Liquid chromatography quadrupole linear ion trap mass spectrometry for quantitative steroid hormone analysis in plasma, urine, saliva and hair

A Dual Biomarker Approach to Stress: Hair and Salivary Cortisol Measurement in Students via LC-MS/MS

Stress is a significant issue among students, affecting both their mental and physical health. In this study, we investigated cortisol levels, a key biomarker for stress, in students at the United Arab Emirates University (UAEU) during their exam period. Using a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodology we measured cortisol concentrations in hair and saliva samples and explored the potential correlation between exam-induced stress and cortisol levels. The results revealed an increase in cortisol levels during the exam period, with male students showing an average hair cortisol concentration of 150.625 pg/mg and female students displaying an average of 77.756 pg/mg. Salivary cortisol levels ranged from 0.002 to 9.189 ng/mL, with an overall average of 4.505 ng/mL. Statistical analysis revealed significant differences in cortisol levels between male and female students, underscoring the impact of exam-related stress on both acute and chronic stress markers. This study underscores the importance of addressing academic stress and suggests targeted strategies to mitigate its impact on student health ultimately fostering an environment encouraging both academic success and psychological well-being within the student community. Future research directions include exploring additional clinical parameters and expanding the study population to further understand the long-term effects of academic stress.

Stress responses in blood donors: Oral fluid hormone dynamics and implications for donor support

Glucocorticoids (cortisol and cortisone) hormones are potential biomarkers for monitoring physiological stress in humans. These hormones are released into the bloodstream but are also detectable in other biological matrixes such as oral fluid. Oral fluid hormone levels reflect those found in the blood, but oral fluid sampling is quicker and non-invasive, making it a viable alternative matrix for studying stress markers. This study investigates the stress response of blood donors at three different donation moments by analyzing cortisol and cortisone levels in oral fluid samples. To simultaneously detect these analytes, we developed and validated a new highly sensitive method using high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer (HPLC-MS/MS). Glucocorticoid hormones were found in all samples with cortisone exhibiting higher concentrations than cortisol. Statistical results revealed a weakly negative trend over time for both analytes levels, indicating that the most crucial donation moment is upon donors' arrival. A notable distinction was found in the evolution of the glucocorticoid hormones in different locations, suggesting that different environmental factors influence stress level more than the act of donation itself.

Multistage fragmentation (MS3) detection enhances quantitative sensitivity and accuracy for LC-MS analysis of serum steroid hormones

A determination method using a home-built quadrupole-linear ion trap tandem mass spectrometry (Q-LIT) multistage fragmentation function to accurate measure ultra-trace steroid hormones in human serum was established. The capability of ion trap for multistage fragmentation (MS3) overcomes the limitation of triple quadrupole systems restricted to MS2, enabling deeper structural characterization. Multistage fragmentation (MS3) enables the accurate detection of steroid hormones in serum samples without requiring extensive derivatization or time-consuming sample preparation and improves sensitivity by effectively reducing noise. Hydrocortisone, 4-androstenedione, 11-deoxycortisol, 21-deoxycortisol, and 17α-hydroxyprogesterone were quantified by MS3 transitions m/z 363.2 → 327.2→309.2, m/z 287.2 → 97.0→79.0, m/z 347.1 → 311.2→293.2, m/z 347.0 → 311.1→293.1, and m/z 331.2 → 313.3→295.2, respectively. Multistage fragmentation mass spectrometry effectively prevents matrix interference, and the quantitative results of MS3 are less affected by matrix effect than those of MS2. The established multistage fragmentation quantitative method showed good linearity (R2 ≥ 0.99), and the limits of detection and quantification of 5 steroid hormones were lower than 0.06 and 0.20 ng/mL, respectively. The recovery was 86.56 %-123.14 %, with an RSD of ≤13.57 %. A total of 22 real serum samples were accurately and sensitively measured using the Q-LIT multistage fragmentation method. Therefore, Q-LIT based multistage fragmentation has great potential for applications, such as detecting steroid hormones with severe matrix effects and distinguishing among related isomers in complex biological samples.

An isotope dilution-liquid chromatography-tandem mass spectrometry-based candidate reference measurement procedure for the quantification of cortisone in human serum and plasma

OBJECTIVES

Cortisone is an inert precursor/metabolite of the potent steroid hormone cortisol. Measurement of serum cortisone levels and the cortisol-cortisone ratio can be useful for the diagnosis of dysfunction in the regulation of cortisol levels (i.e., severe and subtle apparent mineralocorticoid excess, low-renin primary aldosteronism). Therefore, an isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC MS/MS)-based candidate reference measurement procedure (RMP) to quantify cortisone in human serum/plasma was developed and validated.

METHODS

Quantitative nuclear magnetic resonance (qNMR) was utilized to assign absolute content (g/g) and SI-traceability to reference materials used as primary calibrators. A supported liquid extraction sample preparation protocol as well as a two-dimensional heart-cut LC approach for LC-MS/MS analysis were employed to mitigate matrix effects and prevent co-elution of interferences. Selectivity was determined by analyzing a matrix sample containing the analyte, the internal standard and six potential interferents. A post-column infusion experiment and a comparison of standard line slopes were performed to evaluate matrix effects. An extensive protocol over five days was applied to determine precision, accuracy and trueness. Measurement uncertainty (MU) was evaluated in compliance with current guidelines.

RESULTS

This RMP is suitable for analyzing cortisone within the 0.0800-120 ng/mL (0.222-333 nmol/L) range, demonstrating selectivity, sensitivity and matrix independence. Intermediate precision was ≤3.4 %, repeatability was ≤2.9 % across all concentration levels and relative mean bias ranged from -3.7 to 2.8 % across all tested matrices and concentrations. Expanded MU (k=2) for target value assignment (n=6) ranged from 2.1 to 5.5 %, irrespective of concentration or sample type.

CONCLUSIONS

This RMP allows for accurate and reproducible determination of cortisone in human serum and plasma. Implementation of this method supports routine assay standardization and patient sample measurement with confirmed traceability.

A Highly Efficient and Automated Magnetic Bead Extraction Method Overcomes the Matrix Effect in LC-MS/MS Analysis of Human Serum Steroid Hormones

Profiling of steroid hormones is incredibly valuable in clinical settings for diagnosing endocrine disorders. However, the presence of matrix effects and labor-intensive manual work in LC-MS/MS analysis has hindered its routine application. In the present study, a highly efficient and automated magnetic bead extraction method was developed to address matrix effects and quantitatively profile 15 steroid hormones in human serum. Octadecyl (C18) and N-vinylpyrrolidone divinylbenzene (HLB) modified magnetic beads were compared for enriching steroids from human serum. Following enrichment, the beads were separated using a magnetic field; the matrix was cleaned, and the steroid hormones were eluted from the beads for LC-MS/MS analysis. This entire process of enrichment, cleanup, and elution was conducted automatically, making it simple, fast, and cost-effective. The results indicated that steroid hormones could be selectively enriched from human serum in just 1 min using C18 magnetic beads. The absolute matrix effect, evaluated as the relative response between human serum matrix and methanol solution, ranged from 89.2% to 113.1% for low levels, from 82.3% to 112.0% for medium levels, and from 91.7% to 111.0% for high levels. The intrabatch coefficients of variation (CVs) and interbatch CVs were between 3.1% and 13.4% and between 3.0% and 13.7%, respectively. Recoveries were between 87.6% and 114.3% for low levels, 94.0% and 105.0% for medium levels, and 91.9% and 111.7% for high levels. The clinical application was demonstrated by profiling steroid hormones in 160 pregnant women at various gestational weeks. The results suggested that the automated magnetic bead extraction method for LC-MS/MS could effectively address matrix effects in profiling steroid hormones. To our knowledge, this is the first automated magnetic bead extraction method for LC-MS/MS profiling of steroid hormones in clinical practice.

Extended Steroid Profiling in Human Serum and Plasma With Simultaneous Quantitative Determination Using One-Point Internal Calibration

Steroids are a major set of endogenous bioactive compounds. Although increasingly popular, their analysis in biofluids by LC-MS is associated with enduring challenges, such as their low endogenous concentrations or the coexistence of numerous isobaric compounds. Their natural presence in biological matrices complicates their absolute quantification in blood, as the obtention of a blank matrix to establish an external calibration curve is impossible. This protocol describes a strategy for developing an LC-MS/MS method for the extended profiling of steroids in serum and plasma, including as much as 171 target compounds, with the additional absolute quantification of four main steroids (cortisol, testosterone, progesterone, and androstenedione). The proposed sample preparation involves protein precipitation in organic solvents and subsequent filtration of the sample on HLB cartridge. The LC method is developed to resolve most isobaric species thanks to a biphenyl stationary phase. MS detection is performed in multiple reaction monitoring mode with post-column addition of ammonium fluoride to enhance sensitivity. A one-point internal calibration strategy is presented for the absolute quantification of endogenous steroids. The application of this method to the NIST Plasma Reference Material (SRM 1950) led to the identification of 69 distinct endogenous steroids, making it the most comprehensive profiling of these compounds in this reference matrix to date. The quantitative performance of the method is assessed with two certified materials and shows satisfactory precision and trueness.

Effect of sex, pubertal stage, body mass index, oral contraceptive use, and C-reactive protein on vitamin D binding protein reference values

Objective

Vitamin D binding protein (DBP) regulates the transport and availability of vitamin D. We aimed to establish age- and sex-specific reference ranges for serum concentrations of DBP in healthy infants, children, and adolescents. In addition, we investigated DBP's associations with age, sex, puberty, body mass index (BMI), and oral contraceptive use.

