronide were −18 ± 25%, 579 ± 572%, and 1267 ± 1675% in the groups receiving 0, 100, and 300 mg/d androstenedione, respectively.We conclude that the administration of both 100 and 300 mg androstenedione increases the excretion rates of conjugated testosterone, androsterone, etiocholanolone, and dihydrotestosterone and the serum levels of testosterone glucuronide in men. The magnitude of these increases is much greater than the changes observed in serum total testosterone concentrations. These findings demonstrate that orally administered androstenedione is largely metabolized to testosterone glucuronide and other androgen metabolites before release into the general circulation.

The serum concentration of sex hormone-binding globulin (SHBG) is inversely related to weight and in animal studies is inversely related to protein intake. As SHBG can affect the biological activity of testosterone and estradiol, we wished to determine the role of protein intake on SHBG levels in men. Using data from the Massachusetts Male Aging Study we examined cross-sectional relationships between dietary components and SHBG levels in 1552 men (aged 40-70 yr) for whom these factors were known. Analyzed by multiple regression, controlling for testosterone and estradiol levels, age (P

The relationships of cigarette smoking, age, relative weight, and dietary intake to serum dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), androstenedione, cortisol, 3-alpha-androstanediol, 3-alpha-androstanediol-glucuronide, testosterone, albumin-bound testosterone, free testosterone, dihydrotestosterone (DHT), and sex hormone-binding globulin (SHBG) were examined cross-sectionally in 1241 randomly sampled middle-aged U.S. men. Compared with nonsmokers and independent of relative weight (body mass index) and age, cigarette smokers had increased serum levels of DHEA (18% higher, P = 0.0002), DHEAS (13% higher, P = 0.0007), cortisol (5% higher, P = 0.01), androstenedione (33% higher, P = 0.0001), testosterone (9% higher, P = 0.009), DHT (14% higher, P = 0.004), and SHBG (8% higher, P = 0.004). Androstenedione, total plasma testosterone, albumin-bound testosterone, DHT, and SHBG decreased with increasing relative weight. Age was positively associated with serum SHBG and negatively associated with albumin-bound testosterone, DHEA, and DHEAS. An association was found between alcohol intake and DHEA (r = 0.15; P = 0.0001), cortisol (r = 0.10; P = 0.0007), and 3-alpha-androstanediol-glucuronide (r = 0.08; P = 0.0004). Cortisol was the only hormone that was associated with carbohydrate intake (r = -0.09; P = 0.002). The only hormones associated with dietary lipids were DHT (for vegetable fat, r = 0.07; P = 0.02), cortisol (for total fat, r = 0.08; P = 0.007), and SHBG (for animal fat, r = -0.06; P = 0.05). In addition, SHBG was positively associated with dietary (r = 0.07; P = 0.008) and crude (r = 0.08; P = 0.007) fiber. These data suggest that serum adrenal steroid and sex hormone concentrations in middle-aged men are more influenced by cigarette smoking, age, and obesity than by dietary intake; however, serum adrenal steroids were influenced by alcohol intake.

Obesity offers protection against osteoporosis in older women. The mechanisms are not well understood, but relate in part to increased aromatization of adrenal androgens to estrone in peripheral fat and muscle tissue. Two hundred and one white and 77 black women previously reported to be free of skeletal disease and to have normal bone mass had measurements of total body bone mineral (TBBM), fat mass (TBFM), and lean mass (TBLM) performed by dual energy x-ray absorptiometry. Serum estrone, androstenedione, and dihydroepiandrostenedione sulfate were measured on the same day. Body weight, body mass index, TBFM, and TBLM were all significantly higher in the black women. However, proportionately, there were no differences in body composition between the two groups. This suggests that the black women were not more obese despite their greater body mass index, and that future studies on the health impact of obesity in older black women should take this into consideration. Despite the greater TBFM and TBLM in the black women and no difference in serum androstenedione levels, the serum estrone level was not higher in the black women, and the higher bone mass in blacks was not related to serum estrone. In both ethnic groups, TBBM was significantly related to body weight (white, r = 0.80; black, r = 0.85; P0.001 for both). Both TBFM and TBLM were significantly related to TBBM in both ethnic groups. Serum estrone was significantly related to all measures of body mass in the white women, but to no measures of body mass in the black women, indicating apparent differences in the metabolism of estrone between older white and black women.

