Higher Sex Hormone-binding Globulin Levels Research Articles

Clustering Identifies Subtypes With Different Phenotypic Characteristics in Women With Polycystic Ovary Syndrome.

Hierarchical clustering (HC) identifies subtypes of polycystic ovary syndrome (PCOS). This work aimed to identify clinically significant subtypes in a PCOS cohort diagnosed with the Rotterdam criteria and to further characterize the distinct subtypes. Clustering was performed using the variables body mass index (BMI), luteinizing hormone (LH), follicle-stimulating hormone, dehydroepiandrosterone sulfate, sex hormone-binding globulin (SHBG), testosterone, insulin, and glucose. Subtype characterization was performed by analyzing the variables estradiol, androstenedione, dehydroepiandrosterone, cortisol, anti-Müllerian hormone (AMH), total follicle count (TFC), lipid profile, and blood pressure. Study participants were girls and women who attended our university hospital for reproductive endocrinology screening between February 1993 and February 2021. In total, 2502 female participants of European ancestry, aged 13 to 45 years with PCOS (according to the Rotterdam criteria), were included. A subset of these (n = 1067) fulfilled the National Institutes of Health criteria (ovulatory dysfunction and hyperandrogenism). Main outcome measures included the identification of distinct PCOS subtypes using cluster analysis. Additional clinical variables associated with these subtypes were assessed. Metabolic, reproductive, and background PCOS subtypes were identified. In addition to high LH and SHBG levels, the reproductive subtype had the highest TFC and levels of AMH (all P < .001). In addition to high BMI and insulin levels, the metabolic subtype had higher low-density lipoprotein levels and higher systolic and diastolic blood pressure (all P < .001). The background subtype had lower androstenedione levels and features of the other 2 subtypes. Reproductive and metabolic traits not used for subtyping differed significantly in the subtypes. These findings suggest that the subtypes capture distinct PCOS causal pathways.

Sex hormone binding globulin and total testosterone levels are associated with in vivo tau burden differentially between the sexes: findings from the Framingham Study

AbstractBackgroundIn men and women, sex steroid hormones are associated with increased risk of Alzheimer’s disease (AD) dementia. In older men, lower levels of testosterone are associated with higher rates of AD dementia. The relationship between estradiol levels on AD dementia risk in post‐menopausal women, however, is less clear, with studies reporting protective, deleterious and no effects. Finally, higher levels of sex hormone binding globulin (SHBG), a glycoprotein that regulates, and actively influences sex hormones, has been consistently linked with increased risk for AD dementia. Studies have yet to examine mid‐life hormonal levels in association with later‐life in vivo AD biomarkers in cognitively healthy adults.Method175 women and 159 men from the Framingham Study 3rd Generation cohort underwent blood (hormones) collection in 2002‐2005, and 18F‐Flortaucipir (FTP)‐PET and 11C‐PiB‐PET scans in 2016‐2020 (Table1). We examined FTP‐PET signal (referenced to cerebellar grey) in six a priori regions that previously demonstrated sex differences (entorhinal, inferior temporal, rostral middle frontal, inf/sup parietal and lateral occipital). Linear regressions examined sex‐stratified analyses of free/total testosterone, estradiol, and SHBG in each region, adjusting for age, age2, PET camera and plasma‐PET date‐difference (mean = 15(±2)yrs). Separate models examined interactions with a neocortical PiB‐PET composite and APOEε4.ResultIn men, elevated SHBG was associated with lower FTP‐PET in entorhinal (p = 0.007), inferior temporal (p = 0.04) and rostral middle frontal regions (p = 0.02; Table2). Higher total testosterone was marginally associated with lower FTP‐PET signal in the latter region (p = 0.06), but other relationships were apparent. In women, higher total testosterone associated with lower FTP‐PET signal in inferior temporal (p = 0.05) and parietal regions (p = 0.04). Women APOEε4 carriers with higher estradiol showed higher levels of entorhinal FTP‐PET signal (p = 0.03;Table3).ConclusionHigher levels of SHBG are associated with lower risk of AD‐related comorbidities, such as osteoporosis, diabetes, and visceral weight gain. A strong link between higher SHBG levels and higher HDL‐cholesterol may suggest a potential protective cardiovascular pathway for men against higher tau burden later in life. A lack of protective effect of pre‐menopausal estradiol in female APOEε4 carriers supports the notion that the role of estrogen in AD risk is centered around timing of decline.

Associations of bone mineral density with sex hormone-binding globulin (SHBG) and testosterone in middle-aged Saudi men: a cross-sectional study.

