Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 182
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Lancet Oncol ; 25(1): 108-116, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38070530

RESUMO

BACKGROUND: An increased risk of breast cancer is associated with high serum concentrations of oestradiol and testosterone in postmenopausal women, but little is known about how these hormones affect response to endocrine therapy for breast cancer prevention or treatment. We aimed to assess the effects of serum oestradiol and testosterone concentrations on the efficacy of the aromatase inhibitor anastrozole for the prevention of breast cancer in postmenopausal women at high risk. METHODS: In this case-control study we used data from the IBIS-II prevention trial, a randomised, controlled, double-blind trial in postmenopausal women aged 40-70 years at high risk of breast cancer, conducted in 153 breast cancer treatment centres across 18 countries. In the trial, women were randomly assigned (1:1) to receive anastrozole (1 mg/day, orally) or placebo daily for 5 years. In this pre-planned case-control study, the primary analysis was the effect of the baseline oestradiol to sex hormone binding globulin (SHBG) ratio (oestradiol-SHBG ratio) on the development of all breast cancers, including ductal carcinoma in situ (the primary endpoint in the trial). Cases were participants in whom breast cancer was reported after trial entry and until the cutoff on Oct 22, 2019, and who had valid blood samples and no use of hormone replacement therapy within 3 months of trial entry or during the trial. For each case, two controls without breast cancer were selected at random, matched on treatment group, age (within 2 years), and follow-up time (at least that of the matching case). For each treatment group, we applied a multinominal logistic regression likelihood-ratio trend test to assess what change in the proportion of cases was associated with a one-quartile change in hormone ratio. Controls were used only to determine quartile cutoffs. Profile likelihood 95% CIs were used to indicate the precision of estimates. A secondary analysis also investigated the effect of the baseline testosterone-SHBG ratio on breast cancer development. We also assessed relative benefit of anastrozole versus placebo (calculated as 1 - the ratio of breast cancer cases in the anastrozole group to cases in the placebo group). The trial was registered with ISRCTN (number ISRCTN31488319) and completed recruitment on Jan 31, 2012, but long-term follow-up is ongoing. FINDINGS: 3864 women were recruited into the trial between Feb 2, 2003, and Jan 31, 2012, and randomly assigned to receive anastrozole (n=1920) or placebo (n=1944). Median follow-up time was 131 months (IQR 106-156), during which 85 (4·4%) cases of breast cancer in the anastrozole group and 165 (8·5%) in the placebo group were identified. No data on gender, race, or ethnicity were collected. After exclusions, the case-control study included 212 participants from the anastrozole group (72 cases, 140 controls) and 416 from the placebo group (142 cases, 274 controls). A trend of increasing breast cancer risk with increasing oestradiol-SHBG ratio was found in the placebo group (trend per quartile 1·25 [95% CI 1·08 to 1·45], p=0·0033), but not in the anastrozole group (1·06 [0·86 to 1·30], p=0·60). A weaker effect was seen for the testosterone-SHBG ratio in the placebo group (trend 1·21 [1·05 to 1·41], p=0·011), but again not in the anastrozole group (trend 1·18 [0·96 to 1·46], p=0·11). A relative benefit of anastrozole was seen in quartile 2 (0·55 [95% CI 0·13 to 0·78]), quartile 3 (0·54 [0·22 to 0·74], and quartile 4 (0·56 [0·23 to 0·76]) of oestradiol-SHBG ratio, but not in quartile 1 (0·18 [-0·60 to 0·59]). INTERPRETATION: These results suggest that serum hormones should be measured more routinely and integrated into risk management decisions. Measuring serum hormone concentrations is inexpensive and might help clinicians differentiate which women will benefit most from an aromatase inhibitor. FUNDING: Cancer Research UK, National Health and Medical Research Council (Australia), Breast Cancer Research Foundation, and DaCosta Fund.


Assuntos
Neoplasias da Mama , Feminino , Humanos , Anastrozol , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/prevenção & controle , Neoplasias da Mama/patologia , Inibidores da Aromatase , Estradiol/uso terapêutico , Estudos de Casos e Controles , Pós-Menopausa , Nitrilas , Triazóis/efeitos adversos , Método Duplo-Cego , Testosterona
2.
Clin Chem Lab Med ; 62(6): 1080-1091, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38205643

RESUMO

OBJECTIVES: Current liquid chromatography-tandem mass spectrometry (LC-MS/MS) applications for circulating androgen measurements are technically diverse. Previously, variable results have been reported for testosterone. Data are scarce for androstenedione and absent for dehydroepiandrosterone sulfate (DHEAS). We assessed the agreement of androstenedione, DHEAS and testosterone LC-MS/MS measurements among nine European centers and explored benefits of calibration system unification. METHODS: Androgens were measured twice by laboratory-specific procedures in 78 patient samples and in EQA materials. Results were obtained by in-house and external calibration. Intra- and inter-laboratory performances were valued. RESULTS: Intra-laboratory CVs ranged between 4.2-13.2 % for androstenedione, 1.6-10.8 % for DHEAS, and 4.3-8.7 % and 2.6-7.1 % for female and male testosterone, respectively. Bias and trueness in EQA materials were within ±20 %. Median inter-laboratory CV with in-house vs. external calibration were 12.0 vs. 9.6 % for androstenedione (p<0.001), 7.2 vs. 4.9 % for DHEAS (p<0.001), 6.4 vs. 7.6 % for female testosterone (p<0.001) and 6.8 and 7.4 % for male testosterone (p=0.111). Median bias vs. all laboratory median with in-house and external calibration were -13.3 to 20.5 % and -4.9 to 18.7 % for androstenedione, -10.9 to 4.8 % and -3.4 to 3.5 % for DHEAS, -2.7 to 6.5 % and -11.3 to 6.6 % for testosterone in females, and -7.0 to 8.5 % and -7.5 to 11.8 % for testosterone in males, respectively. CONCLUSIONS: Methods showed high intra-laboratory precision but variable bias and trueness. Inter-laboratory agreement was remarkably good. Calibration system unification improved agreement in androstenedione and DHEAS, but not in testosterone measurements. Multiple components, such as commutability of calibrators and EQA materials and internal standard choices, likely contribute to inter-laboratory variability.


