Serum Total Testosterone Concentrations Research Articles

Obesity may influence the relationship between sex hormones and lower urinary tract symptoms.

The effects of serum testosterone in the lower urinary tract symptoms (LUTS) in patients with benign prostatic hyperplasia (BPH) are not well established. The objective of the study is to evaluate the association of sex hormones with LUTS and control the results by patient weight. The study comprised a cross-sectional analysis of 725 men included in a prostate cancer screening program at University of Sao Paulo Medical School. The serum concentrations of total testosterone (TT), free testosterone (FT) and sex hormone binding globulin (SHBG) were measured. Variables analyzed were age, American Urological Association (AUA) symptom score, storage symptoms, voiding symptoms, quality of life score, prostate specific antigen levels and prostate volume. Obesity was measured through the calculation of body mass index (BMI). A regression analysis model was performed. Median patient age was 65 years (48 to 94). A higher TT level was significantly associated with a severe AUA symptom score only among patients with a BMI ≥ 25. Median TT was 371, 370 and 427ng/dL (p = 0.017) in patients with mild, moderate and severe LUTS respectively. The multivariate regression analysis in patients with BMI ≥ 25 showed that only age, TT and sex score were related to LUTS. A higher TT is associated with a severe AUA score symptom index only in obese patients. Further analysis are necessary to evaluate the mechanisms through which testosterone may influence LUTS in these patients.

Obesity and Testosterone Levels in Ghanaian Men With Type 2 Diabetes.

Testosterone plays a vital role in obesity, glucose homeostasis, and lipid metabolism. The aim of this study was to investigate androgen levels and its association with obesity in Ghanaian men with type 2 diabetes. The study showed that serum total and free testosterone concentrations were lower in male patients with type 2 diabetes and that obesity was strongly associated with low levels of total and free testosterone in Ghanaian men with type 2 diabetes.

Small for gestational age babies are not related to changes in markers of adipose tissue dysfunction during reproductive age

BackgroundSmall for gestational age (SGA) birth has been associated with adipocyte dysfunction during later phases of life. Because SGA women are at a higher risk of developing polycystic ovary syndrome (PCOS), adipocyte dysfunction detected in patients with PCOS may be associated with SGA birth. AimsTo determine whether SGA birth is related to altered serum markers of adipose tissue dysfunction during the third decade of life in Brazilian women. A secondary objective was to relate the presence of PCOS with serum markers of adipose tissue dysfunction. Study designProspective cohort observational study. SubjectsA total of 384 women born at 37 to 42weeks of gestation from June 1, 1978 to May 31, 1979 in Ribeirão Preto, State of São Paulo, Brazil. After exclusion, 165 women participated in the study. Of these women, 43 were in the SGA group and 122 were in the adequate for gestational age group based on birth weight determined from cohort files. Outcome measuresBody mass index (BMI), arterial systolic and diastolic pressures, abdominal circumference and serum concentrations of total testosterone, fasting glucose and insulin, lipid profile, adiponectin, leptin and necrosis factor alpha tumor (TNFα). ResultsBMI was an independent predictor of lower adiponectin (adjusted coefficient=−0.02, p=0.01) and higher leptin (adjusted coefficient=0.06, p=0.01) concentrations. The serum insulin concentration was associated with higher leptin (adjusted coefficient=0.03, p=0.02) and TNF-α (adjusted coefficient=0.01, p=0.03) concentrations. Having PCOS or being born SGA did not predict any markers of adipocyte dysfunction.

Testosterone 2% Gel Can Normalize Testosterone Concentrations in Men with Low Testosterone Regardless of Body Mass Index

