Measurement Of Testosterone Research Articles

Effect of Endogenous Hormone Levels on Basal Metabolic Rate in Men With Obesity.

Basal metabolic rate (BMR) is an important factor in weight management and is influenced by fat-free mass (FFM), fat mass (FM) and age. Current knowledge of the influence of hormonal levels on BMR is based on studies with small populations, studies that investigate exogenous administration and studies frequently lacking correction for body composition. Cross-sectional study. All men (n = 457) who were referred to our centre for a metabolic work-up were eligible for inclusion. Median age was 47 (18-78) years and the vast majority had obesity (BMI ≥ 30 kg/m², 90.9%). All men had a measurement of BMR, body composition and measurement of testosterone, sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS), insulin-like growth factor 1 (IGF-1), thyroid-stimulating hormone (TSH) and free thyroxine (fT4). Men with low, normal and/or high levels of each of these hormones were compared. The association between hormone levels and BMR was assessed through linear regression models. All analyses were controlled for FFM, FM and age. In men with obesity, testosterone (total or free) was not associated with BMR. Linear regression analysis showed that DHEAS was positively associated with BMR in a sample of men with obesity and normal endogenous DHEAS levels, with the following equation: BMR (adjusted R² = 0.72): (BMR [kcal/d] = 513.402 + 18.940 × FFM [kg] + 9.507 × FM [kg] - 3.362 × age [years] + 0.307 × DHEAS [µg/dL]) (p < 0.01). TSH, fT4 and IGF-1 were not associated with BMR. In men with obesity, endogenous DHEAS is positively associated with BMR. Testosterone, TSH, fT4 and IGF-1 were not associated with BMR in men with obesity. Since we examined the specific population of men with obesity and only examined endogenous hormone levels, no extrapolation of results to other populations or the overall population can be made.

Use of calculated free testosterone in men: advantages and limitations.

Due to technical requirements and high cost, equilibrium dialysis-free testosterone (T) measurements are not commonly available in clinical practice. Clinicians rely on calculated free T (cFT) as a proxy. This review discusses using free T as a second-line assessment, highlighting its relevance in preventing misdiagnosis and overtreatment of male hypogonadism. While there is consensus on measuring total T - comprising sex hormone-binding globulin (SHBG)-bound, albumin-bound, and free T - as a first step in diagnosing male hypogonadism, evidence confirms that aging and conditions like obesity influence both total T and SHBG levels. Furthermore, low free T has been associated with symptoms of androgen deficiency, even in men with normal total T. Clinicians should, however, be aware of limitations of free T calculations, particularly the lack of standardization. Recent developments include establishing age-stratified free T reference ranges measured by equilibrium dialysis. Free T remains a subject of longstanding controversy. Factors such as age and obesity can alter total T and SHBG levels. Free T serves as a second-line indicator of androgen exposure, taking SHBG fluctuations into account. Given that commonly used free T calculators only provide approximations of free T, there is a need to further standardize free T calculators.

12260 Assessing The Impact Of Saliva Collection Devices On Analyte Recovery

Abstract Disclosure: D. Marshall: None. M. Dolan: None. M. Mctaggart: None. B.G. Keevil: None. Introduction: Analysis of saliva is gathering momentum, often conveying advantages over regular venepuncture, offering a convenient way of collecting multiple samples throughout the day with relative ease from the comfort of a patient’s home or workplace. The advent of more sensitive mass spectrometry equipment has opened the possibility of measuring analytes previously unsuitable, offering a multitude of steroid hormones for diagnosis and monitoring of a range of endocrine disorders. Traditionally, samples are collected onto a Sarstedt Salivette device comprising of a synthetic swab enclosed within a polypropylene tube. For certain analytes, the Salivette device is known to impede analyte recovery, resulting in the requirement for a passive drool sample which can be difficult and unpleasant to collect for some patients. Methods Previous work has been undertaken showing the SalivaBio Oral Swab (SOS) to have less of an impact on analyte recovery. Here, through addition of low, medium and high spikes and subsequent LC-MS/MS analysis of 19 different steroid hormones (11-dehydrocorticosterone, 11-deoxycorticosterone, 11-deoxycortisol, 11-hydroxyandrostenedione, 11-hydroxytestosterone, 11-ketoandrostenedione, 11-ketotestosterone, 17-hydroxyprogesterone, 18-hydroxycortisol, 18-oxocortisol, 21-deoxycortisol, aldosterone, androstenedione, corticosterone, cortisol, cortisone, dexamethasone, testosterone and tetrahydro11-deoxycortisol) we aimed to assess a broader repertoire of analytes and whether saliva collection devices impact on analyte recovery. Results With an acceptability criterion of 10% difference from baseline passive drool samples, Salivette devices were acceptable for 12 out of 18 analytes, SOS were acceptable for 16 analytes. Both devices were unacceptable for measurement of androstenedione, testosterone and 11-deoxycorticosterone. When 10% is deemed as an acceptable difference, the SOS performs better than the Salivette device for the steroid hormones investigated in this study. This may have implications for research studies, patient diagnosis and monitoring of endocrine disorders where saliva collection devices were previously deemed unacceptable due to issues with analyte recovery. Presentation: 6/2/2024