Design and methods

2,503 serum samples from children and adolescents aged 3 months to 17 years from the LIFE Child cohort were analyzed to study DBP levels in this population (49.3% female subjects, 50.7% male subjects). Age- and sex-dependent reference percentiles were established using generalized additive models. We used linear mixed effects models to assess DBP's associations with age, sex, pubertal status, the BMI standard deviation score (SDS), and oral contraceptives. To investigate associations between DBP and vitamin D metabolites, we applied univariate regression analysis. We used hierarchical regression models and linear mixed effects models to assess DBP's associations with bone parameters, hormones, and inflammatory markers.

Results

Mean DBP values differed between males (347 mg/l) and females (366 mg/l) (p < 0.001). Age had no significant association with DBP levels. In both males and females, DBP levels remained relatively stable from infancy through late adolescence. Children and adolescents with obesity had lower mean DBP levels compared with normal-weight subjects (ß = -14.28, p < 0.001). The BMI-SDS was inversely associated with DBP levels in males (ß = -5.7, p < 0.001). Female subjects using oral contraceptives had higher levels of DBP (ß = 141.38, p < 0.001). DBP was positively associated with the vitamin D metabolites: 25(OH)D3 (females: ß = 0.8, p < 0.001; males: ß = 1.2, p < 0.001) and 1,25(OH)2-D3 (females: ß = 0.3, p < 0.001; males: ß = 0.4, p < 0.001). An inverse association between osteocalcin and DBP (females: ß = -0.1, p < 0.022; males: ß = -0.1, p = 0.027) was found. CRP levels were also positively associated with DBP levels (females: ß = 2.8, p = 0.001; males: ß = 5.1, p < 0.001).

Conclusion

We established age- and sex-specific reference ranges for the serum concentration of DBP. We suggest that BMI, pubertal stages, oral contraceptive use, and inflammation markers need to be considered when interpreting DBP as a stabilizer and regulator of vitamin D metabolism and vitamin D status in children and adolescents.

Clinical trial registration

ClinicalTrial.gov, identifier NCT02550236.

An isotope dilution-liquid chromatography-tandem mass spectrometry-based candidate reference measurement procedure for the quantification of cortisol in human serum and plasma

OBJECTIVES

Accurate measurement of serum cortisol is crucial for the diagnosis and management of adrenal disorders. Thus, we have developed a novel isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC MS/MS)-based candidate reference measurement procedure (RMP) to quantify cortisol in human serum/plasma, offering higher sensitivity and reliability compared to existing RMPs.

METHODS

Quantitative Nuclear Magnetic Resonance spectroscopic (qNMR) methodology has been utilized to assign the absolute content (g/g) and SI-traceability to the reference materials. A novel two-dimensional heart-cut liquid chromatography (LC) approach was implemented for the LC-MS/MS, combined with a supported liquid extraction (SLE) sample preparation protocol. A multi-day validation experiment assessed precision and accuracy. Reproducibility was assessed by comparing procedure results between two independent laboratories, and measurement uncertainty (MU) was evaluated in compliance with current guidelines.

RESULTS

The established RMP exhibited high sensitivity, with a quantification range of 0.800-600 ng/mL (2.21-1,655 nmol/L), exceeding the ranges of existing JCTLM-listed RMPs. Intermediate precision was ≤2.6 %, and repeatability ranged from 0.9 to 1.9 % across all concentration levels. The relative mean bias ranged from -1.3 to 1.4 % for all matrices and concentration levels. Measurement uncertainties (MU) for cortisol in single measurements were ≤2.8 % regardless of the concentration level and sample type. Using the certified International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference panel, the equivalence between the candidate RMP and the Joint Committee on Traceability in Laboratory Medicine (JCTLM) listed RMPs (NRMeth 57 and NRMeth 8) was assessed, revealing excellent agreement.

CONCLUSIONS

This RMP allows for highly sensitive and reproducible determination of cortisol. The performance of the RMP facilitates the standardization of routine assays and ensures traceability in the measurement of individual patient samples.

The determination of endogenous steroids in hair and fur: A systematic review of methodologies

BACKGROUND

Endogenous steroid hormone assessment is essential for clinical practice. These hormones are typically measured in blood. More recently, measurement of steroids in hair samples has been gaining in popularity, so we have reviewed the methodologies used for this to-date.

METHODS

Ovid Medline, CINAHL, Psychinfo, and EMBASE were searched to identify manuscripts that analysed cortisol, testosterone, androstenedione, 17-hydroxyprogesterone (17OHP), dehydroepiandrosterone sulphate (DHEAS), and/or 25-hydroxyvitamin D (25(OH)D), in hair or fur. Data related to sampling and measurement procedures were extracted and analysed.

RESULTS

The systematic review included a total of 180 papers, with 82 % published in the past 8 years; 67 % were human and 33 % animal studies. Cortisol was by far the most common analyte. Incomplete reporting on sample harvest, preparation, and measurement procedures was common. Typically, samples were collected from posterior vertex of humans or back/neck of animals, weighing between 11 and 50 mg (with a range of 1.25-1000 mg). Samples were usually stored at room temperature, often using aluminium foil. Isopropanol was the most common cleaning solution. Hair was normally powdered or segmented prior to extraction. Extraction was typically carried out over 18-24 hours using methanol. Validation and precision information was provided in 47 % of studies.

CONCLUSIONS

This systematic review highlights the lack of standardisation in the analysis of endogenous steroids in hair. Reporting was typically incomplete, and assay validations were partial or absent. Together, these limit the value of these exciting new methods and hold back transition to clinical use.

Cortisol quantification in human plasma and urine by liquid chromatography coupled to mass spectrometry: Validation, analysis and application in a reference population and patients with adrenal incidentalomas

Cortisol is a glucocorticoid hormone, which is involved in cardiovascular, metabolic, inflammatory and behavioral processes in the human body. Immunoassays, used for routine analysis of analytes, usually lead to erroneous quantification due to the low specificity of these methods. In this study, we developed LC-MS/MS methods with surrogating matrices for evaluating cortisol in both urine and plasma samples and validated them according to Brazilian Health Regulatory Agency guidelines. Urine samples were prepared with an enzymatic hydrolysis stage, followed by a solid-phase extraction (C18 cartridges) using dichloromethane:methanol 9:1 as elution solvent. Plasma samples were prepared by protein precipitation with acetonitrile, using 50 μL of sample. HPLC was performed using a C8 column under 300 mL min-1 flow gradient conditions with water and methanol, both containing 5 mM ammonium formate and 0.1 % formic acid. Mass spectrometer with electrospray ionization in positive mode and selected reaction monitoring as detection technique were employed. Calibration curves were linear over a concentration range of 1-200 ng mL-1 for urine (r2 = 0.9950) and 0.5-300 ng mL-1 for plasma (r2 = 0.9970). The methods were selective, showed suitable precision, accuracy, and sensibility (limit of quantification = 0.85 ng mL-1 for urine and 0.15 ng mL-1 for plasma). Validated methods were successful applied to 22 real samples and a cohort of patients [n = 63 urines and n = 79 plasmas (from the Clementino Fraga Filho University Hospital, Rio de Janeiro, Brazil)].

Age- and sex-specific differences in myocardial sympathetic tone and left ventricular remodeling following myocardial injury

BACKGROUND

Presentations and outcomes of acute myocardial infarction (MI) differ between women and men, with the worst outcomes being reported in younger women. Mental stress induced ischemia and sympathetic activation have been suggested to play a prominent role in the pathogenesis of MI in younger women, however, the impact of sex hormones on these parameters remains unknown.

METHODS

The effect of sex hormones and age on myocardial infarct size and myocardial sympathetic activity (MSA) was assessed in male and female, as well as young (4-6 months) and aged (20-22 months) FVB/N mice (n = 106, 60 gonadectomized and 46 sham-operated animals) who underwent in vivo [11C]meta-hydroxyephedrine ([11C]mHED) positron emission tomography (PET) and cardiac magnetic resonance (CMR) imaging 24 h after a 30 min myocardial ischemic injury.

RESULTS

MSA and catecholamine levels following myocardial injury were highest in young males (p = 0.008 and p = 0.043 vs. young females, respectively) and were reduced by orchiectomy. Accordingly, testosterone serum levels correlated positively with MSA (r = 0.66, p < 0.001). Males had a larger average infarct size and lower left ventricular contractility following myocardial injury than females (p < 0.05 vs. females). These sex differences were no longer evident in gonadectomized animals (p = NS vs. females). In female animals, estrogen depletion did not affect MSA (ovariectomy effect, p = 0.892). Female animals showed an age-dependent increase in MSA (p = 0.011), which was absent in males.

CONCLUSION

Testosterone associates with an increase in sympathetic tone, contributing to adverse cardiac remodeling following MI. Conversely, females maintain sympathetic integrity, independent of sex hormones. Our results suggest a biological advantage of female sex in post MI recovery. Further research is warranted to confirm these findings in humans.

Development of an automated immunologic mass spectrometry (iMS) method to overcome matrix effect for quantification: Steroid hormones as the example

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) shows great promise in clinical application for its high specificity, high sensitivity and wide linear range for the determination of small molecules. However, its application in clinical laboratory is hampered by matrix effect of clinical samples which could greatly affect quantification accuracy and the difficulty to be automated for the traditional sample preparation procedures. Thus, new techniques which could achieve selective enrichment to minimize matrix effect and automatic sample preparation of mass spectrometry are needed. We developed an immunologic mass spectrometry (iMS) method to overcome matrix effect and its clinical application was demonstrated for automatic analysis of testosterone (T), progesterone (P) and estradiol (E2) in human serum simultaneously. Firstly, three monoclonal antibodies were coupled to magnetic beads for selective enrichment of target hormones from serum. The immunomagnetic beads were separated, washed and eluted automatically for LC-MS/MS analysis. Analytical performance of the iMS method was validated and compared with traditional LC-MS/MS and chemiluminescence immunoassay (CLIA). Hormone levels were measured for 160 pregnancy women at different gestational weeks. Results showed that target hormones could be selectively captured with absolute recoveries of 93.9%-110.8 %. Relative responses for high, medium and low concentrations of the hormones between serum and methanol solution were 98.0%-109.7 %, 92.2%-105.3 % and 91.7%-96.0 % for T, P and E2, respectively. Calibration curves prepared in methanol solution, BSA solution and blank serum showed good consistency for the iMS method. The automated iMS method could overcome matrix effect of LC-MS/MS and cross-reaction of CLIA. Matrix effect of the iMS method was negligible as high specificity of target hormone enrichment before LC-MS/MS analysis. Matrix-matched calibration standards were no longer necessary for accurate quantification, which was of great benefit for the clinical application of mass spetrometry.

