Increased serum inhibin B levels after varicocele treatment

Effects of Varicocele Surgical Repair on Serum Hormone and Inhibin B Levels for Patients With Varicocele: A Systematic Review and Meta-Analysis

Varicocele surgical repair can improve the function of the testis for patients with varicocele. We carried out a systematic review and meta-analysis to assess the effects of varicocele surgical repair on serum hormones and inhibin B levels in patients with varicocele. A literature search was performed in August 2022, and no language or geographic region restrictions were applied. The search included the following databases: PubMed, Embase, and Medline. A literature review was performed to identify all published clinical trials assessing serum hormone and inhibin B levels before and after varicocele surgical repair. The reference lists of retrieved studies were also investigated. A systematic review and meta-analysis were conducted. Eight articles were selected from 162 articles, including 452 patients. The combined analysis showed that after surgical treatment, mean serum testosterone, inhibin B, and sperm concentration levels increased compared with preoperative levels (p < .05). After surgical treatment, mean serum follicle-stimulating hormon (FSH), and Luteinizing hormone (LH) levels decreased compared with preoperative levels (p < .05). This meta-analysis demonstrates that varicocele surgical repair can improve testicular function, increase serum testosterone, and inhibin B levels and decrease serum FSH and LH levels in patients with varicocele. This might be related to the improvement of infertility. A large-scale multicenter randomized controlled study is needed for further confirmation.

Recent Advances in Treatment of Recurrent Spontaneous Abortion

Importance

Recurrent spontaneous abortion (RSA) is a distressing condition experienced by approximately 1% of women trying to conceive. However, the treatment of RSA is a challenge both for clinicians and patients.

Objective

The aim of this review is to discuss the medical and surgical approach to the management of RSA, including those caused by anatomical, genetic, male, infectious, endocrine, and immune factors.

Evidence Acquisition

A literature search using MeSH terms for each topic was undertaken using PubMed, supplemented by hand searching for additional references. Retrieved articles were reviewed, synthesized, and summarized.

Results

Available treatments target hypothetical risk factors for RSA, although the effectiveness of many treatment options is controversial. Intervention should depend on the benefit-to-risk ratio of the proposed treatment.

Conclusions and Relevance

The etiology of RSA is heterogeneous, and patients often lack specific clinical manifestations, which has hindered the progress in predicting and preventing RSA to some extent. Despite intensive workup, at least 50% of couples do not have a clear underlying pathology. In addition, an evidence-based treatment is not available in most patients even if abnormal test results are present. Many new treatment directions are also still actively exploring; empirical and combined multiple treatments are still the main methods.

Target Audience

Obstetricians and gynecologists, family physicians.

Learning Objectives

After completing this activity, the learner should be better able to describe common risk factors for RSA; formulate individualized treatment plans to improve pregnancy outcomes; and propose supportive treatment recommendations for patients with unclear causes.

Varicoceles in Men With Non-obstructive Azoospermia: The Dilemma to Operate or Not

The knowledge on male reproduction is constantly expanding, especially in treating infertility due to non-obstructive azoospermia (NOA). Varicocele is occasionally diagnosed in a subpopulation of males with NOA. Varicocele repair in NOA-men may contribute to the reappearance of spermatozoa in semen. However, spontaneous pregnancies are observed in only a small percentage of NOA-men post-varicocelectomy. Additionally, it has been reported that the repair of varicocele in NOA-men (before the performance of sperm retrieval techniques) may increase the testicular sperm recovery rate. In addition, it increases the pregnancy rate in intracytoplasmic sperm injection (ICSI) programs in NOA-men without spermatozoa in the semen post-varicocelectomy. In addition, to the improvement in Sertoli cellular secretory function, varicocelectomy may increase the secretory function of Leydig cells, which subsequently results in improved androgen production, raising the probability to negate the need for testosterone replacement therapy in cases of late-onset hypogonadism. On the other hand, the benefit of varicocelectomy in patients with NOA is still debatable. The current review study aims to provide a critical and extensive review of varicocele repair in males with NOA. This study additionally focuses on the impact of varicocele repair on sperm retrieval rates and its influence on the ICSI outcomes for those couples who remain negative for spermatozoa in their semen samples post-varicocelectomy.