Assuntos
Androstenodiona , Sulfato de Desidroepiandrosterona , Espectrometria de Massas em Tandem , Testosterona , Androstenodiona/sangue , Androstenodiona/análise , Testosterona/sangue , Testosterona/análise , Testosterona/normas , Humanos , Espectrometria de Massas em Tandem/normas , Espectrometria de Massas em Tandem/métodos , Calibragem , Masculino , Feminino , Cromatografia Líquida/normas , Cromatografia Líquida/métodos , Sulfato de Desidroepiandrosterona/sangue , Sulfato de Desidroepiandrosterona/análise , Sulfato de Desidroepiandrosterona/normas , Pessoa de Meia-Idade , Espectrometria de Massa com Cromatografia Líquida
3.
Endocr Pract ; 30(4): 348-355, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38244859

RESUMO

OBJECTIVE: We determined (1) if 11-oxygenated androgens better identify polycystic ovary syndrome (PCOS) diagnosis in women with obesity compared to total or free testosterone (T) and free androgen index; (2) how biochemical hyperandrogenism and metabolic factors cluster in a cohort of women with infertility and obesity. METHODS: Women with obesity and PCOS comprised the study group (N = 132). Ovulatory women with obesity and idiopathic, tubal or male factor infertility were the control group (N = 83). Steroid hormones were measured by means of liquid chromatography tandem mass spectrometry. Receiver operating characteristic curves and principal component analysis were used. RESULTS: Women with obesity and PCOS had higher 11-ketotestosterone (11 KT) (1.22 nmol/L [0.84; 1.65] vs 1.05 [0.78; 1.35], P = .04) compared to controls, but not 11ß-hydroxyandrostenedione 4.30 [2.87; 5.92] vs 4.06 [3.22; 5.73], P = .44). 11-ketotestosterone (area under the curve: 0.59) did not better discriminate PCOS in women with obesity compared to: total T (0.84), free T (0.91), and free androgen index (0.85). We identified 4 principal components (PCs) in the PCOS group (72.1% explained variance): (1) insulin resistance status; (2) blood pressure; (3) obesity; (4) androgen status and 4 PCs in the control group (68.7% explained variance) with variables representing metabolism being dispersed in component 2, 3, and 4. CONCLUSIONS: Eleven-oxygenated androgens do not aid in the diagnosis of PCOS in women with obesity. Insulin resistance is the strongest PC in the PCOS group. There is no major dominant characteristic that defines obese non-PCOS women.


Assuntos
Hiperandrogenismo , Infertilidade , Resistência à Insulina , Síndrome do Ovário Policístico , Feminino , Masculino , Humanos , Síndrome do Ovário Policístico/complicações , Hiperandrogenismo/diagnóstico , Hiperandrogenismo/metabolismo , Androgênios , Testosterona , Obesidade/complicações , Obesidade/metabolismo , Análise por Conglomerados
4.
Clin Endocrinol (Oxf) ; 99(6): 517-524, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37820012

RESUMO

OBJECTIVE: Worldwide, adults and children are at risk of adrenal insufficiency largely due to infectious diseases and adrenal suppression from use of anti-inflammatory glucocorticoids. Home waking salivary cortisone is an accurate screening test for adrenal insufficiency, it has potential to reduce costs, and patients prefer it to the adrenocorticotropin (ACTH) (synacthen) stimulation test. We carried out a service evaluation of home waking salivary cortisone in clinical care to identify implementation barriers. DESIGN, PATIENTS AND MEASUREMENTS: Service evaluation in a centre where 212 patients referred for adrenal insufficiency had a waking salivary cortisone. Problems encountered during testing were recorded and patient feedback, via focus groups, collected. RESULTS: From all patients providing a waking salivary cortisone 55% had a normal test, 23% adrenal suppression, and 22% an equivocal result requiring a clinical centre ACTH stimulation test. The median (interquartile range [IQR]) for the time of the saliva sample was 07:40 (07:00-08:40). The median (IQR) days between collection and (i) delivery to local laboratory was 1 (0.25-2) day; (ii) reporting by local laboratory was 13 (11-18) days. Patients considered the test is "easy to do" and preferred it to the inpatient ACTH stimulation test. The principal challenge to clinical implementation was results reporting to clinicians due to delays at the local laboratory. CONCLUSIONS: This service evaluation provides real-world evidence that home waking salivary cortisone is an effective, practical screening test for adrenal insufficiency. It identified key barriers to testing implementation that need to be addressed when introducing the test to a health service.


