Report from the HarmoSter study: different LC-MS/MS androstenedione, DHEAS and testosterone methods compare well; however, unifying calibration is a double-edged sword.

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.

Current National and International Guidelines for the Management of Male Hypogonadism: Helping Clinicians to Navigate Variation in Diagnostic Criteria and Treatment Recommendations.

Male hypogonadism-rebadged by some as testosterone deficiency syndrome-is a clinical and biochemical diagnosis of increasing worldwide interest. Organic male hypogonadism-usually permanent-is well-established, but aging men may also exhibit lower serum testosterone levels; principally due to burden of extra-gonadal comorbidities such as obesity, diabetes and metabolic syndrome, but with an underlying intact hypothalamo-pituitary-testicular (HPT) axis capable of springing back into operation once comorbidities are addressed. Despite encouraging observational data and plausible theoretical underpinning, evidence for efficacy and safety of testosterone in this "aging" group of men is lacking; addressing comorbid illnesses remains the key priority instead. Nevertheless, in recent years, accumulation of misleading information online has triggered a global tsunami of testosterone prescriptions. Despite this, many men with organic hypogonadism remain undiagnosed or untreated; many more face a diagnostic odyssey before achieving care by the appropriate specialist. As testosterone therapy is not without risk several clinical practice guidelines have been published specialist societies to guide physicians on best practice. However, these are heterogeneous in key areas, reflecting divergent approaches to the same evidence basis. Herein, we navigate the major clinical practice guidelines on male hypogonadism and test their respective recommendations against current best evidence.

Development of a total serum testosterone, androstenedione, 17-hydroxyprogesterone, 11ß-hydroxyandrostenedione and 11-ketotestosterone LC-MS/MS assay and its application to evaluate pre-analytical sample stability.

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.

Simple and accurate candidate reference measurement procedure for total testosterone in human serum by one-step liquid-liquid extraction coupled with isotope dilution mass spectrometry.

Testosterone in human serum is commonly tested in clinical laboratories using immunoassay methods as well as liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. To standardize and ensure the accuracy of the measurement results, reference procedures with higher metrological order are required. A simple measurement procedure based on one-step liquid-liquid extraction (LLE) and liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) was developed for total testosterone in human serum. The procedure involved serum spiked with 13C3-testosterone, equilibration for 2 h, and extraction with an organic solvent. Testosterone certified reference material (CRM) was used as the calibration standard to ensure the traceability to the International System of Units (SI). Testosterone in serum CRMs from the National Institute for Standards and Technology (NIST) and LGC were used to validate the accuracy of the newly developed method. The deviations of the obtained values from the NIST and LGC certified values ranged from -0.55% to 0.45%. Similarly, the coefficient of variations (CVs) of the replicate measurements were in the range of 0.55% and 0.78%, respectively. The relative expanded uncertainties were comparable with those of the certified materials. The newly developed LC-IDMS/MS procedure demonstrated adequate trueness and precision, and was simple to perform. The method can be used for value assignment of testosterone in external quality assessment (EQA) materials as well as certification of CRMs in the future. Graphical abstract.

Clinical practice update on testosterone therapy for male hypogonadism: Contrasting perspectives to optimize care.

US Endocrine Society (ES) published a clinical practice guideline on testosterone therapy in men with hypogonadism, and Endocrine Society of Australia (ESA) a position statement on management of male hypogonadism. Both emphasize the importance of diagnosing men who are androgen deficient due to organic (classical or pathological) hypogonadism arising from disorders of the hypothalamus, pituitary or testes, who assuredly benefit from testosterone therapy. Both recognize that men with an intact gonadal axis may have low testosterone concentrations, for instance older men or men with obesity or other medical comorbidities. ES guidelines classify such symptomatic men as having organic (advanced age) or functional (obesity, medical comorbidities) hypogonadism, giving an option for testosterone therapy as a shared decision between clinicians and individual patients. ESA did not recommend testosterone therapy in these men. ES offers a reference range for total testosterone established in young men, while ESA cites age-standardized reference ranges. ES recommends using free testosterone as well as total testosterone to identify men with hypogonadism in conditions where sex hormone-binding globulin (SHBG) is altered, or when total testosterone is borderline. ESA recommends confirmatory biochemical testing with total testosterone, recognizing that this may be lower than expected if SHBG concentrations are low. Both emphasize the importance of identifying pre-existing prostate and cardiovascular disease prior to initiating testosterone therapy, with ES providing specific recommendations for PSA measurement, deferring testosterone therapy after major cardiovascular events and indications for pituitary imaging. These contrasting approaches highlight gaps in the evidence base where individualized patient management is required.