Varicocele: An Endocrinological Perspective

Varicocele affects 15% of male population but it is more frequently identified in patients searching medical care for infertility. The impact of varicocele on semen production and fertility is known, but the relationship between clinical varicocele and impaired hormonal production is not clear. In published literature there are some studies regarding hormonal alterations in patients with varicocele but no review in which all the hormonal findings are explained. The aim of this review is to evaluate, by most common search engine, what is known about hormonal alterations in varicocele-bearing patients, to verify if a cause-effect relationship is documented and to give a useful contribution to in clinical management of this kind of patients. We found contradictory results about hormonal status from literature. Some studies confirmed a decrease of testosterone levels and higher FSH and LH levels that normalize after varicocelectomy, others found lower than normal levels of dihydrotestosterone due to decreased activity of epididymal 5-α-reductase. Lower circulating Anti-Müllerian Hormone levels, accompanied by a decreased Inhibin-B level, were reported as indicators of the decreased Sertoli cells function in varicocele-bearing adult patients. The finding of higher basal 17-OH-progesterone concentrations in patients with varicocele was explained by some authors with a testicular C-17,20-lyase deficiency. There is no doubt that varicocele could led to hormonal alterations. This review proposes that the impaired free sexual steroid levels are the result of a slight, deep-rooted defect in the testes of a certain amount of men with varicocele but further multicentre, randomized controlled studies remain mandatory to better clarify the hormonal features of patients with varicocele and to assess the utility of hormonal evaluation for establishing the duration of varicocele and for better identifying patients who need surgical correction.

Sertoli Cell Alterations in Peripubertal Varicocelized Rats: Evidence of Primary Damage on Spermatogenesis

Idiopathic varicocele is closely associated with male infertility or subfertility. Sertoli cell is a very important regulator of spermatogenesis. We investigated the morphofunctional alterations in the Sertoli cell and its possible involvement in the establishment of testicular primary lesion in experimental left-sided varicocele, induced from peripuberty. Twenty-five male peripubertal rats (44 days postpartum [dpp]) were distributed into two groups: control (C) and varicocele (V). Experimental left varicocele was induced in rats through the partial ligature of the left renal vein. Euthanasia was performed at 100 dpp. Testicular histopathology and testosterone plasmatic level were evaluated. Transferrin and vimentin proteins were, respectively, used as immunomarkers of Sertoli cell function and structure. Significant reductions in vimentin and transferrin expressions were noticed in androgen-dependent stages (VII and VIII) of the seminiferous epithelium cycle in V rats; testosterone plasmatic level was also reduced. Bilateral testicular histopathological alterations were found in V rats, mainly massive germ cell desquamation. The histological damage and changes in protein expressions occurred bilaterally. The relevant impairment of the functional and structural characteristics of the Sertoli cell, together with the typical massive germ cell desquamation, indicates that Sertoli cell changes can primarily contribute to the significant testicular dysfunction associated with varicocele.

Effects of varicocelectomy on serum testosterone

Varicocele is most often surgically repaired due to male infertility, however, has recently been linked to low serum testosterone. This paper serves to review the current literature regarding varicocele and its subsequent repair on serum testosterone. Twenty-eight human studies were identified with fifteen showing improved serum testosterone after repair. The majority of the studies that demonstrated improvement had preoperative testosterone levels that were low or below normal. Additionally, multiple well-designed studies with control groups not undergoing surgical repair demonstrated significant difference between groups. This improvement was less observed in studies with normal preoperative serum testosterone. A majority of these patients studied were presenting for infertility. It remains to be determined if these findings can be reproduced in men without infertility. The findings suggest that microsurgical varicocele repair can improve serum testosterone in men with low levels preoperatively in appropriately counseled men. It remains to be seen whether varicocele repair can help prevent the development of low testosterone in the future or which patients are at risk of developing low testosterone due to varicocele.