Assuntos
Insuficiência Adrenal , Cortisona , Adulto , Criança , Humanos , Hidrocortisona , Saliva , Insuficiência Adrenal/diagnóstico , Hormônio Adrenocorticotrópico
5.
Clin Chem Lab Med ; 61(2): 302-310, 2023 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-36395058

RESUMO

OBJECTIVES: During 2020, the UK's Department of Health and Social Care (DHSC) established the Moonshot programme to fund various diagnostic approaches for the detection of SARS-CoV-2, the pathogen behind the COVID-19 pandemic. Mass spectrometry was one of the technologies proposed to increase testing capacity. METHODS: Moonshot funded a multi-phase development programme, bringing together experts from academia, industry and the NHS to develop a state-of-the-art targeted protein assay utilising enrichment and liquid chromatography tandem mass spectrometry (LC-MS/MS) to capture and detect low levels of tryptic peptides derived from SARS-CoV-2 virus. The assay relies on detection of target peptides, ADETQALPQRK (ADE) and AYNVTQAFGR (AYN), derived from the nucleocapsid protein of SARS-CoV-2, measurement of which allowed the specific, sensitive, and robust detection of the virus from nasopharyngeal (NP) swabs. The diagnostic sensitivity and specificity of LC-MS/MS was compared with reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) via a prospective study. RESULTS: Analysis of NP swabs (n=361) with a median RT-qPCR quantification cycle (Cq) of 27 (range 16.7-39.1) demonstrated diagnostic sensitivity of 92.4% (87.4-95.5), specificity of 97.4% (94.0-98.9) and near total concordance with RT-qPCR (Cohen's Kappa 0.90). Excluding Cq>32 samples, sensitivity was 97.9% (94.1-99.3), specificity 97.4% (94.0-98.9) and Cohen's Kappa 0.95. CONCLUSIONS: This unique collaboration between academia, industry and the NHS enabled development, translation, and validation of a SARS-CoV-2 method in NP swabs to be achieved in 5 months. This pilot provides a model and pipeline for future accelerated development and implementation of LC-MS/MS protein/peptide assays into the routine clinical laboratory.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Pandemias , COVID-19/diagnóstico , Teste para COVID-19 , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida , Estudos Prospectivos , Técnicas de Laboratório Clínico/métodos , Sensibilidade e Especificidade , Peptídeos
6.
Clin Chem Lab Med ; 60(5): 726-739, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35172417

RESUMO

OBJECTIVES: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is recommended for measuring circulating steroids. However, assays display technical heterogeneity. So far, reproducibility of corticosteroid LC-MS/MS measurements has received scant attention. The aim of the study was to compare LC-MS/MS measurements of cortisol, 17OH-progesterone and aldosterone from nine European centers and assess performance according to external quality assessment (EQA) materials and calibration. METHODS: Seventy-eight patient samples, EQA materials and two commercial calibration sets were measured twice by laboratory-specific procedures. Results were obtained by in-house (CAL1) and external calibrations (CAL2 and CAL3). We evaluated intra and inter-laboratory imprecision, correlation and agreement in patient samples, and trueness, bias and commutability in EQA materials. RESULTS: Using CAL1, intra-laboratory CVs ranged between 2.8-7.4%, 4.4-18.0% and 5.2-22.2%, for cortisol, 17OH-progesterone and aldosterone, respectively. Trueness and bias in EQA materials were mostly acceptable, however, inappropriate commutability and target value assignment were highlighted in some cases. CAL2 showed suboptimal accuracy. Median inter-laboratory CVs for cortisol, 17OH-progesterone and aldosterone were 4.9, 11.8 and 13.8% with CAL1 and 3.6, 10.3 and 8.6% with CAL3 (all p<0.001), respectively. Using CAL1, median bias vs. all laboratory-medians ranged from -6.6 to 6.9%, -17.2 to 7.8% and -12.0 to 16.8% for cortisol, 17OH-progesterone and aldosterone, respectively. Regression lines significantly deviated from the best fit for most laboratories. Using CAL3 improved cortisol and 17OH-progesterone between-method bias and correlation. CONCLUSIONS: Intra-laboratory imprecision and performance with EQA materials were variable. Inter-laboratory performance was mostly within specifications. Although residual variability persists, adopting common traceable calibrators and RMP-determined EQA materials is beneficial for standardization of LC-MS/MS steroid measurements.


Assuntos
Hidrocortisona , Progesterona , Aldosterona , Calibragem , Cromatografia Líquida/métodos , Humanos , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos
7.
Clin Exp Allergy ; 51(1): 49-62, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33190234