To study the interrelationships of steroids within the follicle, combined 6-h infusions of [3H]dehydroepiandrosterone sulfate and [14C] testosterone ([14C]T) were performed in four normal women treated with menotropins who were undergoing medically indicated surgery. The concentrations of tracer and/or nonisotopic dehydroepiandrosterone sulfate, androst-5-ene-3 beta,17 beta-diol sulfate, androst-5-ene-3 beta,17 beta-diol, dehydroepiandrosterone, androstenedione, T, dihydrotestosterone, estrone (E1), and estradiol (E2) were determined in arterial and venous blood and follicular fluid. The log-transformed product/precursor ratio of [3H]dihydrotestosterone/[3H]T in follicular fluid was negatively correlated with the log-transformed follicular concentrations of E1 (P = 0.01) and E2 (P = 0.02), suggesting a reciprocal relationship between 5 alpha-reductase and follicular E1 and E2. E2 and T were positively correlated in follicular fluid (r = 0.84; P = 0.0003), suggesting a stimulatory action of follicular T on aromatase. These findings along with extensive published data suggest that follicular T functions as a follicular regulator, enhancing follicular aromatase activity when adequate amounts of FSH are available. These conclusions have important implications with regard to mechanisms for selecting the dominant follicle and producing atresia in the remaining cohort of follicles, and they describe a final common path in the pathophysiology of anovulation.

Previous studies have shown a relationship between age and weight and the MCR and conversions ([rho]) of androgens and estrogens. To assess the relative importance of these relationships in the metabolism and conversion of the androgens and estrogens, we used a series of statistical analyses, including t test, Pearson's correlation, and a step-wise regression analysis of the data obtained from the constant infusion of radiolabeled androgens and estrogens to normal women, 18-90 yr old. The MCRs of testosterone (T), androstenedione (A), and estrone (E1) were strongly correlated with weight, but not age or menopausal status. The MCR of estradiol (E2) was strongly correlated with weight and less strongly correlated with age, but was not correlated with menopausal status. The interconversions of the androgens ([rho]T,ABB and [rho]A,TBB, i.e. percentage of precursor infused measured as product in blood) and estrogens ([rho]E1,E2BB and [rho]E2,E1BB) were not correlated with age or weight, but there was a weak correlation between [rho]T,ABB and menopausal status. The aromatization of androgens to estrogens ([rho] A,E1BM and [rho]T,E2BM, i.e. percentage of androgens infused measured as estrogen glucuronide in the urine) was highly correlated with age, less strongly correlated with weight, and not correlated with menopausal status. The correlation with weight and MCR is a reflection of the extrasplanchnic metabolism of steroids. The lack of correlation with weight for the interconversions of androgens and estrogens indicates that the enzyme(s) responsible is affected differently in extrasplanchnic tissue than is the aromatase complex. The relationship between age and aromatization, while strong, remains unexplained.

