Association Between Biomarkers of Ovarian Reserve and Infertility Among Older Women of Reproductive Age

IMPORTANCE

Despite lack of evidence of their utility, biomarkers of ovarian reserve are being promoted as potential markers of reproductive potential.

OBJECTIVE

To determine the associations between biomarkers of ovarian reserve and reproductive potential among women of late reproductive age.

DESIGN, SETTING, AND PARTICIPANTS

Prospective time-to-pregnancy cohort study (2008 to date of last follow-up in March 2016) of women (N = 981) aged 30 to 44 years without a history of infertility who had been trying to conceive for 3 months or less, recruited from the community in the Raleigh-Durham, North Carolina, area.

EXPOSURES

Early-follicular-phase serum level of antimüllerian hormone (AMH), follicle-stimulating hormone (FSH), and inhibin B and urinary level of FSH.

MAIN OUTCOMES AND MEASURES

The primary outcomes were the cumulative probability of conception by 6 and 12 cycles of attempt and relative fecundability (probability of conception in a given menstrual cycle). Conception was defined as a positive pregnancy test result.

RESULTS

A total of 750 women (mean age, 33.3 [SD, 3.2] years; 77% white; 36% overweight or obese) provided a blood and urine sample and were included in the analysis. After adjusting for age, body mass index, race, current smoking status, and recent hormonal contraceptive use, women with low AMH values (<0.7 ng/mL [n = 84]) did not have a significantly different predicted probability of conceiving by 6 cycles of attempt (65%; 95% CI, 50%-75%) compared with women (n = 579) with normal values (62%; 95% CI, 57%-66%) or by 12 cycles of attempt (84% [95% CI, 70%-91%] vs 75% [95% CI, 70%-79%], respectively). Women with high serum FSH values (>10 mIU/mL [n = 83]) did not have a significantly different predicted probability of conceiving after 6 cycles of attempt (63%; 95% CI, 50%-73%) compared with women (n = 654) with normal values (62%; 95% CI, 57%-66%) or after 12 cycles of attempt (82% [95% CI, 70%-89%] vs 75% [95% CI, 70%-78%], respectively). Women with high urinary FSH values (>11.5 mIU/mg creatinine [n = 69]) did not have a significantly different predicted probability of conceiving after 6 cycles of attempt (61%; 95% CI, 46%-74%) compared with women (n = 660) with normal values (62%; 95% CI, 58%-66%) or after 12 cycles of attempt (70% [95% CI, 54%-80%] vs 76% [95% CI, 72%-80%], respectively). Inhibin B levels (n = 737) were not associated with the probability of conceiving in a given cycle (hazard ratio per 1-pg/mL increase, 0.999; 95% CI, 0.997-1.001).

CONCLUSIONS AND RELEVANCE

Among women aged 30 to 44 years without a history of infertility who had been trying to conceive for 3 months or less, biomarkers indicating diminished ovarian reserve compared with normal ovarian reserve were not associated with reduced fertility. These findings do not support the use of urinary or blood follicle-stimulating hormone tests or antimüllerian hormone levels to assess natural fertility for women with these characteristics.

Endogenous sex hormone exposure and repetitive element DNA methylation in healthy postmenopausal women

PURPOSE

Epigenetic mechanisms may help to explain the complex and heterogeneous relation between sex hormones and cancer. Few studies have investigated the effects of sex hormones on epigenetic markers related to cancer risk such as levels of methylation within repetitive DNA elements. Our objective was to describe the association between endogenous sex hormone exposure and levels of LINE-1 and Alu methylation in healthy postmenopausal women.

METHODS

We nested a cross-sectional study within the Alberta Physical Activity and Breast Cancer Prevention Trial (2003-2006). Study participants consisted of healthy postmenopausal women who had never been diagnosed with cancer (n = 289). Sex hormone exposures included serum concentrations of estradiol, estrone, testosterone, androstenedione, and sex hormone-binding globulin. We estimated the participants' lifetime number of menstrual cycles (LNMC) as a proxy for cumulative exposure to ovarian sex hormones. Buffy coat samples were assessed for DNA methylation. Linear regression was used to model the associations of interest and to control for confounding.