Glucocorticoids and mineralocorticoids in hair: facilitating accurate diagnosis of adrenal-related endocrine disorders

Background

Glucocorticoids and androgens in the hair follicle have been of interest for many years, particularly cortisol and cortisone in retrospective studies associated with chronic stress and Cushing's syndrome. No studies have reported aldosterone or 18-hydroxycorticosterone in the adrenal mineralocorticoid panel in the hair follicle. This study aimed to identify potential biomarkers in endocrine conditions associated with steroid excess or deficiency using a novel extraction protocol in the analysis of mineralocorticoids and glucocorticoids in the hair follicle.

Methods and findings

Hair was collected from 15 healthy male and female volunteers. Segments that were cut along the length of long, medium, and short hair and segments shaved on the scalp and the cheek were prepared for analysis. Hair samples were extracted using an automated accelerated solvent extraction (ASE) system. Steroids were analyzed using high-throughput ultra-performance convergence chromatography-tandem mass spectrometry. All mineralocorticoids and glucocorticoids were detected above the lower limit of quantification and none of the steroids differed statistically comparing male and female concentrations. Deoxycortisol, deoxycorticosterone, and aldosterone were detected for the first time in men. In both genders, 18-hydroxycortisosterone was detected for the first time. The median concentrations for women and men, respectively, were as follows: deoxycortisol, 14.2 and 19.2 pg/mg; cortisol, 34.7 and 33.9 pg/mg; cortisone, 22.4 and 22.0 pg/mg; deoxycorticosterone, 83.0 and 50.2 pg/mg; corticosterone, 10.9 and 11.5 pg/mg; 18-hydroxycorticosterone, 24.8 and 24.8 pg/mg; and aldosterone, 23.4 and 22.7 pg/mg. Deoxycortisol and deoxycorticosterone showed marked fluctuation along the hair follicle in both genders and showed inter-individual variance. Conversely, cortisol, cortisone, corticosterone, 18-hydroxycortisosterone, and aldosterone did not fluctuate, with no inter-individual variance. Cortisol was 1.5-fold higher than cortisone in accordance with the circulatory cortisol/cortisone relationship.

Conclusions

The novel extraction method optimized steroid measurement, showing the consistency of measurement for glucocorticoids, cortisol and cortisone, and mineralocorticoids, corticosterone, 18-hydroxycorticosterone, and aldosterone. Data suggest these steroids in the hair follicle to be ideal biomarkers in improving diagnostic testing, investigating conditions of steroid excess or deficiency in hypoaldosteronism, primary hyperaldosteronism, Cushing's syndrome, and the congenital adrenal hyperplasia subtypes.

A validated HPLC-MS/MS method for the simultaneous determination of ecdysteroid hormones in subminimal amounts of biological material

Ecdysteroids represent a large class of polyhydroxylated steroids which, due to their anabolic properties, are marketed as dietary supplements. Some ecdysteroids also act as important hormones in arthropods, where they regulate molting, development, and reproduction and many of these insects are miniature organisms that contain submicroliter levels of circulating biofluids. Analysis of ecdysteroids is further complicated by their very low abundance, large fluctuations during development, and difficult access to a pooled sample, which is important for quantitative measurements. In this work, we propose a new method that overcomes the described difficulties and allows validated quantification of four ecdysteroids in minimal amounts of biological material. After methanolic extraction, detectability of the ecdysteroids is increased 16- to 20-fold by conversion to their 14,15-anhydrooximes. These are further purified by pipette tip solid-phase extraction on a three-layer sorbent and subjected to HPLC-MS/MS analysis. Full validation was achieved using hemolymph from larvae of the firebug Pyrrhocoris apterus as a blank matrix and by the determination of ecdysteroids in a single Drosophila larva. The lower limit of quantifications for the four target ecdysteroids (20-hydroxyecdysone, ecdysone, makisterone A, and 2-deoxyecdysone) were 0.01; 0.1; 0.05; and 0.025 pg·ml-1 (20; 200; 100; 50 fmol ml-1), respectively, with very good accuracy, precision (expressed as relative standard deviation <15%) and recoveries (96%-119.9%). The application potential of the new method was demonstrated by quantification of ecdysteroids in various biological materials including human serum.

Polypyrrole as Adsorbent in Magnetic Solid Phase Extraction for Progesterone Determination from Human Plasma

A straightforward and effective chromatographic method has been created for the analysis of progesterone from human plasma using a composite based on polypyrrole/magnetic nanoparticles in the sample preparation procedure. The quantification of progesterone is necessary due to its importance in human development and fertility. The employed conditions used acetonitrile:ultrapure water (70:30, v/v) as the mobile phase at 1.0 mL min-1 and an octadecyl silane column (Phenomenex Gemini, 250 mm × 4.6 mm, 5 μm) at a wavelength of 235 nm. The composite and its precursors were synthesized and properly characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy/energy dispersive spectroscopy, thermogravimetric analysis, and point of zero charge. The main factors affecting the extraction recovery of progesterone from pool human plasma samples employing magnetic solid phase extraction have been studied, such as sample pH (without adjustment), sample volume (1000 μL), washing solvent (ultrapure water), eluent (acetonitrile), eluent volume (1000 μL), and amount of adsorbent (10 mg). The extraction recoveries ranged from 98% to 102%, and linearity ranged from 5 to 3000 ng mL-1. The correlation coefficient (r) was ≥0.99, and acceptable relative standard deviation (precision), relative error (accuracy), and p-values (robustness) were observed. Lastly, the plasma samples from pregnant women were successfully analyzed by the validated method.

Bilirubin Levels in Infancy and Their Associations with Body Weight, Levels of Iron-Related Parameters and Steroid Hormone Levels

It is assumed that bilirubin is hormonally regulated and influences weight development by preventing weight gain. However, studies in healthy infants are limited. The present study established reference values for bilirubin and investigated whether bilirubin levels are significantly associated with body weight, levels of ferritin and transferrin as well as steroid hormone levels in a study population of three- and six-month-old healthy infants. Data from a total of 411 study visits from the LIFE Child study (Leipzig, Germany) were analyzed. Associations were examined using linear regression analyses. Besides laboratory parameters, anthropometric data were gathered. We found statistically significant associations between body weight and bilirubin levels. In girls, we observed additional associations between bilirubin levels and both ferritin and transferrin concentrations at three months of age. At six months, steroid hormone levels were significantly associated with concentrations of total and indirect bilirubin, with effects differing by sex. Our study thus confirms associations already reported from animal studies and studies in adult populations. Furthermore, we showed that these associations already exist in the first year of life, are influenced by sex and age and, further, depend on the bilirubin type. Our results provide reference values for bilirubin and assist, therefore, in interpreting bilirubin levels in infancy.

Detection of 13 emerging soil pollutant compounds using a dual extraction method (QuEChERS and solid phase extraction) and a liquid chromatography/mass spectrometry LC-MS/MS method

Emerging pollutants derived from human and animal sources, are present in soils and pose significant environmental and health impacts, even at low concentrations. Their detection in soil is analytically complex due to soil interference and the rapid degradation of compounds in the matrix. In this study, a protocol was optimized for quantifying hormonal steroids (n = 7), human drugs (n = 3), and antibiotics (n = 3) by a dual-phase extraction using QuEChERS and Solid Phase Extraction (SPE), followed by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The double extraction phase allows an accurate and effective purification of the target compounds while eliminating the interference in the soil matrix. The method is optimized to detect environmental concentrations of these pollutants, to suit large-scale sampling campaigns and to maintain the efficiency of extraction while reducing analysis time. The limits of detection (LODs) of these compounds ranged between 0.0043 and 0.13 ng/g and recovery rates between 75.9 % and 105.39 %.•Enhanced Analyte Purification: Implements QuEChERS and SPE for robust removal of matrix interferences, optimizing target compound isolation.•Precision at Trace Levels: Secures LODs as minimal as 0.0043 ng/g, enabling accurate detection of low-concentration contaminants.•Adapted for Broad-scale sampling: Modifies extraction and analysis durations to accommodate large-scale environmental assessments.

Evaluation of five multisteroid LC‒MS/MS methods used for routine clinical analysis: comparable performance was obtained for nine analytes

OBJECTIVES

A mass spectrometry (LC‒MS/MS)-based interlaboratory comparison study was performed for nine steroid analytes with five participating laboratories. The sample set contained 40 pooled samples of human serum generated from preanalyzed leftovers. To obtain a well-balanced distribution across reference intervals of each steroid, the leftovers first underwent a targeted mixing step.

METHODS

All participants measured a sample set once using their own multianalyte protocols and calibrators. Four participants used in-house developed measurement platforms, including IVD-CE certified calibrators, which were used by three participants; the 5th lab used the whole LC‒MS kit from an IVD manufacturer. All labs reported results for 17-hydroxyprogesterone, androstenedione, cortisol, and testosterone, and four labs reported results for 11-deoxycortisol, corticosterone, cortisone, dehydroepiandrosterone sulfate (DHEAS), and progesterone.