To evaluate the hypothesis that endocrine profiles change with aging independently of specific disease states, we examined the age trends of 17 major sex hormones, metabolites, and related serum proteins in 2 large groups of adult males drawn from the Massachusetts Male Aging Study, a population-based cross-sectional survey of men aged 39-70 yr conducted in 1986-89. Group 1 consisted of 415 men who were free of obesity, alcoholism, all prescription medication, prostate problems, and chronic illness (cancer, coronary heart disease, hypertension, diabetes, and ulcer). Group 2 consisted of 1294 men who reported 1 or more of the above conditions. Each age trend was satisfactorily described by a constant percent change per yr between ages 39-70 yr. Free testosterone declined by 1.2%/yr, and albumin-bound testosterone by 1.0%/yr. Sex hormone-binding globulin (SHBG), the major serum carrier of testosterone, increased by 1.2%/yr, with the net effect that total serum testosterone declined more slowly (0.4%/yr) than the free or albumin-bound pools alone. Among the major androgens and metabolites, androstane-3 alpha,17 beta-diol (androstanediol; 0.8%/yr) and androstanediol glucuronide (0.6%/yr) declined less rapidly than free testosterone, while 5 alpha-dihydrotestosterone remained essentially constant between ages 39-70 yr. Androstenedione declined at 1.3%/yr, a rate comparable to that of free testosterone, while the adrenal androgen dehydroepiandrosterone (3.1%/yr) and its sulfate (2.2%/yr) declined 2-3 times more rapidly. The levels of testosterone, SHBG, and several androgen metabolites followed a parallel course in groups 1 and 2, remaining consistently 10-15% lower in group 2 across the age range of the study. Subgroup analyses suggested that obese subjects might be responsible for much of the group difference in androgen level. Serum concentrations of estrogens and cortisol did not change significantly with age or differ between groups. Of the pituitary gonadotropins, FSH increased at 1.9%/yr, LH increased at 1.3%/yr, and PRL declined at 0.4%/yr, with no significant difference between groups 1 and 2.(ABSTRACT TRUNCATED AT 400 WORDS)

The precise sites of action of the negative feed-back effects of gonadal steroids in men remain unclear. To determine whether testosterone (T) administration can suppress gonadotropin secretion directly at the level of the pituitary, the pituitary responses to physiological doses of GnRH were assessed in six men with complete GnRH deficiency, whose pituitary-gonadal function had been normalized with long term pulsatile GnRH delivery, before and during a 4-day continuous T infusion (15 mg/day). Their responses were compared with the effects of identical T infusions on spontaneous gonadotropin secretion and the response to a 100-micrograms GnRH bolus in six normal men. Both groups were monitored with 15 h of frequent blood sampling before and during the last day of the T infusion. In the GnRH-deficient men, the first three GnRH doses were identical and were chosen to produce LH pulses with amplitudes in the midphysiological range of our normal men (i.e. a physiological dose), while the last four doses spanned 1.5 log orders (7.5, 25, 75, and 250 ng/kg). The 250 ng/kg dose was always administered last because it is known to be pharmacological. In the GnRH-deficient men, mean LH (P less than 0.02) and FSH (P less than 0.01) levels as well as LH pulse amplitude (P less than 0.05) decreased significantly during T infusion, demonstrating a direct pituitary-suppressive effect of T and/or its metabolites. Mean LH levels were suppressed to a greater extent in the normal than in the GnRH-deficient men (58 +/- 15% vs. 28 +/- 7%; P less than 0.05). In addition, LH frequency decreased significantly (P less than 0.01) during T administration in the normal men. These latter two findings suggest that T administration also suppresses hypothalamic GnRH release. T was unable to suppress gonadotropin secretion in one GnRH-deficient and one normal man. In both groups, the suppressive effect of T administration was present only in response to physiological doses of GnRH. Because the pituitary- and hypothalamus-suppressive effects of T could be mediated by its aromatization to estrogens, five GnRH-deficient and five normal men underwent identical T infusions with concomitant administration of the aromatase inhibitor testolactone (TL; 500 mg, orally, every 6 h). As an additional control, four GnRH-deficient and four normal men received TL alone. TL administration completely prevented the effect of T administration to suppress gonadotropin secretion in both the normal and GnRH-deficient men, and mean LH levels increased significantly in both the GnRH-deficient (P less than 0.01) and the normal (P less than 0.001) men who received TL alone. The increase in mean LH levels was greater (P less than 0.01) in the normal men who received TL alone than in the normal men who received T plus TL, thus revealing a direct effect of androgens in normal men. Measurements of T and estradiol production rates in three men demonstrated that TL effectively blocked aromatization.(ABSTRACT TRUNCATED AT 400 WORDS)

