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Background: 3,3'-diindolylmethane (DIM) is a phytonutrient derived from cruciferous vegetables that is an often-used supplement in the complementary and alternative medicine space. The most common goal for providers when recommending DIM to their patients is to alter estrogen metabolism, yet research into DIM's effect on the estrogen profile is lacking in the published literature. The objective of this study was to comprehensively evaluate DIM's effect on the urinary estrogen profile., Methods: In this retrospective cohort study, we analyzed data from a clinical laboratory, including urinary estrogen and estrogen metabolite concentrations. Analyte concentrations were determined from dried urine samples using a gas chromatography-tandem mass spectrometry assay. Individuals were separated into two groups, either reporting taking DIM (N = 909) or reporting not taking DIM (N = 18,385). Comparisons between individuals in these two groups were made using the Wilcoxon rank sum test. Additionally, we were also able to explore a subset of women who had laboratory results in the database before and after initiating DIM treatment (N = 53). In this subset, differences were assessed with Wilcoxon signed rank tests., Results: In the larger group that was separated into women reporting either DIM use or no use, significant differences were observed in the concentrations of almost every urinary estrogen and estrogen metabolite (with the only exception being 2-methoxyestrone) in the urinary estrogen profiles of those taking DIM compared to those not taking DIM (all P values < 0.001). In the smaller subset of individuals with results before and after initiating DIM use, differences were only seen in 4 of the urinary estrogens and estrogen metabolites (P < 0.001 for estrone, estradiol, estriol, and 16-hydroxyestrone). Differences in total estrogens were significant in both the larger group and the smaller subset (both with P < 0.001). Additionally, observed differences in the ratios of metabolites followed a similar trend with more significant differences observed in the larger group. Notably, the 2-hydroxyestrone:16-hydroxyestrone ratio increased significantly in both the larger group and the smaller subset with results before and after DIM use., Conclusions: The results of this study provide the most comprehensive evaluation to date of DIM's effect on the urinary estrogen profile. Additionally, the results demonstrate that the dried urine collection and accompanying assay used capture changes that are similar in direction, but not necessarily magnitude, to previous reports in the literature. Considered together, these two things highlight the clinical validity and utility of this approach to the evaluation of DIM supplementation and suggest the need for additional studies using this approach to fully understand the potential clinical utility of DIM., Competing Interests: Declarations. Ethics approval and consent to participate: The study was approved by the National University of Natural Medicine Institutional Review Board, and since all data analyzed in this data mining study were deidentified, the institutional review board determined that written informed consent could be waived. Consent for publication: Not applicable. Competing interests: M.N. is the founder and CEO of Precision Analytical, Inc. J.S. is an employee of Precision Analytical, Inc., (© 2024. The Author(s).)

The mass ratio of urinary 2-hydroxyestrone to 16-α-hydroxyestrone (2:16) is hypothesized as a biomarker of breast cancer risk in premenopausal women, with higher ratios being theoretically protective. Cruciferous vegetable intake has been associated with higher urinary 2:16 in some studies. We investigated whether a whole-food supplement made from dried Brussels sprouts and kale would increase urinary 2:16 in comparison with placebo or cruciferous vegetables in women. This randomized, parallel arm, placebo-controlled, partly blinded study included 78 healthy premenopausal women (38-50 y) with screening urinary 2:16 ≤3.0. Subjects received either six capsules containing 550 mg dried Brussels sprouts and kale per capsule, 40 g daily alternating broccoli or Brussels sprouts, or placebo for eight weeks. Urinary 2:16 and creatinine were measured at baseline, four, and eight weeks. Intent-to-treat repeated measures-ANOVA with multiple imputation ( n =100) for missing values identified no treatment effect ( P =0.9) or treatment-by-time interaction ( P =0.6); however, a significant time effect was noted ( P =0.02). Per-protocol analyses including complete cases found no treatment effect ( P =1) or treatment-by-time interaction ( P =0.6); however, the significant time effect remained ( P =0.03). Restricting analysis to subjects with >80% compliance maintained the time effect ( P =0.02). Using Pearson correlations, android-pattern and android:gynoid fat were predictive of change ( P ≤0.05). In conclusion, neither cruciferous supplements nor an added vegetable serving altered urinary 2:16 in premenopausal women with eight weeks treatment. This ratio did vary with time, which is important for designing future trials.

