Fecundability according to male serum inhibin B—a prospective study among first pregnancy planners

Fertility assessment and treatment in adolescent and young adult cancer survivors

In the survivorship setting, adolescent and young adult (AYA) cancer survivors frequently demonstrate little knowledge of infertility risk, are unclear regarding their fertility status, and may under- or overestimate their treatment-related risk for infertility. In female AYA survivors, ovarian function usually parallels fertility, and can be assessed with serum hormone levels and ultrasonography. Posttreatment fertility preservation may be appropriate for survivors at risk for primary ovarian insufficiency. In male AYA survivors, fertility and gonadal function are not always equally affected, and can be assessed with a semen analysis and serum hormones, respectively. As reproductive health issues are commonly cited as an important concern by survivors of AYA cancer, multidisciplinary care teams including oncology, endocrinology, psychology, and reproductive medicine are advocated, with the aim of optimal provision of fertility advice and care for AYA cancer survivors.

Functions of somatic cells for spermatogenesis in stallions

Spermatogenesis and testis development are highly structured physiological processes responsible for post-pubertal fertility in stallions. Spermatogenesis comprises spermatocytogenesis, meiosis, and spermiogenesis. Although germ cell degeneration is a continuous process, its effects are more pronounced during spermatocytogenesis and meiosis. The productivity and efficiency of spermatogenesis are directly linked to pubertal development, degenerated germ cell populations, aging, nutrition, and season of the year in stallions. The multiplex interplay of germ cells with somatic cells, endocrine and paracrine factors, growth factors, and signaling molecules contributes to the regulation of spermatogenesis. A cell-to-cell communication within the testes of these factors is a fundamental requirement of normal spermatogenesis. A noteworthy development has been made recently on discovering the effects of different somatic cells including Leydig, Sertoli, and peritubular myoid cells on manipulation the fate of spermatogonial stem cells. In this review, we discuss the self-renewal, differentiation, and apoptotic roles of somatic cells and the relationship between somatic and germ cells during normal spermatogenesis. We also summarize the roles of different growth factors, their paracrine/endocrine/autocrine pathways, and the different cytokines associated with spermatogenesis. Furthermore, we highlight important matters for further studies on the regulation of spermatogenesis. This review presents an insight into the mechanism of spermatogenesis, and helpful in developing better understanding of the functions of somatic cells, particularly in stallions and would offer new research goals for developing curative techniques to address infertility/subfertility in stallions.

Evaluation of selected semen parameters and biomarkers of male infertility - preliminary study

Background: Because the etiopathogenesis of male infertility is multifactorial our study was designed to clarify the relationship between standard semen parameters, testicular volume, levels of reproductive hormones and the fragmentation of sperm nuclear DNA (SDF). Methods: Patients (n = 130) were clustered as subjects: 1) with an abnormal volume (utrasonography) of at least one testis (<12 mL) or with a normal volume of testes and 2) with abnormal levels of at least one of the reproductive hormones (FSH, LH, PRL, TSH, total T - electrochemiluminescence method) or with normal hormonal profiles and 3) with high level of SDF (>30%), moderate (>15-30%) or low (≤15%) (sperm chromatin dispersion test). Results: In subjects with a decreased testicular volume and in subjects with abnormal levels of reproductive hormones, decreased basic semen parameters were found. Participants with abnormal testicular volume had a higher percentage of SDF and a higher level of FSH (Mann-Whitney U test). In turn, men with a high level of SDF had lower testicular volume and conventional sperm parameters than men with a low level of SDF (Kruskal-Wallis test). Conclusions: We showed that spermatogenesis disorders coexisted with decreased testicular volume and increased FSH levels. The disorders of spermatogenesis were manifested by reduced basic sperm characteristics and a high level of sperm nuclear DNA damage.

Reference range and cutoff value of serum inhibin B to predict successful sperm retrieval: A cross-sectional study of 30 613 Chinese men

BACKGROUND

The power of inhibin B to predict competent spermatogenesis is not fully understood. The aims of this study were to identify the reliable reference range of inhibin B among normozoospermic men in China and to evaluate the diagnostic accuracy of serum inhibin B level as a complementary predictor of successful sperm retrieval in patients with azoospermia.