RESULTS

Both estradiol and estrone had a significant positive dose-response association with LINE-1 methylation. LNMC was associated with both LINE-1 and Alu methylation. Specifically, LNMC had a non-linear "U-shaped" association with LINE-1 methylation regardless of folate intake and a negative linear association with Alu methylation, but only amongst low folate consumers. Androgen exposure was not associated with either outcome.

CONCLUSION

Current and cumulative estrogen exposure was associated with repetitive element DNA methylation in a group of healthy postmenopausal women. LINE-1 and Alu methylation may be epigenetic mechanisms through which estrogen exposure impacts cancer risk.

Abstract 1274: Associations between genetic polymorphisms in genes related to estrogen metabolism and function and prostate cancer risk: results from the Prostate Cancer Prevention Trial

Background: Substantial preclinical data corroborate the critical role of estrogen in prostate cancer development; however, epidemiological studies found no associations between circulating estrogen levels and prostate cancer risk. It was hypothesized that intraprostatic estrogen milieu may play a more important role than circulating estrogen in prostate carcinogenesis. Since it is difficult to obtain data on prostatic estrogen levels, we tested the hypothesis indirectly by investigating associations of prostate cancer risk with genetic variations of enzymes that are involved in estrogen synthesis, metabolism and function, and may affect intraprostatic estrogen milieu.

Methods: A panel of 36 potentially functional single nucleotide polymorphisms (SNPs) in estrogen-related genes was assembled based on information obtained in the literature. After removing SNPs with call rate &lt;95% (1 SNP) or minor allele frequency &lt;3% (10 SNPs), a total of 25 SNPs in 13 genes (PGR, ESR1, ESR2, CYP17A1, HSD17B1, CYP19A1, CYP1A1, CYP1B1, COMT, UGT1A6, UGT1A10, UGT2B7, UGT2B15) were examined for associations with prostate cancer risk using data and DNA samples from 1617 cases and 1731 controls in the Prostate Cancer Prevention Trial (PCPT). Cases and controls were frequency-matched on age, treatment arm and family history. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) separately in the placebo and finasteride arms, adjusting for age, race and family history. Results were similar when restricting analysis to white men only.

Results: Panels of SNPs that were significantly associated with prostate cancer risk were different according to treatment arm, showing rs1801132 in ESR1, rs700518 in CYP19A1, and rs4124874 in UGT1A6 in the placebo arm and rs2445765 in CYP19A1 and rs4680 in COMT in the finasteride arm. When stratified by circulating estrogen and androgen levels, significant associations were only observed in either the high or low category of serum hormone levels; no SNPs were significantly associated with prostate cancer risk in both categories. CYP19A1 was the only gene harboring SNPs that were significantly associated with prostate cancer risk in both the placebo (rs700518) and finasteride arms (rs2445765). In haplotype analysis using all three CYP19A1 SNPs genotyped in the study (rs700518, rs2445765 and rs700519), compared with non-risk haplotype (GCC), certain CYP19A1 haplotypes were significantly associated with increased prostate cancer risk in both arms.

Conclusion: Associations between prostate cancer risk and SNPs in genes involved in estrogen metabolism and function are complicated, and markedly modified by other factors such as finasteride treatment or circulating hormone levels. Supported by grant U10CA37429, 5UM1CA182883 and P01CA108964 from the NCI.

Citation Format: Li Tang, Mary Platek, Song Yao, Cathee Till, Phyllis Goodman, Catherine M. Tangen, Yue Wu, Elizabeth A. Platz, Marian L. Neuhouse, Frank Z. Stanczyk, Juergen K. Reichardt, Regina M. Santella, Ann Hsing, William D. Figg, Scott M. Lippman, Ian M. Thompson, Christine B. Ambrosone. Associations between genetic polymorphisms in genes related to estrogen metabolism and function and prostate cancer risk: results from the Prostate Cancer Prevention Trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1274. doi:10.1158/1538-7445.AM2017-1274

Menopausal symptoms and cardiovascular disease mortality in the Women's Ischemia Syndrome Evaluation (WISE)

OBJECTIVE

Studies have linked vasomotor symptoms (VMS) to markers of cardiovascular disease (CVD) risk, yet few have considered clinical cardiovascular events. Data suggest that associations may depend upon the age that symptoms occur. We examined associations between VMS and cardiovascular events and endothelial function, considering age of symptom onset.