At the time of surgery, women were infused with [3H]dehydroepiandrosterone sulfate ([3H]DS)/[14C]testosterone ([14C]T) for 6 h; blood samples were obtained from an artery the ovarian veins, and a peripheral vein; and fluid was obtained from ovarian follicles. Both blood and follicular fluid samples were analyzed for radioactivity as DS, dehydroepiandrosterone (D), androstenedione (delta 4A). T, and dihydrotestosterone (DHT), and the blood was also analyzed for the concentration of nonisotopic DS by RIA. In other subjects the concentrations of D and DS were measured in paired samples of blood and follicular fluid. From these data, values of 13.6 +/- 0.69 L/day four (mean +/- SE; n = 4) for MCRDS, 607 +/- 90 L/day (n = 3) for MCRT, and 0.0190 +/- 0.0089 (n = 3) for [p]DS-T (fraction of plasma DS metabolized to plasma T) were obtained. The ratio of the concentration of the tracer-labeled steroid in the follicular fluid to the concentration in the arterial plasma sample was elevated significantly above 1 for three 3H-labeled and three [14C-labeled metabolites: [3H]D (21-fold; P less than 0.001), [3H]T (81-fold; P less than 0.001), [3H]DHT (19-fold; P less than 0.001), [14C]T (4-fold; P less than 0.025), [14C]DHT (21-fold; P less than 0.01), and [14C]delta 4A (50-fold; P less than 0.001). The estimated concentrations of steroids in follicular fluid derived from DS based on specific activity calculations were as follows: [geometric mean (95% confidence limits; n)]: DS, 5600 (4800-6500 nmol/L; 12); D, 370 (88-1500 nmol/L; 10); delta 4 A, 120 (67-220 nmol/L; 12); T, 130 (39-450 nmol/L; 10); and DHT, 64 (35-120 nmol/L; 8). Comparison of these data to known follicular fluid steroid concentrations shows that DS from the intravascular pool can be used as an ovarian prehormone.

Although the administration of estrogens and androgens can affect the concentrations of sex hormone-binding globulin (SHBG) in men, the relationships between endogenous estrogens and androgens and SHBG are uncertain. Therefore, in a randomly selected cohort of 1640 middle-aged men we measured androgen, estrogen, and SHBG concentrations and obtained the subjects' weight, ethanol intake, and smoking histories. The data were analyzed by stepwise multiple regression, with SHBG as the dependent variable, to compare the role of hormones with that of other factors in the control of SHBG levels. Neither estrone or estradiol nor the testosterone/estradiol ratio was predictive of SHBG levels. However, SHBG concentrations were positively correlated with total testosterone and negatively correlated with percent free and percent albumin-bound testosterone. SHBG concentrations were negatively correlated with estrone sulfate, but were positively correlated with the testosterone/estrone sulfate ratio and the concentrations of free and albumin-bound testosterone. In addition, in all models tested age and body mass index (wt/ht2), but not smoking or ethanol, were strong predictors of SHBG concentrations. Thus, when present in physiological amounts in the blood as a result of glandular secretion, there is a positive relationship between SHBG concentrations and testosterone and, to a lesser extent, free- and albumin-bound testosterone, but age and body mass index appear to be more important in predicting the SHBG concentration.

Although there have been numerous studies on the production of prostaglandins (PGs) by human endometrium in vitro during the menstrual cycle, considerable variation exists in the levels reported during the proliferative vs. the secretory phase. Such variation may be due in part to the difficulty in obtaining endometrium from a precisely known hormonal environment and in part to the use of the different culture systems employed. The aim of the present study was to develop a non-human primate model in which precisely dated endometrial tissue could be obtained reliably. Moreover, PG levels in the endometrium of the rhesus monkey or other primates have not previously been reported during the artificial menstrual cycle. An important objective in establishing such a model was to permit future manipulations of the cycle in vivo [e.g. by omitting the midcycle estradiol (E) peak] to further dissect specific roles of E and progesterone (P) in regulating PG synthesis during the menstrual cycle. Ovariectomized rhesus monkeys were maintained on a standard artificial menstrual cycle via the insertion and removal of Silastic capsules containing E or P. Samples of endometrium (approximately 50 mg) were obtained by hysterotomy under sterile conditions at predetermined stages of separate menstrual cycles: day 9 (midproliferative; n = 5), day 13 (E peak; n = 3), day 14 (1 day post-E peak; n = 5), and day 23 (midsecretory; n = 8). Measurement of the primary PGs in unextracted medium by RIA over 4 days of organ culture indicated PGF2 alpha greater than 6-keto-PGF1 alpha greater than PGE2 greater than thromboxane-B2, PGD2 greater than leukotrienes. PGF2 alpha, the most abundant PG produced on the first day of culture, was low on day 9 and increased dramatically on day 13 (P less than 0.01). On day 14, PGF2 alpha levels fell significantly only 1 day post-E peak (P less than 0.01), while on day 23, after exposure to P in vivo, PGF2 alpha was 10-fold higher (P less than 0.01) than on cycle days 9 and 14. The other PGs measured showed a lower but similar profile at the cycle stages examined. Physiological concentrations of P (5.0 ng/mL) added to cycle day 23 cultures in both the absence and presence of low or high E markedly inhibited the high levels of PGs found in day 23 cultures (P less than 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