When is a varicocele repair indicated: the dilemma of hypogonadism and erectile dysfunction?

In the past, the indications for varicocelectomy are primarily for infertility with abnormal semen parameters, testicular hypotrophy/atrophy in adolescents, and/or pain. The surgical treatment of varicocele for hypogonadism is controversial and debated. Recently, multiple reports in the literature have suggested that varicocele is associated with hypogonadism and varicocele repair can increase testosterone levels. Men with hypogonadal symptoms should have at least two serum testosterone levels. Microsurgical varicocelectomy may be beneficial for men with clinically palpable varicoceles with documented hypogonadism. In this review, we summarize the most recent literature linking varicocele to hypogonadism and sexual dysfunction and the impact of repair on serum testosterone levels. We performed a search of the published English literature. The key words used were “varicocele and hypogonadism” and “varicocele surgery and testosterone.” We included published studies after 1998. We, also, evaluated the effect of surgery on the changes in the serum testosterone level regardless of the indication for the varicocele repair.

Are anti-Müllerian hormone and its receptor polymorphism associated with the hormonal condition of undescended testes?

PURPOSE

Numerous genetic and endocrine factors are involved in the process of testicular descent, but only a few genetic causes have been reported in human. The aim of this study was to investigate the density and distribution of single nucleotide polymorphisms (SNPs) anti-Müllerian hormone (AMH) and AMHRII receptors in cryptorchid patients and determine potential hormone imbalance connected with undescended testes by assessing the levels of AMH, Insulin-like factor 3 (INSL3) and inhibin B.

MATERIALS AND METHODS

The serum hormone levels (AMH, INSL3 and inhibin B) were compared in the two groups - cryptorchidism (n=105) and control group (n=58). The frequency of AMHRII -482 A>G, AMHRII IVS 10+77 A>G, AMHRII IVS 5-6 C>T, and AMH Ile49Ser polymorphisms among cryptorchid boys were compared with the control group.

RESULTS

None of the hormones levels were different between the cryptorchid and the control groups. All cases of IVS 5-6 C>T homozygote and heterozygote mutation were accompanied by an IVS 10+77 A>G and 482 A>G homozygote and heterozygote mutation. Interestingly, in most cases of all four polymorphisms, homozygote recessive genotype was associated with cases of cryptorchidism. However, the groups of patients were too small to draw definite conclusions.

CONCLUSION

The AMHRII -482 A>G, AMHRII IVS 10+77 A>G, AMHRII IVS 5-6 C>T and AMH Ile49Ser genotypes should be determined in a much larger group of boys with cryptorchidism.

Varicocele - a case for early intervention

Testicular varicocele, which is defined as the dilation of the veins draining the testicle, has long been associated with a detrimental effect on testicular function. Despite a lack of high-quality, prospective data, recent evidence has shed light on potential links between varicocele and male infertility and serum testosterone levels. Similarly, varicocele repair has increasingly been shown to have a beneficial impact on pregnancy rates, semen parameters, and on improving serum testosterone in adult men. Numerous studies have assessed the optimal technique for varicocele repair and the bulk of the evidence has shown the microsurgical inguinal/subinguinal approach to have the highest success rates, the lowest overall complication rates, and the lowest recurrence rates. The management of varicocele in adolescents remains a clinical conundrum, but contemporary evidence suggests early deleterious effects of varicocele on testicular function in some patients. Well-designed prospective trials are critical to delineate the true impact and role of varicocele repair on male infertility and hypogonadism in adult and adolescent men.

Serum levels of inhibin B in adolescents after varicocelelectomy: A long term follow up

Introduction

To study the impact on adult’s fertility of serum inhibin B levels in adolescent patients with idiopathic varicocele after minimally invasive surgical correction and to compare fluctuation of pituitary-testis hormonal values and testicular volumes.