Establishing reference intervals for sex hormones and SHBG in apparently healthy Chinese adult men based on a multicenter study.

BACKGROUND: Measuring sex hormones is essential in diagnosing health issues such as testicular dysfunction, male infertility and feminization syndrome. However, there are no reports on reference intervals (RIs) in Chinese men. We conducted a nationwide multicenter study to establish RIs for seven sex hormones (luteinizing hormone [LH], follicle-stimulating hormone [FSH], prolactin [PRL], total testosterone [TT], free testosterone [FT], bioavailable testosterone [BAT] and estrogen [E2]), as well as sex hormone-binding globulin (SHBG). METHODS: In 2013, 1043 apparently healthy adult men from five representative cities in China (Beijing, Hangzhou, Guangzhou, Dalian and Urumqi) were recruited; hormones were measured using an automated immunoassay analyzer. Multiple regression analysis (MRA) was performed to identify sources of variation (SVs) that might influence the hormone serum levels. RIs were computed using the parametric method. RESULTS: Dalian and Hangzhou had significantly higher E2 values than other cities; age was a major source of variation for FSH, LH, PRL, SHBG, FT and BAT. FSH, LH and SHBG increased significantly with age, while PRL, FT and BAT decreased with age. TT showed no significant age-related changes. Median (RIs) derived without partition by age were as follows: FSH, 5.6 (1.9-16.3) IU/L; LH, 4.2 (1.6-10.0) IU/L; PRL, 189 (88-450) mIU/L; E2, 85 (4.7-195) pmol/L; SHBG, 29.4 (11.5-66.3) nmol/L; TT, 15.6 (7.4-24.5) nmol/L; FT, 0.31 (0.16-0.52) nmol/L; and BAT, 8.0 (3.7-13.2) nmol/L. RIs were also derived in accordance with between-city and between-age differences. CONCLUSIONS: RIs were established for sex hormones and SHBG in apparently healthy Chinese men in consideration of age.

Establishing normal values of total testosterone in adult healthy men by the use of four immunometric methods and liquid chromatography-mass spectrometry.

BACKGROUND: The total testosterone (T) cutoffs clinically adopted to define late-onset hypogonadism (LOH) do not consider the differences that exist between different analytical platforms, nor do they consider the body mass index (BMI) or age of the patient. We aimed at providing method, age and BMI-specific normal values for total T in European healthy men. METHODS: A total of 351 eugonadal healthy men were recruited, and total T was measured with four automated immunometric assays (IMAs): ARCHITECT i1000SR (Abbott), UniCel DxI800 (Beckman Coulter), Cobas e601 (Roche), IMMULITE 2000 (Siemens) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Reference ranges (RRs) were calculated for each method. RESULTS: Passing and Bablok regression analysis and Bland-Altman plot showed an acceptable agreement between Abbott and LC-MS/MS, but a poor one between LC-MS/MS and the other IMAs. Age-specific T concentrations in non-obese (BMI <29.9 kg/m2) men were greater than in all men. The total T normal range, in non-obese men aged 18-39 years, measured with LC-MS/MS was 9.038-41.310 nmol/L. RRs calculated with LC-MS/MS statistically differed from the ones calculated with all individual IMAs, except Abbott and among all IMAs. Statistically significant differences for both upper and lower reference limits between our RRs and the ones provided by the manufacturers were also noticed. CONCLUSIONS: We calculated normal ranges in a non-obese cohort of European men, aged 18-39 years, with four commercially available IMAs and LC-MS/MS and found statistically significant differences according to the analytical method used. Method-specific reference values can increase the accuracy of LOH diagnosis and should be standardly used.