A-078 Harmonization of Immunoassay Reference Intervals with LC-MS/MS for Total and Calculated Free Testosterone Measurement

Abstract Background Management of male hypogonadism relies on accurate serum testosterone testing and reference values. This study aimed to establish harmonized reference ranges for total and calculated free testosterone in adults using the Siemens Atellica immunoassay, validated against a reference method. Methods The Siemens Atellica IM total testosterone assay is a fully automated competitive chemiluminescent immunoassay. We conducted 25 de-identified serum samples. Inter-laboratory correlation studies for total testosterone were performed on in-house Siemens Atellica and liquid chromatography-tandem mass spectrometry (LC-MS/MS) at a reference laboratory. Free testosterone was calculated using the International Society for the Study of the Aging Male (ISSAM) Free Testosterone calculator, which can be accessed from the ISSAM website, http://www.issam.ch/freetesto.htm, using the assayed concentrations of testosterone and Sex Hormone Binding Globulin (SHBG) on the Siemens Atellica IM system. The Siemens Atellica IM SHBG assay is a sandwich monoclonal immunoassay. Calculated free testosterone was compared with LC-MS/MS. Deming and linear regression, and Bland-Altman plot were employed for data analysis. Reference intervals were adopted from the reference laboratory and verified using 20 male and 20 female healthy samples. Total testosterone: Male 240-950 ng/dL, Female 8-60 ng/dL; Free testosterone: Male 2.29-20.7 ng/dL, Female 0-1.08 ng/dL. Results Strong correlations were observed between Siemens Atellica and LC-MS/MS for total testosterone (R^2 = 0.9915, slope = 0.988, intercept = 35) and for calculated free testosterone (R^2 = 0.9645, slope = 0.988, intercept = -0.4). Adopted reference intervals were verified using local healthy samples. Conclusions Harmonized reference intervals for total and calculated free testosterone, validated on Siemens Atellica, offer consistent results comparable to LC-MS/MS. This study demonstrates the feasibility of establishing standardized reference ranges for testosterone assays across laboratories.

A-075 Comparability of Free Testosterone Measurements- Results of the Interlaboratory Study

Abstract Background Assessment of free testosterone (FT) has been recommended as a biomarker for diagnosis and management of hypogonadism and female hyperandrogenism. Reliable laboratory measurements are essential for correctly diagnosing and treating these diseases. FT is currently measured using direct commercial immunoassays, assays employing equilibrium dialysis (ED) or other separation techniques, or it is estimated by calculating free testosterone (cFT). There are concerns about the accuracy and reliability of current methods that may impact patient care. To obtain more information about variability of FT measurements used in patient care, CDC’s Clinical Standardization Programs (CDC CSP) conducted an interlaboratory comparison study. Methods CDC CSP developed an accurate, automated method using ED coupled with isotope dilution ultra-high-performance liquid chromatography tandem mass spectrometry (ED-UHPLC-MS/MS). The ED step follows an internationally recognized procedure. The method is calibrated with primary reference material (National Measurement Institute-M914) and was used to assign target values to sera used in the study. The FT concentrations ranged from 3 to 339 pg/mL. In the interlaboratory comparison study single-donor serum samples were provided to participants operating FT methods used in patient care. The participating methods included commercially available platforms utilizing Chemiluminescence Immunoassay or radioimmunoassay techniques, as well as laboratory-developed assays using ED-LC-MS/MS. Results Preliminary findings of the CSP interlaboratory comparison study found large variability among participating assays. The agreement among IA and among ED-LC-MS/MS assays was close. However, FT concentrations obtained by IAs were in average 6 times lower compared to the ED-LC-MS/MS methods. Results estimated using the Vermeulen equation overestimated FT in average by 15% compared to the ED-LC-MS/MS methods and by over 6 times compared to IAs. Conclusions Large variability is observed between FT laboratory developed tests (LDTs) and IAs. As both LDTs and IAs are used in patient care, standardization of FT measurements to assure better patient care is needed. CDC CSP is addressing the need by developing highly accurate and precise FT method and conducting an interlaboratory comparison studies that can aid with improvement of the agreement among assays and identifying potential factors causing differences among assays.