Little is known about the effect of body mass index (BMI) on the efficacy and safety of testosterone therapy in hypogonadal men. A prior noncomparative trial demonstrated that testosterone 2% gel restored testosterone levels in hypogonadal men and was generally well tolerated. This post hoc analysis evaluated the influence of BMI on the pharmacokinetics of testosterone therapy in men with low testosterone. Men (N = 149) aged 18-75 applied testosterone 2% gel to the front and inner thigh once daily for 90 days. Starting dose was 40 mg/day, which could be adjusted at days 14, 35, and 60. Patients were split into categories depending on baseline BMI: Tertile 1 (≤ 29.1 kg/m(2)), Tertile 2 (29.2-32.4 kg/m(2)), and Tertile 3 (>32.4 kg/m(2)). Efficacy end points were average serum total testosterone concentrations over 24 hours and maximum serum testosterone concentrations at day 90. Adverse events were recorded. The efficacy analysis included 129 men with low testosterone (mean age 52.9, 54.0, and 54.2 years for Tertiles 1, 2, and 3, respectively) defined as serum testosterone <250-300 ng/dL. Baseline testosterone levels were comparable across BMI tertiles. After 90 days of treatment with testosterone 2% gel (≥ 40 mg/day), 79.1%, 79.5%, and 73.8% of patients in Tertiles 1, 2, and 3, respectively, achieved serum testosterone concentrations in the physiologic range (i.e., ≥ 300 to ≤ 1,140 ng/dL). The mean average daily dose at day 90 was higher in participants in Tertiles 3 vs. 2 (P = 0.039) and Tertiles 3 vs. 1 (P = 0.010). The gel was generally well tolerated, with skin reactions the most commonly reported adverse event (16.1%; n = 24). In this study, daily application of testosterone 2% gel was effective at returning serum testosterone to physiologic levels in men with low testosterone and high BMI, although required dose was affected by BMI.

Age-related prevalence of low testosterone in men with spinal cord injury

ObjectiveTo describe the relationship of advancing age in persons with chronic spinal cord injury (SCI) on the prevalence of low testosterone in men with SCI compared to historical normative data from able-bodied men in the general population.DesignRetrospective, cross-sectional study. Two hundred forty-three healthy, non-ambulatory outpatient men with chronic SCI from age of 21 to 78 years were included in this retrospective analysis.ResultsForty-six percent of men with SCI were identified as having low serum total testosterone concentrations (total testosterone <11.3 nmol/l). The age-related decline in SCI for total serum testosterone concentration was 0.6%/year compared to 0.4%/year in the Massachusetts Male Aging Study. Between the third and eighth decade of life, men with SCI had a 15, 39, 50, 53, 58, and 57% prevalence rate of low serum total testosterone, which is higher than values reported for each decade of life for able-bodied men in the Baltimore Longitudinal Study on Aging.ConclusionCompared with the general population, low serum total testosterone concentration occurs earlier in life in men with SCI, at a higher prevalence by decade of life, and their age-related decline in circulating total testosterone concentration is greater. Studies of T replacement therapy in men with SCI should assist in determining the possible functional and clinical benefits from reversing low serum total testosterone concentration.

Metabolic Effects of Resistance Training with or without Caloric Restriction in Dynapenic/Obese Postmenopausal Women

s / Can J Diabetes 37 (2013) S13eS84 S24 Methods: Prediabetes and PCOS-prone and control rats were fed a diet supplemented with the insulin sensitizer metformin and the androgen receptor antagonist flutamide or a combination for 4 weeks. Plasma and intestinal lymph lipid and apoB-lipoprotein metabolism were assessed in the fasted and postprandial state following an oral lipid challenge. Results: Flutamide and combination treatments decreased fasting plasma apoB48 apoB100 and triglyceride concentrations. Metformin treatment alone had no effect on plasma lipids or apoB-lipoproteins, and postprandial lipids and apoB-lipoproteins were not modulated by treatments. Flutamide lowered lymphatic intestinal secretion of triglyceride, cholesterol and apoB48 in the fasted state, and flutamide and combination treatments reduced intestinal apoB48 secretion. Flutamide decreased the serum concentration of total testosterone and estradiol, but not free testosterone. Conclusion: Flutamide appears to independently attenuate circulating plasma apoB-lipoproteins of intestinal and hepatic origin, and reduces the secretion of apoB-lipoproteins into intestinal lymph. We are investigating further the mechanisms associated with testosterone-mediated regulation of these lipidogenic pathways via the androgen receptor.