Identification and Structural Elucidation of New Process Impurity in Testosterone.

The main objective of this study is identification, isolation and characterization of potential impurity of testosterone. Testosterone was analyzed as per European pharmacopeial method for related substances by high-performance liquid chromatography (HPLC). One new unknown impurity was found along with other pharmacopeial impurities at a level more than 0.10%. This unknown impurity was isolated by preparative HPLC using Symmetry C18 column. The isolated impurity was spiked in sample containing impurities and was found to have the same retention time as that of this unknown impurity. This isolated impurity was fully characterized by different spectroscopic techniques such as LC-MS/MS, 1H, 13C NMR and DEPT as per the requirements of the ICH guidelines and was characterized as bisnoralcohol impurity.

Testosterone and Cardiovascular Health.

There is an ongoing debate in the medical community regarding the effects of testosterone on cardiovascular (CV) health. For decades, there has been conflicting evidence regarding the association of endogenous testosterone levels and CV disease (CVD) events that has resulted in much debate and confusion among health care providers and patients alike. Testosterone therapy has become increasingly widespread, and after the emergence of studies that reported increased CVD events in patients receiving testosterone therapy, the US Food and Drug Administration (FDA) released a warning statement about testosterone and its potential risk regarding CV health. Some of these studies were later found to be critically flawed, and some experts, including the American Association of Clinical Endocrinologists and an expert panel regarding testosterone deficiency and its treatment, reported that some of the FDA statements regarding testosterone therapy were lacking scientific evidence. This article summarizes the current evidence regarding the relationship between testosterone (endogenous and supplemental) and CV health. A literature review was conducted via search using PubMed and specific journal databases, including the New England Journal of Medicine and the Journal of the American College of Cardiology. Key search terms included testosterone and cardiovascular health, coronary artery disease, heart failure, androgen deprivation therapy, intima-media thickness, and adrenal androgens. Initial study selection was limited to publications within the past 10 years (January 1, 2007, through December 31, 2016); however, key publications outside of this time frame were selected if they provided important quantitative data or historical perspectives for the review of this topic. The search was further supplemented by reviewing references in selected articles.

Age and Sex Distributions of Age-Related Biomarker Values in Healthy Older Adults from the Long Life Family Study.

OBJECTIVES: To determine reference values for laboratory tests in individuals aged 85 and older. DESIGN: Cross-sectional cohort study. SETTING: International. PARTICIPANTS: Long Life Family Study (LLFS) participants (N~5,000, age: range 25-110, median 67, 45% male). MEASUREMENTS: Serum biomarkers were selected based on association with aging-related diseases and included complete blood count, lipids (triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol), 25-hydroxyvitamin D2 and D3, vitamin D epi-isomer, diabetes mellitus-related biomarkers (adiponectin, insulin, insulin-like growth factor 1, glucose, glycosylated hemoglobin, soluble receptor for advanced glycation endproduct), kidney disease-related biomarkers (albumin, creatinine, cystatin), endocrine biomarkers (dehydroepiandrosterone, sex-hormone binding globulin, testosterone), markers of inflammation (interleukin 6, high-sensitivity C-reactive protein, N-terminal pro b-type natriuretic peptide), ferritin, and transferrin. RESULTS: Of 38 measured biomarkers, 34 were significantly correlated with age. Summary statistics were generated for all biomarkers according to sex and 5-year age increments from 50 and up after excluding participants with diseases and treatments that were associated with biomarkers. A biomarker data set was also generated that will be useful for other investigators seeking to compare biomarker levels between studies. CONCLUSION: Levels of several biomarkers change with older age in healthy individuals. The descriptive statistics identified herein will be useful in future studies and, if replicated in additional studies, might also become useful in clinical practice. The availability of the reference data set will facilitate appropriate calibration of biomarkers measured in different laboratories.