RESUMO

BACKGROUND: Although the efficacy of corticosteroid treatment in controlling asthma is widely accepted, its effectiveness is undermined by poor adherence. However, the optimal method for measuring adherence to asthma therapy remains unclear. OBJECTIVE: To perform a review of the literature reporting biological, objective methods for assessing adherence to inhaled or oral corticosteroids in asthma; we included studies reporting direct measurement of exogenous corticosteroids in blood, or the effect of adherence on exhaled nitric oxide. DESIGN: We searched three databases MEDLINE (using both PubMed and Ovid), the Cumulative Index of Nursing and Allied Health Literature (CINAHL) and Web of Science for articles published between January 1975 and July 2020. Quality of the studies was assessed using the National Institute of Health checklist. RESULTS: From 2850 screened articles, 26 fulfilled the inclusion criteria. Measurement of blood prednisolone with or without cortisol was used in eight studies as a measure of oral corticosteroid adherence, and fractional exhaled nitric oxide (FeNO) in 17 studies for inhaled corticosteroid adherence. Inhaled corticosteroids were measured directly in the blood in one study. By direct measurement of drug levels in the blood, adherence rates to oral corticosteroids ranged from 47% to 92%, although the performance and timing of the test were often not known, making interpretation of findings and serum prednisolone concentrations difficult. FeNO is generally lower in adherent than non-adherent patients, but no absolute cut-off can be proposed based on the available data. However, a fall in FeNO following supervised inhaled corticosteroid dosing could indicate previous poor adherence. CONCLUSIONS AND CLINICAL RELEVANCE: Despite prednisolone and cortisol levels commonly being used as adherence markers in clinical practice, further work is required to assess the influence of the dose and timing on blood levels. The promising findings of FeNO suppression testing should be explored in further prospective studies.


Assuntos
Asma/tratamento farmacológico , Teste da Fração de Óxido Nítrico Exalado , Glucocorticoides/uso terapêutico , Adesão à Medicação , Prednisolona/uso terapêutico , Administração por Inalação , Administração Oral , Asma/metabolismo , Asma/fisiopatologia , Monitoramento de Medicamentos , Humanos , Hidrocortisona/sangue , Prednisolona/sangue
8.
Rheumatology (Oxford) ; 60(1): 125-131, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-32596718

RESUMO

OBJECTIVE: MTX remains the cornerstone for therapy for RA, yet research shows that non-adherence is significant and correlates with response to therapy. This study aimed to halve self-reported non-adherence to MTX at the Kellgren Centre for Rheumatology. METHODS: An anonymous self-report adherence questionnaire was developed and data collected for 3 months prior to the introduction of interventions, and then regularly for the subsequent 2.5 years. A series of interventions were implemented, including motivational interviewing training, consistent information about MTX and development of a summary bookmark. Information on clinic times was collected for consultations with and without motivational interviewing. Surveys were conducted to ascertain consistency of messages about MTX. A biochemical assay was used to test MTX serum levels in patients at two time points: before and 2.8 years following introduction of the changes. Remission rates at 6 and 12 months post-MTX initiation were retrieved from patient notes and cost savings estimated by comparing actual numbers of new biologic starters compared with expected numbers based on the numbers of consultants employed at the two time points. RESULTS: Between June and August 2016, self-reported non-adherence to MTX was 24.7%. Following introduction of the interventions, self-reported non-adherence rates reduced to an average of 7.4% between April 2018 and August 2019. Clinic times were not significantly increased when motivational interviewing was employed. Consistency of messages by staff across three key areas (benefits of MTX, alcohol guidance and importance of adherence) improved from 64% in September 2016 to 94% in January 2018. Biochemical non-adherence reduced from 56% (September 2016) to 17% (June 2019), whilst remission rates 6 months post-initiation of MTX improved from 13% in 2014/15 to 37% in 2017/18, resulting is estimated cost savings of £30 000 per year. CONCLUSION: Non-adherence to MTX can be improved using simple measures including focussing on the adherence and the benefits of treatment, and providing consistent information across departments.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Adesão à Medicação/estatística & dados numéricos , Metotrexato/uso terapêutico , Entrevista Motivacional , Melhoria de Qualidade , Antirreumáticos/sangue , Artrite Reumatoide/sangue , Produtos Biológicos/uso terapêutico , Consultores/estatística & dados numéricos , Redução de Custos , Humanos , Metotrexato/sangue , Educação de Pacientes como Assunto , Indução de Remissão , Autorrelato/estatística & dados numéricos , Inquéritos e Questionários/estatística & dados numéricos , Fatores de Tempo
9.
Clin Transplant ; 35(2): e14186, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33314283

RESUMO

BACKGROUND: Cardiovascular disease (CVD) is common after cardiothoracic transplantation and causes substantial morbidity. AIMS: To assess feasibility and potential effectiveness of dietary interventions to reduce CVD risk. MATERIALS AND METHODS: In a pilot intervention, we recruited patients from a tertiary hospital and randomly allocated them to a Mediterranean or low-fat diet for 12 months. Feasibility was measured by patient participation, retention, and adherence. Changes in weight, body mass index (BMI), heart rate, blood pressure, glucose markers, and blood lipids were assessed using longitudinal generalized estimating equation regression models with 95% confidence intervals. RESULTS: Of 56 heart and 60 lung transplant recipients, 52 (45%) consented, 41 were randomized, and 39 (95%) completed the study with good adherence to randomized diets. After 12 months, changes in many risk factors were seen in the Mediterranean and low-fat-diet groups, respectively, including mean BMI (-0.5 vs. 0.0 kg/m2 ), systolic/diastolic blood pressure +0.5/+0.1 vs -4.4/-3.5 mmHg; fasting glucose -0.26 vs -0.27 mmol/L; total cholesterol -0.56 vs -0.40 mmol/L. Changes in BMI and systolic/diastolic blood pressure in 49 eligible patients who did not take part were +0.7 kg/m2 and +2.5/+1.8 mmHg. DISCUSSION: Dietary interventions in cardiothoracic transplant patients are feasible and potentially beneficial. CONCLUSION: A definitive nutritional intervention study in these high-risk patients is warranted.