Postmenopausal women and renal transplant recipients are at increased risk of recurrent urinary tract infections (RUTI). Urine and vaginal microbiota of premenopausal controls (N = 18) and RUTI cases (18), and of postmenopausal controls (30) and RUTI cases (20) with and without a renal transplant, were characterized using 16S rRNA sequencing. Participants did not have UTI symptoms at the time of sampling. Gram-negative uropathobionts (predominantly Escherichia/Shigella, Pseudomonas, Klebsiella, and Acinetobacter) had a much higher mean relative abundance in urine than vaginal samples, especially in premenopausal women. No statistically significant differences in mean relative abundances of bacterial groups were found within the premenopausal group or within the postmenopausal group by RUTI or renal transplant status without chronic antibiotic use. Comparing postmenopausal to premenopausal women, mean relative abundances of lactobacilli (especially L. crispatus) in urine and vaginal samples and of Gram-negative uropathobionts in urine were lower, and of BV-anaerobes and Gram-positive uropathobionts in urine and vaginal samples were higher. While RUTI in premenopausal women is predominantly caused by Escherichia, the causative organisms in postmenopausal women are likely more diverse. The relative importance of individual organisms is currently unknown. We recommend that future studies, including intervention studies, include longitudinal microbiota assessments., (© 2022. The Author(s).)

Background: The understanding of longitudinal changes in the urinary microbiota of healthy women and its relation to intestinal microbiota is limited., Methods: From a cohort of 15 premenopausal women without known urogenital disease or current symptoms, we collected catheter urine (CU), vaginal and periurethral swabs, and fecal samples on four visits over six months. Additionally, ten participants provided CU and midstream urine (MU) to assess comparability. Urine was subjected to expanded culture. 16S rRNA gene sequencing was performed on all urine, fecal, and selected vaginal and periurethral samples. Sequence reads were processed (DADA2 pipeline) and analyzed using QIIME 2 and R., Results: Relative abundances of urinary microbiota were variable over 6-18 months. The degree of intraindividual variability of urinary microbiota was higher than that found in fecal samples. Still, nearly half of the observed beta diversity of all urine samples could be attributed to differences between volunteers (R2 = 0.48, p = 0.001). After stratification by volunteer, time since last sexual intercourse was shown to be a factor significantly contributing to beta diversity (R2 = 0.14, p = 0.001). We observed a close relatedness of urogenital microbial habitats and a clear distinction from intestinal microbiota in the overall betadiversity analysis. Microbiota compositions derived from MU differed only slightly from CU compositions. Within this analysis of low-biomass samples, we identified contaminating sequences potentially stemming from sequencing reagents., Conclusions: Results from our longitudinal cohort study confirmed the presence of a rather variable individual urinary microbiota in premenopausal women. These findings from catheter urine complement previous observations on temporal dynamics in voided urine. The higher intraindividual variability of urinary microbiota as compared to fecal microbiota will be a challenge for future studies investigating associations with urogenital diseases and aiming at identifying pathogenic microbiota signatures., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: LMB has received lecture honoraria from Astellas and Merck/MSD, and travel grants from 3M and Gilead. MJGTV reports grants and personal fees from 3M, Alb Fils Kliniken GmbH, Astellas Pharma, Basilea, bioMérieux, DaVolterra, Gilead Sciences, Ferring, Glycom, Heel, MaaT Pharma, Merck/MSD, Organobalance, Pfizer, Roche Pharma, Seres Therapeutics. YK has received lecture honoraria from Merck/MSD and Gilead, and travel grants from Gilead. All remaining authors have declared no conflicts of interest. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Recent studies suggest that alterations in the female urinary microbiota is associated to development of bladder disease. However, the normal microbiota composition and variation in healthy women are poorly described. Moreover, the effects of hormonal changes on microbiota during menopause is not well understood. The aim of our study was to investigate the urinary microbiota in healthy pre- and postmenopausal women without urinary tract symptoms. Microbiota composition in catheterized urine samples was mapped using 16S rRNA gene sequencing. In total, 41 premenopausal and 42 postmenopausal women were initially included. Samples with first PCR amplification concentration below level of the negative control were excluded, resulting in 34 premenopausal and 20 postmenopausal women included in data analysis. Urine from postmenopausal women showed significantly higher alpha diversity compared to premenopausal women. Lactobacillus was the most abundant bacteria in both groups, however the relative abundance of Lactobacillus accounted for 77.8% in premenopausal versus 42.0% in postmenopausal women. In conclusion, urine from premenopausal mostly presented with Lactobacillus dominated urotypes, whereas urine from postmenopausal women presented a more diverse urinary microbiota with higher abundance of the genera Gardnerella and Prevotella. The clinical and pathophysiological implications of this difference remain to be elucidated.