Quantification of endogenous metabolites by the postcolumn infused-internal standard method combined with matrix normalization factor in liquid chromatography-electrospray ionization tandem mass spectrometry.

Quantification of endogenous metabolites has enabled the discovery of biomarkers for diagnosis and provided for an understanding of disease etiology. The standard addition and stable isotope labeled-internal standard (SIL-IS) methods are currently the most widely used approaches to quantifying endogenous metabolites, but both have some limitations for clinical measurement. In this study, we developed a new approach for endogenous metabolite quantification by the postcolumn infused-internal standard (PCI-IS) method combined with the matrix normalization factor (MNF) method. MNF was used to correct the difference in MEs between standard solution and biofluids, and PCI-IS additionally tailored the correction of the MEs for individual samples. Androstenedione and testosterone were selected as test articles to verify this new approach to quantifying metabolites in plasma. The repeatability (n=4 runs) and intermediate precision (n=3 days) in terms of the peak area of androstenedione and testosterone at all tested concentrations were all less than 11% relative standard deviation (RSD). The accuracy test revealed that the recoveries were between 95.72% and 113.46%. The concentrations of androstenedione and testosterone in fifty plasma samples obtained from healthy volunteers were quantified by the PCI-IS combined with the MNF method, and the quantification results were compared with the results of the SIL-IS method. The Pearson correlation test showed that the correlation coefficient was 0.98 for both androstenedione and testosterone. We demonstrated that the PCI-IS combined with the MNF method is an effective and accurate method for quantifying endogenous metabolites.

Testosterone trajectories and reference ranges in a large longitudinal sample of male adolescents.

PURPOSE: Pubertal dynamics plays an important role in physical and psychological development of children and adolescents. We aim to provide reference ranges of plasma testosterone in a large longitudinal sample. Furthermore, we describe a measure of testosterone trajectories during adolescence that can be used in future investigations of development. METHODS: We carried out longitudinal measurements of plasma testosterone in 2,216 samples obtained from 513 males (9 to 17 years of age) from the Avon Longitudinal Study of Parents and Children. We used integration of a model fitted to each participant's testosterone trajectory to calculate a measure of average exposure to testosterone over adolescence. We pooled these data with corresponding values reported in the literature to provide a reference range of testosterone levels in males between the ages of 6 and 19 years. RESULTS: The average values of total testosterone in the ALSPAC sample range from 0.82 nmol/L (Standard Deviation [SD]: 0.09) at 9 years of age to 16.5 (SD: 2.65) nmol/L at 17 years of age; these values are congruent with other reports in the literature. The average exposure to testosterone is associated with different features of testosterone trajectories such as Peak Testosterone Change, Age at Peak Testosterone Change, and Testosterone at 17 years of age as well as the timing of the growth spurt during puberty. CONCLUSIONS: The average exposure to testosterone is a useful measure for future investigations using testosterone trajectories to examine pubertal dynamics.

The standardization of nonsterile compounding: a study in quality control and assessment for hormone compounding.

Sterile and nonsterile compounding of medication has attracted much attention over the last few years due to the onset of various infections and negative compounding practices. This paper reports on the standardization of compounded hormones utilizing the Wiley Protocol, which provides nonsynthetic bioidentical estradiol, progesterone, dehydroepiandrosterone, and testosterone in a transdermal topical cream base for women and men in a standardized dosing regimen. Here, we present data from 2008 through 2012, which details the process of standardization and quality testing of the hormones through submission of random compounded samples for quality control and assessment. Pharmacies delivering the Wiley Protocol were required to follow the same compounding formulation, as well as submit random samples for quarterly testing. Sample concentrations were tested using high-performance liquid chromatography. We found that pharmacies that submitted samples had a 91% passing rating with a percent of target of 98.6% +/- 8.4%. It was also determined that pharmacies that prepared more compounded cream had a higher passing rating than those that prepared limited quantities. We found that standardization across multiple pharmacies could be achieved through quarterly testing of submitted samples by a third-party laboratory when following necessary procedures as defined by the Wiley Protocol. It was also determined that experience and training were a critical factor in the mixing of compounded prescriptions, with high consistency and accuracy providing patient safety.

