Sex hormones differently regulate lipid metabolism genes in primary human hepatocytes.

BACKGROUND: Prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is higher in men than in women. Hormonal and genetic causes may account for the sex differences in MASLD. Current human in vitro liver models do not sufficiently take the influence of biological sex and sex hormones into consideration. METHODS: Primary human hepatocytes (PHHs) were isolated from liver specimen of female and male donors and cultured with sex hormones (17ß-estradiol, testosterone and progesterone) for up to 72 h. mRNA expression levels of 8 hepatic lipid metabolism genes were analyzed by RT-qPCR. Sex hormones and their metabolites were determined in cell culture supernatants by LC-MS analyses. RESULTS: A sex-specific expression was observed for LDLR (low density lipoprotein receptor) with higher mRNA levels in male than female PHHs. All three sex hormones were metabolized by PHHs and the effects of hormones on gene expression levels varied depending on hepatocyte sex. Only in female PHHs, 17ß-estradiol treatment affected expression levels of PPARA (peroxisome proliferator-activated receptor alpha), LIPC (hepatic lipase) and APOL2 (apolipoprotein L2). Further changes in mRNA levels of female PHHs were observed for ABCA1 (ATP-binding cassette, sub-family A, member 1) after testosterone and for ABCA1, APOA5 (apolipoprotein A-V) and PPARA after progesterone treatment. Only the male PHHs showed changing mRNA levels for LDLR after 17ß-estradiol and for APOA5 after testosterone treatment. CONCLUSIONS: Male and female PHHs showed differences in their expression levels of hepatic lipid metabolism genes and their responsiveness towards sex hormones. Thus, cellular sex should be considered, especially when investigating the pathophysiological mechanisms of MASLD.

In vivo induction of male sexual behavior in zebrafish by adding agents to water.

Successful fertilization in fish mating occurs when egg maturation in the ovary of the female, ovulation, sperm maturation in the testis of the male, and reproductive behaviors in both sexes are triggered in synchrony. The male sexual behavior of fish is induced by hormones and pheromones. In a previous study, we demonstrated that externally applied hormones added to the water can induce oocyte maturation and ovulation in female zebrafish. Here, we attempted to establish a similar method to induce the sexual behavior of male zebrafish. The male sex steroid testosterone (Tes) triggered sexual behavior within several hours in vivo when administered directly into the surrounding water. A selective agonist for membrane progesterone receptor (mPR), Org OD-02 (Org), also induced sexual behavior. Through trials of various combinations of compounds, we found that the most effective conditions were achieved by treatment with a mixture of testosterone (Tes) and Org. The effect of treatment was evaluated by the number of fertilized eggs obtained by pairing with females with induced ovulation in vivo. The period necessary for the induction of male sexual behavior was evaluated by time course experiments. The success rate of mating and the number of fertilized eggs reached the maximum level at 3-4 hours of treatment. The duration of hormonal treatment was confirmed by counting the number of hooking occurrences, which is the final cue to induce spawning by females. In summary, we have established a method to induce male sexual behavior in zebrafish in vivo. The method can be used to obtain fertilized eggs in zebrafish by simply adding agents into the water.

Testosterone replacement therapy for hypogonadism: A primer for primary care.

ABSTRACT: Testosterone replacement therapy (TRT) is a crucial intervention for men diagnosed with hypogonadism, a condition characterized by inadequate testosterone production. As primary care NPs play an essential role in managing patients with hypogonadism, they must comprehensively understand TRT. This article serves as a primer for primary care NPs, based on current guidelines, to provide evidence-based care for men with hypogonadism. It offers an overview of the etiology, clinical presentation, diagnostic criteria, and treatment options for hypogonadism, focusing on using TRT appropriately in primary care settings.

Sex Hormones and Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study and Mendelian Randomization Analysis.