Association of serum total testosterone concentration with skeletal muscle mass in men under hemodialysis

Although skeletal muscle wasting can occur in chronic kidney diseases, its relationship with the serum testosterone concentration remains uncertain. This study investigates the relationship between serum testosterone and skeletal muscle mass in men under hemodialysis (HD). Sixty men aged between 41 and 89 years undergoing HD for 15.0 ± 8.1 years were enrolled for this study. The muscle areas of the thigh (TMA) and abdomen (AMA) were measured by computed tomography (CT), and the association between these muscle areas and serum total testosterone was examined with adjustment of age and other nutritional variables. The mean serum total testosterone in our HD patients (6.33 ± 2.90 ng/mL) was not lower than that of the Japanese general population, but showed a positive correlation with TMA (r = 0.39, p < 0.05), AMA (r = 0.52, p < 0.001), serum creatinine (r = 0.33, p < 0.05), and the creatinine generation rate (r = 0.26, p < 0.05). Serum total testosterone was inversely correlated with age (r = -0.32, p < 0.05), CRP (r = -0.31, p < 0.05), and IL-6 (r = -0.24, p < 0.05). A multiple-regression analysis showed both serum total testosterone and age to be an independent determinant of the muscle mass in these patients. This study identified testosterone as a determinant of muscle mass in HD men.

The free hormone hypothesis: Correlation of decreases in PSA with free testosterone rather than total testosterone in men with advanced prostate cancer treated with GTx-758.

e16015 Background: Androgen deprivation therapy (ADT) improves disease-free survival but disease progression is related, in part, to ineffective castration. The free hormone hypothesis states that the biological activity of steroid hormones is affected by its unbound (free) rather than its protein-bound concentration. Serum total testosterone (T) concentrations predominantly reflect the T bound to plasma proteins and do not accurately predict prostatic levels of T. Methods: In a Phase II study (G200705), men with advanced prostate cancer (n=159) were randomized to receive 1000 mg or 2000 mg GTx-758 daily or leuprolide as their initial ADT. Serum total T (mass spectrometry), free T (equilibrium dialysis), SHBG and PSA concentrations were measured. A second Phase II study (G20007) was performed in men (n=9) with CRPC who then received GTx-758 2000 mg daily. Results: Although both treatments reduced serum total T levels to &lt; 50 ng/dL, leuprolide decreased them to a greater extent. However, GTx-758 caused greater reductions in serum PSA, suggesting that total T concentrations did not accurately reflect the suppression of androgen activity. Both dosages of GTx-758 reduced free T levels to a greater extent (mean of 0.7 and 0.4 pg/ml at day 60, and 0.4 and 0.4 pg/ml on day 90, respectively) than leuprolide (mean of 1.4 pg/ml on day 60 and 1.4 pg/ml on day 90; p values &lt;0.03). Similar clinical results were observed in CRPC patients where GTx-758 daily resulted in a 71% decrease in %free T and clinically relevant PSA reductions in men maintained on ADT with LHRH agonists. As a result of adverse events at higher doses of GTx-758, the trial was stopped early. Conclusions: The ERα agonist, GTx-758, reduced the biologically active form of T, free T, to significantly lower levels than leuprolide. Reductions in PSA appeared to be more highly associated with changes in free T. These data provide compelling evidence to support the free hormone hypothesis and suggest that serum free T concentrations would provide a better measure of therapeutic efficacy in ADT than total T. A Phase II clinical trial utilizing lower doses of GTx-758 (G200712) is currently being performed. Clinical trial information: NCT01326312.

Episodes of Paralysis in Chinese Men with Thyrotoxic Periodic Paralysis Are Associated with Elevated Serum Testosterone