Assuntos
Doenças Cardiovasculares , Glicemia , Pressão Sanguínea , Índice de Massa Corporal , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Fatores de Risco de Doenças Cardíacas , Humanos , Fatores de Risco
10.
Clin Chem Lab Med ; 58(5): 741-752, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-31926069

RESUMO

Background Classically, serum testosterone (T) and androstenedione (A4) have been the mainstay for the biochemical assessment of hyperandrogenism. However, recent evidence suggests 11ß-hydroxyandrostenedione (11OHA4) and 11-ketotestosterone (11KT) may also be important. Here, we describe the development of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for quantitation of total serum T, A4, 17-hydroxyprogesterone (17OHP), 11OHA4 and 11KT. In addition, we applied the method to assess pre-analytical stability. Methods An isotopically labelled internal standard was added to samples prior to supported liquid extraction (SLE). Extracts were analysed using LC-MS/MS to detect T/A4/17OHP/11OHA4 and 11KT along with their corresponding internal standards. Samples (n = 7) were collected from healthy volunteers (n = 14) and left incubated at 20 °C for up to 72 h. Tubes were retrieved at select time points, centrifuged, separated and frozen prior to analysis. Results The total run time was 4 min. For all analytes, intra- and inter-assay imprecision did not exceed 7.9% and 5.3%, respectively; matrix effects were negligible and mean recoveries ranged from 95.3 to 111.6%. The limits of quantitation (LOQs) were 0.25 nmol/L for T, A4 and 11OHA4, 0.50 nmol/L for 17OHP, and 0.24 nmol/L for 11KT. No significant change was observed in pre-centrifugation A4 or female T concentrations over 72 h. Significant increases (p < 0.01) in concentrations of 11KT, 17OHP, 11OHA4 and male T were observed after 2, 8, 12 and 24 h, respectively. Conclusions We developed a robust LC-MS/MS assay for the quantitation of total serum T/A4/17OHP/11OHA4 and 11KT. Applying the method to determine pre-analytical stability suggests samples requiring 11KT need separating from the cells within 2 h.


Assuntos
17-alfa-Hidroxiprogesterona/sangue , Androstenodiona/análogos & derivados , Androstenodiona/sangue , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Testosterona/análogos & derivados , Testosterona/sangue , 17-alfa-Hidroxiprogesterona/isolamento & purificação , 17-alfa-Hidroxiprogesterona/normas , Adulto , Androstenodiona/isolamento & purificação , Androstenodiona/normas , Cromatografia Líquida de Alta Pressão/normas , Feminino , Humanos , Marcação por Isótopo , Limite de Detecção , Extração Líquido-Líquido , Masculino , Fase Pré-Analítica , Padrões de Referência , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/normas , Testosterona/isolamento & purificação , Testosterona/normas
11.
BMC Endocr Disord ; 20(1): 154, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-33036588

RESUMO

BACKGROUND: Glucocorticoid therapy is the most common cause of iatrogenic osteoporosis. Less is known regarding the effect of glucocorticoids when used as replacement therapy on bone remodelling in patients with adrenal insufficiency. Enhanced intracellular conversion of inactive cortisone to active cortisol, by 11 beta-hydroxysteroid dehydrogenase type 1(11ß-HSD1) and other enzymes leading to alterations in glucocorticoid metabolism, may contribute to a deleterious effect on bone health in this patient group. METHODS: Study design: An open crossover prospective study randomizing ten hypopituitary men, with severe ACTH deficiency, to three commonly used hydrocortisone dose regimens. MEASUREMENTS: Following 6 weeks of each regimen, patients underwent 24-h serum cortisol/cortisone sampling, measurement of bone turnover markers, and a 24-h urine collection for measurement of urinary steroid metabolites by gas chromatography-mass spectrometry (GC-MS). Serum cortisone and cortisol were analysed by liquid chromatography-mass spectrometry (LC-MS). RESULTS: Dose-related and circadian variations in serum cortisone were seen to parallel those for cortisol, indicating conversion of ingested hydrocortisone to cortisone. The median area under the curve (AUC) of serum cortisone was significantly higher in patients on dose A (20 mg/10 mg) [670.5 (IQR 621-809.2)] compared to those on dose C (10 mg/5 mg) [562.8 (IQR 520.1-619.6), p = 0.01]. A negative correlation was observed between serum cortisone and bone formation markers, OC [1-49] (r = - 0.42, p = 0.03), and PINP (r = - 0.49, p = 0.01). There was a negative correlation between the AUC of night-time serum cortisone levels with the bone formation marker, OC [1-49] (r = - 0.41, p = 0.03) but there were no significant correlations between day-time serum cortisone or cortisol with bone turnover markers. There was a negative correlation between total urinary cortisol metabolites and the bone formation markers, PINP (r = - 0.39, p = 0.04), and OC [1-49] (r = - 0.35, p = 0.06). CONCLUSION: Serum cortisol and cortisone and total urinary corticosteroid metabolites are negatively associated with bone turnover markers in patients receiving replacement doses of hydrocortisone, with nocturnal glucocorticoid exposure having a potentially greater influence on bone turnover. TRIAL REGISTRATION: Irish Medicines Board Clinical Trial Number - CT900/459/1 and EudraCT Number - 2007-005018-37 . Registration date: 07-09-2007.