To determine whether there was a significant relationship between circulating lipids or lipoproteins and circulating estrogens or sex hormone-binding globulin (SHBG) in pre- and premenopausal women, 352 women were chosen randomly from communities in Eastern Massachusetts. These women had nonfasting blood samples drawn and analyzed for total cholesterol, high density lipoprotein cholesterol (HDL-C), HDL-2, HDL-3, apolipoprotein-A-I (apo-A-I), apo-B, triglycerides (TG), estrone, estradiol (E2), free E2, SHBG, and FSH. In addition, their body mass index (BMI; wt/ht2) was calculated, and a history of smoking, ethanol intake, current medication use, and the date of their last menstrual period was obtained. When the women were grouped according to the months from their last menses (less than 1, 1-3, and 4-11 months), those 4 months or longer since last menses had significantly lower E2 concentrations and significantly greater total cholesterol and FSH concentrations than the other two groups. However, when regressed on hormones, BMI, ethanol intake, and last menstrual period, total cholesterol was significantly related only to the time from last menses; TG, HDL-C, HDL-2, and apo-A-I were related to SHBG. Relationships between the lipids, with the exception of cholesterol and apo-B, were also noted with BMI and/or ethanol. Apo-B was related to the time from last menses. Differences in circulating estrogens appeared to be related only minimally, if at all, to the differences in total cholesterol that are seen in perimenopausal women. The relationships between lipids and lipoproteins and SHBG are probably epiphenomena as a result of similar sites of synthesis. Changes in lipids and lipoproteins that are seen at the time of the menopause are probably multifactorial in origin.

To examine the effects of hypothyroidism on androstenedione (A) and estrone (E1) metabolism, we infused eight women with [3H]androstenedione and [14C]estrone when they were hypothyroid and again when they were euthyroid after levo-T4 administration. MCRs and conversion ratios were measured using concentrations of radioactivity in the blood pools of A and E1. Peripheral aromatization was measured from the concentrations of radioactivity in the E1 glucuronide pool in the urine. After the women were euthyroid, the MCR of A had increased in seven of eight, the MCR of E1 increased in all eight, and peripheral aromatization had decreased in seven of eight. These findings indicate that hypothyroidism results in a decrease in the MCRs of A and E1 and, in most subjects, an increase in peripheral aromatization of A to E1.

[7-3H]Androstenedione and [4-14C]es-trone or [7-3H]testosterone and [14C]estradiol were infused at constant rates into brachial arm veins of 15 normal men. During the infusions blood samples were obtained from the brachial artery, a deep vein draining primarily muscle, and a superficial vein draining primarily adipose tissue of the arm contralateral to the infusion. In seven men the mean ± SE value for the fractional conversion of androstenedione to estrone was 0.013 ± 0.004 for muscle and 0.014 ± 0.002 for adipose tissue. In eight men the mean SEvalue for the frac-tional conversion of testosterone to estradiol was 0.0007± 0.0001 for muscle and 0.0012 ± 0.0002 for adipose tissue. Both of these values were significantly (P < 0.01) less than the respective values of androstenedione aromatization to estrone. If constancy of tissue aromatization throughout the body is assumed, the muscle accounts for 25-30% and adipose tissue for 10-15% of the total extragonadal aromatization of androgens to estrogens. (J Cli...