Regulatory perspective of bioanalysis from a clinical pharmacology reviewer standpoint: do you see what I see?

Clinical pharmacology plays an important role in drug development, including the evaluation of the drug's pharmacokinetics, pharmacodynamics, drug-interaction potential, exposure-response relationship and safety considerations when being used in specific populations. Clinical pharmacology data is pivotal in ensuring the delivery of the right drug, in the right dose, at the right time, to each particular patient and it has significantly influenced the risk/benefit assessment and labeling recommendations. Consequently, the reliability of the bioanalytical methods and data are of considerable importance, and the solid footing in drug development. Documentation of bioanalytical data from method validation or clinical trials is a critical element supporting regulatory submissions such as new drug applications or biologics license applications. Case examples are presented to highlight the utility and importance of bioanalysis in drug development to ensure that drug products are safe, efficacious, and given at the right dose.

Challenges and improvements in testosterone and estradiol testing.

Assays that measure steroid hormones in patient care, public health, and research need to be both accurate and precise, as these criteria help to ensure comparability across all clinical and research applications. This review addresses major issues relevant to assay variability and describes recent activities by the US Centers for Disease Control and Prevention (CDC) to improve assay performance. Currently, high degrees of accuracy and precision are not always met for testosterone and estradiol measurements; although technologies for steroid hormone measurement have advanced significantly, measurement variability within and across laboratories has not improved accordingly. Differences in calibration and specificity are discussed as sources of variability in measurement accuracy. Ultimately, a combination of factors appears to cause inaccuracy of steroid hormone measurements, with nonuniform assay calibration and lack of specificity being two major contributors to assay variability. Within-assay variability for current assays is generally high, especially at low analyte concentrations. The CDC Hormone Standardization (HoSt) Program is improving clinical assays, as evidenced by a 50% decline in mean absolute bias between mass spectrometry assays and the CDC reference method from 2007 to 2011. This program provides the measurement traceability to CDC reference methods and helps to minimize factors affecting measurement variability.

Isotope-dilution liquid chromatography-tandem mass spectrometry candidate reference method for total testosterone in human serum.

BACKGROUND: We developed and evaluated a candidate reference measurement procedure (RMP) to standardize testosterone measurements, provide highly accurate and precise value assignments for the CDC Hormone Standardization Program, and ensure accurate and comparable results across testing systems and laboratories. METHODS: After 2 liquid/liquid extractions of serum with a combination of ethyl acetate and hexane, we quantified testosterone by isotope-dilution liquid chromatography-tandem mass spectrometry with electrospray ionization in the positive ion mode monitoring 289→97 m/z (testosterone) and 292→112 m/z ((3)C(13) testosterone). We used calibrator bracketing and gravimetric measurements to give higher specificity and accuracy to serum value assignments. The candidate RMP was evaluated for accuracy by use of NIST-certified reference material SRM971 and validated by split-sample comparison to established RMPs. We evaluated intraassay and interassay imprecision, measurement uncertainty, potential interferences, and matrix effects. RESULTS: A weighted Deming regression comparison of the candidate RMP to established RMPs showed agreement with no statistical difference (slope 0.99, 95% CI 0.98-1.00, intercept 0.54, 95% CI -1.24 to 2.32) and a bias of ≤0.3% for NIST SRM971. The candidate RMP gave maximum intraassay, interassay, and total percent CVs of 1.5%, 1.4%, and 1.7% across the concentrations of testosterone typically found in healthy men and women. We tested structural analogs of testosterone and 125 serum samples and found no interferences with the measurement. CONCLUSIONS: This RMP for testosterone can serve as a higher-order standard for measurement traceability and can be used to provide an accuracy base to which routine methods can be compared in the CDC Hormone Standardization Program.