Assuntos
Insuficiência Adrenal/tratamento farmacológico , Reabsorção Óssea/patologia , Cortisona/sangue , Glucocorticoides/metabolismo , Terapia de Reposição Hormonal/efeitos adversos , Hidrocortisona/efeitos adversos , Insuficiência Adrenal/patologia , Adulto , Densidade Óssea , Reabsorção Óssea/etiologia , Reabsorção Óssea/metabolismo , Estudos Cross-Over , Humanos , Masculino , Estudos Prospectivos
12.
Br J Cancer ; 120(4): 404-406, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30679781

RESUMO

Biochemical evaluation of menopausal status is used to inform treatment decisions, including clinical trial eligibility in women with oestrogen receptor positive breast cancer. However, fulvestrant may interfere with oestradiol immunoassays and confound accurate assessment in this context. We conducted a service evaluation of two immunoassays and an LC-MS/MS assay to determine the extent of the interference. Serum oestradiol levels were analysed by two immunoassays (Siemens Centaur XP and Abbott Architect) and liquid chromatography-tandem mass spectrometry (LC/MS/MS). Immunoassay gave higher serum oestradiol results than LC-MS/MS at low concentrations, with improved analytical sensitivity demonstrated by LC-MS/MS. Cross-reactivity of fulvestrant was observed for each immunoassay. We have shown that two commonly used immunoassays do not demonstrate the required sensitivity or specificity for the measurement of oestradiol in a breast cancer population. For patients receiving fulvestrant, spurious results may be generated that could impact treatment decisions. LC-MS/MS is recommended in this setting.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Estradiol/sangue , Antagonistas do Receptor de Estrogênio/uso terapêutico , Fulvestranto/uso terapêutico , Adolescente , Adulto , Neoplasias da Mama/sangue , Cromatografia Líquida , Feminino , Humanos , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem , Adulto Jovem
13.
Clin Endocrinol (Oxf) ; 90(1): 66-73, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30311954

RESUMO

OBJECTIVE: Hydrocortisone via nasogastric (NG) tube is used in sick children with adrenal insufficiency; however, there is no licensed formulation for NG administration. METHODS: We investigated hydrocortisone recovery after passage through NG tubes in vitro for three formulations: liquid suspension, crushed tablets mixed with water, and hydrocortisone granules designed for oral administration to children. Cortisol was measured by LC-MS/MS. RESULTS: Hydrocortisone content was variable and recovery low after preparation in syringe and prior to passage through NG tubes. For doses, 0.5 and 2.0 mg mean percentage recovery was as follows: liquid suspension 57% and 58%; crushed tablets 46% and 30%; and hydrocortisone granules 78% and 71%. Flushing the administering syringe increased recovery. Hydrocortisone recovery after passage with flushing through 6-12Fr gauge NG tubes was variable: liquid suspension 61%-92%, crushed tablets 40%-174%, hydrocortisone granules 61%-92%. Administration of hydrocortisone granules occluded 6 and 8Fr NG tubes; however, administration using a sampling needle to prevent granules being administered gave a recovery of 74%-98%. CONCLUSIONS: The administration of hydrocortisone through NG tubes is possible; however, current methods deliver a variable dose of hydrocortisone, generally less than that prescribed. Attention should be placed on the technique used to optimize drug delivery such as flushing of the administering syringe. Hydrocortisone granules block small NG tubes but behaved as well as the commonly used liquid suspension when prepared with a filtering needle that filters out granules.


Assuntos
Hidrocortisona/administração & dosagem , Intubação Gastrointestinal/métodos , Disponibilidade Biológica , Criança , Cromatografia Líquida , Composição de Medicamentos/métodos , Feminino , Humanos , Hidrocortisona/análise , Masculino , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem
15.
Ther Drug Monit ; 41(4): 409-430, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31268966

RESUMO

Dried blood spot (DBS) analysis has been introduced more and more into clinical practice to facilitate Therapeutic Drug Monitoring (TDM). To assure the quality of bioanalytical methods, the design, development and validation needs to fit the intended use. Current validation requirements, described in guidelines for traditional matrices (blood, plasma, serum), do not cover all necessary aspects of method development, analytical- and clinical validation of DBS assays for TDM. Therefore, this guideline provides parameters required for the validation of quantitative determination of small molecule drugs in DBS using chromatographic methods, and to provide advice on how these can be assessed. In addition, guidance is given on the application of validated methods in a routine context. First, considerations for the method development stage are described covering sample collection procedure, type of filter paper and punch size, sample volume, drying and storage, internal standard incorporation, type of blood used, sample preparation and prevalidation. Second, common parameters regarding analytical validation are described in context of DBS analysis with the addition of DBS-specific parameters, such as volume-, volcano- and hematocrit effects. Third, clinical validation studies are described, including number of clinical samples and patients, comparison of DBS with venous blood, statistical methods and interpretation, spot quality, sampling procedure, duplicates, outliers, automated analysis methods and quality control programs. Lastly, cross-validation is discussed, covering changes made to existing sampling- and analysis methods. This guideline of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology on the development, validation and evaluation of DBS-based methods for the purpose of TDM aims to contribute to high-quality micro sampling methods used in clinical practice.