The strong predilection for thyrotoxic periodic paralysis (TPP) to occur in males suggests androgen may contribute to its pathogenesis. We therefore sought to determine if serum total and free testosterone (TT and FT) concentrations differed among patients with TPP during episodes of paralysis, patients with TPP between episodes of paralysis, and patients with Graves' disease (GD) not having TPP. A total of 105 Chinese men were included in the study, and were divided into three groups. Group 1 consisted of men with TPP who were studied during episodes of paralysis; group 2 consisted of men with TPP who were studied between episodes of paralysis; group 3 consisted of men with GD not having TPP. Patients in each were different persons. Serum electrolytes, free triiodothyronine (FT3), free thyroxine (FT4), TT, and FT were measured. Multiple regression analyses and analysis of covariance were performed to analyze the relationship of serum parameters, group status, and age. One multiple regression analysis was used to determine if serum TT concentrations were associated with age, FT3, FT4, or group status. This analysis indicated that age, FT4 level, and group status were significantly and independently associated with serum TT concentrations. With regard to group status, patients in group 1 had serum TT concentrations 0.92 ng/mL higher than patients in group 3 (p=0.033). As to FT4 level, TT concentrations increased by 0.016 ng/mL for each additional pmol/L of FT4 (p=0.002). Another multiple regression analysis was used to determine if serum FT concentrations were associated with age, FT3, FT4, group status, or serum TT concentrations. This analysis revealed that serum TT concentrations and group status were significantly and independently associated with serum FT concentrations. In terms of group status, patients in group 1 had serum FT concentrations of 2.11 pg/mL greater on average than patients in group 3 (p=0.006). We infer that episodes of paralysis in Chinese men with TPP are associated with elevated serum testosterone. We also found serum TT and FT concentrations of men with GD are both affected by group status; serum TT rather than FT concentrations are associated with thyroid function.

Androgen-secreting adrenocortical carcinoma

A 47-year-old woman presented with abdominal pain. She had recently noticed increased growth of facial hair and loss of scalp hair, and her menstrual cycle had become erratic. Abdominal examination revealed a right upperquadrant abdominal mass. A CT scan of the abdomen revealed a 10 cm adrenal mass (fi gure, A, B; green arrows) that was well encapsulated and heterogeneous. Endocrine studies were ordered to exclude a functioning adrenal neoplasm. The serum total testosterone concentration was 8·6 nmol/L (reference range 0·13–2·53 nmol/L) and the serum dehydroepiandrostenedione sulphate (DHEAS) con cen tration was 22 μmol/L (reference range 1·0–11·6 μmol/L). The free androgen index (ratio of testosterone to sex-hormone-binding globulin) was 30·2% (reference range 75% of tumour cells, and necrosis; fi gure, C [haematoxylin and eosin staining]). Immuno histochemistry was positive for melan-A, vimentin, synaptophysin, and epithelial membrane antigen. Cytoplasmic staining was positive with calretinin (fi gure, D) and inhibin (fi gure, E). The Ki-67 proliferative index was 32%. Mitotane was recommended as adjuvant therapy for 2 years. No evidence of recurrence or metastatic disease was recorded 12 months postoperatively and androgen concentrations remain suppressed. Women presenting with hirsutism or virilisation are more likely to have polycystic ovarian syndrome than an androgen-secreting adrenal neoplasm. Assessment of patients requires thorough hormonal investigation and imaging, including CT, MRI, and FDG-PET.

Hormonal profile in Indian men with premature androgenetic alopecia

Introduction:Alopecia in male is considered as a genetically determined disorder characterized by increased level of local androgen metabolite and increase androgen receptor binding in balding areas. Frequent deviations of hormones from normal values have been reported in men diagnosed with premature androgenetic alopecia (AGA) especially for androgens, gonadotropins and sex hormone binding globulin (SHBG). Different studies in the past have inferred that premature baldness before the age of thirty in males could be considered equivalent to the polycystic ovary syndrome (PCOS) in female.Materials and Methods:Hormonal profile of 50 men with severe premature balding before 30 years of age were compared with same numbers of age matched controls. The serum concentrations of total testosterone, dehydroepiandrosterone sulfate, luteinizing hormone, follicle stimulating hormone, SHBG, insulin and fasting blood sugar were estimated. Statistical analysis was performed with paired Student's t-test for cases and controls.Results:Decreased levels of SHBG with high free androgen index were found in cases when compared with the controls.Conclusion:Though altered hormonal profile may coexist in some of men with premature AGA it can’t be considered as male equivalent to PCOS in female or the metabolic syndrome.