Purpose: Bone turnover markers (BTMs) are not widely used in clinical decision-making partly due to the wide variation of the reference values. This paper describes the geographical variation in BTMs reported from Asian countries., Method: A systematic search was conducted using the PubMed, EMBASE, and Ovid. We searched for BTMs or individual BTMs in Asia or different countries in the Asian region. Original research which published BTM values were included while reviews, comments, and meta-analyses were excluded., Results: Of 650 articles, 23 fulfilled the selection criteria and were considered for this study. Among premenopausal women, mean intact OC ranged from 3.35 in Japan to 7.38 ng/mL (55%) in Thailand while it ranged between 3.35 and 5.8 ng/mL (42%) within Japan. Mean BALP varied from 15.9 in India to 41.2 U/L (61%) in Japan whereas in India, it ranged between 15.9 and 53.7 U/L (70%). Mean sP1NP ranged from 29.5 in Japan to 38.02 ng/mL in China (22%) whereas sCTX varied from 0.26 in Thailand to 0.099 ng/mL (62%) in Japan. Among postmenopausal women, mean total OC ranged from 10.02 in India to 29.8 ng/mL (66%) in Japan and intact OC ranged between 2.69 and 9.49 ng/mL (72%) within China. Mean BALP ranged from 20.9 in Japan to 60.28 U/L (65%) in China, and within China, it ranged from 28.2 to 60.28 U/L (53%). Mean sP1NP ranged from 40.11 in China to 56.4 ng/mL (29%) in Japan whereas it ranged within China from 40.11 to 53.76 ng/mL (25%). Mean sCTX varied from 0.25 to 0.433 ng/mL (42%) between the same countries respectively while within China, it varied from 0.25 to 0.395 ng/mL (37%). Urinary BTMs showed a lesser variation., Conclusion: A wide inter-country and intra-country variation of serum BTMs was observed among pre and postmenopausal women in Asia. Differences in selection criteria of subjects and those inherited to analytical methods may have contributed to these differences.