To determine whether menstrual status had an effect on plasma sex hormone-binding globulin (SHBG) capacity and nonprotein-bound estradiol (% free E2) and testosterone (% free T), we measured these as well as plasma FSH, total E2, and T and the MCRs of E2 and T in a group of 78 perimenopausal women. The women were allocated to 4 groups: women with cycles whose plasma FSH level was less than 40 mIU/mL (A; n = 16), women with cycles whose plasma FSH level was greater than 40 mIU/mL (B; n = 19), women who were amenorrheic for less than 1 yr (C; n = 13), and women who were amenorrheic for more than 1 yr (D; n = 30). The mean plasma SHBG values were 51.4 +/- 5.7 (+/- SE), 48.3 +/- 4.3, 45.9 +/- 5.4, and 51.1 +/- 3.7 nM in groups 1-4 respectively, and were not significantly different from one another. The mean % free E2 and % free T values also were not different between the groups. However, the mean total E2 and free E2 (% free E2 X E2/100) concentrations were significantly (P less than 0.05) higher in both groups A and B than in groups C and D. The E2 concentration was also higher in group A than in group B. There were strong correlations between the E2 and free E2 concentrations between the T and free T (% free T X T/100); (P less than 0.0001) concentrations, between SHBG capacity and weight, and between the MCRs of both E2 and T and % free E2 and % free T. In normal women, the menopause is not associated with changes in SHBG or % free steroids. Hence, the measurement of E2 could be used to predict the mass of free E2 in these women.

The responses of serum TSH and PRL to TRH (500 microgram) were studied in normal young women in the early follicular, periovulatory, and midluteal phases of the menstrual cycle in order to examine the relationship of these responses to the levels of estradiol relationship of these responses to the levels of estradiol (E2) and progesterone. Each woman was studied twice in each phase in order to assess intraindividual variability. There was no significant difference in either the TSH or PRL responses among the phases of the menstrual cycle nor was either response affected by the periovulatory rise in E2 or by the luteal rise in both E2 and progesterone. Thus, the interpretation of the TSH and PRL responses to TRH in normal women is not affected by the menstrual cycle although both responses are greater in women that in men. Both the peak TSH and peak PRL after TRH were highly correlated with the basal levels of TSH (r = 0.85; P less than 0.01) and PRL (r = 0.67; P less than 0.01), respectively, indicating that the TSH and PRL responses to TRH in women are directly proportionate to the basal levels of the respective hormones, as previously shown for the TSH response in men. The mean intraindividual variability (coefficient of variation) of the TSH response to TRH was 18%, but ranged as high as 56%, while that of the PRL response was 16% and ranged up to 31%; variability was not affected by the phase of the menstrual cycle. The normal range of the peak TSH after TRH in women is 7-33 microU/ml (mean +/- 2 SD); however, because of the variability, a normal woman may sometimes have a peak TSH after TRH as low as 4 microU/ml. Repeating the test will result in a normal value if the woman is truly normal. Similarly, the normal peak PRL after TRH in women is 22-111 ng/ml (mean +/- 2 SD); usually, however, the lower limit is 30 ng/ml with lower values due to intraindividual variation. The data suggest that the higher average level of E2 in women compared to women, but that the cyclic changes in serum E2 or progesterone in women have little or no additional effect.The relationship of changes in serum estradiol and progesterone during the menstrual cycle to the thyrotropin (TSH) and prolactin (PRL) responses to thyrotropin-releasing hormone (TRH) was investigated. Serum TSH and PRL responses to TRH (500 mcg) were studied in 10 healthy women, aged 19-32 years, in the early follicular, periovulatory, and midluteal phases of the menstrual cycle. Peak TSH and peak PRL after TRH were highly correlated with the basal levels of TSH (R=.85; P .01) and PRL (R=.67; P .01); respectively, indicating that the TSH and PRL responses to TRH are directly proportionate to the basal levels of the respective hormones. Neither TSH and PRL responses to TRH nor variability was affected by the phase of the menstrual cycle. The normal range of peak TSH after TRH was 7-33 mcU/ml and the normal range of peak PRL after TRH was 22-111 ng/ml. These results suggest that the higher average level of estradiol in women compared to men may account for the greater responses in women, however, the cyclic changes in serum estradiol or progesterone in women have little or no additional effect.