Endoplasmic Reticulum Stress in Myometrial Smooth Muscle Cells and Spontaneous Contraction Changes in the Uterus of Dehydroepiandrosterone-induced Polycystic Ovary Syndrome Rats.

Myometrial changes in polycystic ovary syndrome (PCOS) are poorly investigated. Thus, we aimed to investigate endoplasmic reticulum (ER) stress in myometrial smooth muscle cells and changes in spontaneous uterine contraction in PCOS. Twenty-one female Sprague-Dawley rats (21 days old) were divided into control (n = 7), vehicle (n = 7) and PCOS (n = 7) groups. While the control group was not injected subcutaneously, the vehicle group was injected subcutaneously with sesame oil (0.2 ml/day) for 20 consecutive days. The PCOS group was injected subcutaneously with dehydroepiandrosterone (6 mg/100 g/day dissolved in 0.2 ml sesame oil) for 20 consecutive days. Blood samples were collected for the measurement of follicle stimulating-hormone (FSH), luteinizing hormone (LH), testosterone (T), estradiol (E2) and glucose-regulated protein 78 (GRP78). The mRNA expression of GRP78 in the uterine tissue samples was analysed by quantitative real-time polymerase chain reaction. GRP78 protein expression was assessed by immunohistochemistry. Myometrial smooth muscle cells were examined by transmission electron microscopy. Uterine contractions were evaluated with isolated organ bath experiments. In the PCOS group, T and LH levels increased significantly, although FSH and E2 levels decreased, but this decrease was not statistically significant. Additionally, GRP78 levels increased significantly in the PCOS group. In the PCOS group, the mRNA level, immunostaining intensity of GRP78, and ER damage grade increased, but the uterine tissue calcium levels, and the frequency and amplitude of spontaneous uterine contractions decreased. The results indicated that increased ER stress in myometrial smooth muscle cells may play a causative role in the decreased spontaneous uterine contractions in PCOS.

The effects and safety of testosterone replacement therapy for men with hypogonadism: the TestES evidence synthesis and economic evaluation.

Low levels of testosterone cause male hypogonadism, which is associated with sexual dysfunction, tiredness and reduced muscle strength and quality of life. Testosterone replacement therapy is commonly used for ameliorating symptoms of male hypogonadism, but there is uncertainty about the magnitude of its effects and its cardiovascular and cerebrovascular safety. The primary aim was to evaluate the safety of testosterone replacement therapy. We also assessed the clinical and cost-effectiveness of testosterone replacement therapy for men with male hypogonadism, and the existing qualitative evidence on men's experience and acceptability of testosterone replacement therapy. Evidence synthesis and individual participant data meta-analysis of effectiveness and safety, qualitative evidence synthesis and model-based cost-utility analysis. Major electronic databases were searched from 1992 to February 2021 and were restricted to English-language publications. We conducted a systematic review with meta-analysis of individual participant data according to current methodological standards. Evidence was considered from placebo-controlled randomised controlled trials assessing the effects of any formulation of testosterone replacement therapy in men with male hypogonadism. Primary outcomes were mortality and cardiovascular and cerebrovascular events. Data were extracted by one reviewer and cross-checked by a second reviewer. The risk of bias was assessed using the Cochrane Risk of Bias tool. We performed one-stage meta-analyses using the acquired individual participant data and two-stage meta-analyses to integrate the individual participant data with data extracted from eligible studies that did not provide individual participant data. A decision-analytic Markov model was developed to evaluate the cost per quality-adjusted life-years of the use of testosterone replacement therapy in cohorts of patients of different starting ages. We identified 35 trials (5601 randomised participants). Of these, 17 trials (3431 participants) provided individual participant data. There were too few deaths to assess mortality. There was no difference between the testosterone replacement therapy group (120/1601, 7.5%) and placebo group (110/1519, 7.2%) in the incidence of cardiovascular and/or cerebrovascular events (13 studies, odds ratio 1.07, 95% confidence interval 0.81 to 1.42; p = 0.62). Testosterone replacement therapy improved quality of life and sexual function in almost all patient subgroups. In the testosterone replacement therapy group, serum testosterone was higher while serum cholesterol, triglycerides, haemoglobin and haematocrit were all lower. We identified several themes from five qualitative studies showing how symptoms of low testosterone affect men's lives and their experience of treatment. The cost-effectiveness of testosterone replacement therapy was dependent on whether uncertain effects on all-cause mortality were included in the model, and on the approach used to estimate the health state utility increment associated with testosterone replacement therapy, which might have been driven by improvements in symptoms such as sexual dysfunction and low mood. A meaningful evaluation of mortality was hampered by the limited number of defined events. Definition and reporting of cardiovascular and cerebrovascular events and methods for testosterone measurement varied across trials. Our findings do not support a relationship between testosterone replacement therapy and cardiovascular/cerebrovascular events in the short-to-medium term. Testosterone replacement therapy improves sexual function and quality of life without adverse effects on blood pressure, serum lipids or glycaemic markers. Rigorous long-term evidence assessing the safety of testosterone replacement therapy and subgroups most benefiting from treatment is needed. The study is registered as PROSPERO CRD42018111005. This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/68/01) and is published in full in Health Technology Assessment; Vol. 28, No. 43. See the NIHR Funding and Awards website for further award information.