Clinical and Biochemical Assessment of Hypogonadism in Type 2 Diabetic Men

doiAim: The aim of the study was to assess the prevalence of clinical hypogonadism in type 2 diabetic men based on clinical features and available biochemical measures. Materials and Methods: In this study carried out in a tertiary level hospital, serum concentration of total testosterone was measured in 170 type 2 diabetic (mean age 44.9±7.9 years) subjects who have erectile dysfunction or other features of hypogonadism. Results: The mean total testosterone concentration in type 2 diabetic men was 14.4±5.6 nmol/l. Fifty nine of 170 (34.7%) type 2 diabetic subjects had low serum testosterone levels (d”12 nmol/L). Luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations in type 2 diabetic men were inappropriately low with a very high prevalence of hypogonadotropic hypogonadism. BMI and waist circumference were both negatively correlated with testosterone levels, with the association being stronger for waist circumference. HbA1C level also reveal a negative association with sexual dysfunction and hypogonadotropic hypogonadism among type 2 diabetic men. Metabolic syndrome is also associated with the low serum testosterone levels in the study subjects. Conclusions: This study reveals that serum total testosterone levels are lower in diabetic men with signs/symptoms of hypogonadism. Hypogonadotropic hypogonadism is frequent in diabetic hypogondal population. There is an association between poor glycaemic control and hypogonadism in male diabetic persons. DOI: http://dx.doi.org/10.3329/birdem.v1i1.12378 Birdem Med J 2011; 1(1): 3-9

A Novel Testosterone 2% Gel for the Treatment of Hypogonadal Males

Testosterone replacement therapy (TRT) can improve the symptoms, signs, and well being of hypogonadal men by restoring serum testosterone concentrations to physiologic levels. This multicenter, open-label noncomparative trial of men with hypogonadism evaluated the pharmacokinetic profile and safety of a novel testosterone 2% gel (Fortesta™ Gel), administered once daily to the front and inner thighs at starting doses of 40 mg/d. The metered-dose delivery system allowed dose adjustments in 10-mg increments between 10 and 70 mg/d. Of the 149 patients enrolled, 138 patients (92.6%) completed the study and 129 patients (86.6%) were included in the efficacy analysis. On day 90, mean testosterone concentration (C(avg) [0-24 hours] ± SD) was 438.6 ± 162.5 ng/dL. Overall, 100 (77.5%) patients achieved serum total testosterone concentrations within the normal physiologic range (≥ 300 and ≤ 1140 ng/dL). On day 90, mean testosterone C(max) (± SD) was 827.6 ± 356.5 ng/dL. On day 90, a total of 122 patients (94.6%) had C(max) levels of 1500 ng/dL or less and 2 patients (1.6%) had values between 1800 and 2500 ng/dL. Similar results for C(avg) (0-24 hours) and C(max) were observed on day 35. All enrolled patients were included in the safety analysis. Testosterone 2% gel was generally well tolerated, with the most common adverse events (AE) being mild and moderate skin reactions. There were no serious AEs related to testosterone 2% gel. Once-daily testosterone 2% gel restored levels of testosterone in more than 75% of patients, with low risk of supraphysiologic testosterone levels. Patients may find this a suitable option for TRT because of its application site and low volume.

Pharmacokinetics of testosterone and estradiol gel preparations in healthy young men

The paucity of pharmacokinetic data on testosterone gel formulations and absence of such data on estradiol administration in healthy young men constitutes a fundamental gap of knowledge in behavioral endocrinological research. We addressed this issue in a double-blind and placebo controlled study in which we applied a topical gel containing either 150mg of testosterone (N=10), 2mg of estradiol (N=8) or a respective placebo (N=10) to 28 healthy young men. We then assessed serum concentrations of estradiol and testosterone in one hour intervals up to seven hours after drug application, measured LH, SHBG and cortisol levels once at baseline and three, four as well as six hours after gel administration. Treatment with testosterone gel resulted in maximum total serum testosterone concentration three hours after administration and did not suppress LH, cortisol and SHBG levels at any time point. Administration of estradiol gel led to maximum estradiol serum concentration two hours after administration. There was no suppression of cortisol, SHBG and absolute LH levels. We report here, for the first time, pharmacokinetic data on both high dose testosterone and estradiol gel application in healthy young males. The proposed model will assist in the design of future studies that seek to establish causality between testosterone and estradiol gel administration and behavioral as well as neurophysiological effects.