Assuntos
Teste em Amostras de Sangue Seco/métodos , Teste em Amostras de Sangue Seco/normas , Monitoramento de Medicamentos/métodos , Monitoramento de Medicamentos/normas , Humanos , Reprodutibilidade dos Testes , Manejo de Espécimes/métodos , Manejo de Espécimes/normas
16.
Clin Endocrinol (Oxf) ; 88(5): 706-710, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29405348

RESUMO

OBJECTIVE/CONTEXT: The free androgen index (FAI) is known to give erroneous results in men, but it is still a commonly used test for the investigation of hyperandrogenism in women. This study aimed to compare the results of the FAI with the gold standard equilibrium dialysis method for free testosterone in women. DESIGN/PATIENTS: Free serum testosterone T (ED-T) and total serum T (T) were measured by equilibrium dialysis and LC-MS/MS in patients with polycystic ovarian syndrome (n = 130), normal female controls (n = 53) and normal males (n = 120). Calculated free T (cFT) and free androgen index (FAI) were also measured in these patients. In addition, cFT was retrospectively calculated in 4223 female patients with a normal T (<1.6 nmol/L) routinely investigated for hyperandrogenism. RESULTS: The cFT showed good agreement with measured ED-T, and the ratio cFT/ED-T was stable across all SHBG concentrations. In contrast, the FAI/ED-T ratio and the FAI/cFT ratio increased when the concentration of SHBG fell below 30 nmol/L. CONCLUSIONS: The FAI is not a reliable indicator of free T when the SHBG concentration is low and would give misleading information in a large number of women being investigated for hyperandrogenism.


Assuntos
Androgênios/sangue , Hiperandrogenismo/sangue , Globulina de Ligação a Hormônio Sexual/metabolismo , Cromatografia Líquida , Feminino , Humanos , Síndrome do Ovário Policístico/sangue , Estudos Retrospectivos , Espectrometria de Massas em Tandem , Testosterona/sangue
17.
Clin Endocrinol (Oxf) ; 88(6): 772-778, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29106701

RESUMO

CONTEXT: Salivary cortisone reflects serum cortisol levels, is more sensitive than salivary cortisol at lower values of serum cortisol and is noninvasive. OBJECTIVE: To investigate the relationship between serum cortisol and salivary cortisol and cortisone following low- and high-dose synacthen. DESIGN AND SETTING: Prospective pharmacodynamic studies in clinical research facilities. PARTICIPANTS AND INTERVENTION: Thirty-five dexamethasone-suppressed, healthy adult males underwent an intravenous synacthen test: N = 23 low-dose (1 mcg), N = 12 high-dose (250 mcg). Paired serum and salivary samples were taken at 15 sampling points over 120 minutes. MAIN OUTCOME MEASURE: Serum cortisol and salivary cortisol and cortisone were analysed for correlations and by a mixed-effects model. RESULTS: At baseline, the correlation between serum cortisol and salivary cortisol was weak with many samples undetectable (r = .45, NS), but there was a strong correlation with salivary cortisone (r = .94, P < .001). Up to 50 minutes following synacthen, the correlation coefficient between serum cortisol and salivary cortisol and cortisone was <0.8, but both had a stronger correlation at 60 minutes (salivary cortisol r = .89, P < .001, salivary cortisone r = .85, P < .001). The relationship was examined excluding samples in the dynamic phase (baseline to 60 minutes). Salivary cortisol and cortisone showed a close relationship to serum cortisol. Salivary cortisone showed the stronger correlation: salivary cortisol r = .82, P < .001, salivary cortisone r = .96, P < .001. CONCLUSION: Following synacthen, both salivary cortisol and cortisone reflect serum cortisol levels, but there is a lag in their rise up to 60 minutes. The results support further research for possible future use of a 60-minute salivary cortisone measurement during the synacthen test.


Assuntos
Cortisona/sangue , Cortisona/metabolismo , Hidrocortisona/sangue , Hidrocortisona/metabolismo , Saliva/química , Adulto , Cosintropina/administração & dosagem , Cosintropina/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
18.
Clin Endocrinol (Oxf) ; 88(3): 479-490, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29178359

RESUMO

OBJECTIVE: Elevated luteinizing hormone (LH) with normal testosterone (T) suggests compensated dysregulation of the gonadal axis. We describe the natural history, risk factors and clinical parameters associated with the development of high LH (HLH, LH >9.4 U/L) in ageing men with normal T (T ≥ 10.5 nmol/L). DESIGN, PATIENTS AND MEASUREMENTS: We conducted a 4.3-year prospective observational study of 3369 community-dwelling European men aged 40-79 years. Participants were classified as follows: incident (i) HLH (n = 101, 5.2%); persistent (p) HLH (n = 128, 6.6%); reverted (r) HLH (n = 46, 2.4%); or persistent normal LH (pNLH, n = 1667, 85.8%). Potential predictors and changes in clinical features associated with iHLH and rHLH were analysed using regression models. RESULTS: Age >70 years (OR = 4.12 [2.07-8.20]), diabetes (OR = 2.86 [1.42-5.77]), chronic pain (OR = 2.53 [1.34-4.77]), predegree education (OR = 1.79 [1.01-3.20]) and low physical activity (PASE ≤ 78, OR = 2.37 [1.24-4.50]) predicted development of HLH. Younger age (40-49 years, OR = 8.14 [1.35-49.13]) and nonsmoking (OR = 5.39 [1.48-19.65]) predicted recovery from HLH. Men with iHLH developed erectile dysfunction, poor health, cardiovascular disease (CVD) and cancer more frequently than pNLH men. In pHLH men, comorbidities, including CVD, developed more frequently, and cognitive and physical function deteriorated more, than in pNLH men. Men with HLH developed primary hypogonadism more frequently (OR = 15.97 [5.85-43.60]) than NLH men. Men with rHLH experienced a small rise in BMI. CONCLUSIONS: Elevation of LH with normal T is predicted by multiple factors, reverts frequently and is not associated with unequivocal evidence of androgen deficiency. High LH is a biomarker for deteriorating health in aged men who tend to develop primary hypogonadism.