Background: Sex steroid hormones, including testosterone and estradiol, play significant roles in various aspects of pulmonary health and diseases. However, although there were a few studies trying to link sex hormones with COPD, their effect remained limited due to small sample size and insufficient causal results. This study aims to investigate the association between sex hormones and chronic obstructive pulmonary disease (COPD) based on the National Health and Nutrition Examination Survey (NHANES) database and evaluate causality via a two-sample Mendelian randomization (MR). Methods: Data from NHANES 2013-2016 were enrolled for the cross-sectional study. The association between sex hormones and COPD was evaluated via multivariable logistic regression. Sex-stratified analysis, subgroup analyses and interaction tests were performed to further evaluate the correlation. For MR analysis, data were collected from genome-wide association studies and FinnGen datasets. The inverse-variance-weighted (IVW) approach, along with four other approaches, was applied in the analysis. Further sensitivity analysis was conducted to assess the existence of pleiotropy and heterogeneity. Results: 7,617 eligible participants were enrolled in the cross-sectional analysis. Negative associations were observed in both testosterone-COPD (OR 0.770, 95% CI 0.626, 0.948, p = 0.018) and estradiol-COPD (OR 0.794, 95% CI 0.688, 0.915, p = 0.005) relationships after covariate adjustments. However, the results from IVW-MR analysis showed that no causal relationship was observed in either the testosterone-COPD (OR 0.83, 95% CI 0.53, 1.29, p = 0.407) or estradiol-COPD (OR 0.74, 95% CI 0.23, 2.38, p = 0.616) relationship, which was also supported by the other four approaches (all p values > 0.05). Conclusion: Although a significant negative association was observed between sex hormones and COPD, the results of MR analysis did not support the causality of this relationship. Our study suggested that sex hormones may indirectly rather than directly affect the development of COPD via potential covariates, which warranted further investigations.

Loss of Function of Vasoactive-intestinal Peptide Alters Sex Ratio and Reduces Male Reproductive Fitness in Zebrafish.

Vasoactive-intestinal peptide (Vip) is a pleiotropic peptide with a wide range of distribution and functions. Zebrafish possess 2 isoforms of Vip (a and b), in which Vipa is most homologous to the mammalian form. In female zebrafish, Vipa can stimulate LH secretion from the pituitary but is not essential for female reproduction, as vipa-/- females display normal reproduction. In contrast, we have found that vipa-/- males are severely subfertile and sex ratio of offspring is female-biased. By analyzing all aspects of male reproduction with wild-type (WT) males, we show that the testes of vipa-/- are underdeveloped and contain ∼70% less spermatids compared to WT counterparts. The sperm of vipa-/- males displayed reduced potency in terms of fertilization (by ∼80%) and motility span and duration (by ∼50%). In addition, vipa-/- male attraction to WT females was largely nonexistent, indicating decreased sexual motivation. We show that vipa mRNA and protein is present in Leydig cells and in developing germ cells in the testis of WT, raising the possibility that endogenous Vipa contributes to testicular function. Absence of Vipa in vipa-/- males resulted in downregulation of 3 key genes in the androgen synthesis chain in the testis, 3ß-hsd, 17ß-hsd1, and cyp11c1 (11ß-hydrogenase), associated with a pronounced decrease in 11-ketotestosterone production and, in turn, compromised reproductive fitness. Altogether, this study establishes a crucial role for Vipa in the regulation of male reproduction in zebrafish, like in mammals, with the exception that Vipa is also expressed in zebrafish testis.

Identification of MAP1LC3A as a promising mitophagy-related gene in polycystic ovary syndrome.

Increasing evidence suggests that mitophagy is crucially involved in the progression of polycystic ovary syndrome (PCOS). Exploration of PCOS-specific biomarkers related to mitophagy is expected to provide critical insights into disease pathogenesis. In this study, we employed bioinformatic analyses and machine learning algorithms to determine novel biomarkers for PCOS that may be tied with mitophagy. A grand total of 12 differential expressed mitophagy-related genes (DE-MRGs) associated with PCOS were identified. TOMM5 and MAP1LC3A among the 12 DE-MRGs were recognized as potential marker genes by LASSO, RF and SVM-RFE algorithms. The area under the ROC curve (AUROC) of MAP1LC3A were all greater than 0.8 both in the training set and validation sets. The CIBERSORT analysis indicated a potential association between alterations in the immune microenvironment of PCOS individuals and MAP1LC3A expression. In addition, we found that MAP1LC3A was positively related to the testosterone levels of PCOS patients. Overall, MAP1LC3A was identified as optimal PCOS-specific biomarkers related to mitophagy. Our findings created a diagnostic strength and offered a perspective for investigating the mitophagy process in PCOS.

The genetic effects of hormones modulated by the Pituitary-Thyroid/Adrenal/Gonadal axis on the risk of developing venous thromboembolism: a mendelian randomization study.

BACKGROUND: The aim of this study was to explore the genetic effects of hormones modulated through the pituitary-thyroid/adrenal/gonadal axis on the risk of developing venous thromboembolism (VTE) and to investigate the potentially causal relationships between them. METHODS: A two-sample Mendelian randomization (MR) design was used. The single-nucleotide polymorphisms (SNPs) used as instrumental variables for various hormones and hormone-mediated diseases were derived from published genome-wide association studies (GWASs). Summary statistics for the risk of developing VTE (including deep venous thrombosis [DVT] and pulmonary embolism [PE]) were obtained from the UK Biobank and the FinnGen consortium. Inverse-variance weighting (IVW) was applied as the primary method to analyse causal associations. Other MR methods were used for supplementary estimates and sensitivity analysis. RESULTS: A genetic predisposition to greater free thyroxine (FT4) concentrations was associated with a greater risk of developing DVT (OR = 1.0007, 95%CI [1.0001-1.0013], p = 0.0174) and VTE (OR = 1.0008, 95%CI [1.0002-1.0013], p = 0.0123). Genetically predicted hyperthyroidism was significantly associated with an increased risk of developing DVT (OR = 1.0685, 95%CI [1.0139-1.1261], p = 0.0134) and VTE (OR = 1.0740, 95%CI [1.0165-1.1348], p = 0.0110). According to the initial MR analysis, testosterone concentrations were positively associated with the risk of developing VTE (OR = 1.0038, 95%CI [1.004-1.0072], p = 0.0285). After sex stratification, estradiol concentrations were positively associated with the risk of developing DVT (OR = 1.0143, 95%CI [1.0020-1.0267], p = 0.0226) and VTE (OR = 1.0156, 95%CI [1.0029-1.0285], p = 0.0158) in females, while the significant relationship between testosterone and VTE did not persist. SHBG rs858518 was identified as the only SNP that was associated with an increased risk of developing VTE, mediated by estradiol, in females. CONCLUSIONS: Genetically predicted hyperthyroidism and increased FT4 concentrations were positively associated with the risk of developing VTE. The effects of genetically predicted sex hormones on the risk of developing VTE differed between males and females. Greater genetically predicted estradiol concentrations were associated with an increased risk of developing VTE in females, while the SHBG rs858518 variant may become a potential prevention and treatment target for female VTE.

The effect of testosterone on the gut microbiome in mice.

The role of hormones in gut-brain crosstalk is largely elusive, but recent research supports specific changes in hormone levels correlated with the gut microbiota. An interesting but unstudied area in microbial endocrinology is the interplay between the microbiota and sex hormones. The aim of this study is to investigate the effect of testosterone and sex on the mouse gut microbiome. We use in vitro experiments to test direct effects of testosterone on bacteria in fecal samples collected from male and female mice pre- and post-puberty. Sex-specific microbial and metabolic differences surrounding puberty are also examined in vivo. We then explore effects of testosterone supplementation in vivo, characterizing microbiota and metabolomes of male and female mice. We detect sex-specific differences in microbiota and associated metabolites of mice post-puberty, but in vitro experiments reveal that testosterone only affects microbiota of fecal samples collected before puberty. Testosterone supplementation in vivo affects gut microbiota and metabolomes in both male and female mice. Taking our results from in vitro and in vivo experiments, we conclude that the shift in the microbiome after puberty is at least partially caused by the higher levels of sex hormones, mainly testosterone, in the host.

Association between life's essential 8 and male biochemical androgen deficiency: evidence from NHANES 2013-2016.

Purpose: To evaluate the association of Life's Essential 8 (LE8) and its subscales with male biochemical androgen deficiency (MBAD) and total testosterone based on the data from the national health and nutrition examination survey (NHANES) database. Methods: Data of males aged 20 years or older from NHANES of 2013-2016 were extracted. LE8 score was calculated based on American Heart Association definitions. Total testosterone (TT) values were measured in NHANES using precise isotope dilution liquid chromatography. MBAD was defined as serum TT of <300 ng/dL. Univariate and multivariable analyses were conducted. Propensity score matching (PSM) and weighted regression after matching were added as sensitivity analyses. The generalized additive model, smooth curve fitting, and the recursive algorithm were used to determine the potential inflection points. Piecewise regression models with log-likelihood ratio test were used to quantify nonlinear effects. Results: A total of 3094 participants who were males and aged 20 years or above were included. Out of them, 805 males were diagnosed with MBAD. After adjusting the confounders in the multivariable model, LE8 was independently associated with MBAD (OR 0.96, P < 0.001) and TT (ß 2.7, P < 0.001). The association remained robust even after PSM. The non-linear relationship of LE8 behaviors score with MBAD and TT was revealed. Conclusion: LE8 was an independent protective factor of MBAD and a feasible approach to promote male endocrine sexual function.

Association between life's essential 8 and testosterone deficiency in US men: findings from national health and nutrition examination survey (NHANES) 2011-2016.

Background: Testosterone deficiency (TD) is closely associated with cardiovascular diseases (CVD). We intended to explore the association of Life's Essential 8 (LE8), the recently updated measurement of cardiovascular health, with the prevalence of TD among US male adults. Methods: The population-based cross-sectional study selected male adults aged 20 years or older from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2016. According to the American Heart Association definitions, the LE8 score was measured on a scale of 0-100, and divided into health behavior and health factor scores, simultaneously. Furthermore, these scores were categorized into low (0-49), moderate (50-79), and high (80-100) classifications. TD is defined as a total testosterone level below 300ng/dL. Correlations were investigated by weighted multivariable logistic regression, and the robustness of the results were verified by subgroup analysis. Results: A total of 4971 male adults with an average age of 47.46 ± 0.41 years were eligible for the final analyses, of whom 1372 were determined to have TD. The weighted mean LE8 score of the study population was 68.11 ± 0.41. After fully adjusting potential confounders, higher LE8 scores were significantly associated with low risk of TD (odd ratio [OR] for each 10-point increase, 0.79; 95% CI, 0.71-0.88) in a linear dose-response relationship. Similar patterns were also identified in the association of health factor scores with TD (OR for each 10-point increase, 0.74; 95% CI, 0.66-0.83). These results persisted when LE8 and health factor scores was categorized into low, moderate, and high groups. The inversed association of LE8 classifications and TD remained statistically significant among older, obese, and men without CVD. Conclusions: LE8 and its health factor subscales scores were negatively associated with the presence of TD in linear fashions. Promoting adherence to optimal cardiovascular health levels may be advantageous to alleviate the burden of TD.

Ursolic acid attenuates oligospermia in busulfan-induced mice by promoting motor proteins.

Background: Oligospermia is one of the most common reasons for male infertility which is troubling numerous couples of child-bearing age. This investigation scrutinizes the implications and mechanistic underpinnings of ursolic acid's effect on busulfan-induced oligospermia in mouse models. Methods: A singular intraperitoneal injection of busulfan at a dosage of 30 mg/kg induced oligospermia. Two weeks subsequent to this induction, mice were subjected to various dosages of ursolic acid (10, 30, and 50 mg/kg body weight, respectively) on a daily basis for four consecutive weeks. Following this treatment period, a meticulous analysis of epididymal sperm parameters, encompassing concentration and motility, was conducted using a computer-assisted sperm analysis system. The histopathology of the mice testes was performed utilizing hematoxylin and eosin staining, and the cytoskeleton regeneration of the testicular tissues was analyzed via immunofluorescent staining. Serum hormone levels, including testosterone, luteinizing hormone, and follicle-stimulating hormone, as well as reactive oxygen species levels (inclusive of reactive oxygen species and malondialdehyde), were gauged employing specific enzyme-linked immunosorbent assay kits. Differentially expressed genes of testicular mRNA between the oligospermia-induced group and the various ursolic acid treatment groups were identified through RNA sequencing analysis. Results: The results revealed that a dosage of 50 mg/kg ursolic acid treatment could increase the concentration of epididymal sperm in oligospermia mice, promote the recovery of testicular morphology, regulate hormone levels and ameliorate oxidative damage. The mechanism research results indicated that ursolic acid increased the expression level of genes related to motor proteins in oligospermia mice.

Acute Hormonal and Inflammatory Responses following Lower and Upper Body Resistance Exercises Performed to Volitional Failure.

This study aimed to investigate the effects of a single bench press (BP) vs. leg press (LP) resistance training sessions on testosterone, cortisol, C-reactive protein (CRP) interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) concentrations, and creatine kinase (CK) activity in strength-trained males. Eleven strength-trained males participated in a cross-over randomized trial, undergoing two experimental sessions each consisting of five sets of the BP or the LP exercise to volitional failure with a load corresponding to 50% of one-repetition maximum. Blood samples were taken at baseline (BA), immediately post (POST), and 1 h after the cessation of exercise (POST-1). A significant increase in IL-6 concentration from BA to POST-1 was observed during the LP condition (p = 0.004; effect size [ES] = 0.64). Additionally, a significant main effect of time was found for increasing testosterone concentrations from BA to POST exercise (p = 0.014; ES = 0.25). A significantly lower cortisol concentration at POST-1 compared to POST (p = 0.001; ES = 1.02) was noted in the BP condition. Furthermore, a significantly lower cortisol concentration was found at POST-1 in the BP compared to the LP condition (p = 0.022; ES = 1.3). A significant increase in CK activity was reported from BA to POST (p = 0.024; ES = 0.69) and POST-1 (p = 0.045; ES = 0.55) during the LP condition, and from BA to POST-1 (p = 0.014; ES = 0.96) during the BP condition. No significant differences were found in the CRP (p = 0.659) and TNF-α concentrations (p = 0.487). These results suggest that the amount of muscle mass engaged during the resistance exercise may influence the changes in IL-6 and cortisol concentrations. Larger muscle groups, as engaged in the LP, more likely lead to elevated concentrations of IL-6 myokine.

Gene-vegetarianism interactions in calcium, estimated glomerular filtration rate, and testosterone identified in genome-wide analysis across 30 biomarkers.

We examined the associations of vegetarianism with metabolic biomarkers using traditional and genetic epidemiology. First, we addressed inconsistencies in self-reported vegetarianism among UK Biobank participants by utilizing data from two dietary surveys to find a cohort of strict European vegetarians (N = 2,312). Vegetarians were matched 1:4 with nonvegetarians for non-genetic association analyses, revealing significant effects of vegetarianism in 15 of 30 biomarkers. Cholesterol measures plus vitamin D were significantly lower in vegetarians, while triglycerides were higher. A genome-wide association study revealed no genome-wide significant (GWS; 5×10-8) associations with vegetarian behavior. We performed genome-wide gene-vegetarianism interaction analyses for the biomarkers, and detected a GWS interaction impacting calcium at rs72952628 (P = 4.47×10-8). rs72952628 is in MMAA, a B12 metabolic pathway gene; B12 has major deficiency potential in vegetarians. Gene-based interaction tests revealed two significant genes, RNF168 in testosterone (P = 1.45×10-6) and DOCK4 in estimated glomerular filtration rate (eGFR) (P = 6.76×10-7), which have previously been associated with testicular and renal traits, respectively. These nutrigenetic findings indicate genotype can modify the associations between vegetarianism and health outcomes.

Decoding connections in the European population: serum uric acid, sex hormone-binding globulin, total testosterone, estradiol, and female infertility - advanced bidirectional and mediative Mendelian randomization.

Background: Despite observational links between serum uric acid (SUA), sex hormone-related phenotypes, and female infertility, the causality behind these associations remains uncertain. Objective: This study utilizes Bidirectional Two-Sample and Mediation Mendelian Randomization to explore the causal relationships and mediation effects of sex hormone-binding globulin (SHBG), total testosterone (TT), and estradiol on these associations. Methods: We analyzed single-nucleotide polymorphisms (SNPs) associated with SUA and sex hormone levels using data from large-scale GWAS of European populations. Female infertility data were sourced from 6,481 cases and 75,450 controls in the FinnGen Consortium. We employed methods including Inverse Variance Weighted (IVW), Weighted Median, and MR-Egger regression to assess causality. Results: We found that elevated SUA levels causally increase the risk of female infertility (IVW OR: 1.13, P=0.047). Elevated SUA levels significantly decrease SHBG levels (ß=-0.261; P=2.177e-04), with SHBG mediating 27.93% of the effect of SUA on infertility (OR=0.854; 95%CI, 0.793-0.920; P=2.853e-05). Additionally, elevated TT levels, which were associated with decreased SUA levels (ß=-0.127), showed an indirect effect on infertility mediated by SUA (ß=-0.0187; 95% CI, -0.041 to -0.003; P=0.046). Conclusion: Our findings demonstrate causal links between high SUA and increased risk of female infertility mediated by hormonal factors such as SHBG and TT. These insights suggest new avenues for infertility treatment and highlight the need for further research into these mechanisms.

Intracerebroventricular injection of spexin stimulates the hypothalamic-pituitary-testicular axis and increases the secretion of male reproductive hormones in rats.

BACKGROUND: Male reproductive functions are regulated in the hypothalamic-pituitary-gonadal (HPG) axis. Any problem in this axis would lead to the deterioration of reproductive functions. The present study aimed to investigate the effects of intracerebroventricular (icv) Spexin (SPX) infusion on the HPG axis in detail. METHODS: 40 Wistar albino rats were divided into four groups: control, sham, SPX 30 nmol and SPX 100 nmol (n=10). 30 nmol/1 µl/hour SPX was administered icv to the rats in the SPX 30 nmol group for 7 days, while rats in the SPX 100 nmol group were administered 100 nmol/1 µl/hour SPX. On the 7th day, the rats were decapitated, blood and tissue samples were collected. Serum LH, FSH and testosterone levels were determined with the ELISA method, GnRH mRNA expression level was determined in hypothalamus with the RT-PCR method. Seminiferous tubule diameter and epithelial thickness were determined with the hematoxylin-eosin staining method. RESULTS: SPX infusion was increased GnRH mRNA expression in the hypothalamus tissue independent of the dose (p<0.05). Serum LH, FSH and testosterone levels in the SPX groups were increased when compared to the control and sham groups independent of the dose (p <0.05). Histological analysis revealed that SPX infusion did not lead to any changes in seminiferous epithelial thickness, while the tubule diameter increased in the SPX groups (p<0.05). CONCLUSION: The study findings demonstrated that icv SPX infusion stimulated the HPG axis and increased the secretion of male reproductive hormones.

Gonadal hormones and metabolic syndrome in middle-aged and elderly males: results from a prospective cohort study in China.

Background: Research has shown that gonadal hormones are involved in metabolic pathways relevant to metabolic syndrome (MetS). Nevertheless, no longitudinal study has been conducted on the association between SHBG and MetS in Chinese. The objective of our study was to determine whether there is any association between middle-aged and elderly males in China. Methods: A total of 531 eligible male subjects, aged above 40 years or older, without MetS at baseline, were recruited. Sex hormone binding globulin (SHBG), total testosterone (TT), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured. A harmonized definition and recommended thresholds for the Chinese population were used to determine metabolic syndrome. Results: During 3.2 years of follow-up, 20.7% of subjects had developed MetS. Compared with the non-MetS group, subjects in the new-onset MetS group had significantly lower SHBG (43.5 nmol/L [28.8, 74.9] vs 53.7nmol/L [33.8, 115.0], P=0.0018), TT (18.1nmol/L [13.6-21.7] vs 19.5nmol/L[15.0-23.6], P=0.0204), and LH (5.13mIU/L [3.63-7.29] vs 5.87mIU/L [4.05-8.36]) at baseline. The incidence of MetS was decreased according to elevated SHBG quartiles (Q1:26.9%, Q2:22.7%, Q3:21.1%, Q4:12.1%, P for trend =0.0035), TT (Q1: 25.2%, Q2:23.7%, Q3: 17.3%, Q4: 16.7%, P for trend=0.0425), and LH (Q1:25.0%, Q2:21.8%, Q3: 21.8%, Q4: 14.3%, P for trend=0.0411). Compared with those in quartile 4, the OR[CI] of incident MetS for participants in Quartile 1 was 2.33[1.13-4.79] after multiple adjustments. But associations between incident MetS and different quartiles of LH, TT, and FSH were not observed after multiple adjustments. In the subgroup analyses, the significant association between SHBG level and Mets was detected in subjects over 60 years or older, with normal BMI, without insulin resistance, and with eGFR ≥90 mL/min per 1.73m2. Conclusion: Compared with TT, LH, and FSH, a lower level of SHBG is significantly related to the incidence of MetS among middle-aged and elderly males in China.

Risk of erythrocytosis in transgender individuals undergoing testosterone therapy: a systematic review.

INTRODUCTION: In transgender individuals assigned female at birth, testosterone therapy is employed for body masculinization. Guidelines recommend close monitoring for potential side effects of hormonal therapy, especially during the first year. Erythrocytosis is a common finding during testosterone therapy and has been associated with a potential risk of thrombotic and cardiovascular events. Currently, the hematologic effects of testosterone therapy are understudied, with existing data primarily derived from the cisgender male population. The aim of this study was to comprehensively examine the hematological changes induced by testosterone therapy in the transgender population. EVIDENCE ACQUISITION: A systematic search was conducted using the electronic database PubMed. EVIDENCE SYNTHESIS: Thirty-six manuscripts were retrieved. After screening for original studies, 19 articles were included. Selected articles were published between 2005 and 2023. CONCLUSIONS: In our systematic review, the prevalence of erythrocytosis varied from 0% to 29.3%, with severe erythrocytosis ranging from 0.5% to 2.3%. Testosterone therapy was associated with an increase in hemoglobin and hematocrit, particularly within the first year of therapy. Factors such as serum testosterone levels, along with the duration, doses, and formulation of testosterone therapy, were found to be associated with the development of erythrocytosis. Further research is crucial to provide specific recommendations for clinical practice.