The present cross-sectional study examined the association between circulating levels of sex hormone-binding globulin (SHBG) and testosterone with bone mineral density (BMD) in middle-aged Arab men. Clinical data of 103 middle-aged Saudi men (mean age 60.7±7.2) were extracted from the Osteoporosis Registry of the Chair for Biomarkers of Chronic Diseases, King Saud University in Riyadh, Saudi Arabia. Participants were categorized according to the presence of osteopenia (T-score -1.0 to -2.5) (N=47) and controls (N=56). Data collected included demographics and anthropometrics as well as levels of sex hormone-binding globulin (SHBG), testosterone and follicle-stimulating hormone (FSH) which were measured using commercially available assays. Free androgen index (FAI) was calculated. Those with osteopenia had significantly lower levels of FAI (p<0.05), and higher levels of SHBG (p<0.004) and FSH (p<0.005). In the osteopenia group, SHBG was positively correlated with age (r=0.33, p<0.05), while it was inversely correlated with BMD spine (r = -0.39, p<0.05) and T-score femur (r= -0.35, p<0.05) in the same group. Furthermore, testosterone was inversely correlated with BMI in the osteopenia group (r= -0.33, p<0.05) while FAI was positively correlated with T-score femur (r = 0.36, p<0.05) as well as in all participants (r= 0.24, p<0.05). Among controls, FAI had an inverse correlation with FSH (r= -0.28, p<0.05) and over-all (r= -0.22, p<0.05). In summary, the associations elicited suggest that circulating levels of SHBG and FAI may be against age-related bone loss in middle-aged men.

Do testosterone and sex hormone-binding globulin affect cancer risk? A Mendelian randomization and bioinformatics study

Using Mendelian Randomization (MR) and large-scale Genome-Wide Association Study (GWAS) data, this study aimed to investigate the potential causative relationship between testosterone and sex hormone-binding globulin (SHBG) levels and the onset of several cancers, including pathway enrichment analyses of single nucleotide polymorphisms (SNPs) associated with cancer allowed for a comprehensive bioinformatics approach, which offered a deeper biological understanding of these relationships. The results indicated that increased testosterone levels in women were associated with a higher risk of breast and cervical cancers but a lower risk of ovarian cancer. Conversely, increased testosterone was linked to lower stomach cancer risk for men, whereas high SHBG levels were related to decreased risks of breast and prostate cancers. The corresponding genes of the identified SNPs, as revealed by pathway enrichment analysis, were involved in significant metabolic and proliferative pathways. These findings emphasize the need for further research into the biological mechanisms behind these associations, paving the way for potential targeted interventions in preventing and treating these cancers.

Frequency and Clinical Significance of Low or High Sex Hormone Binding Globulin Levels in Patients Suspected of Harboring Abnormal Testosterone Levels

Purpose: We aim to examine the frequency of low or high sex hormone binding globulin (SHBG) levels and to investigate whether they are associated with comorbidities and hormonal derangements in patients suspected of harboring abnormal testosterone levels. Methods: This was a retrospective study of adult patients who underwent SHBG testing as part of a panel for testosterone at UCLA Health between May and July 2019. Results: A total of 1102 male and 689 female patients underwent SHBG testing; the most common indications of the tests were suspected hypogonadism in male and hyperandrogenism in female patients. Eight male (0.7%, 9.4±1.0 nmol/L) and 66 female patients (9.6%, 21.7±5.2 nmol/L) exhibited low SHBG levels, and 113 male (10.3%, 106.6±29.6 nmol/L) and 118 female (17.1%, 187.1±59.6 nmol/L) patients exhibited high SHBG levels. Patients with low SHBG levels were younger, had higher body mass index, and less commonly receive sex hormone treatments than those with high SHBG levels but they were not different in other assessed clinical parameters. Bioavailable and free testosterone levels were not different in males with low or high SHBG levels but were significantly higher in females with low SHBG levels than in those with high SHBG levels.

Circulating Sex Hormone Levels and Risk of Gastrointestinal Cancer: Systematic Review and Meta-Analysis of Prospective Studies.

Sex hormones may influence the development of gastrointestinal cancer, but evidence is inconsistent. We systematically searched MEDLINE and Embase databases to identify prospective studies examining associations between prediagnostic circulating levels of sex hormones and risk of five gastrointestinal cancers: esophageal, gastric, liver, pancreatic, and colorectal cancer. Pooled odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated using random-effects models. Among 16,879 identified studies, 29 were included (11 cohort, 15 nested case-control, and 3 case-cohort studies). Comparing the highest versus lowest tertiles, levels of most sex hormones were not associated with the studied tumors. Higher levels of sex hormone-binding globulin (SHBG) were associated with increased risk of gastric cancer (OR=1.35; 95%CI, 1.06-1.72), but such associations were restricted in men only (OR=1.43; 95%CI, 1.10-1.85) when stratified by sex. Higher SHBG levels were associated with increased risk of liver cancer (OR=2.07; 95%CI, 1.40-3.06). Higher testosterone levels were associated with increased risk of liver cancer overall (OR=2.10; 95%CI, 1.48-2.96), particularly in men (OR=2.63; 95%CI, 1.65-4.18), Asian populations (OR=3.27; 95%CI, 1.57-6.83) and in hepatitis B surface antigen-positive individuals (OR=3.90; 95%CI, 1.43-10.64). Higher levels of SHBG and testosterone were associated with decreased risk of colorectal cancer in men (OR=0.89; 95%CI, 0.80-0.98 and OR=0.88; 95%CI, 0.80-0.97, respectively) but not in women. Circulating levels of sex hormone-binding globulin and testosterone may influence the risk of gastric, liver, and colorectal cancer. Further clarifying the role of sex hormones in the development of gastrointestinal cancer may unravel future novel targets for prevention and treatment.

Sex Hormone-Binding Globulin and Risk of Coronary Heart Disease in Men and Women.

The role of sex hormone-binding globulin (SHBG) levels in clinical risk stratification and intervention for coronary heart disease (CHD) remains uncertain. We aimed to examine whether circulating levels of SHBG are predictive of CHD risk in men and women. We investigated the association between SHBG and the risk of incident CHD in 128 322 men and 135 103 women free of CHD at baseline in the prospective United Kingdom Biobank (UKB) cohort. The unconfounded associations were estimated using Mendelian randomization (MR) analysis. We further conducted a meta-analysis to integrate currently available prospective evidence. CHD events included nonfatal and fatal myocardial infarction and coronary revascularization. In the UKB, during a median of 11.7 follow-up years, 10 405 men and 4512 women developed CHD. Serum levels of SHBG were monotonically associated with a decreased risk of CHD in both men (adjusted hazard ratio [HR] per log nmol/L increase in SHBG: 0.88 [0.83-0.94]) and women (HR: 0.89 [0.83-0.96]). MR-based analyses suggested causality and a dose-response relationship of SHBG with CHD risk. A cumulative meta-analysis including 216 417 men and 138 282 women from 11 studies showed that higher levels of SHBG were prospectively associated with decreased CHD risk in men comparing the highest with the lowest quartile: pooled relative risk (RR) 0.81 (0.74-0.89) and women (pooled RR: 0.86 [0.78-0.94]). Higher circulating SHBG levels were directly and independently predictive of lower CHD risk in both men and women. The utility of SHBG for CHD risk stratification and prediction warrants further study.

Mendelian randomization analyses identified bioavailable testosterone mediates the effect of sex hormone-binding globulin on prostate cancer.

A better knowledge of the hormonal etiology of prostate cancer is essential for its prevention and treatment. The goal of this study was to provide causal estimates of the connection between sex hormone-binding globulin and prostate cancer and investigate the possible mediating function of other modifiable risk indicators. We used two-step, two-sample multivariable Mendelian randomization using single-nucleotide polymorphisms as instrumental variables for exposure and mediators. Single-nucleotide polymorphisms associated with sex hormone-binding globulin and bioavailable testosterone were screened via a genome-wide association study enrolling European-descent adult male individuals. Summary-level data for prostate cancer (79,148 cases and 61,106 controls) were extracted from the PRACTICAL consortium. The total effect of sex hormone-binding globulin on prostate cancer risk was decomposed into direct and indirect effects through the mediator, bioavailable testosterone. An inverse-variance-weighted method was the primary Mendelian randomization analysis method. Sensitivity analyses were performed via Mendelian randomization-Egger regression, heterogeneity test, pleiotropy test, and leave-one-out test. The directionality that exposure causes the outcome was verified using Mendelian randomization-Steiger test. In the univariable Mendelian randomization analysis, genetically predicted higher sex hormone-binding globulin levels had a causal association with lower prostate cancer risk (odds ratio = 0.944, 95% confidence interval = 0.897-0.993, p = 0.027) and an inverse association with bioavailable testosterone level (odds ratio = 0.945, 95% confidence interval = 0.926-0.965, p = 1.62E-07) without controlling for other factors. Moreover, an increase of one standard deviation (59.5 pmol/L) in genetically predicted bioavailable testosterone level was significantly associated with a 22.0% increase in the overall prostate cancer risk (odds ratio = 1.220, 95% confidence interval = 1.064-1.398, p = 0.004) after adjusting for sex hormone-binding globulin level. The effect size ratio of bioavailable testosterone-mediated sex hormone-binding globulin to prostate cancer was further analyzed to clarify the importance of the mediating effect. Notably, the mediator bioavailable testosterone explained 19.28% (95% confidence interval = 10.76%, 73.78%) of the total effect of sex hormone-binding globulin level on prostate cancer risk. The results support the potentially protective causal effect of genetically predicted higher sex hormone-binding globulin levels against prostate cancer with mediation by the modifiable risk factor, bioavailable testosterone. More research is needed to determine how this possible sex hormone-binding globulin-bioavailable testosterone-prostate cancer link works. Targeting sex hormone-binding globulin and bioavailable testosterone traits may be a valuable strategy for preventing prostate cancer.

Associations between urinary concentrations of bisphenols and serum concentrations of sex hormones among US. Males

BackgroundBisphenol A (BPA) exposure and its structural analogs (BPS and BPF) might cause endocrine alterations and adverse physiological effects. Few studies to date have directly explored the association between its structural analogs (BPS, BPF) and sex hormones in adult male participants. Therefore, we aimed to assess the associations between BPA, BPS, BPF, and sex hormones in American adult men.MethodsWe used data from the U.S. National Health and Nutrition Examination Survey 2011–2016. We excluded participants without data available on sex hormones and urinary bisphenols. Furthermore, participants consuming sex hormone medications were excluded. Multivariable regression models were performed to assess the association between bisphenols and sex hormones.ResultsIn this study, 2367 participants were included. Of 2367, in 1575 participants, the data on BPS and BPF were available. We found that a per unit increase in BPF was associated with 0.575 ng/dL higher total testosterone (TT) (Model 2: 95% CI: 0.047, 1.103, P = 0.033). However, there was no significant association between BPA or BPS and TT. Furthermore, increased BPA and BPS levels were associated with higher levels of sex hormone-binding globulin (SHBG) (Model 2: β = 0.364, 95% CI: 0.158, 0.571; β = 0.25, 95% CI: 0.071, 0.429, respectively). Additionally, participants in the highest BPA exposure quartile (quartile 4) had 4.072 nmol/L higher levels of SHBG than those in quartile 1 (Model 2: 95% CI: 0.746, 7.397, P = 0.017; P for trend =0.005). Both BPA and BPS were negatively associated with free testosterone (FT, nmol/L) after full adjustment (Model 2, β = − 0.01%, P = 0.0211, P = 0.0211; Model 2, β = − 0.01%, P = 0.0258, respectively). However, BPF was positively associated with FT (Model 2, β = 0.0029%, P = 0.0028).ConclusionOur study indicated that exposure to both BPA and its substitutions could alter sex hormone levels. This finding supports the possibility that human exposure to bisphenols at environmental levels might affect the endogenous hormone balance.

Exposure to heavy metals and hormone levels in midlife women: The Study of Women's Health Across the Nation (SWAN)

Exposure to heavy metals may alter the circulating levels of sex hormones. However, epidemiologic studies on heavy metals and sex hormones have been limited, and results have been inconsistent. We assessed the associations of heavy metals assayed in urine, including arsenic, cadmium, lead, and mercury, with repeated measures of serum estradiol (E2), follicle-stimulating hormone (FSH), testosterone, and sex hormone-binding globulin (SHBG) levels in the Study of Women's Health Across the Nation Multi-Pollutant Study. The sample included 1355 White, Black, Chinese, and Japanese women, aged 45–56 years at baseline (1999–2000), whose serum hormone levels were repeatedly measured through 2017. Urinary metal concentrations were measured at baseline. Linear mixed effect models were used to calculate percent changes in serum hormone levels per doubling of urinary metal concentrations, adjusting for demographics, socioeconomic status, lifestyle, health-related factors, and urinary creatinine. After multivariable adjustment, a doubling of urinary metal concentration was associated with lower E2 levels by 2.2% (95% CI: 4.0%, −0.3%) for mercury and 3.6% (95% CI: 5.7%, −1.6%) for lead; higher FSH levels by 3.4% (95% CI: 0.9%, 5.9%) for lead; and higher SHBG levels by 3.6% (95% CI: 1.3%, 5.9%) for cadmium. The overall joint effect using the Bayesian kernel machine regression showed that metal mixtures were inversely associated with E2 and positively associated with FSH levels. No association was found between metals and testosterone levels. Results from this prospective cohort study demonstrate that environmental heavy metal exposures, including cadmium, mercury, and lead, may disturb circulating levels of E2, FSH, and SHBG in midlife women.