RESULTS

Good or acceptable overall comparability was found in Bland‒Altman and Passing‒Bablok analyses. Mean bias against the overall mean remained less than ±10 % except for DHEAS, androstenedione, and progesterone at one site and for cortisol and corticosterone at two sites (max. -18.9 % for androstenedione). The main analytical problems unraveled by this study included a bias not previously identified in proficiency testing, operator errors, non-supported matrix types and higher inaccuracy and imprecision at lower ends of measuring intervals.

CONCLUSIONS

This study shows that intermethod comparison is essential for monitoring the validity of an assay and should serve as an example of how external quality assessment could work in addition to organized proficiency testing schemes.

Unveiling the presence of endocrine disrupting chemicals in northern French soils: Land cover variability and implications

Endocrine disrupting chemicals (EDCs) are chemicals that can be found in the environment and have adverse effects on human health by mimicking, perturbing and blocking the function of hormones. They are commonly studied in water surfaces, rarely in soils, although it can be an important source of their presence in the environment. Their detection in soils is analytically challenging to quantify, hence the lack of known background concentrations found in the literature. This scientific research aimed to detect EDCs in soils by analyzing 240 soil samples using an optimized protocol of double extraction and analysis using liquid chromatography coupled to mass spectrometry. The optimized protocol allowed for very sensitive detection of the targeted compounds. The results showed a high concentration of 29.391 ng/g of 17β-estradiol in soils and 47.16 ng/g for 17α-ethinylestradiol. Testosterone and Progesterone were detected at a highest of 1.02 and 6.58 ng/g, respectively. The ∑EDCs which included estrogens, progesterone, testosterone and Bisphenol A was found at an average of 22.72 ± 35.46 ng/g in the study area. The results of this campaign showed a heterogeneous geographic distribution of the EDCs compounds in the different zones of study. Additionally, the study conducted a comparison of the concentration of EDCs in different land covers including urban areas, agricultural lands, grasslands and forests. We observed a significant difference between forests and other land covers (p < 0.0001) for 17α-ethinylestradiol, estriol, and progesterone. This presence of EDCs in forest lands is not yet understood and requires further studies concerning its origins, its fate and its effect on human health. This study is the first large-scale sampling campaign targeting EDCs in soils in Europe and the second in the world. It is also the first to assess the concentrations of these compounds based on different land covers.

The mitochondrial protease PARL is required for spermatogenesis

Mitochondrial function plays an important role in the maintenance of male fertility. However, the mechanisms underlying mitochondrial defect-related infertility remain mostly unclear. Here we show that a deficiency of PARL (Parl-/-), a mitochondrial protease, causes complete arrest of spermatogenesis during meiosis I. PARL deficiency led to severe downregulation of proteins of respiratory chain complex IV in testes that did not occur in other tested organs, causing a deficit in complex IV activity and ATP production. Furthermore, Parl-/- testes showed an almost complete loss of HSD17B3, a protein of the sER responsible for the last step in testosterone synthesis. While testosterone production appeared to be restored by overexpression of HSD17B12, loss of the canonical testosterone synthesis led to an upregulation of luteinizing hormone (LH) and of LH-regulated responses. These results suggest an important impact of the downstream regulation of mitochondrial defects that manifest in a cell-type-specific manner and extend beyond mitochondria.

Bone turnover in lactating and nonlactating women

PURPOSE

During lactation, bone turnover increases, reflecting the mobilization of Calcium from maternal skeletal stores and resulting in bone loss. However, mechanisms are not yet fully understood, and previous studies have been comparatively small. We aim to assess bone metabolism during lactation by comparing bone-metabolism-related-parameters between large cohorts of lactating and nonlactating women.

METHODS

In a retrospective cohort study, we recruited 779 postpartum women and 742 healthy, nonpregnant, nonlactating controls. Postpartum women were examined 3 and 6 months after delivery and retrospectively assigned to either the exclusively breastfeeding (exc-bf) group if they had exclusively breastfed or the nonexclusively breastfeeding (nonexc-bf) group if they had not exclusively breastfed up to the respective visit. Serum levels of PTH, Estradiol, total Calcium, Phosphate, and bone turnover markers (ßCTX, P1NP, Osteocalcin) were compared between the groups.

RESULTS

Bone turnover markers were significantly increased in exc-bf and nonexc-bf women compared with the controls (all ps < .001). ßCTX was approximately twice as high in exc-bf women than in the controls. PTH levels were marginally higher in exc-bf (p < .001) and nonexc-bf women (p = .003) compared with the controls (6 months). Estradiol was suppressed in exc-bf women compared with the controls (p < .001, 3 months).

CONCLUSION

Exc-bf and even nonexc-bf states are characterized by an increase in bone formation and resorption markers. The PTH data distribution of exc-bf, nonexc-bf, and control groups in the underpart of the reference range suggest that lactational bone loss is relatively independent of PTH.

Long-term green-Mediterranean diet may favor fasting morning cortisol stress hormone; the DIRECT-PLUS clinical trial

Background

Fasting morning cortisol (FMC) stress hormone levels, are suggested to reflect increased cardiometabolic risk. Acute response to weight loss diet could elevate FMC. Richer Polyphenols and lower carbohydrates diets could favor FMC levels. We aimed to explore the effect of long-term high polyphenol Mediterranean diet (green-MED) on FMC and its relation to metabolic health.

Methods

We randomized 294 participants into one of three dietary interventions for 18-months: healthy dietary guidelines (HDG), Mediterranean (MED) diet, and Green-MED diet. Both MED diets were similarly hypocaloric and lower in carbohydrates and included walnuts (28 g/day). The high-polyphenols/low-meat Green-MED group further included green tea (3-4 cups/day) and a Wolffia-globosa Mankai plant 1-cup green shakeFMC was obtained between 07:00-07:30AM at baseline, six, and eighteen-months.

Results

Participants (age=51.1years, 88% men) had a mean BMI of 31.3kg/m2, FMC=304.07nmol\L, and glycated-hemoglobin-A1c (HbA1c)=5.5%; 11% had type 2 diabetes and 38% were prediabetes. Baseline FMC was higher among men (308.6 ± 90.05nmol\L) than women (269.6± 83.9nmol\L;p=0.02). Higher baseline FMC was directly associated with age, dysglycemia, MRI-assessed visceral adiposity, fasting plasma glucose (FPG), high-sensitivity C-reactive-protein (hsCRP), testosterone, Progesterone and TSH levels (p ≤ 0.05 for all). The 18-month retention was 89%. After 6 months, there were no significant changes in FMC among all intervention groups. However, after 18-months, both MED groups significantly reduced FMC (MED=-1.6%[-21.45 nmol/L]; Green-MED=-1.8%[-26.67 nmol/L]; p<0.05 vs. baseline), as opposed to HDG dieters (+4%[-12 nmol/L], p=0.28 vs. baseline), whereas Green-MED diet FMC change was significant as compared to HDG diet group (p=0.048 multivariable models). Overall, 18-month decrease in FMC levels was associated with favorable changes in FPG, HbA1c, hsCRP, TSH, testosterone and MRI-assessed hepatosteatosis, and with unfavorable changes of HDLc (p<0.05 for all, weight loss adjusted, multivariable models).

Conclusion

Long-term adherence to MED diets, and mainly green-MED/high polyphenols diet, may lower FMC, stress hormone, levels,. Lifestyle-induced FMC decrease may have potential benefits related to cardiometabolic health, irrespective of weight loss.

Clinical trial registration

ClinicalTrials.gov, identifier NCT03020186.

An isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS)-based candidate reference measurement procedure (RMP) for the quantification of aldosterone in human serum and plasma

OBJECTIVES

An isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC MS/MS)-based candidate reference measurement procedure (RMP) for aldosterone quantification in human serum and plasma is presented.

METHODS

The material used in this RMP was characterized by quantitative nuclear magnetic resonance (qNMR) to assure traceability to SI Units. For liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis a two-dimensional heart cut LC approach, in combination with an optimal supported liquid extraction protocol, was established for the accurate analysis of aldosterone in human serum and plasma in order to minimize matrix effects and avoid the co-elution of interferences. Assay validation was performed according to current guidelines. Selectivity and specificity were assessed using spiked serum; potential matrix effects were examined by a post column infusion experiment and the comparison of standard line slopes. An extensive protocol over 5 days was applied to determine precision, accuracy and trueness. Measurement uncertainty was evaluated according to the Guide to the Expression of Uncertainty in Measurement (GUM), for which three individual sample preparations were performed on at least two different days.

RESULTS

The RMP allowed aldosterone quantification within the range of 20-1,200 pg/mL without interference from structurally-related compounds and no evidence of matrix effects. Intermediate precision was ≤4.7% and repeatability was 2.8-3.7% for all analyte concentrations. The bias ranged between -2.2 and 0.5% for all levels and matrices. Total measurement uncertainties for target value assignment (n=6) were found to be ≤2.3%; expanded uncertainties were ≤4.6% (k=2) for all levels.

CONCLUSIONS

The RMP showed high analytical performance for aldosterone quantification in human serum and plasma. The traceability to SI units was established by qNMR content determination of aldosterone, which was utilized for direct calibration of the RMP. Thus, this candidate RMP is suitable for routine assay standardization and evaluation of clinical samples.

Effect of cosmetic hair treatment and natural hair colour on hair testosterone concentrations

PURPOSE

Testosterone analysis in hair allows for retrospective evaluation of endogenous testosterone concentrations, but studies devoted to investigating confounders in hair testosterone analysis have hitherto been scarce. The current study examined the stability of testosterone concentrations between two hair samples collected three months apart and investigated two potential confounding factors: natural hair colour and cosmetic hair treatments.

METHODS

Testosterone was analysed with an in-house radioimmunoassay with a limit of detection adequate for the purpose.

RESULTS

The testosterone concentrations from the two samplings, at baseline and three months later, had an intra-individual correlation of moderate strength (rho = 0.378, p<0.001, n = 146). Hair treatment, such as colouring or bleaching, seemed to increase testosterone concentrations (p = 0.051, n = 191, and in a paired analysis in a subset of the cohort p = 0.005, n = 24), while no effect of natural colour in untreated hair (p = 0.133) could be detected.

CONCLUSION

The current results suggest that cosmetic hair treatments need to be considered in hair testosterone analyses and demonstrate the utility of a radioimmunoassay to reliably measure testosterone concentrations in small hair samples in women.

Segmental hair analysis as a retrospective testosterone diary: possibilities and pitfalls

Testosterone is thought to be incorporated in growing hair strands so that specific hair segments reflect average free hormone concentrations from the corresponding time period. However, the exact mechanisms of hormone integration in scalp hair have not yet been established and it is not known how testosterone is stored in the hair segments over time. The aim of this study was to investigate the stability of testosterone concentrations in hair as it grows and to determine if segmental hair analysis can be used as a retrospective testosterone diary. Thirty men and 40 women provided two hair samples and 16 saliva samples during a period of three months. Hair growth between the two samplings was measured. Hair samples were cut into 10 mm segments resulting in three segments from the first sampling and six segments from the second sampling. Hair samples were pulverised and extracted with methanol. Hair testosterone concentrations were analysed using an in-house radioimmunoassay. Salivary testosterone was analysed using a commercial enzyme-linked immunosorbent assay (Demeditec). The results demonstrated that there is a degree of segmental hormone conservation over time (rho = 0.405-0.461, p < 0.001, n = 66-67), but also highlighted three potential confounders. Firstly, testosterone concentrations were higher in distal hair segments (mean concentration ratio most distal by most scalp-near was 1.55, SD 0.70), which may be due to continuous hormone integration from sebum and changes in hair matrix composition. Secondly, more frequent hair washing stunted the increase in testosterone concentrations in distal segments (rho = -0.404, p =  < 0.001, n = 66). And lastly, intra- and inter- individual variability in hair growth rate influenced the temporal resolution along the hair, although mean growth rate was indeed 30.0 mm for three months. In a multiple regression model the biological sex, natural hair colour, and relationship status were significant explanatory variables to hair testosterone concentrations. The current results indicate that repeated hair sampling near the hair roots during a study may be preferable to analysing concentration changes between proximal and distal segments within the same hair sample. Also, hair testosterone analysis needs to be adjusted for sex and the natural hair colour.

Derivatized versus non-derivatized LC-MS/MS techniques for the analysis of estrogens and estrogen-like endocrine disruptors in human plasma

Bisphenols, parabens, alkylphenols and triclosan are anthropogenic substances with a phenolic group that have been introduced to the environment in recent decades. As they possess hormone-like effects, they have been termed endocrine disruptors (EDs), and can interfere with steroid pathways in organisms. To evaluate the potential impact of EDs on steroid biosynthesis and metabolism, sensitive and robust methods enabling the concurrent measurement of EDs and steroids in plasma are needed. Of crucial importance is the analysis of unconjugated EDs, which possess biological activity. The aim of the study was to develop and validate LC-MS/MS methods with and without a derivatization step for the analysis of unconjugated steroids (estrone-E1, estradiol-E2, estriol-E3, aldosterone-ALDO) and different groups of EDs (bisphenols, parabens, nonylphenol-NP and triclosan-TCS), and compare these methods on a set of 24 human plasma samples using Passing-Bablok regression analysis. Both methods were validated according to FDA and EMA guidelines. The method with dansyl chloride derivatization allowed 17 compounds to be measured: estrogens (E1, E2, E3), bisphenols (bisphenol A-BPA, BPS, BPF, BPAF, BPAP, BPZ, BPP), parabens (methylparaben-MP, ethylparaben-EP, propylparaben-PP, butylparaben-BP, benzylparaben-BenzylP), TCS and NP, with lower limits of quantification (LLOQs) between 4 and 125 pg/mL. The method without derivatization enabled 15 compounds to be analyzed: estrogens (E1, E2, E3), ALDO, bisphenols (BPA, BPS, BPF, BPAF, BPAP, BPZ), parabens (MP, EP, PP, BP, BenzylP) with LLOQs between 2 and 63 pg/mL, and NP and BPP in semiquantitative mode. Adding 6 mM ammonium fluoride post column into mobile phases in the method without derivatization achieved similar or even better LLOQs than the method with the derivatization step. The uniqueness of the methods lies in the simultaneous determination of different classes of unconjugated (bioactive) fraction of EDs together with selected steroids (estrogens + ALDO in the method without derivatization), which provides a useful tool for evaluating the relationships between EDs and steroid metabolism.

Verification of sex- and age-specific reference intervals for 13 serum steroids determined by mass spectrometry: evaluation of an indirect statistical approach

OBJECTIVES

Conventionally, reference intervals are established by direct methods, which require a well-characterized, obviously healthy study population. This elaborate approach is time consuming, costly and has rarely been applied to steroid hormones measured by mass spectrometry. In this feasibility study, we investigate whether indirect methods based on routine laboratory results can be used to verify reference intervals from external sources.

METHODS

A total of 11,259 serum samples were used to quantify 13 steroid hormones by mass spectrometry. For indirect estimation of reference intervals, we applied a "modified Hoffmann approach", and verified the results with a more sophisticated statistical method (refineR). We compared our results with those of four recent studies using direct approaches.

RESULTS

We evaluated a total of 81 sex- and age-specific reference intervals, for which at least 120 measurements were available. The overall agreement between indirectly and directly determined reference intervals was surprisingly good as nearly every fourth reference limit could be confirmed by narrow tolerance limits. Furthermore, lower reference limits could be provided for some low concentrated hormones by the indirect method. In cases of substantial deviations, our results matched the underlying data better than reference intervals from external studies.

CONCLUSIONS

Our study shows for the first time that indirect methods are a valuable tool to verify existing reference intervals for steroid hormones. A simple "modified Hoffmann approach" based on the general assumption of a normal or lognormal distribution model is sufficient for screening purposes, while the refineR algorithm may be used for a more detailed analysis.

Germ Cell Maintenance and Sustained Testosterone and Precursor Hormone Production in Human Prepubertal Testis Organ Culture with Tissues from Boys 7 Years+ under Conditions from Adult Testicular Tissue

Human prepubertal testicular tissues are rare, but organ culture conditions to develop a system for human in vitro-spermatogenesis are an essential option for fertility preservation in prepubertal boys subjected to gonadotoxic therapy. To avoid animal testing in line with the 3Rs principle, organ culture conditions initially tested on human adult testis tissue were applied to prepubertal samples (n = 3; patient ages 7, 9, and 12 years). Tissues were investigated by immunostaining and transmission electron microscopy (TEM), and the collected culture medium was profiled for steroid hormones by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Culture conditions proved suitable for prepubertal organ culture since SSCs and germ cell proliferation could be maintained until the end of the 3-week-culture. Leydig cells (LCs) were shown to be competent for steroid hormone production. Three additional testis tissues from boys of the same age were examined for the number of germ cells and undifferentiated spermatogonia (SPG). Using TEM micrographs, eight tissues from patients aged 1.5 to 13 years were examined, with respect to the sizes of mitochondria (MT) in undifferentiated SPG and compared with those from two adult testicular tissues. Mitochondrial sizes were shown to be comparable between adults and prepubertal boys from approximately 7 years of age, which suggests the transition of SSCs from normoxic to hypoxic metabolism at about or before this time period.

A novel fully-automated method to measure steroids in serum by liquid chromatography-tandem mass spectrometry

Background

Steroids play a key role in numerous physiological processes. Steroid determination is a useful tool to explore various endocrine diseases. Because of its specificity, mass spectrometry is considered to be a reference method for the determination of steroids in serum compared to radioimmunoassay. This technology could progress towards more automation for the optimal organization of clinical laboratories and ultimately for the benefit of patients.

Methods

A fully automated ultra-high-performance liquid chromatography-tandem mass spectrometry method was developed and fully validated to determine five steroids in serum. Sample preparation was based on protein precipitation with filtration followed by online solid phase extraction. Chromatographic separation was performed using a biphenyl stationary phase.

Results

The method was successfully validated according to European Medicine Agency guidelines. Coefficients of variation did not exceed, respectively, 8.4% and 8.1% for intra- and inter-assay precision. Method comparison with radioimmunoassay showed a proportional bias for all compounds, except for testosterone in men. Comparison with another LC-MS/MS method demonstrated acceptable concordance for all steroids, although a small bias was observed for androstenedione.

Conclusion

The novelty of this method is that it has been fully automated. Automation provides benefits in traceability and allows significant savings in cost and time.

Rapid volumetric brain changes after acute psychosocial stress

Stress is an important trigger for brain plasticity: Acute stress can rapidly affect brain activity and functional connectivity, and chronic or pathological stress has been associated with structural brain changes. Measures of structural magnetic resonance imaging (MRI) can be modified by short-term motor learning or visual stimulation, suggesting that they also capture rapid brain changes. Here, we investigated volumetric brain changes (together with changes in T1 relaxation rate and cerebral blood flow) after acute stress in humans as well as their relation to psychophysiological stress measures. Sixty-seven healthy men (25.8±2.7 years) completed a standardized psychosocial laboratory stressor (Trier Social Stress Test) or a control version while blood, saliva, heart rate, and psychometrics were sampled. Structural MRI (T1 mapping / MP2RAGE sequence) at 3T was acquired 45 min before and 90 min after intervention onset. Grey matter volume (GMV) changes were analysed using voxel-based morphometry. Associations with endocrine, autonomic, and subjective stress measures were tested with linear models. We found significant group-by-time interactions in several brain clusters including anterior/mid-cingulate cortices and bilateral insula: GMV was increased in the stress group relative to the control group, in which several clusters showed a GMV decrease. We found a significant group-by-time interaction for cerebral blood flow, and a main effect of time for T1 values (longitudinal relaxation time). In addition, GMV changes were significantly associated with state anxiety and heart rate variability changes. Such rapid GMV changes assessed with VBM may be induced by local tissue adaptations to changes in energy demand following neural activity. Our findings suggest that endogenous brain changes are counteracted by acute psychosocial stress, which emphasizes the importance of considering homeodynamic processes and generally highlights the influence of stress on the brain.

Inclusion of 11-Oxygenated Androgens in a Clinical Routine LC-MS/MS Setup for Steroid Hormone Profiling

11-Oxygenated androgens (11-OAs) are being discussed as potential biomarkers in diagnosis and therapy control of disorders with androgen excess such as congenital adrenal hyperplasia and polycystic ovary syndrome. However, quantification of 11-OAs by liquid chromatography-tandem mass spectrometry (LC-MS/MS) still relies on extensive sample preparation including liquid-liquid extraction, derivatization and partial long runtimes, which is unsuitable for high-throughput analysis under routine laboratory settings. For the first time, an established online-solid-phase extraction-LC-MS/MS (online-SPE-LC-MS/MS) method for the quantitation of seven serum steroids in daily routine use was extended and validated to include 11-ketoandrostenedione, 11-ketotestosterone, 11β-hydroxyandrostenedione and 11β-hydroxytestosterone. Combining a simple protein precipitation step with fast chromatographic separation and ammonium fluoride-modified ionization resulted in a high-throughput method (6.6 min run time) featuring lower limits of quantification well below endogenous ranges (63-320 pmol/L) with recoveries between 85% and 117% (CVs ≤ 15%). Furthermore, the ability of this method to distinguish between adrenal and gonadal androgens was shown by comparing 11-OAs in patients with hyperandrogenemia to healthy controls. Due to the single shot multiplex design of the method, potential clinically relevant ratios of 11-OAs and corresponding androgens were readily available. The fully validated method covering endogenous concentration levels is ready to investigate the diagnostic values of 11-OAs in prospective studies and clinical applications.

Establishing and Verifying a Robust Liquid Chromatography–Tandem Mass Spectrometry Method to Simultaneously Measure Seven Androgens Present in Plasma Samples

Objectives: To develop a robust liquid chromatography–tandem mass spectrometry (LC–MS/MS) method to simultaneously measure seven human plasma androgens, namely testosterone (T), dihydrotestosterone (DHT), androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), 11-ketotestosterone (11-KetoT), and 11β-hydroxytestosterone (11β-OHT). Design and Methods: Plasma was extracted via a solid phase extraction method, and the analytical performance of the assay was validated according to the Clinical & Laboratory Standards Institute guidelines. Overall, 73 apparently healthy volunteers were recruited to evaluate the distribution of these seven androgens; their levels in 25 females with acne and 33 obese females were also evaluated. Results: The developed method exhibited a good precision, with the total coefficient variations (CV) and the intra-assay CVs being within 10%. Furthermore, the recoveries of T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11β-OHT were 90.3–105.8, 88.7–98.1, 92.4–102.5, 90.5–106.7, 87.6–99.9, 93.3–105.3, and 90.2–104.4%, respectively, and no significant matrix effect was observed after internal standard correction (<20%). Moreover, the limits of quantification were 0.01, 0.01, 0.01, 0.10, 5.00, 0.02, and 0.02 ng/mL for T, DHT, A4, DHEA, DHEAS, 11-KetoT, and 11β-OHT, respectively, which are adequate for their accurate measurement in human plasma samples. It was also determined that patients diagnosed with acne had significantly higher levels of DHT, A4, and DHEAS, while those suffering from obesity had significantly higher levels of T and A4 but lower levels of DHT. Conclusions: A robust LC-MS/MS method for the simultaneous determination of seven androgens in plasma samples was successfully established and validated, which plays important roles in clinical application.

Sex steroid hormones and risk of breast cancer: a two-sample Mendelian randomization study

BACKGROUND

Breast cancer (BC) has the highest cancer incidence and mortality in women worldwide. Observational epidemiological studies suggest a positive association between testosterone, estradiol, dehydroepiandrosterone sulphate (DHEAS) and other sex steroid hormones with postmenopausal BC. We used a two-sample Mendelian randomization analysis to investigate this association.

METHODS

Genetic instruments for nine sex steroid hormones and sex hormone-binding globulin (SHBG) were obtained from genome-wide association studies (GWAS) of UK Biobank (total testosterone (TT) N: 230,454, bioavailable testosterone (BT) N: 188,507 and SHBG N: 189,473), The United Kingdom Household Longitudinal Study (DHEAS N: 9722), the LIFE-Adult and LIFE-Heart cohorts (estradiol N: 2607, androstenedione N: 711, aldosterone N: 685, progesterone N: 1259 and 17-hydroxyprogesterone N: 711) and the CORtisol NETwork (CORNET) consortium (cortisol N: 25,314). Outcome GWAS summary statistics were obtained from the Breast Cancer Association Consortium (BCAC) for overall BC risk (N: 122,977 cases and 105,974 controls) and subtype-specific analyses.

RESULTS

We found that a standard deviation (SD) increase in TT, BT and estradiol increased the risk of overall BC (OR 1.14, 95% CI 1.09-1.21, OR 1.19, 95% CI 1.07-1.33 and OR 1.03, 95% CI 1.01-1.06, respectively) and ER + BC (OR 1.19, 95% CI 1.12-1.27, OR 1.25, 95% CI 1.11-1.40 and OR 1.06, 95% CI 1.03-1.09, respectively). An SD increase in DHEAS also increased ER + BC risk (OR 1.09, 95% CI 1.03-1.16). Subtype-specific analyses showed similar associations with ER+ expressing subtypes: luminal A-like BC, luminal B-like BC and luminal B/HER2-negative-like BC.

CONCLUSIONS

TT, BT, DHEAS and estradiol increase the risk of ER+ type BCs similar to observational studies. Understanding the role of sex steroid hormones in BC risk, particularly subtype-specific risks, highlights the potential importance of attempts to modify and/or monitor hormone levels in order to prevent BC.

Multi-steroid profiling by UHPLC-MS/MS with post-column infusion of ammonium fluoride

BACKGROUND

Multi-steroid profiling is a powerful analytical tool that simultaneously quantifies steroids from different biosynthetic pathways. Here we present an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) assay for the profiling of 23 steroids using post-column infusion of ammonium fluoride.

METHODS

Following liquid-liquid extraction, steroids were chromatographically separated over 5 min using a Phenomenex Luna Omega C₁₈ column and a water (0.1 % formic acid) methanol gradient. Quantification was performed on a Waters Acquity UHPLC and Xevo® TQ-XS mass spectrometer. Ammonium fluoride (6 mmol/L, post-column infusion) and formic acid (0.1 % (vol/vol), mobile phase additive) were compared as additives to aid ionisation.

RESULTS

Post-column infusion of ammonium fluoride enhanced ionisation in a steroid structure-dependent fashion compared to formic acid (122-140 % for 3βOH-Δ5 steroids and 477-1274 % for 3-keto-Δ4 steroids). Therefore, we analytically validated post-column infusion of ammonium fluoride. Lower limits of quantification ranged from 0.3 to 3 nmol/L; All analytes were quantifiable with acceptable accuracy (bias range -14 % to 11.9 % for 21/23, -21 % to 11.9 % for all analytes). Average recovery ranged from 91.6 % to 113.6 % and average matrix effects from -29.9 % to 19.9 %. Imprecision ranged from 2.3 % to 23 % for all analytes and was < 15 % for 18/23 analytes. The serum multi-steroid profile of 10 healthy men and 10 healthy women was measured.

CONCLUSIONS

UHPLC-MS/MS with post-column infusion of ammonium fluoride enables comprehensive multi-steroid profiling through enhanced ionisation particularly benefiting the detection of 3-keto-Δ4 steroids.

Quantification of cortisol and its metabolites in human urine by LC-MSn: applications in clinical diagnosis and anti-doping control

The objective of the current research was to develop a liquid chromatography-MSⁿ (LC-MSⁿ) methodology for the determination of free cortisol and its 15 endogenous metabolites (6β-hydroxycortisol, 20α-dihydrocortisol, 20α-dihydrocortisone, 20-β-dihydrocortisol, 20β-dihydrocortisone, prednisolone, cortisone, α-cortolone, β-cortolone, allotetrahydrocortisol, 5α-dihydrocortisol, tetrahydrocortisol, allotetrahydrocortisone, 5β-dihydrocortisol, tetrahydrocortisone) in human urine. Due to its optimal performance, a linear ion trap operating in ESI negative ion mode was chosen for the spectrometric analysis, performing MS³ and MS⁴ experiments. The method was validated for limit of detection (LOD) and limit of quantification (LOQ) (0.01 ng mL⁻¹ and 0.05 ng mL⁻¹, for all compounds, respectively), intra- and inter-day precision (CV = 1.4–9.2% and CV = 3.6–10.4%, respectively), intra- and inter-day accuracy (95–110%), extraction recovery (65–95%), linearity (R2 > 0.995), and matrix effect that was absent for all molecules. Additionally, for each compound, the percentage of glucuronated conjugates was estimated. The method was successfully applied to the urine (2 mL) of 50 healthy subjects (25 males, 25 females). It was also successfully employed on urine samples of two patients with Cushing syndrome and one with Addison’s disease. This analytical approach could be more appropriate than commonly used determination of urinary free cortisol collected in 24-h urine. The possibility of considering the differences and relationship between cortisol and its metabolites allows analytical problems related to quantitative analysis of cortisol alone to be overcome. Furthermore, the developed method has been demonstrated as efficient for antidoping control regarding the potential abuse of corticosteroids, which could interfere with the cortisol metabolism, due to negative feedback on the hypothalamus-hypophysis-adrenal axis. Lastly, this method was found to be suitable for the follow-up of prednisolone that was particularly important considering its pseudo-endogenous origin and correlation with cortisol metabolism.

