Abstract Study Objective:To determine whether clinically available data on risk factors are adequate to identify perimenopausal women with either low or high bone mass. Design:Cross-sectional obser...

BACKGROUND:Men undergoing heart transplantation during the early 1990s had declines in testosterone associated with rapid bone loss. It is unclear whether low testosterone still occurs in an era of lower prednisone doses, whether cyclosporine A (CsA) contributes, whether hypothalamic-pituitary-gonadal (HPG) suppression or direct testicular effects are responsible, and whether low testosterone influences bone loss in men receiving therapy to prevent osteoporosis. METHODS:Serum testosterone, estradiol, sex hormone binding globulin, gonadotropins, and bone density were measured and prednisone and CsA doses and levels for the first 2 years after transplantation were recorded in a more recently transplanted cohort of 108 participants in a trial comparing alendronate and calcitriol for prevention of posttransplant osteoporosis. RESULTS:Total and free testosterone levels were lowest during the first month (257+/-131 and 6.2+/-3 ng/dL, respectively) and normalized by 2 months. Gonadotropins were low in the majority, suggesting HPG suppression. Low total testosterone persisted in 14% at 1 year and 18% at 2 years. Prednisone was the major predictor of serum testosterone. No adverse effect of CsA and no relationship between serum testosterone and bone density change were detected. CONCLUSIONS:Low serum testosterone levels still occur in the early posttransplant period, probably related to HPG suppression by prednisone rather than direct testicular effects of CsA. They are not associated with bone loss in men receiving therapies to prevent osteoporosis. At later time points, low testosterone levels are common and apparently related to primary gonadal dysfunction, suggesting that long-term male heart transplant recipients should be evaluated for hypogonadism.

With critical illness, serum testosterone levels fall markedly, whereas estrogen levels rise. Although animal studies suggest adaptive advantages, no prospective model has been available for studies in humans. We hypothesized that coronary artery bypass graft (CABG) surgery would provide such a model by eliciting the same reproductive hormone and other endocrine responses as reported with major nonsurgical illnesses. We further hypothesized that those responses would occur consistently in all CABG patients with predictable time courses, providing reliable windows for prospective studies. In 17 men undergoing CABG, serum levels of reproductive hormones, cortisol, thyroid hormones, and IGF-I were measured before and for up to 5 wk after surgery. Changes in serum levels of reproductive and other hormones were similar to those reported in nonsurgical critically ill patients. Time course for onset, duration, and recovery of reproductive hormone changes were consistent among all patients. A window for studying the testosterone and estrogen responses was established as the first 5 days following CABG. Practical use of this model was demonstrated by evaluating, in another seven men, changes in gonadotroph responsiveness to GnRH following CABG. Finally, to determine whether our findings in CABG could be extended to other surgeries, we demonstrated similar endocrine responses in 12 men following abdominal aortic aneurysm resection. We conclude that patients undergoing CABG surgery provide a useful human model for the prospective evaluation of the reproductive axis responses to acute illness. Other major surgeries are likely to also be suitable for these studies.

5581 Introduction: Seaweed and soy foods are common in Japan and Korea where the incidence and mortality of breast cancer are significantly lower than in the US. Most attention has focused on soy foods and their phytoestrogen content. Seaweeds are known to have an antibiotic effect in vitro and in vivo studies support the idea that dietary seaweed modifies gastrointestinal bacteria populations. We investigated the possibility that dietary seaweed could act as a probiotic when consumed with soy, and enhance the gastrointestinal metabolism of phytoestrogens, especially the increasing the production of equol. Equol production is associated with decreased breast cancer risk. Methods: In a double-blinded placebo-controlled clinical trial, 28 healthy postmenopausal women (average age = 58 years) were recruited to our 17 week study. Ten of the women had been treated for early breast cancer but were disease free at the time of the study. None of the women took antibiotics during the study, and alcoholic beverage consumption was limited to one or fewer drinks per week. The women were randomized to either seaweed or placebo for six weeks, followed by a week when soy supplementation (2 mg isoflavones/kg body weight) was added. A 3-week washout period separated the two arms of the study, after which women were crossed over to the alternate intervention arm. Blood samples for estradiol, estrone, and sex hormone binding globulin were obtained at baseline and each of the 6 clinic endpoints. Women collected 48-hour urine specimens at each of the 7 time points for phytoestrogen determination. Results: Blood levels of estrone and estradiol did not change during the study, but SHBG levels significantly decreased during the seaweed plus soy supplementation period. No urinary phytoestrogen excretion was reported during the placebo or seaweed interventions, but urinary phytoestrogens were detected during both the soy and seaweed plus soy intervention periods. Equol production was only seen in women who had never been treated for breast cancer, and not in any of the breast cancer survivors. For 6 of the 7 disease-free women who produced equol when taking soy, the combination of seaweed plus soy further increased equol levels. Conclusions: The presence of seaweed in the Asian diet may act as a probiotic, enhancing intestinal conversion of phytoestrogens, particularly the production of equol, and could account for some of the breast cancer protective effects of dietary soy.