Occupational Hazard Exposure: Assessment of Hypogonadism and Dyslipidemia in House and Automobile Painters in Ilorin, Nigeria

Aims: To investigate the impact of human exposure to the constituents of paint on serum reproductive hormone and Lipid profile among occupationally exposed House and Automobile spray painters in Yakuba district of Ilorin East Local Government area of Kwara State. Nigeria. Study Design: Experimental./ Cross sectional. Place and Duration of Study: Yakuba district of Ilorin East Local Government area of Kwara State. Nigeria, 6months; between July 23 and January 2024. Methodology: 120 male participants were recruited for this study with the mean age 33.15±0.86 years. The participants included 40 automobile painters, 40 house painters, and male artisans who were not painters and served as the control group .Venous Blood samples were collected from both the test and control subjects for the measurement of serum lipids and testosterone using reference techniques. Results: Total Cholesterol, Triglyceride, HD and LDL cholesterol were significantly higher (P&lt;0.05) in the exposed automobile and house painters than the control groups. There was no significant difference (P&gt;0.05) between the serum lipid values of the automobile and the house painters. The serum testosterone level in both group of exposed painters was statistically similar(P&gt;0.05). There was no significant correlation (P&gt;0.05) between the frequency of cars or houses painted per month and work experience with the lipid profile parameters and testosterone levels in the occupationally exposed house and automobile painters. Conclusion: Occupational exposure to some chemical constituents of paint is associated with dyslipidemia and decrease serum testosterone which may precipitate adverse ill health among the painters.

Testosterone concentrations and associated predictors in men with cystic fibrosis: A retrospective, single-center study

BackgroundMen with cystic fibrosis (CF) have sexual health concerns such as delayed puberty, infertility, and hypogonadism. The causes and prevalence of hypogonadism have not been well studied. The purpose of this study was to determine the prevalence of a low testosterone concentration in men with CF. MethodsThis retrospective study was approved by the Emory University Institutional Review Board (IRB). Data were extracted from the electronic medical records of adult men with CF receiving care at the Emory Cystic Fibrosis Center. A total of 129 men with CF were followed at our center from 2016 to 2023. Of these individuals, 76 men with CF (58.9%) had at least one serum total testosterone measurement. Seven individuals were excluded from this study since they were currently receiving testosterone therapy, leaving a final sample size of 69 individuals for the analysis. Demographic data, serum testosterone concentrations, and other factors associated with low testosterone concentrations were collected. Low testosterone was defined as a value below 300 ng/dL. Regression analyses were used to determine factors associated with low testosterone levels. ResultsThe mean (± SD) age of the 69 eligible participants was 33.34 ± 10.98 years. The mean testosterone concentration was 421 ± 158.5 ng/dL with 27.54 percent of men with a testosterone value below 300 ng/dL. The mean hemoglobin level was 14.23 ± 2.18 g/dL. Testosterone levels were positively related to hemoglobin levels. Time of day of measurement and age were not associated with testosterone levels. ConclusionRoughly a quarter of men with CF demonstrated low testosterone in our sample. Low hemoglobin was associated with low testosterone levels in men with CF. Neither time of day nor age influenced testosterone concentrations in this sample.

Fetal gender prediction by monitoring circulating steroid hormones and some biochemical parameters in maternal dromedary camels.