Association between hair cortisol concentration and behavioral difficulties in children and adolescents

This study aimed to assess associations between behavioral difficulties and an objectively measurable indicator for long-term stress (hair cortisol) in children and adolescents. We expected increased hair cortisol levels in participants with more externalizing (conduct problems, hyperactivity/inattention) or internalizing (peer relationship problems, emotional problems) behavioral difficulties. Behavioral difficulties were assessed using the parent version of the Strengths and Difficulties Questionnaire (SDQ). Hair cortisol concentration (HCC), measured via liquid chromatography mass spectrometry (LC-MS3), was used as stress marker. A 1 cm strand of hair was cut off from the occipital or parietal cranium closest to the scalp. The study sample comprised 1321 children and adolescents aged between 3 and 17 years participating in the LIFE Child cohort study (Leipzig, Germany). To assess associations, we applied multiple linear regression analyses. Only a few associations met expectations, others contradicted our hypotheses. No association reached statistical significance. The present findings may suggest that behavioral difficulties gathered by SDQ are not associated with stress measured through HCC.

Development of a Liquid Chromatography-Mass Spectrometry-Based In Vitro Assay to Assess Changes in Steroid Hormones Due to Exposure to Per- and Polyfluoroalkyl Substances

Per- and poly-fluorinated substances (PFASs) are organic pollutants that have been linked to numerous health effects, including diabetes, cancers, and dysregulation of the endocrine system. This study aims to develop a liquid chromatography with tandem mass spectrometry (LC-MS/MS) assay to measure changes in 17 hormones in H295R cell line (a steroid producing adrenocortical cells) upon exposure to PFASs. Due to the challenges in the analysis of steroid hormones using electrospray ionization MS, a chemical derivatization method was employed to achieve 0.07-2 μg/L detection limits in LC-MS/MS. Furthermore, a 10-fold concentration factor through solid-phase extraction (SPE) allows for consistent sub-parts per billion detections. Optimization of the derivatization conditions showed doubly-derivatized products in some hormone analytes, including progesterone, corticosterone, and cortisol, and gave improved ionization efficiency up to 20-fold higher signal than the singly-derivatized product. The use of SPE for sample cleanup to analyze hormones from cellular media using weak anion exchange sorbent yielded 80-100% recovery for the 17 targeted hormones. The method was validated by exposing H295R cells to two known endocrine disruptors, forskolin and prochloraz, which showed expected changes in hormones. An initial exposure of H295R cells with various PFAS standards and their mixtures at 1 μM showed significant increases in progestogens with some PFAS treatments, which include PFBS, PFHxA, PFOS, PFDA, and PFDS. In addition, modest changes in hormone levels were observed in cells treated with other sulfonated or carboxylated headgroup PFASs. This sensitive LC-MS/MS method for hormone analysis in H295R cells will allow for the investigations of the alterations in the hormone production caused by exposure to various environmental insults in cell-based assays and other in vitro models.

Role of sex hormones in modulating myocardial perfusion and coronary flow reserve

BACKGROUND

A growing body of evidence highlights sex differences in the diagnostic accuracy of cardiovascular imaging modalities. Nonetheless, the role of sex hormones in modulating myocardial perfusion and coronary flow reserve (CFR) is currently unclear. The aim of our study was to assess the impact of female and male sex hormones on myocardial perfusion and CFR.

METHODS

Rest and stress myocardial perfusion imaging (MPI) was conducted by small animal positron emission tomography (PET) with [18F]flurpiridaz in a total of 56 mice (7-8 months old) including gonadectomized (Gx) and sham-operated males and females, respectively. Myocardial [18F]flurpiridaz uptake (% injected dose per mL, % ID/mL) was used as a surrogate for myocardial perfusion at rest and following intravenous regadenoson injection, as previously reported. Apparent coronary flow reserve (CFRApp) was calculated as the ratio of stress and rest myocardial perfusion. Left ventricular (LV) morphology and function were assessed by cardiac magnetic resonance (CMR) imaging.

RESULTS

Orchiectomy resulted in a significant decrease of resting myocardial perfusion (Gx vs. sham, 19.4 ± 1.0 vs. 22.2 ± 0.7 % ID/mL, p = 0.034), while myocardial perfusion at stress remained unchanged (Gx vs. sham, 27.5 ± 1.2 vs. 27.3 ± 1.2 % ID/mL, p = 0.896). Accordingly, CFRApp was substantially higher in orchiectomized males (Gx vs. sham, 1.43 ± 0.04 vs. 1.23 ± 0.05, p = 0.004), and low serum testosterone levels were linked to a blunted resting myocardial perfusion (r = 0.438, p = 0.020) as well as an enhanced CFRApp (r = -0.500, p = 0.007). In contrast, oophorectomy did not affect myocardial perfusion in females. Of note, orchiectomized males showed a reduced LV mass, stroke volume, and left ventricular ejection fraction (LVEF) on CMR, while no such effects were observed in oophorectomized females.

CONCLUSION

Our experimental data in mice indicate that sex differences in myocardial perfusion are primarily driven by testosterone. Given the diagnostic importance of PET-MPI in clinical routine, further studies are warranted to determine whether testosterone levels affect the interpretation of myocardial perfusion findings in patients.

Online In-Tube Solid-Phase Microextraction Coupled with Liquid Chromatography-Tandem Mass Spectrometry for Automated Analysis of Four Sulfated Steroid Metabolites in Saliva Samples

Accurate measurement of sulfated steroid metabolite concentrations can not only enable the elucidation of the mechanisms regulating steroid metabolism, but also lead to the diagnosis of various related diseases. The present study describes a simple and sensitive method for the simultaneous determination of four sulfated steroid metabolites in saliva, pregnenolone sulfate (PREGS), dehydroepiandrosterone sulfate (DHEAS), cortisol sulfate (CRTS), and 17β-estradiol-3-sulfate (E2S), by online coupling of in-tube solid-phase microextraction (IT-SPME) and stable isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS). These compounds were extracted and concentrated on Supel-Q PLOT capillary tubes by IT-SPME and separated and detected within 6 min by LC-MS/MS using an InertSustain swift C18 column and negative ion mode multiple reaction monitoring systems. These operations were fully automated by an online program. Calibration curves using their stable isotope-labeled internal standards showed good linearity in the range of 0.01-2 ng mL^-1 for PREGS, DHEAS, and CRTS and of 0.05-10 ng mL^-1 for E2S. The limits of detection (S/N = 3) of PREGS, DHEAS, CRTS, and E2S were 0.59, 0.30, 0.80, and 3.20 pg mL^-1, respectively. Moreover, intraday and interday variations were lower than 11.1% (n = 5). The recoveries of these compounds from saliva samples were in the range of 86.6-112.9%. The developed method is highly sensitive and specific and can easily measure sulfated steroid metabolite concentrations in 50 μL saliva samples.

Metabolic Alteration Analysis of Steroid Hormones in Niemann-Pick Disease Type C Model Cell Using Liquid Chromatography/Tandem Mass Spectrometry

Niemann–Pick disease type C (NPC) is an autosomal recessive disease caused by a functional deficiency of cholesterol-transporting proteins in lysosomes, and exhibits various clinical symptoms. Since mitochondrial dysfunction in NPC has recently been reported, cholesterol catabolism to steroid hormones may consequently be impaired. In this study, we developed a comprehensive steroid hormone analysis method using liquid chromatography/tandem mass spectrometry (LC–MS/MS) and applied it to analyze changes in steroid hormone concentrations in NPC model cells. We investigated the analytical conditions for simultaneous LC–MS/MS analysis, which could be readily separated from each other and showed good reproducibility. The NPC phenotype was verified as an NPC model with mitochondrial abnormalities using filipin staining and organelle morphology observations. Steroid hormones in the cell suspension and cell culture medium were also analyzed. Steroid hormone analysis indicated that the levels of six steroid hormones were significantly decreased in the NPC model cell and culture medium compared to those in the wild-type cell and culture medium. These results indicate that some steroid hormones change during NPC pathophysiology and this change is accompanied by mitochondrial abnormalities.

Solid-phase analytical derivatization as a tool for the quantification of steroid hormones in human urine with HPLC-Q-ToF detection

A possibility of application of solid-phase analytical derivatization (SPAD) for the quantification of seven steroid hormones (testosterone, dihydrotestosterone, cortisone, cortisol, progesterone, 11α-hydroxyprogesterone, and estrone) in human urine was evaluated. To prepare urine samples for instrumental analysis, SPAD with hydroxylamine was applied after enzymatic hydrolysis of the sample. To achieve high recovery values, extraction and derivatization conditions were optimized. Cartridges packed with end-capped octadecylsilyl silica sorbent provided optimum extraction of target analytes, while the reaction with hydroxylamine in the cartridge was found as a simple and efficient way for the chemical derivatization of steroids. The obtained derivatives were detected by using reversed-phase ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry. The proposed procedure was validated and applied to the analysis of real urine samples to prove the applicability of the proposed method for the routine analysis.