Assuntos
Hormônio Luteinizante/metabolismo , Testosterona/sangue , Adulto , Fatores Etários , Idoso , Envelhecimento , Disfunção Erétil/etiologia , Europa (Continente) , Humanos , Hipogonadismo/etiologia , Hormônio Luteinizante/sangue , Masculino , Pessoa de Meia-Idade , História Natural , Prognóstico , Estudos Prospectivos , Fatores de Risco
19.
Clin Endocrinol (Oxf) ; 89(4): 459-469, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29855071

RESUMO

OBJECTIVE: Limited evidence supports the use of free testosterone (FT) for diagnosing hypogonadism when sex hormone-binding globulin (SHBG) is altered. Low total testosterone (TT) is commonly encountered in obesity where SHBG is typically decreased. We aimed to assess the contribution of FT in improving the diagnosis of symptomatic secondary hypogonadism (SH), identified initially by low total testosterone (TT), and then further differentiated by normal FT (LNSH) or low FT (LLSH). DESIGN: Prospective observational study with a median follow-up of 4.3 years. PATIENTS: Three thousand three hundred sixty-nine community-dwelling men aged 40-79 years from eight European centres. MEASUREMENTS: Subjects were categorized according to baseline and follow-up biochemical status into persistent eugonadal (referent group; n = 1880), incident LNSH (eugonadism to LNSH; n = 101) and incident LLSH (eugonadism to LLSH; n = 38). Predictors and clinical features associated with the transition from eugonadism to LNSH or LLSH were assessed. RESULTS: The cumulative incidence of LNSH and LLSH over 4.3 years was 4.9% and 1.9%, respectively. Baseline obesity predicted both LNSH and LLSH, but the former occurred more frequently in younger men. LLSH, but not LNSH, was associated with new/worsened sexual symptoms, including low desire [OR = 2.67 (1.27-5.60)], erectile dysfunction [OR = 4.53 (2.05-10.01)] and infrequent morning erections [OR = 3.40 (1.48-7.84)]. CONCLUSIONS: These longitudinal data demonstrate the importance of FT in the diagnosis of hypogonadism in obese men with low TT and SHBG. The concurrent fall in TT and FT identifies the minority (27.3%) of men with hypogonadal symptoms, which were not present in the majority developing low TT with normal FT.


Assuntos
Hipogonadismo/sangue , Hipotireoidismo/sangue , Obesidade/sangue , Testosterona/sangue , Adulto , Idoso , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Observacionais como Assunto , Estudos Prospectivos
20.
Clin Endocrinol (Oxf) ; 86(5): 660-668, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28160328

RESUMO

OBJECTIVES: To assess ethnic differences in male reproductive hormone levels and to determine whether any differences are explained by adiposity, insulin resistance (IR) or comorbidities in older men. DESIGN: Multi-ethnic cross-sectional observational study. PARTICIPANTS: Community dwelling middle-aged and elderly men residing in the UK aged 40-84 years of South Asian (SA; n = 180), White European (WE; n = 328) or African Caribbean (AC; n = 166) origin. OBSERVATIONS: Measured testosterone (T), calculated free T (cFT), sex hormone-binding globulin and LH in SA, WE and AC men along with an assessment of body composition, IR, lifestyle factors and medical conditions. RESULTS: Age-adjusted mean T and cFT levels were lower in SA men when compared to WE and AC men (mean (SEM) T: SA: 14·0 ± 0·4; WE: 17·1 ± 0·3; AC: 17·2 ± 0·5 nmol/l, P < 0·001; cFT: SA: 283 ± 7; WE: 313 ± 5; AC: 314 ± 8 pmol/l, P < 0·006). Compared to WE and AC men, SA men had higher levels of body fat, IR, comorbidities and diabetes. After adjusting for body fat, IR and other confounders, T levels in SA men remained lower than in WE men (P = 0·04) but ethnic differences in cFT became nonsignificant. LH levels were higher in SA than WE men in age-adjusted and fully adjusted models. CONCLUSIONS: T and cFT are lower in SA men than in WE and AC men. Whether ethnic-specific reference ranges for T and cFT might be appropriate in clinical practice requires further investigation. Ethnic differences in cFT, but not T, appear to be, more readily, explained by ethnic differences in adiposity, thus providing insights into potential pathophysiological mechanisms.


Assuntos
Adiposidade/etnologia , Envelhecimento/etnologia , Resistência à Insulina/etnologia , Hormônio Luteinizante/metabolismo , Globulina de Ligação a Hormônio Sexual/metabolismo , Testosterona/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Humanos , Masculino , Pessoa de Meia-Idade , Reino Unido/etnologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA