Effect of free androgen index on blood pressure variability and target organ damage in postmenopausal hypertensive women: findings from a cross-sectional study

Association Between Female Androgen Levels, Metabolic Syndrome, and Cardiovascular Disease: An NHANES Analysis (2013-2016)

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. Logistic regression models were developed to assess the associations of androgen markers, including total testosterone (TT), Free Androgen Index (FAI), with MS, CVD, and cox regression models were used to explore the relationships with mortality.

Results

Our results show that, even without adjustment for age, age at menarche, marital status, and smoking status, both in patients with hyperandrogenemia and across the general population stratified by quartiles of FAI, higher androgen levels are associated with increased waist circumference, weight, Body Mass Index, fasting insulin, and the monocyte/high-density lipoprotein cholesterol ratio. In adjusted correlational analysis, MS remained positively correlated with FAI, even after controlling for age, tobacco use, and alcohol consumption. As FAI quartiles increased, the correlation strengthened, achieving an odds ratio (OR) of 1.45 (95% CI 1.04 to 2.02, P=0.03) in the highest quartile. This indicates that androgen levels are strongly associated with metabolic syndrome, with FAI proving more sensitive than TT.

Conclusion

The greater sensitivity of FAI may be attributed to its ability to reflect bioavailable testosterone more accurately than TT, underscoring its potential utility in clinical assessments of metabolic risk. This study found no significant correlation between androgen levels and CVD or mortality.

Impact of dehydroepiandrosterone sulfate and free androgen index on pregnancy and neonatal outcomes in PCOS patients

BACKGROUND

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder associated with infertility and pregnancy complications. The pathogenesis of PCOS and its impact on reproductive function may be influenced by the source of androgens, including testosterone, free androgen, dehydroepiandrosterone sulfate (DHEAS). However, the differential effects of these androgen on pregnancy and neonatal outcomes and the cut-off value of East Asian population with PCOS remain unclear.

METHODS

A retrospective cohort study was conducted at the Reproductive Medicine Center of the First Affiliated Hospital of Sun Yat-sen University from January 2015 to November 2022, involving 636 cycles of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). Subgroup analyses were performed using cut-off values of 6.4 for free androgen index (FAI), 9.5 µmol/L for DHEAS. Pregnancy and neonatal outcomes were compared between groups. Restricted cubic spline (RCS) was used to identify significant cut-off values affecting pregnancy.

RESULTS

Higher FAI levels (> 6.4) were associated with decrease in clinical pregnancy rate (PR) (50.61% vs. 41.66%, p = 0.024), live birth rate (LBR) (42.42% vs. 32.35%, p = 0.011). When DHEAS levels exceeded 9.5 µmol/L, there was a significant decrease in clinical PR (51.27% vs. 42.73%, P = 0.039), LBR (42.73% vs. 32.73%, P = 0.012). Negative correlations were also observed between DHEAS levels and cumulative pregnancy rate (70.57% vs 56.62% p = 0.002) and cumulative live birth rate (CLBR) (59.35% vs 43.37%, p = 0.0007). Both FAI and DHEAS elevated is associated with the lowest clinical pregnancy rate (37.84%). Conversely, when solely FAI is elevated, the pregnancy rate increases to 52.38%, while an elevation in DHEAS alone is associated with a pregnancy rate of, both of which are lower than when neither FAI nor DHEAS are elevated (60.68%). The live birth rates exhibit a similar trend (30.00% vs 40.00% vs 41.83% vs 44.48%). RCS revealed a significant decrease in CPR and CLBR when DHEA levels exceeded 7.69 umol/L, while the cut-off value of FAI was 6.36 for CPR and CLBR.

CONCLUSION

In conclusion, PCOS patients with biochemical hyperandrogenism show unsatisfactory clinical PR and CLBR when undergoing assisted reproductive technology (ART). This may be attributed to the influence of both adrenal-derived DHEAS and ovarian-derived FAI on the unfavorable pregnancy outcomes.

Role of sex hormone-binding globulin in the free hormone hypothesis and the relevance of free testosterone in androgen physiology

According to the free hormone hypothesis, biological activity of a certain hormone is best reflected by free rather than total hormone concentrations. A crucial element in this theory is the presence of binding proteins, which function as gatekeepers for steroid action. For testosterone, tissue exposure is governed by a delicate equilibrium between free and total testosterone which is determined through interaction with the binding proteins sex hormone-binding globulin and albumin. Ageing, genetics and various pathological conditions influence this equilibrium, hereby possibly modulating hormonal exposure to the target tissues. Despite ongoing controversy on the subject, strong evidence from recent in vitro, in vivo and human experiments emphasizes the relevance of free testosterone. Currently, however, clinical possibilities for free hormone diagnostics are limited. Direct immunoassays are inaccurate, while gold standard liquid chromatography with tandem mass spectrometry (LC-MS/MS) coupled equilibrium dialysis is not available for clinical routine. Calculation models for free testosterone, despite intrinsic limitations, provide a suitable alternative, of which the Vermeulen calculator is currently the preferred method. Calculated free testosterone is indeed associated with bone health, frailty and other clinical endpoints. Moreover, the added value of free testosterone in the clinical diagnosis of male hypogonadism is clearly evident. In suspected hypogonadal men in whom borderline low total testosterone and/or altered sex hormone-binding globulin levels are detected, the determination of free testosterone avoids under- and overdiagnosis, facilitating adequate prescription of hormonal replacement therapy. As such, free testosterone should be integrated as a standard biochemical parameter, on top of total testosterone, in the diagnostic workflow of male hypogonadism.