To predict the sex of the foetus, healthy pregnant dromedary camels (n = 24) were included. Blood samples were collected for measurements of progesterone, estradiol, testosterone, and cortisol as well as total proteins, albumin, glucose, creatinine, blood urea nitrogen, phosphorus, calcium, creatine kinase, alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), gamma glutamyl transpeptidase (GGT), calcium, phosphorus, and magnesium. Statistical analysis revealed differences between pregnant camels and pregnant camels in terms of female or male foetuses depending on the actual sex of the born calf. The results revealed that testosterone and ALP concentrations were significantly (P < 0.001) greater in camels given to males than in those given to calves. There were strong positive correlations between male calf birth and testosterone and ALP concentrations (r = 0.864; P < 0.0001 and r = 0.637; P < 0.001, respectively). On the other hand, the cortisol, glucose and creatinine concentrations were significantly lower (P lower in camel calved males than in females). There were significant negative correlations between male calf birth and the cortisol, glucose and creatinine concentrations (r =-0.401; P = 0.052; r =-0.445; P = 0.029 and r =-0.400; P = 0.053, respectively). The concentrations of calcium, phosphorus, calcium/phosphorus ratio, magnesium, and albumin and the albumin/globulin ratio were not significantly different (P > 0.05) between the two groups. In conclusion, testosterone could be used as a biomarker to determine the sex of foetuses in dromedary camels.

Effect of Ziziphus Spina-Christi Leaves on the Level of Testosterone Hormone and ‎Semen Parameters of Iraqi Bucks Semen

The study aimed to assess the effects of different concentrations of Ziziphus spina-Christi (ZSC) leaves on the fertility of buck goats. Twelve buck goats aged 12–15 months with an average body weight of 22±2 kg were divided randomly into three dietary treatments: T1, T2, and T3, each given a basal diet daily plus feeds of 20 g/kg (2%) of ZSC for T1 and 40 g/kg (4%) of ZSC for ‎T2; and T3 was used as the control that consumed a basal diet only. The experiment lasted for 3 months. On days 45 and 90, blood samples were collected for plasma testosterone measurement using an immunochromatographic assay. Additionally, semen samples were collected at the same time points for physical (volume, color, and pH) and microscopic (semen concentration, mass and individual motility percentage, and live-dead sperm percentages) evaluations. ‎ The results showed that ZSC at 4% significantly (P&lt;0.05) increased the testosterone hormone concentration and all physical parameters at 45 and 90 days comparing to 2% ZSC and control ‎groups. ‎Additionally, ZSC at 4% significantly improved (P&lt;0.05) the microscopic parameters at both ‎time periods compared to 2% ZSC and control groups. The present findings revealed that ZSC at 4% diet could enhance goat semen processing and ‎goat fertility enhanced significantly (P&lt;0.05) the testosterone hormone that had higher values ‎compared to ‎‎(2%) of the ZSC control group. Similarly, (4%) of ZSC affected the physical ‎assessment of ‎semen, such as the volume, color, and pH values. Thus, adding ZSC with a high ‎concentration ‎‎(4%) could enhance goat semen processing and goat fertility in general.

The Utility of SHBG Assay in Clinical Biochemistry for Iraqi Women

Polycystic ovarian syndrome, additionally called PCOS is the most widespread endocrine illness amongst women. The aetiology of PCOS is attributed to a multi-factorial interplay among environmental and genetic effects. The overarching goal evaluates the correlation among blood concentrations of total testosterone, sex-hormone-binding globulin (SHBG), estradiol (E2), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in ladies with PCOS and the impact of obesity, age, marital popularity on the obtained results. This study was conducted at the National Center for Educational Laborites /Medical City/ Baghdad. The study comprised of a sample of 83 women, elderly between 17 -45 years, who had been selected in a random manner from a Gynaecology Clinic. The statistics collection duration spanned from November 2022 to March 2023. Women with polycystic ovary syndrome (PCOS) were based on their body mass index (BMI), age and marital status. Investigations included serum-free testosterone measurements by enzyme-linked immune sorbent assay (ELISA), total testosterone, SHBG, E2, FSH and LH by Automated Immunoassay Analyzer (AIA-2000). The current findings showed non-significant distinctions in mean values of BMI between studied groups of patients and controls which reflect matches between them. This study revealed the effect of marital status compared to PCOS and healthy control subjects. Married PCOS patients were non significantly affected (83.9% vs. 85.2%, p&gt;0.05) as compared to married controls. Results of these studies showed a significantly higher mean rate of serum FSH level in PCOS-affected women when opposed to normal individuals.

