8 research outputs found

    Dynamics of serum testosterone during the menstrual cycle evaluated by daily measurements with an ID-LC-MS/MS method and a 2nd generation automated immunoassay

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    Background: Testosterone concentrations in normally cycling women are assumed to be elevated around the time of ovulation. The clinical relevance of changing testosterone concentrations during the menstrual cycle, however, is unclear. Poor performance of current direct immunoassays for testosterone at low concentrations confounds this issue. Therefore, our objective was to assess daily testosterone fluctuation during the menstrual cycle by a thoroughly validated isotope dilution-liquid chromatography-Tandem mass spectrometry (ID-LC-MS/MS) method and to evaluate whether an ARCHITECT® 2nd Generation Testosterone fully automated immunoassay is equally suited for this purpose. Methods: Testosterone was measured in serum obtained daily during the menstrual cycle of 25 healthy women, characterized by biochemical and physical examination. Results: Performance of the ID-LC-MS/MS method was concordant with a published reference method (y = 1.007x - 0.056 nmol/L; r = 0.9998). Comparison of the immunoassay to ID-LC-MS/MS yielded y = 1.095x + 0.104 nmol/L (r = 0.9031). Overall, testosterone concentrations were higher mid-cycle, but a peak was not discernible in each individual. Apart from a persistent positive bias, the immunoassay measured the same testosterone profiles as the ID-LC-MS/MS method. The reference interval in women was 0.30-1.69 nmol/L (8.7-48.7 ng/dL) for ID-LC-MS/MS and 0.50-2.00 nmol/L (14.4-57.7 ng/dL) for the immunoassay. Conclusion: The elevation of mid-cycle testosterone concentrations is statistically significant, although not clinically relevant since day-To-day variation is higher and independent of the menstrual cycle. In this light, a single testosterone measurement might not be reflective of the overall testosterone status in an individual. Measurements obtained using the 2nd generation immunoassay gave comparable results across the menstrual cycle. © 2012 Elsevier Inc. All rights reserved

    Testosterone, free testosterone, and free androgen index in women: Reference intervals, biological variation, and diagnostic value in polycystic ovary syndrome

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    Objective: The objective of our study was to determine reference intervals and biologic variation for testosterone (T), free testosterone (fT), and free androgen index (FAI) in women with accurate methods and to test the discriminative value of these parameters in a polycystic ovary syndrome (PCOS)-population. Methods: Serumwas obtained daily during a normal menstrual cycle from 25 healthy women (677 data-points). A single serum sample was obtained from 44 PCOS-patients. T was measured by LC-MS/MS and by Architect® 2nd generation T Immunoassay. Sex hormone-binding globulin was measured to calculate fT and FAI. Results: Reference intervals which were established in healthy women with an ovulatory menstrual cycle were T = 0.3-1.6 nmol/L and 0.5-2.0 nmol/L, fT = 5.2-26 pmol/L and 7.2-33 pmol/L, and FAI = 0.4-2.9 and 0.6-4.4, by LC-MS/MSand immunoassay, respectively. T, fT and FAIwere higher in PCOS patients than in controls (p b 0.0001). The areas under the curve of receiver operator characteristic (ROC) plots were not different for T, fT, or FAIwhen Twasmeasured by LC-MS/MSversus immunoassay based on prediction of PCOS. FAI and fTwere the strongest predictors of PCOS. Conclusions: When based upon the appropriate reference intervals and ROC analysis, LC-MS/MS and second generation immunoassay have equivalent clinical utility for the diagnosis of PCOS

    Trial of recombinant follicle-stimulating hormone pretreatment for gnrh-induced fertility in patients with congenital hypogonadotropic hypogonadism.

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    CONTEXT AND OBJECTIVE: The optimal strategy for inducing fertility in men with congenital hypogonadotropic hypogonadism (CHH) is equivocal. Albeit a biologically plausible approach, pretreatment with recombinant FSH (rFSH) before GnRH/human chorionic gonadotropin administration has not been sufficiently assessed. The objective of the study was to test this method. DESIGN AND SETTING: This was a randomized, open-label treatment protocol at an academic medical center. PATIENTS AND INTERVENTIONS: GnRH-deficient men (CHH) with prepubertal testes (<4 mL), no cryptorchidism, and no prior gonadotropin therapy were randomly assigned to either 24 months of pulsatile GnRH therapy alone (inducing endogenous LH and FSH release) or 4 months of rFSH pretreatment followed by 24 months of GnRH therapy. Patients underwent serial testicular biopsies, ultrasound assessments of testicular volume, serum hormone measurements, and seminal fluid analyses. RESULTS: rFSH treatment increased inhibin B levels into the normal range (from 29 ± 9 to 107 ± 41 pg/mL, P < .05) and doubled testicular volume (from 1.1 ± 0.2 to 2.2 ± 0.3 mL, P < .005). Histological analysis showed proliferation of both Sertoli cells (SCs) and spermatogonia, a decreased SC to germ cell ratio (from 0.74 to 0.35), and SC cytoskeletal rearrangements. With pulsatile GnRH, the groups had similar hormonal responses and exhibited significant testicular growth. All men receiving rFSH pretreatment developed sperm in their ejaculate (7 of 7 vs 4 of 6 in the GnRH-only group) and showed trends toward higher maximal sperm counts. CONCLUSIONS: rFSH pretreatment followed by GnRH is successful in inducing testicular growth and fertility in men with CHH with prepubertal testes. rFSH not only appears to maximize the SC population but also induces morphologic changes, suggesting broader developmental roles

    Anti-Mullerian hormone and endometrial cancer: A multi-cohort study

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    Background: TheMullerian ducts are the embryological precursors of the female reproductive tract, including the uterus; anti-Mullerian hormone (AMH) has a key role in the regulation of foetal sexual differentiation. Anti-Mullerian hormone inhibits endometrial tumour growth in experimental models by stimulating apoptosis and cell cycle arrest. To date, there are no prospective epidemiologic data on circulating AMH and endometrial cancer risk. Methods: We investigated this association among women premenopausal at blood collection in a multicohort study including participants from eight studies located in the United States, Europe, and China. We identified 329 endometrial cancer cases and 339 matched controls. Anti- Mullerian hormone concentrations in blood were quantified using an enzyme-linked immunosorbent assay. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) across tertiles and for a doubling of AMH concentrations (ORlog2). Subgroup analyses were performed by ages at blood donation and diagnosis, oral contraceptive use, and tumour characteristics. Results: Anti-Mullerian hormone was not associated with the risk of endometrial cancer overall (ORlog2: 1.07 (0.99-1.17)), or with any of the examined subgroups. Conclusions: Although experimental models implicate AMH in endometrial cancer growth inhibition, our findings do not support a role for circulating AMH in the aetiology of endometrial cancer. © 2017 Cancer Research UK. All Rights Reserved
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