Testosterone concentrations, using different assays, in different types of ovarian insufficiency: a systematic review and meta-analysis

Increasing age and post-menopausal status are associated with decreasing androgen concentrations in females. Women with premature loss of ovarian function, such as primary ovarian insufficiency (POI) or iatrogenic menopause may be at increased risk for diminished testosterone levels at a relatively young age. Differentiation between a hypoandrogenic or normoandrogenic state in women with premature loss of ovarian function is problematic due to trueness and precision problems using various testosterone assays. The current meta-analysis was conducted to evaluate current literature reporting serum total testosterone concentrations under these conditions, including stratification for various testosterone assays. A systematic review and meta-analysis of controlled observational studies were performed. The electronic databases of Pubmed, Embase and the Cochrane Library were systematically searched until October 2011 for comparative studies on total testosterone concentrations in women with spontaneous POI or iatrogenic menopause compared with controls. The literature search, data extraction and critical appraisal, using the Newcastle-Ottawa Scale, were performed by two independent investigators. The effect measure was the weighted mean difference (WMD) with 95% confidence interval (95% CI) in a random effects model. A total of 206 articles for spontaneous POI and 1358 for iatrogenic menopause were reviewed, of which 9 and 17 papers, respectively, were selected for final analysis. Both groups demonstrated significantly lower total testosterone concentrations compared with controls [WMD (95% CI) -0.38 (-0.55 to -0.22) nmol/l, and -0.29 (-0.39 to -0.18) nmol/l, respectively], but with substantial between-study heterogeneity. Subgroup analysis for assay type was statistically significant for spontaneous POI only. Sensitivity analyses of high-quality studies did not change the results, and resulted in a substantial decrease in heterogeneity in spontaneous POI studies. The current meta-analysis demonstrates that total testosterone concentrations are decreased in women with spontaneous POI or iatrogenic menopause. The potential implications of hypoandrogenism in these women remain to be elucidated.

Polycystic Ovary Syndrome Mimicking an Androgen-Secreting Tumor

Hirsutism affects approximately 5 percent of reproductive-aged women. The most common causes of hirsutism are polycystic ovary syndrome (PCOS) and idiopathic hirsutism. Rapid onset or progression of hirsutism, as well as an elevated serum total testosterone concentration higher than 200 ng/dL should prompt further investigation to exclude an androgen-secreting tumor.

Testosterone increases the muscle protein synthesis rate but does not affect very-low-density lipoprotein metabolism in obese premenopausal women

Men and women with hyperandrogenemia have a more proatherogenic plasma lipid profile [e.g., greater triglyceride (TG) and total and low-density lipoprotein-cholesterol and lower high-density lipoprotein-cholesterol concentrations] than healthy premenopausal women. Furthermore, castration of male rats markedly reduces testosterone availability below normal and decreases plasma TG concentration, and testosterone replacement reverses this effect. Testosterone is, therefore, thought to be an important regulator of plasma lipid homeostasis. However, little is known about the effect of testosterone on plasma TG concentration and kinetics. Furthermore, testosterone is a potent skeletal muscle protein anabolic agent in men, but its effect on muscle protein turnover in women is unknown. We measured plasma lipid concentrations, hepatic very low density lipoprotein (VLDL)-TG and VLDL-apolipoprotein B-100 secretion rates, and the muscle protein fractional synthesis rate in 10 obese women before and after trandermal testosterone (1.25 g of 1% AndroGel daily) treatment for 3 wk. Serum total and free testosterone concentrations increased (P < 0.05) by approximately sevenfold in response to testosterone treatment, reaching concentrations that are comparable to those in women with hyperandrogenemia, but lower than the normal range for eugonadal men. Except for a small (∼10%) decrease in plasma high-density lipoprotein particle and cholesterol concentrations (P < 0.04), testosterone therapy had no effect on plasma lipid concentrations, lipoprotein particle sizes, and hepatic VLDL-TG and VLDL-apolipoprotein B-100 secretion rates (all P > 0.05); the muscle protein fractional synthesis rate, however, increased by ∼45% (P < 0.001). We conclude that testosterone is a potent skeletal muscle protein anabolic agent, but not an important regulator of plasma lipid homeostasis in obese women.