Objective: We aimed to establish correlations for the levels of follicle-stimulating hormone (FSH), estrone (E1) and estradiol (E2) between urine and serum in premenopausal and postmenopausal women using immunoassays., Methods: In this study of 92 women (61 postmenopausal, 31 premenopausal), both urine and blood specimens were collected on the same day and stored at 4 °C for analysis by chemiluminescent immunoassay, radioimmunoassay and/or electrochemiluminescent immunoassay., Results: There were correlations in the levels of FSH, E1 and E2 between urine and serum in both postmenopausal (r = 0.96 for FSH, r = 0.91 for E1, r = 0.80 for E2) and premenopausal (r = 0.98 for FSH, r = 0.92 for E1, r = 0.90 for E2) women. It is indicated that the correlations were stronger in the premenopausal group compared with the postmenopausal group, especially for FSH., Conclusion: The levels of FSH, E1 and E2 in urine correlated with those in the serum in premenopausal and postmenopausal women. Urine samples could be used instead of serum samples to measure hormone levels, which would reduce the difficulty of conducting large survey studies., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Results of studies on the associations of soy food intake with urinary estrogen levels in premenopausal women and in postmenopausal women have been inconsistent. We examined the associations of urinary isoflavone levels as well as soy food intake with estrone (E1) and estradiol (E2) in pre- and postmenopausal women. In addition, we compared the levels of isoflavones, E1 and E2 across current hormone users such as those receiving hormone replacement therapy and those using oral contraceptives and non-users among both pre- and postmenopausal women. Urinary levels of isoflavones, E1 and E2 in 498 women (36 hormone users and 462 non-users) were analyzed. Premenopausal women with a higher frequency of soy food intake had higher urinary isoflavone levels, but there were no significant associations between E1 and E2 levels and urinary isoflavone levels. Levels of E1 and E2 in hormone users were significantly lower than those in hormone non-users among premenopausal women, but levels of E1 and E2 in hormone users were significantly higher than those in hormone non-users among postmenopausal women. Postmenopausal women with a higher frequency of soy food intake had higher urinary isoflavone levels, and postmenopausal women with high urinary isoflavone levels had significantly higher E1 and E2 levels. In conclusion, the associations of urinary isoflavone levels with urinary estrogen levels differed with menopausal status. Urinary levels of E1 and E2 were high in postmenopausal women with high urinary isoflavone levels but not in premenopausal women with high urinary isoflavone levels., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: In the present study, we aimed to characterize the pathological development of menopausal osteoporosis, as well as to explore potential biomarkers and metabolic pathways involved in osteoporosis., Methods: Urine samples from 322 female participants categorized by menopause status and different bone conditions were collected and analyzed based on a gas chromatography-mass spectrometry (GC-MS) approach. Multivariate and univariate statistical analyses were carried out for urinary metabolomic profile characterization and comparison., Results: Seventeen metabolites in the low bone mineral density (BMD) groups were clearly differentiated from those in normal BMD groups. Among these 17 differentiating metabolites, taurine, β-alanine, and 5-hydroxycaproic acid were found to be potential biomarkers of osteoporosis. The taurine metabolic pathway and the β-alanine metabolic pathway were found to be related to menopause and bone loss., Conclusions: Based on the GC-MS metabolomic platform, four typical pathological phases during the progression of postmenopausal osteoporosis were described. Several differentiating metabolites and metabolic pathways were found to be closely related to the pathology of postmenopausal osteoporosis. Our results provided a solid foundation for further studies on early diagnosis and pathomechanistic evaluation.

Background: Estrogen metabolism in premenopausal women may be related to early life body fatness. Methods: Premenopausal women participating in the Nurses' Health Study II recalled their body fatness at ages 5, 10, and 20 years using a validated 9-level pictogram. Fifteen estrogens and estrogen metabolites (EM) were measured using LC/MS-MS in luteal phase urines from 603 women ages 32-54 years. Geometric means of individual EM, metabolic pathway groups, and pathway ratios were examined by body fatness categories using linear mixed models. Results: Body fatness at each age was inversely associated with adult concentrations of all EM combined, parent estrogens (estrone, estradiol), and the 2-hydroxylation pathway. Women in the top (vs. bottom) category of body fatness at age 10 had 21% lower levels of all EM ( P trend = 0.003), 24% lower parent estrogens ( P trend = 0.002), and 36% lower 2-pathway ( P trend = 0.0003). Body fatness at age 10 was inversely associated with 2-catechols (35% lower, P trend = 0.0004) and 2-methylated catechols (30% lower, P trend = 0.002). After adjusting for premenopausal body mass index (BMI), these associations remained inverse but were attenuated; only parent estrogens remained statistically significant (21% lower, P trend = 0.01). Body fatness at ages 5 and 20 were similarly, but more weakly, associated with estrogen pathways. Conclusions: Estimates of body fatness during early life were inversely associated with premenopausal levels of all EM combined, parent estrogens, and 2-pathway estrogen metabolites. These relationships were not fully explained by adult BMI. Impact: These findings inform investigations of diseases linked to early life body fatness and estrogen metabolism. Cancer Epidemiol Biomarkers Prev; 27(5); 585-93. ©2018 AACR ., (©2018 American Association for Cancer Research.)

