Background: Bioavailable testosterone (BT), circulating testosterone not bound to sex hormone-binding globulin (SHBG), is thought to easily penetrate cells. We compared BT measurements obtained by assays with those obtained by calculation with different testosterone association constants.
Methods: We obtained sera from 2 groups of hypogonadal men [group 1 (G1), 1421 samples; group 2 (G2), 170 samples] and a group of healthy men [group 3 (G3), 109 samples]. We added minute doses of [3H]testosterone to the sera, precipitated the SHBG-bound fraction of testosterone with ammonium sulfate (50% saturation), and then assayed serum BT (ABT) as %BT x total. Calculated BT (CBT) was determined with theoretical association constants of testosterone for SHBG (Ks = 1 x 10(9) L/mol) and albumin (Ka = 3.6 x 10(4) L/mol) and paired optimal Ks and Ka values obtained by use of Microsoft Excel software.
Results: CBT calculated with theoretical constants differed from ABT by >30% in 85.7% (G1), 84.1% (G2), and 77.9% (G3) of samples, and the mean CBT/ABT ratios were 1.57 (G1), 1.85 (G2), and 1.50 (G3) in spite of fairly good correlations. CBT calculated with paired optimal K(s) and K(a) differed from ABT by <30% in 87.4% (G1), 87.5% (G2), and 97.5% (G3) of samples, and mean CBT/ABT ratios were 0.95-1.04.
Conclusions: To obtain CBT values as close as possible to ABT, optimal paired association constants determined for each studied population must be used instead of the theoretical association constants. Considering the uncertainty of calculating BT, however, use of the ammonium sulfate precipitation method for determining BT is advisable.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1373/clinchem.2005.052126 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Persistent organic pollutants and endogenous sex-related hormones in Hispanic/Latino adults: The Hispanic Community health study/study of Latinos (HCHS/SOL).
Environ Res
December 2024
Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois Chicago, USA.
Background: Previous studies have demonstrated associations of persistent organic pollutants (POPs) with sex-related hormones; however, findings were inconsistent. Sex-specific impacts and pathways through which adiposity influences associations are not completely understood. We sought to evaluate sex-specific associations of POPs serum concentration with sex-related hormones and to explore pathways through which adiposity may modify associations.
View Article and Find Full Text PDFNew endocrine method of oral male contraception.
Contraception
December 2024
R&D Department, Pandora Endocrine Innovation, Bergen, Netherlands. Electronic address:
Essential for hormonal male contraception (HMC) is the inhibition of follicle-stimulating hormone (FSH), the hormone responsible for spermatogenesis. No drugs exist that can selectively suppress FSH without also inhibiting luteinizing hormone (LH), the hormone responsible for the biosynthesis of testosterone (T) and estradiol (E2) in men. The consequences are a loss of T and E2, with the accompanying symptoms and signs of T deficiency and E2 deficiency, respectively.
View Article and Find Full Text PDFBackground: Although sex differences in coronary artery disease (CAD) risk have been observed, little is known about the role of sex hormones in CAD genetics. Accounting for sex hormone levels may help identify CAD-risk loci and extend our knowledge of its genetic architecture.
Methods And Results: A total of 365 662 individuals of European ancestry enrolled in the UK Biobank were considered.
Association Between Female Androgen Levels, Metabolic Syndrome, and Cardiovascular Disease: An NHANES Analysis (2013-2016).
Int J Womens Health
December 2024
Department of Obstetrics and Gynecology, Zhongda Hospital, Nanjing, Jiangsu, People's Republic of China.
Background: The impact of androgens on metabolic diseases, cardiovascular diseases (CVD), and long-term mortality in the general female population remains poorly understood. This study, utilizing data from the National Health and Nutrition Examination Survey (NHANES) database managed by the Centers for Disease Control and Prevention, seeks to elucidate the relationship between androgen levels and metabolic syndrome (MS), CVD, and mortality in adult women.
Methods: After excluding ineligible individuals, descriptive analyses were conducted on demographic characteristics, metabolic-related indicators, and disease prevalence, based on the presence of high androgenemia and androgen quartile grouping.
Optimizing Testosterone Levels and Fertility Outcomes: A Case Series on the Impact of (Maca-OG) in Andropause and Sperm Dysfunction.
Am J Mens Health
December 2024
Symphony Natural Health, West Lake City, UT, USA.
Low testosterone levels in men contribute to altered sexual health, including low libido, erectile dysfunction, impaired sleep, and changes in mood and energy. Nearly half of all infertility cases are implicated by male factors, such as low testosterone levels and altered semen and sperm health. The purpose of this case series is to share the experience of two men taking a concentrated, highly bioavailable gelatinized form of specific phenotypes (sometimes referred to as colors) of (Maca-OG™) to improve reproductive health.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!