Association of Exposure to Phthalate Metabolites With Sex Hormones, Obesity, and Metabolic Syndrome in US Women

Obesity and metabolic syndrome are highly prevalent among the US population and are associated with the dysregulation of sex hormones. An increase in obesity and metabolic syndrome may also be associated with exposure to phthalates. The association of exposure to phthalate metabolites with sex hormones and metabolic health has been understudied in the female population. To evaluate the association between exposure to common phthalate metabolites with total testosterone (TT) levels, sex hormone-binding globulin (SHBG) levels, obesity, and metabolic syndrome among women. This cross-sectional study used data collected from the National Health and Nutrition Examination Survey during 2013 to 2016. Female participants aged 15 years or older with urinary profiles containing common phthalate metabolites were included in this study. Statistical analyses were performed from March 15, 2021, to April 30, 2022. Urinary concentrations of phthalate metabolites were classified into tertiles, and the lowest tertile was used as a reference category. The concentrations of phthalate metabolites and their composite scores based on clustering were also used in the analysis. Serum concentrations of TT and SHBG were dichotomized into high TT levels (>46 ng/dL [to convert to nanomoles per liter, multiply by 0.0347] for age <50 years and >32 ng/dL for age ≥50 years) and low SHBG levels (<2.85 μg/mL [to convert to nanomoles per liter, multiply by 10.53]) as established for the female population. Obesity was defined as a body mass index of 30 or more (calculated as weight in kilograms divided by height in meters squared), and metabolic syndrome was defined using the National Cholesterol Education Program criteria. The serum concentrations of TT and SHBG were also included in the validation analyses. Modified Poisson models were used to estimate the adjusted relative risk (RR) with 95% CIs for the associations. Among the 2004 women included in this study, the mean (SD) age was 46.6 (18.5) years (14.7% Hispanic participants, 62.7% non-Hispanic White participants, and 13.2% non-Hispanic Black participants; 17.4% of participants were born outside the US [weighted percentages]; 230 (11.8%) had high TT levels, 210 (10.4%) had low SHBG levels, 825 (39.8%) had obesity, and 965 (45.5%) had metabolic syndrome (weighted percentages). Of the 13 phthalate metabolites, 8 had the highest tertile level greater than 6.2 ng/mL (range, 0.5-75.2 ng/mL). High levels of exposure to mono(2-ethyl-5-carboxypentyl) phthalate (RR, 1.84 [95% CI, 1.33-2.54]), mono(2-ethyl-5-oxohexyl) phthalate (RR, 1.77 [95% CI, 1.21-2.59]), mono(2-ethyl-5-hydroxyhexyl) phthalate (RR, 1.94 [95% CI, 1.34-2.81]), and monobenzyl phthalate (RR, 1.75 [95% CI, 1.21-2.54]) were associated with low SHBG levels but not with high TT levels. High levels of exposure to some of these metabolites were also associated with obesity and metabolic syndrome. Most associations were specific to premenopausal or postmenopausal women. In this cross-sectional study, exposure to certain phthalate metabolites could be associated with low SHBG levels, obesity, and metabolic syndrome depending on menopausal status.

Could Hormone Levels Impact the Severity of Clitoral Phimosis?

ABSTRACT Introduction Clitoral adhesions (CA) occur when the prepuce adheres to the glans clitoris. CA can be classified as mild, moderate, or severe, based on if more than 75%, 25% to 75%, or less than 25% of the glans clitoris is exposed. Symptoms of CA include pain, difficulty with arousal, and muted or absent orgasm. There is a paucity of information on how hormone levels may contribute to the formation of CA. We hypothesize that patients with lower levels of free and total testosterone, and higher levels of the blood transport protein sex hormone binding globulin (SHBG) could have more severe adhesions. Higher free and total testosterone can yield more oily skin, which may break up or prevent adhesions. Additionally, with higher SHBG, there is less free testosterone available to be used by tissues in the body. Objective To determine if patients with lower free and total testosterone, and higher SHBG have more severe adhesions. Methods Charts of females with CA who underwent the non-surgical lysis procedure at one sexual medicine practice were considered for this study. 24 charts contained information on the severity of phimosis before lysis, total and free testosterone levels, as well as SHBG levels around the time of lysis. The study group consisted of patients with mild (n=9), moderate (n=8), or severe (n=7) CA. Results The average calculated free testosterone among patients with mild, moderate, and severe CA was 0.23ng/dL, 0.35ng/dL, and 0.14ng/dL. The average total testosterone among patients with mild, moderate, and severe CA was 24.79ng/dL, 27.81ng/dL, and 20.26ng/dL. The average SHBG among patients with mild, moderate, and severe CA was 98.69nmol/L, 95.76nmol/L, and 109.40nmol/L. Conclusions We predicted that patients with more severe adhesions would have lower levels of free and total testosterone, as well as higher levels of SHBG, yet this trend did not appear overall in this data among patients with mild, moderate, or severe adhesions. Additional studies with larger sample sizes are needed to explore the potential impact of free and total testosterone, as well as SHBG levels on the development and severity of CA. Studies could also compare levels of these hormones in patients with and without adhesions, or consider patients with recurrence of adhesions. Insight into a hormonal etiology could be important to patients with altered levels of these hormones - for example, patients with medical conditions such as PCOS, patients taking medications such as oral contraceptive pills, and menopausal women on oral estrogen (as increased estrogen raises levels of SHBG) could be at an increased risk for developing CA. Further studies could also consider if the clitoides of transgender males on gender-affirming hormone therapy with testosterone have lower incidences of CA. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Sprout (Raleigh, NC), Absorption Pharmaceuticals

Review of Mendelian Randomization Studies on Endometrial Cancer.