Sex-specific young adult reference ranges for sex hormone concentrations measured on the Siemens ADVIA Centaur/Geschlechtsspezifische Referenzbereiche für Sexualhormonkonzentrationen junger Erwachsener gemessen auf dem Siemens ADVIA Centaur

AbstractThe present study aims to determine reference ranges for sex hormone concentrations measured on the Siemens ADVIA CentaurThe study sample consisted of 1638 individuals (814 men and 824 women) aged 18–60 years with measured serum concentrations of total testosterone (TT), sex hormone-binding globulin (SHBG), and dehydroepiandrosterone sulfate (DHEAS). Values for free testosterone (free T) and free androgen index (FAI) were calculated. Sex- and age-specific (18 to &lt;25, 25 to &lt;35, 35 to &lt;45, and ≥45 years) reference ranges for these sex hormones were determined using quantile regression models for each sex hormone separately.Sex hormone reference ranges were determined across each single year of age separately for men (TT: 5.60–29.58 nmol/L, SHBG: 17.65–73.64 nmol/L, DHEAS: 0.96–4.43 mg/L, free T: 0.10–0.51 nmol/L, and FAI: 15.04–70.37 nmol/L) and women (TT: 0.77–2.85 nmol/L, SHBG: 27.06–262.76 nmol/L, DHEAS: 0.50–3.15 mg/L, free T: 0.005–0.05 nmol/L, and FAI: 0.51–8.30 nmol/L), respectively.

Low serum free testosterone level is associated with carotid intima-media thickness in middle-aged Japanese men

In the present study, we measured carotid artery intima-media thickness (CIMT) and assessed several metabolic factors in middle-aged healthy Japanese men to clarify the relation between testosterone and atherosclerosis. The study comprised 176 male employees aged ≥40 years who visited Osaka University Healthcare Center for their annual health examinations. Serum total testosterone (TT) concentration was measured using radioimmunoassay (RIA) and serum free testosterone concentration was measured using analog ligand RIA (aFT). A multivariate model adjusted for age, body mass index, mean arterial pressure and treatment for hypertension demonstrated a significant association between aFT and CIMT. Even after adjustment for other clinically relevant factors, the significant association between aFT and CIMT was not attenuated. After adjustment for all other clinically relevant factors, both univariate and multivariate models ascertained the stepwise association that a level of aFT of ≤10.0 pg/mL was significantly associated with CIMT. However, the association between TT and CIMT was not significant in either univariate or multivariate models. We conclude that our finding showing that low serum aFT level is an influencing and independent risk factor for CIMT is of value in the clinical setting because no other studies, to our knowledge, have conducted multivariate analyses using the various metabolic factors included in the present analyses.

Age-Specific Reference Ranges for Serum Testosterone and Androstenedione Concentrations in Women Measured by Liquid Chromatography-Tandem Mass Spectrometry

RIA-based sex hormone measurements offer only limited precision and specificity in the low concentration range of women. Therefore, we aimed to establish age-specific reference ranges for serum sex hormone concentrations in women using mass spectrometry and quantile regression. Data from 985 women aged 20-80 yr, recruited for the prospective Study of Health in Pomerania, were included in the analyses. Quantile regressions models were performed to calculate the age-specific 2.5th and 97.5th percentiles for sex hormone concentrations in women. Serum total testosterone (TT) and androstenedione (AD) concentrations were measured by liquid chromatography-tandem mass spectrometry. Measured concentrations of SHBG and TT were used to calculate free testosterone (free T). TT, AD, and free T concentrations showed a distinct age-related decline across 10-yr age groups (one way ANOVA P < 0.001). Sex hormone reference ranges for TT, AD, and free T were determined across each single year of age and for 10-yr age groups. Reference ranges over the whole age range of 20-80 yr were 0.35-1.97 nmol/liter for TT, 0.89-4.56 nmol/liter for AD, and 0.0025-0.0253 nmol/liter for free T. Separate reference ranges were provided for pre- and postmenopausal women as well as after inclusion of women using oral contraceptives or hormone therapy (n = 1357). This is the first study to establish age-specific reference ranges for liquid chromatography-tandem mass spectrometry-measured TT and AD and calculated free T concentrations based on quantile regression analyses, accurately accounting for the observed low concentration range and the strong age dependency of these sex hormones in women.