Molecular Probes, Chemosensors, and Nanosensors for Optical Detection of Biorelevant Molecules and Ions in Aqueous Media and Biofluids

Synthetic molecular probes, chemosensors, and nanosensors used in combination with innovative assay protocols hold great potential for the development of robust, low-cost, and fast-responding sensors that are applicable in biofluids (urine, blood, and saliva). Particularly, the development of sensors for metabolites, neurotransmitters, drugs, and inorganic ions is highly desirable due to a lack of suitable biosensors. In addition, the monitoring and analysis of metabolic and signaling networks in cells and organisms by optical probes and chemosensors is becoming increasingly important in molecular biology and medicine. Thus, new perspectives for personalized diagnostics, theranostics, and biochemical/medical research will be unlocked when standing limitations of artificial binders and receptors are overcome. In this review, we survey synthetic sensing systems that have promising (future) application potential for the detection of small molecules, cations, and anions in aqueous media and biofluids. Special attention was given to sensing systems that provide a readily measurable optical signal through dynamic covalent chemistry, supramolecular host-guest interactions, or nanoparticles featuring plasmonic effects. This review shall also enable the reader to evaluate the current performance of molecular probes, chemosensors, and nanosensors in terms of sensitivity and selectivity with respect to practical requirement, and thereby inspiring new ideas for the development of further advanced systems.

Is subcutaneous adipose tissue expansion in people living with lipedema healthier and reflected by circulating parameters?

Lipedema may be considered a model for healthy expandability of subcutaneous adipose tissue (SAT). This condition is characterized by the disproportional and symmetrical SAT accumulation in the lower-body parts and extremities, avoiding the abdominal area. There are no circulating biomarkers facilitating the diagnosis of lipedema. We tested the hypothesis that women living with lipedema present a distinct pattern of circulating parameters compared to age- and BMI-matched women. In 26 women (Age 48.3 ± 13.9 years, BMI 32.6 ± 5.8 kg/m2; lipedema group: n=13; control group: n=13), we assessed circulating parameters of glucose and lipid metabolism, inflammation, oxidative stress, sex hormones and a proteomics panel. We find that women with lipedema have better glucose metabolism regulation represented by lower HbA1c (5.55 ± 0.62%) compared to controls (6.73 ± 0.85%; p&lt;0.001); and higher adiponectin levels (lipedema: 4.69 ± 1.99 mmol/l; control: 3.28 ± 1.00 mmol/l; p=0.038). Despite normal glycemic parameters, women with lipedema have significantly higher levels of total cholesterol (5.84 ± 0.70 mmol/L vs 4.55 ± 0.77 mmol/L in control; p&lt;0.001), LDL-C (3.38 ± 0.68 mmol/L vs 2.38 ± 0.66 mmol/L in control; p=0.002), as well as higher circulating inflammation (top 6 based on p-values: TNFSF14, CASP8, EN-RAGE, EIF4EBP1, ADA, MCP-1) and oxidative stress markers (malondialdehyde, superoxide dismutase and catalase). Our findings suggest that the expected association between activation of inflammatory and oxidative stress pathways and impaired glucose metabolism are counterbalanced by protective factors in lipedema.

A developed HPLC-MS/MS method to quantitate 5 steriod hormones in clinical human serum by using PBS as the surrogate matrix

Steroid hormones play an essential role in regulating physiological and reproductive development throughout the lifetime of an individual. One of the difficulties in determining endogenous substances is the lack of a blank matrix. Especially when the level of analytes is lower than the level in the so-called blank matrix. In the present study, an optimized HPLC-MS/MS method was developed and validated to quantify androstenedione (ASD), testosterone (Ts), dehydroepiandrosterone (DHEA), 5α-dihydrotestosterone (DHT), and progesterone (P) in serum samples from healthy people using PBS (pH = 7.4) as the blank surrogate matrix. Simultaneously, the method investigated the characteristics of NaCl, bull serum albumin, pure water as surrogate matrices for the analysis of steroid hormones. The data showed that the matrix effects of ASD, Ts, DHEA, DHT, and P in the same groups were not significantly different between PBS and twice charcoal-stripped serum (CS₂S) as a blank surrogate matrix. Furthermore, the LLOQ using PBS as the blank matrix was up to 0.005 ng/mL for ASD, Ts, and P and 0.05 ng/mL for DHEA and DHT. The reference ranges of concentration (C_PBS) of 5 steroid hormones were provided. Compared to the concentration with CS₂S (C_CSS) as the blank surrogate matrix, the relative biases (RBs) of Ts, DHT, P, and DHEA were finally stabilized at approximately -0.7%, -15%, -1.2%, and 9.2%, respectively. The results suggest that, in the cases of special required, the developed HPLC-MS/MS method can be used to determine the absolute concentration of 5 hormones in biological samples with PBS as the blank surrogate matrix.

New reference intervals for endocrinological biomarkers in pediatric patients: what can we learn from the LIFE child study?

Objectives

We established reference intervals for serum concentrations of hormones from healthy pediatric subjects and investigated their associations with gender, body mass index (BMI), puberty and oral contraceptives (oC).

Methods

We calculated reference intervals for the thyroid parameters thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), and calcitonin (Ct); the bone markers osteocalcin, procolagen type 1 N-propeptide, and carboxy-terminal cross-linking telopeptide of type 1 collagen; the calciotropic hormones 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone and the steroids cortisol, progesterone, 17-hydroxyprogesterone, androstenedione, testosterone, estradiol, dehydroepiandrosterone sulfate and aldosterone. Up to 10,002 blood serum samples from 3,229 healthy children and adolescents (age interval: 3 months to 20 years) were measured. To investigate the associations between the hormone levels with age, sex, weight status and the role of puberty-based changes, the measurement and BMI values were transformed into standard deviation scores.

Results

Most of the hormones depended on age- and gender. Puberty was linked to a, in part, temporary decrease in TSH, FT3 (for females), FT4, Ct, cortisol (for girls) and aldosterone (for boys) and peak in the bone marker and calciotropic hormones (excluding 25(OH)D) and nearly all remaining steroids. BMI had effects on the thyroid, bone, and calciotropic parameters, whereas oC led to increased cortisol, suppressed progesterone and estradiol values.

Conclusions

Age- and gender-specific reference intervals are essential for the interpretation of pediatric patients’ hormone measurements. Influencing factors as puberty, BMI, or oC should be taken into consideration for diagnosis and treatment monitoring.

Sex-Specific Causal Relations between Steroid Hormones and Obesity-A Mendelian Randomization Study

Steroid hormones act as important regulators of physiological processes including gene expression. They provide possible mechanistic explanations of observed sex-dimorphisms in obesity and coronary artery disease (CAD). Here, we aim to unravel causal relationships between steroid hormones, obesity, and CAD in a sex-specific manner. In genome-wide meta-analyses of four steroid hormone levels and one hormone ratio, we identified 17 genome-wide significant loci of which 11 were novel. Among loci, seven were female-specific, four male-specific, and one was sex-related (stronger effects in females). As one of the loci was the human leukocyte antigen (HLA) region, we analyzed HLA allele counts and found four HLA subtypes linked to 17-OH-progesterone (17-OHP), including HLA-B*14*02. Using Mendelian randomization approaches with four additional hormones as exposure, we detected causal effects of dehydroepiandrosterone sulfate (DHEA-S) and 17-OHP on body mass index (BMI) and waist-to-hip ratio (WHR). The DHEA-S effect was stronger in males. Additionally, we observed the causal effects of testosterone, estradiol, and their ratio on WHR. By mediation analysis, we found a direct sex-unspecific effect of 17-OHP on CAD while the other four hormone effects on CAD were mediated by BMI or WHR. In conclusion, we identified the sex-specific causal networks of steroid hormones, obesity-related traits, and CAD.

UPLC-TOF-MS Method for Simultaneous Quantification of Steroid Hormones in Tissue Homogenates of Zebrafish with Solid-Phase Extraction

The quantification of steroid hormones of individual zebrafish (Danio rerio) provides perspective to understand endogenous hormone function. A UPLC–TOF–MS method was developed to provide a reproducible, sensitive, and efficient assay to determine the concentration of steroid hormones, including cortisol, testosterone, androstenedione, 11-deoxycortisol, 11-deoxycorticosterone, and 17-hydroxyprogesterone in whole-body homogenates of each zebrafish. Solid-phase extraction was used to sample matrix clean-up and acquired a recovery from 89.7% to 107.9%. The analytes were separated on an Aquity BEH C18 column using gradient elution. Mass spectrometric analysis was performed by single reaction monitoring (SRM) using positive electrospray ionization mode. The total running time was 6 min, which was greatly shortened compared with a previously reported method. The developed method exhibited excellent linearity for all the analytes, with regression coefficients higher than 0.99. The limit of detection varied between 0.1 and 0.5 ng/L and the limit of quantification was 0.5–1.7 ng/L for all analytes. The precision of the method was assessed on replicate measurements and was found to be in the ranges of 1.9 % to 6.6% and 4.3% to 8.6%, for intra- and inter-day analysis, respectively. This method was validated according to FDA guidance and applied to determine steroid hormone levels in the tissue homogenate of zebrafish acutely treated with caffeine and ethanol.

Analysis of hair steroid hormone concentrations at different parts of the head by liquid chromatography-tandem mass spectrometry

BACKGROUND

Steroid hormones are known to be associated with diseases like androgenetic alopecia (AGA) resulting in hair loss. The lack of a detailed analysis of the local concentration of steroids in different parts of the head underlies the rationale and purpose of this study.

METHODS

To evaluate the concentration distributions of steroid hormones in hair in different parts of the head, hair samples of 8 healthy men from 9 point-areas covering the frontal, parietal, and occipital regions were collected. Eight steroid hormones were measured by using the LC-MS/MS and region-wise comparison for different hormones was done using the mean z-score and Tukey's HSD.

RESULTS

Five of the 8 hormones had a high concentration in the parietal region, with dihydrotestosterone (DHT) showing a peak in the central parietal region (z = 1.59) suggesting a correlation with AGA's clinical presentation. Whereas, no significant differences were observed for testosterone and cortisol between the parietal and occipital regions. Higher DHT levels at the parietal region were also verified with a small group of AGA patients.

CONCLUSIONS

This research expands upon the role of steroid hormones in hair follicle tissue elucidating their relationship with disease, thus contributing to disease management.