METHODS

This was a cross-sectional study. The male partners of 30 613 infertile couples who visited our hospital were investigated between March 2017 and March 2019. We analysed semen parameters, serum levels of reproductive hormones (inhibin B, FSH and testosterone) and sperm retrieval results from PESA/TESE in Chinese men.

RESULTS

The normal reference range of inhibin B was 87.42-299.93 pg/mL among men with normozoospermia in China. Inhibin B levels were negatively correlated with age (r = -.111; P < .001) but positively correlated with total sperm counts in the overall population, reference group and case group (r = .311, r = .208 and r = .444, respectively; P < .001). Stepwise multiple regression analyses revealed that compared with the FSH and testosterone levels, the inhibin B level had the closest relationship with the total sperm count. The best cutoff value of inhibin B for predicting the retrieval outcome of testicular/epididymal sperm was >77.72 pg/mL (sensitivity = 59.14%, specificity = 92.00% and AUC = 0.801). The inhibin B:FSH ratio (cutoff value > 6.98, sensitivity = 56.99%, specificity = 96.00% and AUC = 0.814) performed better than either the inhibin B level or the FSH level alone.

CONCLUSION

A new reference range for serum inhibin B was established in China. However, neither serum inhibin B, FSH nor their ratio is adequate for men to decide whether to undergo PESA/TESE to determine the adequacy of spermatogenesis.

Inhibin-A and Inhibin-B in stallions: Seasonal changes and changes after down-regulation of the hypothalamic-pituitary-gonadal axis

The biological function of inhibin is mediated by two heterodimers, inhibin-A and inhibin-B. The relative importance of inhibin-A and -B in male reproductive function varies considerably across species with inhibin-B predominating in many species, whereas inhibin-A appears relatively more important in rams. Research reported to date in stallions has examined total or immunoreactive (ir) inhibin which does not distinguish the two heterodimers. Therefore, the objective of this study was to characterize changes in inhibin-A and inhibin-B concentrations in stallions: 1) across season for a period of one year, and 2) after downregulation of the hypothalamic-pituitary-gonadal (HPG) axis. In Study one, serum samples were obtained monthly from five stallions for a period of one year. Serum concentrations of inhibin-A, inhibin-B, testosterone and estrone sulfate were determined by ELISA. In Study two, stallions were treated with the GnRH antagonist, acyline (n = 4; 330 mg/kg acyline IM) or vehicle control (n = 4; vehicle alone) every five days for 50 days. Plasma concentrations of inhibin-A and -B were determined by ELISA at Days 0, 6, 12, 22, 37, 59, 80, 87 and 104 after initiation of acyline treatment. Testis volume was determined by ultrasonography at weekly intervals. In Study 1, both inhibin-A and inhibin-B showed seasonal changes in concentration with highest concentrations in increasing day length and lowest concentrations in short day lengths. Inhibin-B (overall mean 107.8 ± 4.1 pg/mL) was present at 4.7-fold higher concentrations in serum than inhibin-A (overall mean 23.0 ± 0.7 pg/mL). In Study 2, plasma concentrations of inhibin-B but not inhibin-A were significantly downregulated by administration of the GnRH antagonist, acyline. When the HPG axis was downregulated by acyline, testis volume was strongly correlated with inhibin-B (r = 0.73; P < 0.05) but not inhibin-A (r = 0.22; P = 0.20). In summary, inhibin-B appears to be the predominant form of inhibin in the stallion which undergoes seasonal regulation along with other reproductive parameters and is co-regulated with other endocrine parameters of the HPG axis.

Anthropometric Measurements, Serum Reproductive Hormonal Levels and Sexual Development among Boys in the Rural Western Cape, South Africa

Data on growth and sexual maturation among boys from the rural Western Cape in South Africa is limited. A cross-sectional study of 269 school boys was conducted testing for serum luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone, sex hormone binding globulin (SHBG) and estradiol (E2); height, weight and body mass index (BMI); sexual maturity (using Tanner Stages) and a questionnaire (demographic and medical history). The median age at pubertal onset (Tanner Stage 2) and Tanner Stage 5 was 11.6 and 14.7 years, respectively. The median testicular volume was 5.5 mL at Tanner Stage 2 increasing from 2.5 mL at Tanner Stage 1 to 14.7 mL at Tanner Stage 5. Height and weight measurements were <25th & 50th percentile references at Tanner Stages 1–3. Controlling for confounders, serum FSH and LH increased (p < 0.05) from Tanner Stage 1 to 4 (by 4.1 and 3 mL respectively), and serum testosterone and estradiol increased after Tanner Stage 2 (by 12.7 nmol/L and 59.5 pmol/L respectively). These results indicate some delays in pubertal development of boys in the rural Western Cape when compared to boys from other settings possibly due to nutritional, socio-economic and environmental exposures. Changes in serum hormone levels were consistent with other populations. Initiatives to improve nutrition amongst Western Cape rural communities are recommended.

Epidemiologic methods for investigating male fecundity

Fertility is a couple concept that has been measured since the beginning of demography, and male fecundity (his biological capacity to reproduce) is a component of the fertility rate. Unfortunately, we have no way of measuring the male component directly, although several indirect markers can be used. Population registers can be used to monitor the proportion of childless couples, couples who receive donor semen, trends in dizygotic twinning, and infertility diagnoses. Studies using time-to-pregnancy (TTP) may identify couple subfecundity, and TTP data will correlate with sperm quality and quantity as well as sexual activity and a number of other conditions. Having exposure data available for couples with a fecund female partner would make TTP studies of interest in identifying exposures that may affect male fecundity. Biological indicators such as sperm quality and quantity isolate the male component of fertility, and semen data therefore remain an important source of information for research. Unfortunately, often over half of those invited to provide a sperm sample will refuse, and the study is then subject to a selection that may introduce bias. Because the most important time windows for exposures that impair semen production could be early fetal life, puberty, and the time of ejaculation; longitudinal data over decades of time are required. The ongoing monitoring of semen quality and quantity should continue, and surveys monitoring fertility and waiting TTP should also be designed.

Sperm counts and endocrinological markers of spermatogenesis in long-term survivors of testicular cancer

Background:

The objective of this study was to assess markers of spermatogenesis in long-term survivors of testicular cancer (TC) according to treatment, and to explore correlations between the markers and associations with achieved paternity following TC treatment.

Methods:

In 1191 TC survivors diagnosed between 1980 and 1994, serum-follicle stimulating hormone (s-FSH; n=1191), s-inhibin B (n=441), and sperm counts (millions per ml; n=342) were analysed in a national follow-up study in 1998–2002. Paternity was assessed by a questionnaire.

Results:

At median 11 years follow-up, 44% had oligo- (<15 millions per ml; 29%) or azoospermia (15%). Sperm counts and s-inhibin B were significantly lower and s-FSH was higher after chemotherapy, but not after radiotherapy (RT), when compared with surgery only. All measures were significantly more abnormal following high doses of chemotherapy (cisplatin (Cis)>850 mg, absolute cumulative dose) compared with lower doses (Cis ⩽850 mg). Sperm counts were moderately correlated with s-FSH (−0.500), s-inhibin B (0.455), and s-inhibin B : FSH ratio (−0.524; all P<0.001). All markers differed significantly between those who had achieved post-treatment fatherhood and those with unsuccessful attempts.

Conclusion:

The RT had no long-term effects on the assessed markers of spermatogenesis, whereas chemotherapy had. At present, the routine evaluation of s-inhibin B adds little in the initial fertility evaluation of TC survivors.

Age-dependent inhibin B concentration in relation to FSH and semen sample qualities: a study in 2448 men

Inhibin B is an important serum marker of spermatogenesis, whereas sensitivity and predicting power for the spermatogenic situation at several ages are under debate. We performed a retrospective analysis of data from 2448 men who attended our University-based male infertility clinic to evaluate inhibin B in relation to age and semen sample qualities in comparison with FSH. Moreover, the range of inhibin B in 82 nonobstructive azoospermic patients was correlated with the sperm retrieval in testicular sperm extraction procedures. Inhibin B correlated with FSH (Spearman rank correlation (R)=−0.50; P<0.00001). Inhibin B and inhibin B/FSH ratio (IFR) showed an inverse U-shaped dependence on age, whereas FSH showed a U-shaped dependence on age (optimum 20–40 years). However, in men with normal spermiograms inhibin B concentrations did not differ between age groups. Their levels of inhibin B amounted to 130.5, 54.5–247 ng/l (median, 10th–90th precentile), and of IFR to 38.3, 12.5–104.8 (median, 10th–90th percentile), which might be taken as the reference range. Using the 10th percentile of IFR, correct classification in normal or pathological semen groups was achieved in 99.1%. The percentage of aniline blue-negative spermatozoa, i.e. mature spermatozoa with protamines, did not correlate with FSH (P>0.05) but with inhibin B (R=0.15, P<0.001). The probability of retrieving testicular spermatozoa decreased with declining inhibin B: <20 ng/l sperm could never be found. Our results from a large group of men with a wide spectrum of semen qualities allow estimating reference values for inhibin B and IFR. Inhibin B and especially the IFR are more sensitive markers of male infertility than FSH alone.