Evaluation of the effect of testosterone replacement therapy with a transdermal testosterone on glycemic control in men with type 2 diabetes mellitus

BACKGROUND: It is important to evaluate the effect of androgen replacement therapy on glycemic control.AIMS: Assessment of the effect of transdermal testosterone therapy on glycemic control in men with hypogonadism and T2DM.MATERIALS AND METHODS: The prospective, comparative study included 300 men aged 55[49;61] years: men receiving both glucose-lowering therapy (GLT) and transdermal testosterone; and patients receiving only GLT. Observation period 1 year. A medical history, a questionnaire for symptoms of androgen deficiency, and measurement of total testosterone and glycated hemoglobin were carried out. Groups were compared using nonparametric methods.RESULTS: Patients receiving androgen replacement therapy in combination with GLT at both 6 and 12 months from the moment of inclusion in the study, they had a statistically significantly higher level of total testosterone and less severity of symptoms of androgen deficiency. When assessing the magnitude of changes in the studied parameters, it was found that patients receiving testosterone replacement therapy (TRT) were characterized by a statistically significantly more pronounced decrease in the level of glycated hemoglobin (average difference 0,3%). In 29 (20,4% (95% ДИ 13,8–27,0)) men who received only GLT, hypogonadism was eliminated. In 3 patients from the TRT group, a pathological increase in the level of total blood PSA was observed, and therefore TRT was discontinued. An increase in hemoglobin above the reference value (&gt;172 g/l) was detected in 8% and 1,3% of men on TRT and without correction of hypogonadism, respectively, p=0,011.CONCLUSIONS: The combination of transdermal TRT and GLT has a positive effect on glycemic control, which is manifested by a decrease in glycated hemoglobin to a greater extent than when using GLT alone. Normalization of testosterone levels leads to a decrease in the symptoms of androgen deficiency, which is accompanied by an improvement in quality of life. Elimination of hypogonadism only with GLT is possible in a small number of cases.

Chlorpyrifos impairs sperm parameters and number of Sertoli and Leydig cells in rats after exposure during the peripubertal period

Chlorpyrifos is an organophosphate insecticide used to control pests in crops. Thus, humans are constantly exposed through ingestion of contaminated food or water, inhalation of contaminated air, and through the skin. The juvenile and peripubertal periods comprise a window of development of the reproductive system, sensitive to toxic agents. Considering the scarcity of data on exposure to the insecticide during these periods, the aim of this study was to evaluate the effects of chlorpyrifos on the testis during the juvenile and peripubertal periods. Thirty Wistar rats with an initial age of 25 days were distributed into 3 groups: control, which received corn oil (vehicle); CPS5, which received 5 mg/Kg b.w. of chlorpyrifos; and CPS15, which received 15 mg/Kg b.w. of chlorpyrifos. The groups were treated via gavage daily for 40 days and on the 41st experimental day, the animals were anesthetized and submitted to euthanasia to collect the organs. Blood was collected to obtain plasma and testosterone measurement. The testicles were removed, weighed and used for sperm count analyses, histopathological and morphometric analyzes and for oxidative stress analyses. Spermatozoa from the vas deferens were collected for analyzes of sperm morphology and acrosome integrity. The results showed that the two concentrations of chlorpyrifos caused a decrease in the number of Leydig and Sertoli cells and germ cells and increased the number of morphologically abnormal sperm and sperm with acrosomal damage. Furthermore, a decrease in lipid peroxidation was observed in the CPS5 and CPS15 groups, and a decrease in glutathione-S-transferase activity in the CPS5 group. We conclude that exposure to chlorpyrifos harms the daily production of sperm, as well as their quality, in addition to causing an imbalance in the oxidoreductive balance of the testicle.

Associations between serum testosterone levels and overactive bladder in women: a cross-sectional research of NHANES 2011 to 2016.