Background: Endogenous sex hormones are well-established risk factors for breast cancer; the contribution of specific oestrogen metabolites (EMs) and/or ratios of specific EMs is less clear. We have previously identified a CYP3A7*1C allele that is associated with lower urinary oestrone (E 1 ) levels in premenopausal women. The purpose of this analysis was to determine whether this allele was associated with specific pathway EMs., Methods: We measured successfully 12 EMs in mid-follicular phase urine samples from 30 CYP3A7*1C carriers and 30 non-carriers using HPLC-MS/MS., Results: In addition to having lower urinary E 1 levels, CYP3A7*1C carriers had significantly lower levels of four of the 2-hydroxylation pathway EMs that we measured (2-hydroxyestrone, P=1.1 × 10 -12 ; 2-hydroxyestradiol, P=2.7 × 10 -7 ; 2-methoxyestrone, P=1.9 × 10 -12 ; and 2-methoxyestradiol, P=0.0009). By contrast, 16α-hydroxylation pathway EMs were slightly higher in carriers and significantly so for 17-epiestriol (P=0.002)., Conclusions: The CYP3A7*1C allele is associated with a lower urinary E 1 levels, a more pronounced reduction in 2-hydroxylation pathway EMs and a lower ratio of 2-hydroxylation:16α-hydroxylation EMs in premenopausal women. To further characterise the association between parent oestrogens, EMs and subsequent risk of breast cancer, characterisation of additional genetic variants that influence oestrogen metabolism and large prospective studies of a broad spectrum of EMs will be required.

Background: Exposure to cadmium has been suspected as a risk factor for breast cancer. The present study examined the associations between urinary cadmium levels and circulating sex hormone levels that are linked to breast cancer risk in healthy women., Methods: The study subjects were 396 premenopausal Japanese women who had regular menstrual cycles less than 40 days long and 207 postmenopausal Japanese women. Urinary cadmium was measured using spot urine samples. Plasma estradiol, testosterone, and dehydroepiandrosterone sulfate were measured. Additionally, the follicle-stimulating hormone, luteinizing hormone, and sex hormone-binding globulin were measured for premenopausal women., Results: In premenopausal women, the urinary cadmium level either expressed in μg per liter or per g of urine creatinine was significantly inversely associated with total and free testosterone levels after controlling for age, body mass index, smoking status, alcohol intake, and the phase of the menstrual cycle. Total and free testosterone levels were 14.6% and 15.0% lower, respectively, in women in the highest quartile of urinary cadmium per g creatinine in those in the lowest quartile. In postmenopausal women, the urinary cadmium in μg per liter as well as per g creatinine was significantly inversely associated with the estradiol level after controlling for covariates. The estradiol level was 25.8% lower in women in the highest tertile of urinary cadmium per g creatinine than in those in the lowest tertile., Conclusions: The data suggest inverse associations between urinary cadmium and the plasma estradiol or testosterone level in Japanese women., (Copyright © 2016 Elsevier Inc. All rights reserved.)