METHODS

The Women's Ischemia Syndrome Evaluation enrolled women referred for coronary angiography for suspected myocardial ischemia. A total of 254 women aged more than 50 years, postmenopausal, with both ovaries, not taking hormone therapy underwent a baseline evaluation, were followed annually (median = 6.0 y), and the National Death Index was searched to ascertain CVD mortality (median = 9.3 y). A subset of participants underwent brachial artery ultrasound for flow-mediated dilation (FMD). Receiver-operating curve analysis was used to determine vasomotor symptom groups (symptoms beginning < age 42 [early onset], beginning ≥42 [later onset], never) which were examined in relation to cardiovascular events and FMD in Cox proportional hazard and linear regression models.

RESULTS

Women reporting early onset VMS (HR = 3.35, 95% CI = 1.23-7.86, P = 0.005) and women who never had VMS (HR = 2.17, 95% CI = 1.02-4.62, P = 0.05) had higher CVD mortality than women with later onset symptoms (multivariable models). Women with early onset VMS had lower FMD than women with later onset symptoms (b = -4.31, SE = 2.10, P = 0.04, multivariable).

CONCLUSIONS

Women with signs and symptoms of ischemia who had VMS beginning early in midlife had higher CVD mortality and reduced endothelial function relative to women with later onset symptoms. Future research should evaluate the vascular phenotype of women with early midlife VMS.

Relationship between crown-like structures and sex-steroid hormones in breast adipose tissue and serum among postmenopausal breast cancer patients

Background

Postmenopausal obesity is associated with increased circulating levels of androgens and estrogens and elevated breast cancer risk. Crown-like structures (CLS; microscopic foci of dying adipocytes surrounded by macrophages) are proposed to represent sites of increased aromatization of androgens to estrogens. Accordingly, we examined relationships between CLS and sex-steroid hormones in breast adipose tissue and serum from postmenopausal breast cancer patients.

Methods

Formalin-fixed paraffin embedded benign breast tissues collected for research from postmenopausal women (n = 83) diagnosed with invasive breast cancer in the Polish Breast Cancer Study (PBCS) were evaluated. Tissues were immunohistochemically stained for CD68 to determine the presence of CLS per unit area of adipose tissue. Relationships were assessed between CD68 density and CLS and previously reported sex-steroid hormones quantified using radioimmunoassays in serum taken at the time of diagnosis and in fresh frozen adipose tissue taken at the time of surgery. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the relationships between hormones (in tertiles) and CLS.

Results

CLS were observed in 36% of benign breast tissues, with a higher frequency among obese versus lean women (54% versus 17%, p = 0.03). Detection of CLS was not related to individual hormone levels or breast tumor pathology characteristics. However, detection of CLS was associated with hormone ratios. Compared with women in the highest tertile of estrone:androstenedione ratio in fat, those in the lowest tertile were less likely to have CLS (OR 0.12, 95% CI 0.03–0.59). A similar pattern was observed with estradiol:testosterone ratio in serum and CLS (lowest versus highest tertile, OR 0.18, 95% CI 0.04–0.72).

Conclusions

CLS were more frequently identified in the breast fat of obese women and were associated with increased ratios of select estrogens:androgens in the blood and tissues, but not with individual hormones. Additional studies on CLS, tissue and blood hormone levels, and breast cancer risk are needed to understand and confirm these findings.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-016-0791-4) contains supplementary material, which is available to authorized users.

Soy Food Intake and Biomarkers of Breast Cancer Risk: Possible Difference in Asian Women?