Although serum testosterone levels decrease acutely in critically ill patients, estrogen levels rise. We hypothesized that increased rates of aromatization of androgens to estrogens underlie the increase in serum estrogen levels. Eleven men and three women (age 42-69 yr) were prospectively studied before and again after elective coronary artery bypass graft surgery (CABG). Each patient received priming doses of [(14)C]androgen and [(3)H]estrogen that were immediately followed by peripheral infusions for 210 min. Eight men and three women received androstenedione (A(4))/estrone (E(1)) and three men received testosterone (T)/estradiol (E(2)). Adipose tissue biopsies were obtained in another six men before and after CABG to evaluate levels of P450 aromatase mRNA. Serum T levels decreased postoperatively in all 17 men (P < 0.001), whereas E(1) levels rose (P = 0.004), with a trend toward a rise in E(2) (P = 0.23). Peripheral aromatization rates of androgens to estrogens rose markedly in all 14 patients (P < 0.0001). Estrogen clearance rates rose (P < 0.002). Mean serum A(4) levels increased slightly postoperatively (P = 0.04), although no increase in A(4) production rates (PRs) was observed. T PRs decreased in two of three men, whereas clearance rates increased in all three. Adipose tissue P450 aromatase mRNA content increased postoperatively (P < 0.001). We conclude that the primary cause of increased estrogen levels in acute illness is increased aromatase P450 gene expression, resulting in enhanced aromatization of androgens to estrogens, a previously undescribed endocrine response to acute illness. Both increased T clearance and decreased T production contribute to decreased serum T levels. Animal studies suggest that these opposing changes in circulating estrogen and androgen levels may be important to reduce morbidity and mortality in critical illness.

CONTEXT Risk of coronary heart disease is higher in African-American than in Caucasian women. OBJECTIVE 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. DESIGN This was a cross-sectional study. SETTING The study was conducted in the general community. STUDY PARTICIPANTS Sixty Caucasian and 117 African-American premenopausal women participated. MAIN OUTCOME MEASURES 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. RESULTS Relative to Caucasian women, African-American women had significantly higher mean BMI (23.92 +/- 3.87 vs. 26.99 +/- 5.87 kg/m2, respectively; P < 0.001), and WHR (0.733 +/- 0.052 vs. 0.757 +/- 0.068; P < 0.03). Also, plasma triglyceride (TG) levels were significantly lower in African-American women (81 +/- 61 vs. 55 +/- 24 mg/dl; P < 0.0001). Serum estrone sulfate (556 +/- 323 vs. 442 +/- 332 pg/ml, Caucasian vs. African-American; P < 0.001), estradiol (E2) (55.1 +/- 43.6 vs. 35.8 +/- 17.7 pg/ml; P < 0.0001), androstenedione (2.6 +/- 0.9 vs. 1.6 +/- 0.7 ng/ml; P < 0.0001), and testosterone (0.36 +/- 0.12 vs. 0.31 +/- 0.19 ng/ml; P < 0.002) 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. CONCLUSIONS 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.

The direct effects of hormones on cognition are not significant when salient factors are considered. Further, hormones do not mediate the age-cognition relationship; it is necessary to look to other explanatory pathways.

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 (by>100% each; P < 0.0001 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.

Objectives: Physical activity has demonstrable effects on estrogen levels in pre- and postmenopausal women. Increased oxidation of estrone to 2-hydroxyestrone (2HE) relative to 16α-hydroxyestrone (16HE) has been hypothesized to reduce breast cancer risk, but little is known about the effect of physical activity and body size in relation to the ratio of 2HE and 16HE in women. We examined these relationships in cross-sectional analyses of 157 North American and Chinese women.

A cross-sectional study of 232 healthy children, with about equal numbers of boys and girls and blacks and whites, aged 4 to 16 yr, was conducted to investigate the racial differences in bone mineral. Bone mineral content (BMC) by dual x-ray absorptiometry was found to be similar between blacks and whites at the spine after controlling for age and Tanner stage. However, total body BMC was higher in blacks, compared with whites of the same age and Tanner stage. Height and weight alone reduced the racial difference in BMC from 152 g to 66 g in girls and from 163 g to 105 g in boys, in whom the difference was further reduced to 66 g after accounting for lean and fat body mass and subscapular skinfold. The only significant sex hormone was androstenedione, which explained another 4-5 g of the racial difference in total body BMC for both boys and girls. Among the biochemical variables, only 25OH vitamin D reduced the residual racial difference in total body BMC to 39 g in girls, whereas serum PTH, urine free deoxypyridinoline ratio, and 1,25(OH)(2) vitamin D reduced the residual difference to 25 g in boys. The residual racial differences in bone mass were not statistically significant.

Menopause: July 2003 - Volume 10 - Issue 4 - p 274-276 doi: 10.1097/01.GME.0000072203.41124.52

Mathematical methods exist to determine the fractions of sex hormones bound to albumin, bound to sex hormone binding globulin (SHBG), or unbound, using total hormone concentration and SHBG concentration. We used data from eight prospective studies of postmenopausal women to assess the validity of these estimates for fractions of estradiol (E2) and to investigate the impact of using calculated values in breast cancer relative risk (RR) models. Comparisons were made between measured and calculated concentrations of free and non-SHBG-bound E2 in four studies. Relationships between the hormone fractions were investigated and a sensitivity analysis of the calculation performed. Breast cancer RRs were estimated using conditional logistic regression by quintiles of free E2. There is a high correlation (r > 0.91) between calculated and measured values of both free and non-SHBG-bound E2. The calculation is highly sensitive to total hormone concentration but is relatively insensitive to SHBG concentration. In studies with both measured and calculated values, the RRs of breast cancer by quintile of free E2 were almost identical for both estimates; using calculated values in all possible studies the RR in the highest compared with the lowest quintile of free E2 was 2.29 (95% confidence interval, 1.65-3.19). The mathematical method used to calculate fractions of E2 is valid, and RR analyses using calculated values produce similar results to those using measured values. This suggests that for epidemiological studies, it is only necessary to measure total E2 concentration and SHBG concentration, with hormone fractions being obtained by calculation, producing savings in cost, time, and serum.

Postmenopausal women with elevated serum estrogens and androgens are at an increased risk of breast cancer. We evaluated associations of serum estrogen and androgen levels with age, anthropometry, and reproductive history to assess whether these characteristics could potentially modify breast cancer risk through hormonal mechanisms. A cross-sectional study was conducted among 133 postmenopausal women who donated blood to the serum bank (Columbia, MO) and served as controls in a previous prospective nested case control study of serum hormones and breast cancer risk. Standard regression methods were used to calculate adjusted means and test for trends in relationships of serum hormone concentrations with breast cancer risk factors. All analyses were performed on the log(e) scale, and all models included assay batch, date, and time of blood collection. Serum levels of estradiol, non-sex hormone binding globulin bound estradiol, estrone, estrone sulfate, and testosterone increased significantly with increasing body mass index (BMI), whereas sex hormone binding globulin levels decreased. After adjusting for BMI, nulliparous women tended to have higher testosterone levels compared with parous women (P = 0.05), but there was no evidence of a trend of decreasing testosterone with increasing parity. Dehydroepiandrosterone, its sulfate, and androstenediol decreased significantly with increasing age. Although BMI and parity could potentially modify breast cancer risk through hormonal mechanisms, age-related increases in breast cancer incidence do not appear to be mediated through changes in serum levels of the hormones evaluated.

Obese women and women with upper body fat distribution have been shown to have a hormonal profile associated with increased risk of breast cancer. This study examines the relationships between obesity and body fat distribution, and sex hormones. Data from 47 healthy nulliparous premenopausal Caucasian women were collected cross-sectionally. Eight were obese and 39 non-obese. Thirteen had normal body fat (NBF), while 34 lower body fat (LBF) phenotypes. The concentrations of serum estrone, estrone sulfate, estradiol, free estradiol (Free E2), %Free E2, androstenedione, testosterone, free testosterone (Free T), %Free T, prolactin and sex hormone-binding globulin (SHBG) levels were determined in the mid-follicular phase. Results showed that in multivariate regression analyses controlling for age, age at menarche and body mass index (BMI), a 0.1 unit increase in waist-to-hip circumference ratio (WHR) towards the normal range decreased %FreeT by 18% (p=0.03), %FreeE2 by 15% (p=0.07) and increased SHBG by 36% (p=0.07). In similar analyses controlling for WHR, a unit increase in BMI increased %FreeE2 by 0.25%(p=0.04), %FreeT by 0.23% (p=0.07), and decreased that SHBG by 0.52% (p=0.07). Multivariate comparison showed SHBG levels to be higher by 39% (p=0.02) and %FreeE2 lower by 13% (p=0.07) in NBF compared to LBF phenotype women. Multivariate comparison between obese and nonobese women, however, showed SHBG levels to be lower by 24% (p=0.04), and %FreeE2 higher by 18% (p=0.04) in obese women. Results suggested that obesity and increasing BMI are associated with a serum sex hormone profile that increases breast cancer risk; however, increasing WHR towards the normal range is not associated with a high risk sex hormone profile. WHR in the normal range appears to be associated with a sex hormone profile that is more protective compared to the lower range.

Androstenedione is a steroid hormone and an intermediate in the synthetic pathway of both testosterone and estradiol in men and women. It is available without prescription and taken with the expectation that it may have beneficial effects on strength, general well-being, libido, and quality of life. Although studies have shown that oral androstenedione increases serum testosterone and estradiol levels in men, the hormonal effects of androstenedione in postmenopausal women are unknown. We randomly assigned 30 healthy postmenopausal women to receive 0, 50, or 100 mg androstenedione as a single oral dose. After androstenedione administration, we made hourly measurements of serum androstenedione, estrone, estradiol, and testosterone concentrations during 12 h of frequent blood sampling. The mean change (+/-SD) in serum androstenedione area under the curve (AUC) was greater in both the 50-mg (79 +/- 39%) and 100-mg dose groups (242 +/- 184%) than in the control group (-29 +/- 28%) (P < 0.0001 for controls vs. 50-mg group and controls vs. 100-mg group). The mean change in serum androstenedione AUC was also greater in the 100-mg than 50-mg dose group (P = 0.0026). The mean change in serum estrone AUC was greater in both the 50-mg (108 +/- 72%) and 100-mg dose groups (116 +/- 119%) than in the control group (-5 +/- 19%), although the control vs. 100-mg group comparison did not quite meet statistical significance (P < 0.0001 for controls vs. 50-mg group, P = 0.0631 controls vs. 100-mg group). The mean change in serum estradiol AUC remained stable after supplementation in all groups without any between-group differences observed (-11 +/- 17%, 2.8 +/- 34%, -11 +/- 27%, for the control, 50-mg, and 100-mg groups, respectively). The mean change in serum testosterone AUC was greater in both the 50-mg (185 +/- 146%) and 100-mg dose groups (457 +/- 601%) than in the control group (-27 +/- 13%) (P < 0.0001 for controls vs. 50-mg group and for controls vs. 100-mg group). The mean change in testosterone AUC was also greater in the 100-mg dose group than 50-mg dose group (P = 0.0257). There was considerable individual variability in the changes of serum androstenedione, estrone, and testosterone levels in the treated groups with peak serum testosterone levels exceeding the upper limit of normal in 4 of 10 women in the 50-mg dose group and 6 of 10 in the 100-mg dose group. We concluded that the acute administration of both 50-mg and 100-mg of androstenedione increases serum testosterone and estrone levels, but not estradiol levels, in postmenopausal women. If these hormonal effects are sustained during long-term administration, regular use of this supplement by postmenopausal women could thus cause both beneficial and adverse effects.

We used longitudinal data from the Massachusetts Male Aging Study, a large population-based random-sample cohort of men aged 40-70 yr at baseline, to establish normative age trends for serum level of T and related hormones in middle-aged men and to test whether general health status affected the age trends. Of 1,709 men enrolled in 1987-1989, 1,156 were followed up 7-10 yr afterward. By repeated-measures statistical analysis, we estimated simultaneously the cross-sectional age trend of each hormone between subjects within the baseline data, the cross-sectional trend between subjects within the follow-up data, and the longitudinal trend within subjects between baseline and follow-up. Total T declined cross-sectionally at 0.8%/yr of age within the follow-up data, whereas both free and albumin-bound T declined at about 2%/yr, all significantly more steeply than within the baseline data. Sex hormone-binding globulin increased cross-sectionally at 1.6%/yr in the follow-up data, similarly to baseline. The longitudinal decline within subjects between baseline and follow-up was considerably steeper than the cross-sectional trend within measurement times for total T (1.6%/yr) and bioavailable T (2-3%/yr). Dehydroepiandrosterone, dehydroepiandrosterone sulfate, cortisol, and estrone showed significant longitudinal declines, whereas dihydrotestosterone, pituitary gonadotropins, and PRL rose longitudinally. Apparent good health, defined as absence of chronic illness, prescription medication, obesity, or excessive drinking, added 10-15% to the level of several androgens and attenuated the cross-sectional trends in T and LH but did not otherwise affect longitudinal or cross-sectional trends. The paradoxical finding that longitudinal age trends were steeper than cross-sectional trends suggests that incident poor health may accelerate the age-related decline in androgen levels.