Androgen receptors are expressed in the pelvic floor and lower urinary tract. However, the association between serum testosterone and overactive bladder (OAB) in women remains unclear. This study aimed to investigate their association in a nationally representative population. In this cross-sectional study, we collected data on female participants older than 20years with serum total testosterone measurements and OAB questionnaires from the 2011-2016 National Health and Nutrition Examination Survey (NHANES). Survey-weighted logistic regression models were used to analyze the relationship between testosterone and OAB in women. Data on 4991 women was analyzed in this study, of whom 25.9% had OAB symptoms. Women with lower serum testosterone had an increased frequency of urge urinary incontinence and nocturia compared to participants with enough testosterone. The multivariate logistic models showed that those women with a testosterone level less than 18.5ng/dL had significantly higher odds of OAB compared to those with a testosterone level greater than 18.5ng/dL [OR 95% CI = 1.271 (1.073-1.505), P = 0.0076]. Separate interaction analyses revealed no significant effect of age, BMI, diabetes, education, alcohol use and menopause on the association between serum testosterone and OAB. Sensitivity analyses demonstrated that additional variables (depression, stroke and stress urinary incontinence) had no significant effect on this relationship. Low serum testosterone is associated with an increased likelihood of OAB in women. This supports the potential therapeutic role of testosterone supplementation in women with OAB. Given the direct and indirect effects of testosterone on the pelvic floor and lower urinary tract, a potential mechanism for this relationship can be further explored in translational studies.

Novel reference range values for serum testosterone: a cross-sectional study of 200,000 males.

To better understand the effects of aging, metabolic syndrome, diurnal variation, and seasonal variation on serum testosterone levels in the context of current guideline statements on testosterone deficiency. This cross-sectional study utilized the United Kingdom Biobank. Physical examination, anthropomorphic measurements, and laboratory evaluation were performed at the time of enrollment from 2006 to 2010. The primary outcomes were the effect of age, the presence of metabolic syndrome, the time of day, and the month of the year on serum testosterone levels. Among 197,883 included men, the 5th, 25th, 50th, 75th and 95th percentile testosterone levels in men without metabolic syndrome were significantly higher than those in men with metabolic syndrome at every decade of life (p < 0.001). The average testosterone level within each group (men without metabolic syndrome vs. men with) was clinically similar across decade of life (12.43 in 40's 12.29 in 50's 12.24 in 60's vs. 10.69 in 40's 10.56 in 50's 10.63 in 60's respectively). Average testosterone levels decreased with blood draws later in the day ranging from 10.91 to 12.74nmol/L (p < 0.01). Similarly, there was seasonal variation in serum testosterone ranging from 11.86 to 12.18nmol/L (p < 0.01). We found significant variation in serum testosterone according to the presence of metabolic syndrome and time of laboratory draw, but not according to age. These data challenge the prior dogma of age-related hypogonadism and favor an individualized approach towards serum testosterone measurement and interpretation. However, further studies are needed to correlate these population-based data with individuals' hypogonadal symptoms.

(084) Low Serum Testosterone is Associated with an Increased Risk of First-time Nephrolithiasis in Men Without Testosterone Replacement Therapy

Abstract Introduction Serum testosterone levels in men have declined on a population level since 1999. Although the role of testosterone in nephrolithiasis is unclear, men are twice as likely as women to develop kidney stones. Some studies posit high testosterone levels as a lithogenic factor, but a recent study showed an inverse relationship between testosterone levels and kidney stones, suggesting that low testosterone may increase the risk of kidney stones in men over 40. The relationship between low testosterone in men and kidney stone risk remains unclear. Objective To determine the association of low serum testosterone levels with the development of incident kidney stones in men without a history of testosterone therapy (TTh). Methods Using TriNetX, a tool that de-identifies and aggregates electronic health record data from tens of millions of patients, we used the TriNetX Research Network to examine men aged ≥18 with a known testosterone level. Men with a history of nephrolithiasis before testosterone measurement and a history of TTh at any point in their life were excluded as both are known to increase the risk of subsequent kidney stones. Men were divided into a low testosterone group (&amp;lt;300 ng/dL) and a normal testosterone group (300-1000 ng/dL). Demographic and clinical characteristics, including comorbidities and medications, were compared using descriptive statistics for all patients. To address potential confounders, we used propensity score matching based on demographic and clinical characteristics (Table 1). We used 1:1 greedy nearest-neighbor matching with a caliper of 0.1 pooled standard deviations of the propensity score. A standardized mean difference of less than 0.1 indicated successful matching. Our outcome of interest was all-time risk of developing an initial kidney stone in men aged ≥18 following a laboratory-confirmed low testosterone. Subgroup analyses was performed on age cohorts. Survival analysis was performed using a log-rank test and Cox proportional hazards regression. All analyses were performed on the TriNetX platform without natural language processing. Results 445,682 men ≥18 with low testosterone were included. The number of men before matching (Table 1) and in each age subgroup after matching is seen in table 2. The percentage of men that developed a diagnosis of nephrolithiasis increased with age regardless of testosterone level (Table 2). In men ≥18, low testosterone was associated with higher risk of incident nephrolithiasis (HR 1.14, 1.11-1.17). Men with low testosterone aged 34-44 (HR 1.28, 1.18-1.40) had the highest risk of nephrolithiasis. Low testosterone was not associated with an increased risk of nephrolithiasis in men aged 18-24 (Figure 1). Conclusions In investigating the association of low testosterone with kidney stones in men without a history of kidney stones or TTh, we found that low serum testosterone is associated with a higher risk of a first-time encounter diagnosis of nephrolithiasis in men greater than 25 years of age compared to men with normal testosterone levels. Men aged 33-44 with low serum testosterone had the highest risk of nephrolithiasis. Future work will investigate the risk of kidney stone recurrence in men with low serum testosterone levels. Disclosure No.