Soy foods may protect against breast cancer in Asian but not in Western populations. We examined if the levels of various markers of breast cancer risk and inflammation, as well as the effects of soy food consumption on these markers, differ between Asian and non-Asian premenopausal women in two soy intervention trials. One study randomized 220 women to a 2-yr intervention and the other one randomized 96 women in a crossover design to examine the effects of consumption of 2 daily soy servings on nipple aspirate fluid (NAF) volume; estrogens in serum, NAF, and urine; insulin-like growth factor-1 (IGF-1), IGF-binding protein 3, and inflammatory markers in serum; and mammographic densities. Mixed linear models were applied to assess ethnic differences in biomarkers and response to the soy diet. Serum C-reactive protein, serum leptin, NAF volume, and NAF estrone sulfate were lower, while urinary isoflavones were higher in Asian than in non-Asian women. A significant interaction (p_interaction = 0.05) between ethnicity and soy diet was observed for IGF-1 but not for other biomarkers. The current findings suggest possible ethnic differences in levels of biomarkers for breast cancer risk but little evidence that Asian women respond differently to soy foods than non-Asian women.

Associations of Breast Cancer Risk Factors with Premenopausal Sex Hormones in Women with Very Low Breast Cancer Risk

Breast cancer incidence rates are low but rising in urban Mongolia. We collected reproductive and lifestyle factor information and measured anthropometrics and serum sex steroid concentrations among 314 premenopausal women living in Ulaanbaatar, Mongolia. Mean differences in hormone concentrations by these factors were calculated using age-adjusted quadratic regression splines. Estrone and estradiol in college-educated women were, respectively, 18.2% (p = 0.03) and 23.6% (p = 0.03) lower than in high-school-educated women. Progesterone concentrations appeared 55.8% lower (p = 0.10) in women residing in modern housing compared with women living in traditional housing (gers), although this finding was not statistically significant. Testosterone concentrations were positively associated with adiposity and central fat distribution; 17.1% difference (p = 0.001) for highest vs. lowest quarter for body mass index and 15.1% difference (p = 0.005) for waist-to-height ratio. Estrogens were higher in the follicular phase of women who breastfed each child for shorter durations. A distinct hormonal profile was associated with an urban lifestyle in premenopausal, Mongol women. In particular, heavier, more-educated women living in urban dwellings had higher testosterone and lower estrogen and progesterone levels. Higher breast cancer incidence in urban compared with rural women suggest that the hormonal profile associated with a more traditional lifestyle may be protective among Mongol women.

Cognitive effects of estradiol after menopause: A randomized trial of the timing hypothesis

OBJECTIVE

To test the hypothesis that effects of estrogen-containing hormone therapy on cognitive abilities differ between postmenopausal women near to, and further from, menopause.

METHODS

In this randomized, double-blind, placebo-controlled trial, healthy women within 6 years of menopause or 10+ years after menopause were randomly assigned to oral 17β-estradiol 1 mg/d or placebo. Women with a uterus received cyclic micronized progesterone vaginal gel or placebo. The primary outcome assessed at 2.5 and 5 years, compared between treatment groups, was change in a standardized composite of neuropsychological test scores assessing verbal episodic memory. Secondary outcomes assessed executive functions and global cognition.

RESULTS

A total of 567 women were included in modified intention-to-treat analyses after a mean treatment duration of 57 months. For verbal memory, the mean estradiol minus placebo standardized difference in composite scores (-0.06, 95% confidence interval -0.22 to 0.09) was not significant (2-tailed p = 0.33). Differences were similar in early and late postmenopause groups (2-tailed interaction p = 0.88). Interactions between postmenopause groups and differences between treatment groups were not significant for executive functions or global cognition.

CONCLUSIONS

Estradiol initiated within 6 years of menopause does not affect verbal memory, executive functions, or global cognition differently than therapy begun 10+ years after menopause. Estradiol neither benefits nor harms these cognitive abilities regardless of time since menopause.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that estradiol initiated within 6 years of menopause does not affect cognition at 2.5 years differently than estradiol initiated 10+ years after menopause.