Endometrial cancer (EC) is a common gynecological cancer. In some parts of the world, the incidence and mortality of EC are on the rise. Understanding the risk factors of EC is necessary to prevent the occurrence of this disease. Observational studies have revealed the association between certain modifiable environmental risk factors and EC risk. However, due to unmeasured confounding, measurement errors, and reverse causality, observational studies sometimes have limited ability to judge robust causal inferences. In recent years, Mendelian randomization (MR) analysis has received extensive attention, providing valuable insights for cancer-related research, and is expected to identify potential therapeutic interventions. In MR analysis, genetic variation (alleles are randomly assigned during meiosis and are usually independent of environmental or lifestyle factors) is used instead of modifiable exposure to study the relationship between risk factors and disease. Therefore, MR analysis can make causal inference about exposure and disease risk. This review briefly describes the key principles and assumptions of MR analysis; summarizes published MR studies on EC; focuses on the correlation between different risk factors and EC risks; and discusses the application of MR methods in EC research. The results of MR studies on EC showed that type 2 diabetes, uterine fibroids, higher body mass index, higher plasminogen activator inhibitor-1 (PAI-1), higher fasting insulin, early insulin secretion, longer telomere length, higher testosterone and higher plasma cortisol levels are associated with increased risk of EC. In contrast, later age of menarche, higher circulatory tumor necrosis factor, higher low-density lipoprotein cholesterol, and higher sex hormone-binding globulin levels are associated with reduced risk of EC. In general, despite some limitations, MR analysis still provides an effective way to explore the causal relationship between different risk factors and EC.

Associations between pyrethroid exposure and serum sex steroid hormones in adults: Findings from a nationally representative sample

BackgroundPyrethroids have been considered as potential endocrine-disrupting chemicals and have been shown to be associated with endocrine-related health outcomes. However, limited studies directly explored the link between pyrethroid exposure and sex hormones in the general population. ObjectivesTo explore the associations between exposure to pyrethroids and serum sex steroid hormones in adults. MethodsWe evaluated the cross-sectional associations in 1235 adults aged ≥20 years who had been assigned to the National Health and Nutrition Examination Survey (NHANES) 2013–2014. The urinary concentration of 3-phenoxybenzoic acid (3-PBA) was applied as a biomarker of human pyrethroid exposure levels. Information on sex steroid hormones, including total testosterone (TT), estradiol (E2), and sex hormone-binding globulin (SHBG) in serum were measured. Free androgen index (FAI) and the ratio of TT to E2 (TT/E2) were also calculated. The percent changes with 95% confidence intervals (CIs) for a doubling of 3-PBA concentrations in the serum sex hormone levels were estimated using generalized linear regression models. ResultsThe overall median concentrations of creatinine-adjusted 3-PBA were 0.58 μg/g creatinine, and 90.0% of adults had a detectable level of 3-PBA. In females, every two-fold increase in 3-PBA was associated with 4.34% (95% CI: 1.58%, 7.18%) higher levels of TT and 4.05% (95% CI: 7.03%, 1.16%) higher levels of SHBG, respectively. In males, a doubling in 3-PBA was associated with 3.02% (95% CI: 1.21%, 4.86%) increase in SHBG but 1.85% (−3.59%, −0.07%) decrease in FAI, respectively. In addition, significant non-linear associations of 3-PBA with SHBG in both males and females and TT in females were observed. ConclusionsEnvironmental pyrethroid exposure was associated with altered sex hormones in adults. This study provides important epidemiological evidence for the association of pyrethroids with endocrine disruption.

Relationship between total testosterone, sex hormone–binding globulin levels and the severity of non-alcoholic fatty liver disease in males: a meta-analysis