The metabolism of 2-hydroxyestrone (2-OHE1) was studied in eight normal men with pulse injections of [6,7-3H]2-OHE1 (four subjects) and [6,7-3H]2-OHE1/[4-14C]E1 (four subjects). After the pulses, blood samples were withdrawn at increasing time intervals for 1440 min (24 h) and analyzed for total radioactivity and for radioactivity as 2-OHE1, 2-methoxyestrone (2-MeOE1), 2-hydroxyestrone 3-methyl ether (2-OHE1 3Me), 2-hydroxyestradiol (2-OHE2), 2-methoxyestradiol (2-MeOE2), and 2-hydroxyestradiol 3-methyl ether (2-OHE2 3Me).In addition, all urine was collected for 120 h and analyzed for conjugated metabolites of the above steroids. There was a rapid disappearance of 2-OHE1 from the blood, such that by 100–240 min, none was measurable. The mean (±SE) MCR of 2-OHE1 was 89,600 ± 15,700 liters/day. Most of the 3H radioactivity present in the blood at the initial sampling times was associated with 2-MeOEi, and the mean conversion ratio for 2-OHE1 to 2-MeOE1 [CR 2-OHE1, 2-MeOE1 = ratio of radioactivity (integrate...

Using the constant infusion technique, [7-3H]testosterone and [4-l4C]estradiol were infused into six men and two women and [7-3H]androstenedione and [4-l4C]estrone were infused into two men before and after the administration of 60 U ACTH every 12 h for four doses. Measurements of the MCRs, plasma levels of endogenous hormones, and blood production rates (PBs) were performed before and after ACTH. The fraction of infused androgen converted to and measured as estrogen was also determined before and after ACTH. In all six men, ACTH caused a significant rise in the mean value for the MCR of testosterone from 900 ± 80 to 1250 ± 80 (SE) liters/day, a significant decrease in the mean value for levels of testosterone from 5.2 ± 0.9 to 2.0 ± 0.6 ng/ml, and a significant decrease in the PB of testosterone from 4.5 ± 0.5 to 2.3 ± 0.6 mg/day. In both women, MCR of testosterone rose, the plasma levels remained essentially unchanged, and the PBS increased. In the men, ACTH administration resulted in a nonsignificant r...

Fluoxymesterone, an androgen not converted to estrogen, caused a significant decrease in the TSH response to TRH in 11 men with primary hypogonadism [maximum change in TSH: before treatment, 11.3 +/- microU/ml (mean +/- SE); 8.9 +/- 1.0 after 2 weeks (P less than 0.001); 8.2 +/- 1.1 after 6 weeks (P less than 0.01)]. There was a significant fall in serum T4-binding globulin (TBG) (measured directly by RIA) without a change in the free T4 or free T3 index. Fluoxymesterone had no effect on the PRL response to TRH in hypogonadal men. The results suggest that 1) androgen per se is at least partly responsible for the lower TSH response to TRH in men compared to women and 2) androgen is not a cause of the lower PRL response to TRH in men.

We studied, in four normal men, the metabolism of 2-methoxyestrone (2-MeOE1) using pulse injections of either [3H]2MeOE1 (two men) or [14C]methoxy-2-MeOE1 plus [3H]2-MeOE1 (two men) by analysis of blood samples drawn at increasing time intervals after the pulse and of urine collected for 5 days. The disappearance from the blood of radioactivity as 2-MeOE1 could be characterized as a function that was the sum of three exponentials. The mean +/- SE value for the initial volume of distribution was 32 +/- 9 liters, and the mean MCR was 2470 +/- 770 liters/day. The disappearance of total 3H radioactivity from the blood was considerably slower, with a mean MCR of 290 +/- 30 liters/day, indicating the presence of a slowly turning over pool of 2-MeOE1 metabolites, probably including the 2-MeOE1 3-sulfate conjugate. The disappearance of total 14C radioactivity was slower than that of total 3H, indicating considerable demethylation of 2-MeOE1 with a very slow excretion of 14C from the released methyl group. In none of the subjects could we find in the blood radioactivity as unconjugated [3H]2-hydroxyestrone ( [3H]2-OHE1). However, examination of the urine indicated that considerable demethylation of [3H]2-MeOE1 had occurred. At least 64% of the urinary 3H-containing metabolites from the mixed dose had lost the 14C-bearing methoxylcarbon atom. The fractionated metabolites were qualitatively and quantitatively similar to those found earlier for [3H]2-OHE1. We conclude that 2-MeOE1, which of itself has little biological activity, can act as a pool of potentially active 2-OHE1 in the tissues.