Reproducibility of an assay to measure serum progesterone metabolites that may be related to breast cancer risk using liquid chromatography-tandem mass spectrometry

Recent data suggest a novel role of progesterone in breast cancer etiology involving the progesterone metabolites 3α-dihydroprogesterone (3αHP), 5α-dihydroprogesterone (5αP), and 20α-dihydroprogesterone (20αHP). Accurate and precise measures of progesterone metabolites are needed for etiologic studies of hormonally related cancers. We have developed a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method to measure five hormones, including progesterone, its precursor pregnenolone, and three progesterone metabolites, 5αP, 3αHP, and 20αHP. Hormone levels were measured in serum from 20 healthy volunteers (7 men, 5 premenopausal women, and 8 postmenopausal women). Two blinded, randomized aliquots per individual were assayed in each of four batches. The coefficients of variation (CV) and intraclass correlation coefficients (ICC) were calculated from the individual components of variance. The overall laboratory CVs were <3% and ICCs were uniformly high (>98%) for all hormones measured across sex/menopausal status groups. Our HPLC-MS/MS assay of progesterone metabolites demonstrated excellent sensitivity, laboratory reproducibility, and interindividual variation, suggesting that this serum assay is suitable for epidemiologic research. The high sensitivity of the assay, and thus the ability to quantify concentrations among postmenopausal women and men, further supports that this novel assay is suitable for studies of serum progesterone metabolite concentrations and risk of breast cancer or other hormonally related cancer.

Cardiovascular Disease and 10-Year Mortality in Postmenopausal Women with Clinical Features of Polycystic Ovary Syndrome

BACKGROUND

Women with polycystic ovary syndrome (PCOS) have greater cardiac risk factor clustering but the link with mortality is incompletely described.

OBJECTIVE

To evaluate outcomes in 295 postmenopausal women enrolled in the National Institutes of Health-National Heart, Lung, and Blood Institute (NIH-NHLBI) sponsored Women's Ischemia Syndrome Evaluation (WISE) study according to clinical features of PCOS.

MATERIALS AND METHODS

A total of 25/295 (8%) women had clinical features of PCOS defined by a premenopausal history of irregular menses and current biochemical evidence of hyperandrogenemia, defined as the top quartile of androstenedione (≥701 pg/mL), testosterone (≥30.9 ng/dL), or free testosterone (≥4.5 pg/mL). Cox proportional hazard model estimated death (n = 80).

RESULTS

Women with clinical features of PCOS had an earlier menopause (p = 0.01), were more often smokers (p < 0.04), and trended toward more angiographic coronary artery disease (CAD) (p = 0.07) than women without these features. Cumulative 10-year mortality was 28% for women with (n = 25) versus 27% without clinical features of PCOS (n = 270) (p = 0.85). PCOS was not a significant predictor (p = NS) in prognostic models including diabetes, waist circumference, hypertension, and angiographic CAD.

CONCLUSION

From this longer-term follow up of a relatively small cohort of postmenopausal women with suspected ischemia, the prevalence of PCOS is similar to the general population, and clinical features of PCOS are not associated with CAD or mortality. These findings question whether identification of clinical features of PCOS in postmenopausal women who already have known cardiovascular disease provides any additional opportunity for risk factor intervention.

The Effect of Reduced Dietary Fat and Soy Supplementation on Circulating Adipocytokines in Postmenopausal Women: A Randomized Controlled 2-Month Trial

The reduced risk of breast cancer observed in Asia has been linked with diets rich in soy foods, and observational studies suggest that regular soy food intake is related to lower circulating levels of some inflammatory markers which have been implicated in breast cancer risk. However, short-term intervention studies with soy-based diets in small numbers of women have shown few significant changes in adipocytokine levels. This 8-wk dietary intervention study in 57 healthy postmenopausal women investigated whether soy food supplementation (50 mg isoflavones or 15 g soy protein in the form of tofu) or a very low-fat diet (11.3% of total energy), similar to the traditional Asian diet, is associated with beneficial effects on serum levels of the following adipocytokines: TNF-α, IL-6, adiponectin, and resistin. We found no statistically significant changes in the levels of these adipocytokines in association with the very low-fat diet or soy supplementation. Only the change in TNF-α levels between the very low-fat and control diet groups had borderline statistical significance. We conclude that ingestion of a very low-fat diet or a soy food supplemented diet for 8 wk does not significantly alter important circulating adipocytokines.

Association of estrogen measurements in serum and urine of premenopausal women

AIMS

We evaluated conjugated and unconjugated urinary estrogen metabolites as surrogate biomarkers for serum levels of unconjugated E1 and E2 in premenopausal women.

MATERIALS & METHODS

Repeated blood and urine samples were analyzed for estrogens and their metabolites using radioimmunoassays and liquid chromatography/mass spectrometry.

RESULTS

The strongest correlation (r = 0.39) was observed between serum E1 and urinary E1 and E2. The correlations of urinary E2 (r = 0.35), E1 (r = 0.29), all E2 metabolites (r = 0.30), all E1 metabolites (r = 0.23) and total estrogens (r = 0.26) with serum E2 were only moderate although statistically significant. All correlations were substantially stronger for Whites than Asians.

CONCLUSION

Urinary E2 emerged as the best predictor for serum E1 and E2, but the large intra-subject variability in urinary estrogen levels limits its use as a biomarker.

Vascular Effects of Early versus Late Postmenopausal Treatment with Estradiol

BACKGROUND

Data suggest that estrogen-containing hormone therapy is associated with beneficial effects with regard to cardiovascular disease when the therapy is initiated temporally close to menopause but not when it is initiated later. However, the hypothesis that the cardiovascular effects of postmenopausal hormone therapy vary with the timing of therapy initiation (the hormone-timing hypothesis) has not been tested.

METHODS

A total of 643 healthy postmenopausal women were stratified according to time since menopause (<6 years [early postmenopause] or ≥10 years [late postmenopause]) and were randomly assigned to receive either oral 17β-estradiol (1 mg per day, plus progesterone [45 mg] vaginal gel administered sequentially [i.e., once daily for 10 days of each 30-day cycle] for women with a uterus) or placebo (plus sequential placebo vaginal gel for women with a uterus). The primary outcome was the rate of change in carotid-artery intima-media thickness (CIMT), which was measured every 6 months. Secondary outcomes included an assessment of coronary atherosclerosis by cardiac computed tomography (CT), which was performed when participants completed the randomly assigned regimen.

RESULTS

After a median of 5 years, the effect of estradiol, with or without progesterone, on CIMT progression differed between the early and late postmenopause strata (P=0.007 for the interaction). Among women who were less than 6 years past menopause at the time of randomization, the mean CIMT increased by 0.0078 mm per year in the placebo group versus 0.0044 mm per year in the estradiol group (P=0.008). Among women who were 10 or more years past menopause at the time of randomization, the rates of CIMT progression in the placebo and estradiol groups were similar (0.0088 and 0.0100 mm per year, respectively; P=0.29). CT measures of coronary-artery calcium, total stenosis, and plaque did not differ significantly between the placebo group and the estradiol group in either postmenopause stratum.

CONCLUSIONS

Oral estradiol therapy was associated with less progression of subclinical atherosclerosis (measured as CIMT) than was placebo when therapy was initiated within 6 years after menopause but not when it was initiated 10 or more years after menopause. Estradiol had no significant effect on cardiac CT measures of atherosclerosis in either postmenopause stratum. (Funded by the National Institute on Aging, National Institutes of Health; ELITE ClinicalTrials.gov number, NCT00114517.).

Serum androgens and prostate cancer risk: results from the placebo arm of the Prostate Cancer Prevention Trial

BACKGROUND

Compelling and long-standing data suggest that androgens play an important role in the development of both normal prostate epithelium and prostate cancer. Although testosterone administration can induce prostate cancer (PCA) in laboratory animals, serum-based epidemiologic studies examining androgens in humans have not consistently supported a role for androgens in prostate carcinogenesis. We examined whether pre-diagnostic serum androgens were associated with PCA risk in the placebo arm of the Prostate Cancer Prevention Trial.

METHODS

In this nested case-control study, cases (n = 1,032) were primarily local-stage, biopsy-detected cancers, and controls (n = 1,025) were biopsy-confirmed to be PCA-free. Pre-diagnostic serum androgens (total testosterone, 3α-androstanediol glucuronide, free testosterone), estrogen-to-testosterone ratio, and sex hormone-binding globulin (SHBG) concentrations were measured in pooled (baseline and year 3) blood samples.

RESULTS

We found no significant associations between serum androgens, estrogen-to-testosterone ratios, or SHBG and risk of total, low (Gleason <7) or high-grade (Gleason 7-10) PCA.

CONCLUSION

Much remains to be learned about the role of androgens in prostate carcinogenesis. Further research is needed to evaluate the role of androgens, timing of exposure, genetic modulators of androgen metabolism, or environmental exposures that may affect androgen influence on prostate carcinogenesis.

Methods and baseline cardiovascular data from the Early versus Late Intervention Trial with Estradiol testing the menopausal hormone timing hypothesis

OBJECTIVE

This study aims to present methods and baseline data from the Early versus Late Intervention Trial with Estradiol (ELITE), the only clinical trial designed to specifically test the timing hypothesis of postmenopausal hormone therapy (HT). The timing hypothesis posits that HT effects depend on the temporal initiation of HT relative to time since menopause.

METHODS

ELITE is a randomized, double-blind, placebo-controlled trial with a 2 × 2 factorial design. Six hundred forty-three healthy postmenopausal women without cardiovascular disease were randomized to oral estradiol or placebo for up to 6 to 7 years according to time since menopause (<6 or ≥10 y). Carotid artery intima-media thickness (CIMT) and cardiac computed tomography were conducted to determine HT effects on subclinical atherosclerosis across menopause strata.

RESULTS

Participants in the early and late postmenopausal strata were well-separated by mean age (55.4 vs 65.4 y) and median time since menopause (3.5 vs 14.3 y). Expected risk factors (age, blood pressure, and body mass index) were associated with CIMT at baseline in both strata. In the early postmenopausal group, but not in the late postmenopausal group, we observed significant associations between CIMT and factors that may play a role in the responsiveness of atherosclerosis progression according to timing of HT initiation. These include low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, sex hormone-binding globulin, and serum total estradiol.

CONCLUSIONS

The ELITE randomized controlled trial is timely and unique. Baseline data indicate that ELITE is well-positioned to test the HT timing hypothesis in relation to atherosclerosis progression and coronary artery disease.

The impact of short-term depot-medroxyprogesterone acetate treatment on resting metabolic rate

OBJECTIVE

This study examines the effect of a progestogen (depot-medroxyprogesterone acetate, DMPA) on resting metabolic rate (RMR) in a cohort of young, normal-weight healthy women. We hypothesize an increase in RMR and nonshivering thermogenesis (NST) resulting in increased body temperature by DMPA.

STUDY DESIGN

We performed a prospective cohort study in 13 subjects tested at baseline, 3 weeks and 9 weeks after 150 mg intramuscular DMPA administration. RMR was determined with indirect calorimetry. Secondary endpoints included changes in body mass index (BMI), body composition, temperature and serum levels of estradiol (E2), luteinizing hormone (LH), progesterone and MPA.

RESULTS

The percent change in RMR from baseline to week 3 (9%) was significantly higher than the percent change from baseline to week 9 (1.6%) (p=.045). The greatest percent change from baseline to week 3 compared to baseline to week 9 was seen in women initiating DMPA in the luteal phase of the cycle. Hypothalamic-pituitary-ovarian axis was evident by decreases in E2, LH and progesterone. DMPA resulted in increased body temperature with a significant correlation between the change in body temperature and the change in RMR. No change in body composition was seen.

CONCLUSIONS

RMR and NST increased in young healthy women with normal BMI 3 weeks after receiving the initial dose of 150 mg DMPA for contraception. The effect was augmented when the drug was administered during the luteal phase of the menstrual cycle.

IMPLICATION

DMPA increases RMR and thermogenesis independent of changes in body mass. An increase in weight with chronic DMPA may result from a combination of hyperphagia and abnormal NST in predisposed individuals.

Assay reproducibility of serum androgen measurements using liquid chromatography-tandem mass spectrometry

BACKGROUND

Valid and precise measures of androgen concentrations are needed for etiologic studies of hormonally-related cancers. We developed a high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with two sample preparations to measure 11 androgens, including adrenal and gonadal androgenic precursors and their 5α-reduced metabolites.

METHODS

Androgen levels were measured in serum from 20 healthy volunteers (5 men, 10 premenopausal women, 5 postmenopausal women). Two blinded, randomized aliquots per individual were assayed in each of three batches. A fourth batch of samples was measured at an external laboratory using comparable methodology to measure 9 of the 11 androgens. Coefficients of variation (CV) and intraclass correlation coefficients (ICC) were calculated from the individual components of variance. Comparability of 9 androgens across laboratories was assessed using Spearman ranked correlations, Deming regression and bias plots.