Background:In recent years, many studies have reported the relationship between non-alcoholic fatty liver disease (NAFLD) and sex hormones, especially total testosterone (TT) and sex hormone–binding globulin (SHBG). However, the relationship between sex hormones and the severity of NAFLD is still unclear.Methods:PubMed, Embase, Cochrane Library, Web of Science, WanFang, China National Knowledge Infrastructure and VIP databases were searched for relevant studies from inception to 31 August 2021. Values of weighted mean differences (WMDs) and odds ratios (ORs) with their 95% confidence intervals (CIs) were combined by Stata 12.0 software to evaluate the relationship between TT, SHBG and the severity of NAFLD in males.Results:A total of 2995 patients with NAFLD from 10 published cross-sectional studies were included for further analysis. The meta-analysis indicated that the moderate-severe group had a lower TT than the mild group in males with NAFLD (WMD: −0.35 ng/ml, 95% CI = −0.50 to −0.20). TT and SHBG were important risk factors of moderate-severe NAFLD in males (ORTT = 0.79, 95% CI = 0.73 to 0.86; ORSHBG = 0.22, 95% CI = 0.12 to 0.39; p < 0.001). Moreover, when the analysis was limited to men older than age 50, SHBG levels were lower in those with moderate-severe disease (WMD: −11.32 nmol/l, 95% CI = −14.23 to −8.40); while for men with body mass index (BMI) >27 kg/m2, moderate-severe NAFLD had higher SHBG levels than those with mild disease (WMD: 1.20 nmol/l, 95% CI = −2.01 to 4.42).Conclusion:The present meta-analysis shows that lower TT is associated with the severity of NAFLD in males, while the relationship between SHBG and severity of NAFLD is still to be further verified.

Tree nut consumption is associated with higher sex hormone-binding globulin levels in premenopausal US women

Low levels of sex hormone-binding globulin (SHBG) are associated with many diseases including hypertension, diabetes, and polycystic ovarian syndrome. Walnuts increased circulating SHBG in 31 women complicated with polycystic ovarian syndrome. However, whether tree nuts increase SHBG in women in a general population is unknown. It was hypothesized in this study that consumption of tree nuts was positively associated with SHBG levels in women in a general population. This cohort study included 2699 adult women from the 2013- to 2016 US National Health and Nutrition Examination Survey. Tree nut consumers were defined as those who consumed tree nuts on either of the 2 24-hours recall days. Associations of tree nut consumption with SHBG were assessed using least squares regression. Among the 2699 women, 234 were consuming tree nuts. The median SHBG concentrations were 67.1 and 59.3 nmol/L among tree nut consumers and non-consumers, respectively. Tree nut consumption was positively associated with circulating SHBG (β=0.041, P=.018) but not testosterone nor estradiol after adjustment for all tested confounders. Sub-analyses showed that the positive association of tree nuts with SHBG presented in premenopausal women but not in postmenopausal women. Tree nut consumption remained independently associated with higher circulating levels of SHBG in premenopausal women when tree nut consumption was expressed as percentage of energy derived from tree nuts or when tree nut consumption was defined as a tree nut intake of ≥0.25 ounce per day. Future research will verify the effectiveness of using tree nuts to treat low SHBG in premenopausal women in the general population.

Aging, Cardiovascular Risk, and SHBG Levels in Men and Women From the General Population.

AimsPrior studies have reported inconsistent results for the association between sex hormone-binding globulin (SHBG) and cardiovascular disease among men and women. Although it is suggested that SHBG levels change with aging, the exact trend of SHBG across age and cardiovascular risk and the underlying mechanisms of these changes remain to be elucidated.MethodsUsing data of 3264 men and women from a large population-based cohort study, we first visualized the distribution of serum SHBG levels across age. Second, we computed a cardiovascular risk factor sum score and investigated the mean SHBG levels across categories of the risk factor sum score and stratified per age-category. Next, linear regression models were used to investigate the associations between serum SHBG levels and age and potential regulators of SHBG, including body mass index (BMI), fasting insulin, sex steroids, thyroxine, and triglycerides.ResultsAmong men, a linear increase in SHBG levels with age and among women a U-shaped pattern was observed. Participants with larger number of cardiovascular risk factors had lower SHBG levels. When stratified by age, older participants had higher SHBG levels. A multivariate model including total testosterone and triglyceride levels in men and total testosterone, triglycerides, BMI, and fasting insulin in women explained, respectively, 46.2% and 31.8% of the variance in SHBG levels.ConclusionWe observed a clear sex-specific pattern for SHBG levels with age. Our findings highlight the importance of taking into account the age-related changes in SHBG levels to avoid controversial results in the assessment of the cardiovascular risk associated with SHBG.