Sex-Specific Differences in Serum Kallikrein-8 (KLK8): An Exploratory Study.

Background: There are indications for sex-specific differences regarding the association between kallikrein-8 (KLK8) and cognitive impairment in early stages of Alzheimer's disease for which KLK8 may be an early blood-based biomarker. These may be due to different levels of sex hormones. To correctly interpret KLK8 blood concentrations, sex-specific analyses are needed. Objective: The aim of our exploratory study was to investigate sex-specific differences in blood-based KLK8 in participants of the population-based Heinz Nixdorf Recall study with different cognitive status and the association between KLK8 and sex hormones. Methods: In 290 participants (45% women, 69.7±7.4 years (mean±SD)) we investigated sex-specific serum KLK8 differences between cognitively unimpaired (CU, 43%) and cognitively impaired (CI) participants and the association between KLK8 and dehydroepiandrosteronsulfate (DHEAS), estradiol and testosterone, using adjusted multiple linear regression. Results: The mean±SD KLK8 was similar for CU men (808.1±729.6 pg/ml) and women (795.9±577.7 pg/ml); adjusted mean-difference [95%-CI]: -95.3 [-324.1;133.5] pg/ml. KLK8 was lower in CI women (783.5±498.7 pg/ml) than men (1048.4±829 pg/ml); -261 [-493.1; -29] pg/ml. In men but not women, there was a weak indication for a positive slope between estradiol (11.9 [-0.4;24.3] pg/ml) and DHEAS (1.4 [-0.5;3.3] pg/ml) with KLK8, while testosterone had no impact. Conclusions: The results suggested a different role for KLK8 in the development of cognitive impairment in men and women, potentially influenced by sex hormones. To use blood KLK8 as an early biomarker, further research on hormonal regulation of KLK8 expression is needed as a part of the investigation of the KLK8 involvement in cognitive impairment and Alzheimer's disease pathology.

One out of two idiopathic infertile men has pathologic sperm DNA fragmentation values: Potential implications for clinical practice.

OBJECTIVES: To investigate the distribution of sperm DNA fragmentation (SDF) values and their association with clinical and seminal parameters in idiopathic infertile men. DESIGN, PATIENTS, MEASUREMENTS: Data from 3224 primary infertile men (belonging to couples having failed to conceive a pregnancy within 12 months) who underwent a thorough diagnostic work-up were analysed. A SDF value ≥ 30% (according to Sperm Chromatin Structure Assay) was considered pathologic. We excluded: (1) men with genetic abnormalities; (2) men with history of cryptorchidism; (3) men with biochemical hypogonadism; (4) men with clinical varicocele; and (5) men with other possible known aetiological factors. Descriptive statistics and logistic regression analyses were used to describe the whole cohort. RESULTS: Of all, 792 (23%) men with at least one abnormal WHO semen parameter but without any identified aetiologic factor for infertility, were considered as idiopathic infertile men. Of 792, 418 (52.7%) men had SDF ≥30%. Men with pathologic SDF were older (p = .02), had higher Follicle-stimulating hormone (FSH) (p = .04) but lower total testosterone (p = .03) values than those with SDF <30%. The homoeostatic model assessment index for insulin resistance (HOMA-IR) was higher in men with SDF ≥30% (p = .01). Idiopathic infertile men with SDF ≥30% presented with lower sperm concentration (p < .001) and lower progressive sperm motility (p < .01) than those with SDF < 30%. Logistic regression analysis revealed that older age (OR: 1.1, p = .02) and higher HOMA-IR score (OR: 1.8, p = .03) were associated with SDF ≥ 30%, after accounting for FSH and sperm concentration values. CONCLUSIONS: Approximately half of infertile men categorized as idiopathic had pathologic SDF values. Idiopathic infertile men with pathologic SDF showed worse clinical, hormonal and semen parameters than those with normal SDF values. These results suggest that including SDF testing could be clinically relevant over the real-life management work-up of infertile men.