RESULTS

The laboratory CVs were <5% and ICCs were uniformly high (>95%) for all androgens measured across sex/menopausal status groups. Spearman ranked correlations for 9 hormones measured in the comparison laboratory were high (>0.85), suggesting good agreement.

CONCLUSION

Our high-performance LC-MS/MS assays of 11 androgens, including adrenal and gonadal androgenic precursors and their 5α-reduced metabolites demonstrated excellent laboratory reproducibility, and good comparability with an established method that measured 9 of the 11 hormones tested. The serum androgen metabolite assays are suitable for use in epidemiologic research.

Inflammatory Marker Changes in Postmenopausal Women after a Year-long Exercise Intervention Comparing High Versus Moderate Volumes

This randomized dose comparison trial examined if higher exercise volume decreased inflammatory biomarkers, associated with postmenopausal breast cancer risk, more than moderate exercise volume. The Breast Cancer and Exercise Trial in Alberta was a two-center, two-armed randomized trial in 400 inactive, healthy, postmenopausal women, aged 50 to 74 years, with a body mass index of 22 to 40 kg/m(2). Participants were randomized to high (300 minutes/week) or moderate (150 minutes/week) volumes of aerobic exercise while maintaining usual diet. Fasting blood concentrations of C-reactive protein (CRP), IL6, and TNFα were measured at baseline, 6 and 12 months. Intention-to-treat (ITT) analysis was performed using linear mixed models adjusted for baseline biomarker concentrations. ITT analyses of 386 (97%) participants showed no statistically significant group differences for changes in biomarker levels at 6 and 12 months. In addition, we did not observe any modification of this effect by baseline characteristics of participants. In post hoc analyses based on self-selected exercise level (measured in minutes/week), CRP decreased by 22.45% for participants who exercised >246 minutes/week (highest quintile) and increased by 0.07% for those who exercised <110 minutes/week (lowest quintile, Ptrend = 0.04), adjusted for baseline covariates. When this analysis was restricted to include exercise time in the target heart rate zone only, statistically significant trends were observed for both CRP (P < 0.01) and IL6 (P = 0.04). Prescribing 300 minutes/week of moderate-to-vigorous aerobic exercise did not improve inflammatory markers compared with 150 minutes/week in postmenopausal women. Decreases in CRP were observed with higher self-selected exercise volume.

Brca1 Mutations Enhance Mouse Reproductive Functions by Increasing Responsiveness to Male-Derived Scent

We compared the gene expression profiles of ovarian granulosa cells harboring either mutant or wild type Brca1 to follow up on our earlier observation that absence of a functional Brca1 in these important regulators of menstrual/estrous cycle progression leads to prolongation of the pre-ovulatory phase of the estrous cycle and to increased basal levels of circulating estradiol. Here we show that ovarian granulosa cells from mice carrying a conditional Brca1 gene knockout express substantially higher levels of olfactory receptor mRNA than granulosa cells from wild type littermates. This led us to hypothesize that reproductive functions in mutant female mice might be more sensitive to male-derived scent than in wild type female mice. Indeed, it is well established that isolation from males leads to complete cessation of mouse estrous cycle activity while exposure to olfactory receptor ligands present in male urine leads to resumption of such activity. We found that Brca1-/- female mice rendered anovulatory by unisexual isolation resumed ovulatory activity more rapidly than their wild type littermates when exposed to bedding from cages where males had been housed. The prime mediator of this increased responsiveness appears to be the ovary and not olfactory neurons. This conclusion is supported by the fact that wild type mice in which endogenous ovaries had been replaced by Brca1-deficient ovarian transplants responded to male-derived scent more robustly than mutant mice in which ovaries had been replaced by wild type ovarian transplants. Our findings not only have important implications for our understanding of the influence of olfactory signals on reproductive functions, but also provide insights into mechanisms whereby genetic risk factors for breast and extra uterine Müllerian carcinomas may influence menstrual activity in human, which is itself an independent risk factor for these cancers.