In a cross-sectional analysis, we evaluated the associations of usual total alcohol and wine intake with a comprehensive profile of mid-luteal phase urinary estrogens and estrogen metabolites (referred to jointly as EM) in a sample of 603 premenopausal women participating in the Nurses' Health Study II (NHSII). A total of 15 individual EM (pmol/mg creatinine) were measured by a liquid chromatography/tandem mass spectrometry (LC-MS/MS) method with high accuracy and reproducibility. We used linear mixed models to calculate the adjusted geometric means of individual EM, EM grouped by metabolic pathways, and pathway ratios by category of alcohol intake with non-drinkers of alcohol as the referent. Total alcohol intake was not associated with total EM but was positively associated with estradiol (26% higher among women consuming >15 g/day vs. non-drinkers; P trend = 0.03). Wine consumption was positively associated with a number of EM measures including estradiol (22% higher among women consuming ≥ 5 drinks/week vs. non-drinkers, P trend < 0.0001). In conclusion, the total alcohol intake was positively and significantly associated with urinary estradiol levels. Some differences in urinary estrogen metabolites were observed with wine drinking, when compared with non-drinkers. This study strengthens the evidence that alcohol consumption might play a role in breast cancer and other estrogen-related conditions. Additional studies of premenopausal women are needed to further explore the association of alcohol, particularly the specific types of alcohol, on patterns of estrogen metabolism in blood, urine, and tissue.

Objective: This study measured the differences in bone mineral density and content in relation to changes in serum hormone and bone marker levels during the perimenopausal transition in naturally menopausal cynomolgus monkeys., Methods: The bone mineral density and content of premenopausal, perimenopausal, and early (0-< 5 y), mid (5-10 y), and late (> 10 y) postmenopausal monkeys were measured at the distal radius and proximal tibia in both metaphysis and diaphysis. Hormonal and bone marker levels were also measured., Results: The serum 17β-estradiol level significantly decreased during late postmenopause, whereas the serum follicle-stimulating hormone levels significantly increased from early postmenopause before declining at late postmenopause. Trabecular bone loss at metaphysis occurred once the animals entered into the perimenopausal period, whereas cortical bone loss gradually and continuously decreased, dependent on the time-course after perimenopause, and was greatest in the late postmenopausal period. Serum bone-specific alkaline phosphatase and urinary N-telopeptide of bone type-1 collagen levels were negatively correlated with the trabecular bone mineral content at metaphysis, whereas serum osteocalcin levels showed a negative correlation with the cortical bone mineral density at the diaphysis. The only positive linear correlation observed was between serum follicle-stimulating hormone and urinary N-telopeptide of bone type-1 collagen levels., Conclusions: Unlike the ovariectomized monkey models that do not retain the perimenopausal transition, naturally menopausal monkeys elicit different patterns of bone loss during the transition-an abrupt decline in the trabecular metaphysis and a gradual decline in the cortical diaphysis. Naturally menopausal cynomolgus monkeys offer an alternative model for osteoporosis research for postmenopausal women.

Background: Prior studies have found weak inverse associations between breast cancer and caffeine and coffee intake, possibly mediated through their effects on sex hormones., Methods: High-performance liquid chromatography/tandem mass spectrometry was used to quantify levels of 15 individual estrogens and estrogen metabolites (EM) among 587 premenopausal women in the Nurses' Health Study II with mid-luteal phase urine samples and caffeine, coffee, and/or tea intakes from self-reported food frequency questionnaires. Multivariate linear mixed models were used to estimate geometric means of individual EM, pathways, and ratios by intake categories, and P values for tests of linear trend., Results: Compared with women in the lowest quartile of caffeine consumption, those in the top quartile had higher urinary concentrations of 16α-hydroxyestrone (28% difference; Ptrend = 0.01) and 16-epiestriol (13% difference; Ptrend = 0.04), and a decreased parent estrogens/2-, 4-, 16-pathway ratio (Ptrend = 0.03). Coffee intake was associated with higher 2-catechols, including 2-hydroxyestradiol (57% difference, ≥4 cups/day vs. ≤6 cups/week; Ptrend = 0.001) and 2-hydroxyestrone (52% difference; Ptrend = 0.001), and several ratio measures. Decaffeinated coffee was not associated with 2-pathway metabolism, but women in the highest (vs. lowest) category of intake (≥2 cups/day vs. ≤1-3 cups/month) had significantly lower levels of two 16-pathway metabolites, estriol (25% difference; Ptrend = 0.01) and 17-epiestriol (48% difference; Ptrend = 0.0004). Tea intake was positively associated with 17-epiestriol (52% difference; Ptrend = 0.01)., Conclusion: Caffeine and coffee intake were both associated with profiles of estrogen metabolism in premenopausal women., Impact: Consumption of caffeine and coffee may alter patterns of premenopausal estrogen metabolism., (©2015 American Association for Cancer Research.)