Inhibin B in plasma samples from male volunteer panel selected for health but not fertility: sources of variability

BACKGROUND

Inhibin B was measured in plasma samples obtained from 34 healthy male subjects selected on criteria typical for a phase I clinical trial across a wide age range (19-70 years).

METHODS

Mutiple samples (up to seven per subject) were obtained as a set consisting of one baseline sample then three pairs of morning and evening samples. This allowed assessment of the fed/fasted state and diurnal effects. Samples were analyzed using a commercially available inhibin B ELISA assay. Across all time points, the mean plasma inhibin B was 197 pg/ml ± 67pg/ml.

RESULTS

The results confirmed a diurnal effect where inhibin B concentration is on average about 40 pg/ml greater in the morning and showed a negative influence of age on inhibin B concentrations. There was no overt influence of body mass index on inhibin B. A variance components analysis revealed that more than 80% of the total variability was due to the variability observed between individuals. Within the fed-fasted sampling schedule of this study, inhibin B levels were slightly lower when volunteers had eaten but the magnitude of this effect was within the variance encountered between occasions.

CONCLUSION

These results illustrate that when undertaking longitudinal monitoring of inhibin B in clinical trials as means of monitoring testicular function, it is important to obtain samples from an individual at the same time of day and to use statistical methods which analyze the magnitude of deviation of an individual from their personal baseline as well as looking at group means and influence of study duration.

Fertility-preserving treatment options in patients with malignant hematological diseases

The number of patients of reproductive age diagnosed with various malignant hematological diseases increases every year. These patients undergo chemotherapy, radiotherapy, and various other treatments that may have gonadotoxic effects. The life expectancy of these patients is increasing rapidly due to the variety of treatment options. As such, an increasing number of patients-as well as their parents and spouses-express their concerns about the patient's fertility post treatment. In the present review it was aimed to provide an overview of current fertility-preserving treatment options and the future of fertility preservation.

Metabolic and cardiovascular outcomes of fatherhood: results from a cohort of study in subjects with sexual dysfunction

INTRODUCTION

Previous cross-sectional and longitudinal studies reported a negative correlation between fatherhood and testosterone (T) levels, likely due to a centrally mediated downregulation of the hypothalamic-pituitary-gonadal axis. Moreover, epidemiological data indicate that fatherhood might affect metabolic and cardiovascular outcomes, although different results have been reported. Up to now, no studies have evaluated these associations in a population of men seeking treatment for sexual dysfunction (SD).

AIM

To explore biological and clinical correlates of number of children (NoC) and its possible associations with forthcoming major cardiovascular events (MACE) in a sample of men with SD.

METHODS

A consecutive series of 4,045 subjects (mean age 52 ± 13.1 years old) attending the Outpatient Clinic for SD was retrospectively studied. A subset of the previous sample (N = 1,687) was enrolled in a longitudinal study.

MAIN OUTCOME MEASURES

Information on MACE was obtained through the City of Florence Registry Office.

RESULTS

Among patients studied, 31.6% had no children, while 26.3% reported having one child, 33.4% two, and 8.8% three or more children. Although fatherhood was negatively related with follicle-stimulating hormone levels and positively with testis volume, we found a NoC-dependent, stepwise decrease in T plasma levels, not compensated by a concomitant increase in luteinizing hormone. NoC was associated with a worse metabolic and cardiovascular profile, as well as worse penile blood flows and a higher prevalence of metabolic syndrome (MetS). In the longitudinal study, after adjusting for confounders, NoC was independently associated with a higher incidence of MACE. However, when the presence of MetS was introduced as a further covariate, the association was no longer significant.

CONCLUSIONS

This study supports the hypothesis that bond maintenance contexts and fatherhood are associated with an adaptive downregulation of the gonadotropin-gonadal axis, even in a sample of men with SD. Moreover, our data suggest that NoC predicts MACE, most likely because of an unfavorable, lifestyle-dependent, parenthood-associated behavior.

Assessment of circulating hormones in regulatory toxicity studies II. Male reproductive hormones

When test article-related testicular toxicity or Leydig cell tumors are identified in nonclinical studies, the measurement of circulating hormones such as luteinizing hormone, follicle-stimulating hormone, inhibin, testosterone, or prolactin is often considered in order to aid mechanistic investigations or to identify potential biomarkers in man. Although some hormone levels are relatively constant, others are subject to wide variability owing to pulsatility of secretion, diurnal rhythms, and stress. To avoid being misled, it is important that this variation is factored into any study design that includes hormone measurements. Since all these possibilities start from the pathologist's reading of the tissue sections, we begin with a review of the morphologic changes that are tied to underlying alterations in hormones. We then provide the reader with basic information and representative hormone data, including coefficients of variation, for the major male reproductive hormones in the three main nonclinical species (rats, dogs, and cynomolgus monkeys). Power and probability tables for rats and dogs allow estimates of the number of animals or samples needed to provide a given likelihood of detecting a hormonal change of a given size. More importantly, we highlight the variability of this process and the real value in readers developing this information at their own site.

Does weight loss improve semen quality and reproductive hormones? Results from a cohort of severely obese men

Background

A high body mass index (BMI) has been associated with reduced semen quality and male subfecundity, but no studies following obese men losing weight have yet been published. We examined semen quality and reproductive hormones among morbidly obese men and studied if weight loss improved the reproductive indicators.

Methods

In this pilot cohort study, 43 men with BMI > 33 kg/m² were followed through a 14 week residential weight loss program. The participants provided semen samples and had blood samples drawn, filled in questionnaires, and had clinical examinations before and after the intervention. Conventional semen characteristics as well as sperm DNA integrity, analysed by the sperm chromatin structure assay (SCSA) were obtained. Serum levels of testosterone, estradiol, sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), anti-Müllerian hormone (AMH) and inhibin B (Inh-B) were measured.

Results

Participants were from 20 to 59 years of age (median = 32) with BMI ranging from 33 to 61 kg/m². At baseline, after adjustment for potential confounders, BMI was inversely associated with sperm concentration (p = 0.02), total sperm count (p = 0.02), sperm morphology (p = 0.04), and motile sperm (p = 0.005) as well as testosterone (p = 0.04) and Inh-B (p = 0.04) and positively associated to estradiol (p < 0.005). The median (range) percentage weight loss after the intervention was 15% (3.5 - 25.4). Weight loss was associated with an increase in total sperm count (p = 0.02), semen volume (p = 0.04), testosterone (p = 0.02), SHBG (p = 0.03) and AMH (p = 0.02). The group with the largest weight loss had a statistically significant increase in total sperm count [193 millions (95% CI: 45; 341)] and normal sperm morphology [4% (95% CI: 1; 7)].

Conclusion

This study found obesity to be associated with poor semen quality and altered reproductive hormonal profile. Weight loss may potentially lead to improvement in semen quality. Whether the improvement is a result of the reduction in body weight per se or improved lifestyles remains unknown.

Semen analysis from an epidemiologic perspective

The fifth edition of the World Health Organization (WHO) manual for semen analysis includes for the first time reference values for human semen characteristics. This paper considers whether such values will help to resolve the intensely debated data indicating temporal and geographical shifts in sperm counts and hypotheses that anthropogenic activities that result in the release of chemicals into the environment are detrimental to male reproductive health. The reasons that these reference values will not fulfil these purposes are also explained. Although established reference values for semen characteristics are of limited value in analytical epidemiologic research, the WHO guidelines are of utmost importance for supporting the development of appropriate research protocols. Moreover, in spite of its limitations, semen analysis is still a useful research tool in epidemiological research, and no superior alternatives are on the horizon.

Urinary bisphenol A concentrations in relation to serum thyroid and reproductive hormone levels in men from an infertility clinic

Human exposure to bisphenol A (BPA) is widespread. Animal studies have demonstrated that BPA can alter endocrine function, but human studies are limited. For the present study, we measured urinary BPA concentrations and serum thyroid and reproductive hormone levels in 167 men recruited through an infertility clinic. BPA was detected in 89% of urine samples with a median (range) of 1.3 (<0.4 - 36.4) ng/mL. In multivariable regression models adjusted for potential confounders, BPA concentrations in urine collected on the same day as a blood sample were inversely associated with serum levels of inhibin B and estradiol:testosterone ratio (E(2):T) and positively associated with follicle-stimulating hormone (FSH) and FSH:inhibin B ratio. Because BPA is metabolized quickly and multiple urine measures may better reflect exposure than a single measure, we also considered among a subset of the men the BPA concentrations in repeated urine samples collected weeks or months following serum sample collection. In these analyses, the effect estimates remained consistent for FSH and E(2):T but were somewhat weakened for inhibin B. In addition, we observed inverse relationships between urinary BPA concentrations and free androgen index (ratio of testosterone to sex hormone binding globulin), estradiol, and thyroid stimulating hormone. Our results suggest that urinary BPA concentrations may be associated with altered hormone levels in men, but these findings need to be substantiated through further research.

Phthalates and other additives in plastics: human exposure and associated health outcomes

Concern exists over whether additives in plastics to which most people are exposed, such as phthalates, bisphenol A or polybrominated diphenyl ethers, may cause harm to human health by altering endocrine function or through other biological mechanisms. Human data are limited compared with the large body of experimental evidence documenting reproductive or developmental toxicity in relation to these compounds. Here, we discuss the current state of human evidence, as well as future research trends and needs. Because exposure assessment is often a major weakness in epidemiological studies, and in utero exposures to reproductive or developmental toxicants are important, we also provide original data on maternal exposure to phthalates during and after pregnancy (n = 242). Phthalate metabolite concentrations in urine showed weak correlations between pre- and post-natal samples, though the strength of the relationship increased when duration between the two samples decreased. Phthalate metabolite levels also tended to be higher in post-natal samples. In conclusion, there is a great need for more human studies of adverse health effects associated with plastic additives. Recent advances in the measurement of exposure biomarkers hold much promise in improving the epidemiological data, but their utility must be understood to facilitate appropriate study design.

Pyrethroid insecticide metabolites are associated with serum hormone levels in adult men

Experimental studies have reported that pyrethroid insecticides affect male endocrine and reproductive function, but human data are limited. We recruited 161 men from an infertility clinic between years 2000-2003 and measured serum reproductive and thyroid hormone levels, as well as the pyrethroid metabolites 3-phenoxybenzoic acid (3PBA) and cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DCCA and trans-DCCA) in spot urine samples. When adjusting for potential confounders, categories for all three metabolites, as well as their summed values, were positively associated with FSH (all p-values for trend <0.05). Statistically significant or suggestive positive relationships with LH were also found. In addition, cis-DCCA and trans-DCCA were inversely associated with inhibin B (p for trend=0.03 and 0.02, respectively). Finally, there was evidence that trans-DCCA was inversely associated with testosterone and free androgen index (the ratio of testosterone to sex hormone binding globulin; p for trend=0.09 and 0.05, respectively). The observed relationships were consistent with previous findings, but further research is needed for a better understanding of the potential association between pyrethroid insecticides and male reproduction.

Is overweight a risk factor for reduced semen quality and altered serum sex hormone profile?

OBJECTIVE

To evaluate whether overweight and obesity are related to changes in serum sex hormone concentrations and semen quality.

DESIGN

Cross-sectional study.

SETTING

Data from five previous population-based environmental studies of semen quality were combined into one database at a university hospital in Denmark.

PATIENT(S)

In total, 2,139 men provided data to the database.

INTERVENTION(S)

Data on semen and blood samples and information on lifestyle and reproductive factors, including body mass index (BMI), were collected.

MAIN OUTCOME MEASURE(S)

Semen quality (volume, concentration, total sperm count, and motility) and serum concentration of sex hormones.

RESULT(S)

The T and inhibin B serum concentrations were 25%-32% lower in obese men in comparison with normal-weight men, whereas the E(2) concentration was 6% higher in obese men. Overweight men (BMI, 25.1-30.0 kg/m(2)) had a slightly lower adjusted sperm concentration and total sperm count than did men with a normal BMI (20.0-25.0 kg/m(2)), but no reduction in sperm count was observed among the obese men.

CONCLUSION(S)

These results corroborate earlier findings that overweight and obese men have a markedly changed sex hormone profile in serum, whereas reduction of semen quality, if any, was marginal and below the detection limit of this large study.