We have infused [6,7-3H]estrone or [6,73H]estradiol and [4-14C]estriol into seven women who had had breast cancer and into five normal postmenopausal women. We measured the endogenous concentrations and the metabolic clearance rates of estrone, estradiol, and estriol and calculated the bloodproduction rates for these steroids in each group. There were no significant differences between the respective measurements for each group. Our data does not support the argument that physiological amounts of estriol are protective against breast cancer development in women. {J Clin Endocrinol Metab 46: 44, 1978)

To determine whether smoking affects androgen and estrogen production and metabolism we measured the MCRs, production rates (PB), androgen and estrogen interconversions, and percent peripheral aromatization in 88 pre- and postmenopausal women grouped as smokers or nonsmokers. These women were participating in an on-going study to determine the relationship between androgen and estrogen dynamics and osteoporosis. The dynamic measurements were done using constant infusions of [3H] androgen and [14C]estrogen, and the plasma steroid concentrations were measured by RIA. We found that women who were smokers had lower MCRs for androstenedione (A), testosterone, estrone, and estradiol than those who were nonsmokers, but when the data were adjusted for body weight, the MCRs were not significantly different for any of the steroids between smokers and nonsmokers. The mean plasma A concentration was higher in the smokers than in the nonsmokers but plasma testosterone, estrone, and estradiol concentrations were not different. The PB values for all steroids, the interconversions of the androgens and the estrogens, and the peripheral aromatization of the androgens were not different in the 2 groups. These results indicate that smoking does not alter the production and metabolism of androgens and estrogens in pre- and postmenopausal women. However, because the women who smoked were less heavy than those who were nonsmokers, their androgen and estrogen MCRs were lower, leading to a greater plasma A concentration. Our data do not rule out an effect of smoking on other specific pathways of estrogen metabolism.

3H-androstenedione (6 men) and 3H-estrone (6 men) were infused at a constant rate for 270 min to 12 men. For the first 135 min the subjects were lying in bed and for the last 135 min they were standing upright. Blood samples were obtained prior to and at the end of each infusion period. Isotopic steady states were achieved during each time interval. Concentrations of radioactivity as infused precursor steroids were significantly higher at the end of the standing as compared to the supine period. The mean metabolic clearance rate for androstenedione (MCRa) fell significantly from 1,010 1/day/m2 supine to 710 1/day/m2 on standing, a decrease of 27%. Similarly the metabolic clearance rate of estrone (MCR1) fell significantly from 1,230 1/day/m2 supine to 875 1/day/m2 standing, a decrease of 29%. The conversion of androstenedione to testosterone and to estrone and of estrone to estradiol as given by the conversion ratios (CRpre,peo = ratio of concentrations of radioactivity of product/precursor) did not chang...

Five adult men who developed gynecomastia or tender breasts while undergoing chronic hemodialysis for chronic renal failure all had elevated serum luteinizing hormone (LH) and normal plasma testosterone (T). Four had elevated serum follicle-stimulating hormone (FSH) but only one had an elevated serum prolactin. In no case was plasma estradiol (E2) elevated. One year later, when the gynecomastia had largely disappeared, the level of LH was lower in 2 of 4 patients but remained slightly elevated in all four, while the level of FSH had fallen to normal in 3 of 4 patients. The cause of the gynecomastia is not clear but it is not due to elevated levels of E2 or prolactin or to an elevated ratio of E2 to T; it may be related to elevated FSH, LH, or both.