Purpose: Two main estradiol metabolites have different biological behavior with tumorigenic features of 16-OHE1 and antiproliferative characteristics of 2-OHE1. We investigated the ratio of these estradiol metabolites in pre- and postmenopausal patients with breast cancer (BC) within two case-control studies., Methods: From 41 premenopausal patients with (cases) and without (controls N = 211) BC and 207 postmenopausal patients with and without BC (N = 206), urine samples were collected. Urine samples were collected prior to surgery and stored at -20 °C until measurement by ELISA. The multiple linear regression test with two interactions was performed to evaluate the influence of different factors on the metabolic ratio., Results: In premenopausal patients, log ratio of 2-OHE1/16-OHE1 was 0.25 (CI 0.20;0.29) and 0.21 (CI 0.11;0.31) for controls and cases without significant difference. In postmenopausal patients, log ratio was 0.22 (CI 0.17;0.26) and 0.11 (CI 0.07;0.15) in controls and cases, respectively, and was statistically significantly lower (p = 0.0002). Log ratio was significantly influenced by BMI, but only in postmenopausal patients, an increased BMI resulted in a significantly (p < 0.042) decreased ratio., Conclusions: Our case control studies suggest that in postmenopausal women a different metabolism of estrogens may play a role in the tumorigenesis of breast cancer. This genetically determined metabolism could be influenced by the exogenic factor BMI. In premenopausal women different hormone levels at different time points of the menstrual cycle may be an explanation that why we could not find an influence of estrogen metabolism.

Objective: Vitamin D has been linked to antimüllerian hormone levels, suggesting a possible association with greater ovarian reserve, but large population-based studies are lacking. Our objective was to explore the association between vitamin D and follicle-stimulating hormone (FSH) in premenopausal women., Methods: The Uterine Fibroid Study (1996-1999) enrolled randomly selected 30- to 49-year-old members of a Washington, DC, health plan (N = 1,430). Women provided blood and urine samples in addition to questionnaire data. The vitamin D metabolite 25-hydroxyvitamin D (25(OH)D) was measured in stored plasma samples. Urinary FSH (mIU/mg creatinine) was measured by immunofluorometric assay. To obtain baseline measures, we limited this investigation to urine samples collected in the first 5 days of the menstrual cycle or 5 days before menses onset. In addition, postmenopausal women and women using oral contraceptives were excluded, leaving 527 women for analysis. FSH was creatinine-adjusted, normalized by log transformation, and modeled with multivariable linear regression., Results: The median 25(OH)D level was 12 ng/mL, with approximately 75% of participants below the recommended level of 20 ng/mL. FSH and 25(OH)D were inversely related. For every 10-ng/mL increase in 25(OH)D, urinary FSH decreased by 14% (95% CI, -23 to -5; P = 0.003)., Conclusions: Vitamin D is inversely related to FSH. This is consistent with literature relating low vitamin D levels to lower antimüllerian hormone levels. Prospective studies should investigate whether low vitamin D levels contribute to decreased ovarian reserve.

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.