Longitudinal analysis of external quality assessment of immunoassay-based steroid hormone measurement indicates potential for improvement in standardization.

As hormonal disorders are linked to several diseases, the accurate quantitation of steroid hormone levels in serum is crucial in order to provide patients with a reliable diagnosis. Mass spectrometry-based methods are regarded as having the highest level of specificity and sensitivity. However, immunoassays are more commonly used in routine diagnostics to measure steroid levels as they are more cost effective and straightforward to conduct. This study analyzes the external quality assessment results for the measurement of testosterone, progesterone and 17β-estradiol in serum using immunoassays between early 2020 and May 2022. As reference measurement procedures are available for the three steroid hormones, the manufacturer-specific biases were normalized to the reference measurement values. The manufacturer-specific coefficients of variation were predominantly inconspicuous, below 20% for the three hormones when outliers are disregarded, however there were large differences between the various manufacturer collectives. For some collectives, the median bias to the respective reference measurement value was repeatedly greater than ±35%, which is the acceptance limit defined by the German Medical Association. In the case of testosterone and progesterone determination, some collectives tended to consistently over- or underestimate analyte concentrations compared to the reference measurement value, however, for 17β-estradiol determination, both positive and negative biases were observed. This insufficient level of accuracy suggests that cross-reactivity continues to be a fundamental challenge when antibody detection is used to quantify steroids with a high structural similarity. Distinct improvements in standardization are required to provide accurate analysis and thus, reliable clinical interpretations. The increased accuracy of the AX immunoassay for testosterone measurement, as observed in the INSTAND EQAs between 2020 and 2022, could be the result of a recalibration of the assay and raises hope for further improvement of standardization of immunoassay-based steroid hormone analyses in the coming years.

Effect of Metformin and Vitamin D Supplementation on Metabolic and Hormonal Profiles in Polycystic Ovary Syndrome Women: A Follow-Up Study

Background: Insulin resistance in association with obesity is implicated in the pathogenesis of polycystic ovarian syndrome and its primary characteristic of hyperandrogenism. Metformin at a dose of (1700-2000) mg/day, with and without lifestyle, is associated with a beneficial enhancement in BMI and menstrual cycles. We aimed to determine the role of free testosterone: dihydrotestosterone ratio, and sex hormone binding globulin in the evaluation of the efficacy of metformin and vitamin D in the treatment of polycystic ovary syndrome. Methods: This cross-sectional study included 50 infertile women who were diagnosed with PCOS with an age range of (18-40 years). They were classified into Group I: Twenty-five women treated with metformin 850 mg/twice daily and followed for 8 weeks; Group II: Twenty-five women treated with vitamin D3 50.000 IU/wk for the same period. Serum investigations included measurements of prolactin, 25 hydroxyvitamin D, LH, FSH, free testosterone, DHT and SHBG by ELISA technique. Results: This study revealed that the mean values of BMI, HOMA-IR, prolactin and free testosterone: dihydrotestosterone ratio were significantly improved (by lowering) after treatment with metformin and vitamin D. Moreover, Polycystic Ovary Syndrome women treated with metformin revealed significant negative association between HOMA-IR with SHBG (r= -0.593, p=0.009), also significant positive association between HOMA-IR with BMI (r= 0.631, p=0.003). Conclusion: Serum measurements of free testosterone: dihydrotestosterone ratio, along with SHBG, are good biochemical markers that reflect the enhancement of insulin resistance and BMI in Polycystic Ovary Syndrome women post metformin treatment or vitamin D supplementation.

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

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. 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. 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. 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 andinternal standard choices, likely contribute to inter-laboratory variability.