Hypogonadism and liver fibrosis in HIV-infected patients

PurposeHypogonadism is frequent in HIV-infected men and might impact on metabolic and sexual health. Low testosterone results from either primary testicular damage, secondary hypothalamic-pituitary dysfunction, or from liver-derived sex-hormone-binding-globulin (SHBG) elevation, with consequent reduction of free testosterone. The relationship between liver fibrosis and hypogonadism in HIV-infected men is unknown. Aim of our study was to determine the prevalence and type of hypogonadism in a cohort of HIV-infected men and its relationship with liver fibrosis.MethodsWe performed a cross-sectional retrospective study including 107 HIV-infected men (median age 54 years) with hypogonadal symptoms. Based on total testosterone (TT), calculated free testosterone, and luteinizing hormone, five categories were identified: eugonadism, primary, secondary, normogonadotropic and compensated hypogonadism. Estimates of liver fibrosis were performed by aspartate aminotransferase (AST)-to-platelet ratio index (APRI) and Fibrosis-4 (FIB-4) scores.ResultsHypogonadism was found in 32/107 patients (30.8%), with normogonadotropic (10/107, 9.3%) and compensated (17/107, 15.8%) being the most frequent forms. Patients with secondary/normogonadotropic hypogonadism had higher body mass index (BMI) (p < 0001). Patients with compensated hypogonadism had longer HIV infection duration (p = 0.031), higher APRI (p = 0.035) and FIB-4 scores (p = 0.008), and higher HCV co-infection. Univariate analysis showed a direct significant correlation between APRI and TT (p = 0.006) and SHBG (p = 0.002), and between FIB-4 and SHBG (p = 0.045). Multivariate analysis showed that SHBG was independently associated with both liver fibrosis scores.ConclusionOvert and compensated hypogonadism are frequently observed among HIV-infected men. Whereas obesity is related to secondary hypogonadism, high SHBG levels, related to liver fibrosis degree and HCV co-infection, are responsible for compensated forms.

Lung function changes over 8 years and testosterone markers in both sexes: UK Biobank.

Higher levels of testosterone have been associated with better lung function in cross-sectional population-based studies. The role of testosterone in lung function in women and in lung function decline in men or women is unclear.We studied 5114 men and 5467 women in the UK Biobank with high-quality spirometry at baseline (2006–2010) and 8.4 years later. We studied cross-sectional associations of total testosterone (TT), calculated free testosterone (cFT), free androgen index (FAI) and sex hormone-binding globulin (SHBG) with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC using linear regression and associations of baseline markers with lung function decline using linear mixed-effects regression.Men with higher levels of TT had higher FEV1 (27.56 mL per interquartile range increase TT, 95% CI 5.43–49.68) and FVC (48.06 mL, 95% CI 22.07–74.06) at baseline. Higher cFT levels were associated with higher FEV1 and FVC among physically active men only. In women, higher FAI and cFT levels were associated with lower lung function at baseline and higher levels of TT, cFT and FAI were associated with slightly attenuated FEV1 and FVC decline. Higher levels of SHBG were associated with better lung function in both sexes but slightly accelerated decline in men.In this population-based sample, higher levels of TT were associated with better lung function in men and higher levels of cFT with better lung function in physically active men. A small attenuation of lung function decline with higher levels of TT, cFT and FAI was seen in women only.

SAT-LB134 Aging Related Changes in Sex Hormone-Binding Globulin in Men With HIV

Background: Sex hormone-binding globulin (SHBG) is a glycoprotein that regulates the bioavailability of sex hormones, may directly affect glucose metabolism, and increases with age in the general population. SHBG concentrations are higher in people with HIV, a population in whom accelerated aging has been hypothesized. It is unclear whether age-related trajectories of SHBG differ by HIV serostatus. Methods: SHBG was measured in 182 men with HIV (MWH) and 267 men without HIV (MW/oH) from the Multicenter AIDS Cohort Study (MACS) in four U.S. cities, who had ≥2 samples over a 10 year period. Outcome measure: SHBG, log2SHBG. Multivariable linear mixed-effects regression models were used to evaluate whether SHBG (log2-transformed) and its rate of change differed by HIV serostatus after adjustment for covariates: age, race, BMI, smoking, education, hepatitis C virus infection, total testosterone concentrations, time of day of blood drawn and comorbidities (history of diabetes, kidney disease, liver disease, cancer, depression, hypertension) Results: At baseline, mean age among MWH was similar to MW/oH (51±5 vs 49±6 years). However, SHBG values were higher in MWH compared to MWo/H (65.6±48.8 nmol/L vs. 45.4±22 nmol/L, p<0.001). The rate of SHBG change with age was (1.021 (95% CI:1.010-1.028) or 2.1% per year in MWH and (1.014 nmol/L/year (95% CI:1.010-1.019) or 1.4% per year in MW/oH, p=0.05 for difference in slopes. Among MWH, higher SHBG levels were significantly associated with lower CD4+ T cell count (0.99 (5%CI:0.98-1.00), p<0.05), fewer cumulative years on zidovudine (0.98 nmol/L (95%CI:0.96,1.00), p<0.001) and greater cumulative years on non-nucleoside reverse transcriptase inhibitors drugs (1.02 (95%CI:1.00,1.04), p<0.05). Conclusion: Aging-related increases in SHBG were greater in magnitude among men with HIV and were related to poorer immunologic status and antiretroviral factors. The mechanisms and consequences of these findings require further investigation.