Materials and Methods

A case-control study was carried out on a group adolescent patients (n=60) affected by idiopathic left varicocele (group V) and compared with control adolescents (n=40) in the Paediatric Surgery Section of Siena (from June 1993 till September 2013). Inhibin B levels and testicular volume before (T0) and after at 6 and 12 months from surgery (T1 and T2) were evaluated.

Results

A positive correlation between testicular growth at T1 and T2 (P<0.001) was found. Linear regression analysis showed a positive correlation between inhibin B levels and testicular volume (expressed as the sum of the right and left values) (P<0.0001).

Conclusions

Inhibin B levels are a valid marker for studying the effects of varicocele on the testicular function and confirm the necessity of early surgical correction for preventing the trophic testicular damage and male infertility.

Does the number of veins ligated during varicococele surgery influence post-operative semen and hormone results?

Varicocele is a well-established cause of male subfertility, which is directly proportional to its clinical grade. Although newer ultrasonic grading systems have taken into account the existence of pampiniform venous plexi, little is known about the clinical significance of the number of veins ligated during surgery. Very few undersized studies reported an influence which triggered the need to evaluate such association. This is a retrospective study of 378 patients who underwent left microsurgical subinguinal varicocoelectomy. Semen analyses and blood hormone studies performed pre-operatively were compared to those executed 6 months after surgery. Patients were divided into abnormal semen and normal semen groups based on their initial semen results. They were also subdivided according to the number of veins ligated intraoperatively into three groups: <5, 5-10, and >10 veins. Sperm count, total motility, and progressive motility were significantly increased in 62, 60.3, and 53.3% of patients post-operatively (p = 0.001), respectively. No significant differences in hormone levels were detected overall. Of the 378 patients, 332 had an abnormal semen analysis, while the remaining 46 patients had a normal result. Sperm count, total motility, and progressive motility significantly increased after varicocoelectomy in patients with an abnormal initial semen analysis (p = 0.001). In 48.7% of patients, 5-10 veins were ligated during surgery, whereas 28.3% had >10 and 23% had <5 ligated veins. No statistically significant differences were noted in the initial or the follow-up results among the number of vein subgroups. Varicocele ligation improves patients' fertility potential. This improvement, however, is not influenced by the number of veins ligated intraoperatively. Clinical grading maintains its superiority in the evaluation of varicocele patients.

Beneficial effects of varicocele embolization on semen parameters

BACKGROUND

The value of varicocele repair and the latter's impact on semen parameters are still subject to debate.

METHODS

We analyse changes over time in initially abnormal sperm parameters and serum concentrations of testosterone, FSH and inhibin B after embolization treatment of males with high-grade varicocele. From 2007 to 2012, we recruited 47 male infertile patients with clinically visible left varicocele in the resting patient and at least one abnormal semen parameter. Sperm parameters and serum levels of total testosterone, FSH and inhibin B were measured prior to retrograde embolization (M0) and then 3 (M3) and 6 (M6) months afterwards.

RESULTS

At M0, the median sperm concentration was 5.78 [0.84-37.70] × 10(6)/ejaculate. The mean ± SD sperm progressive motility, vitality and percentage of normal sperm were respectively, 21.83 ± 16.48%, 61.88 ± 15.98% and 12.88 ± 7.15%. The corresponding values at M3 were significantly higher (38.75 [3.96-95] × 10(6)/ejaculate, 29.32 ± 14.21%, 69.14 ± 14.86% and 19.03 ± 11.02%, respectively). The mean percentage of spermatozoa with a thin head was significantly lower at M6 (6.35 ± 5.29%) than at M0 (14.03 ± 13.09%). The mean serum testosterone, FSH and inhibin B levels did not change significantly over time.

CONCLUSIONS

Embolization treatment in men with clinically visible left varicocele, abnormal sperm parameters and documented infertility is associated with a significant improvement in semen parameters including sperm head morphology.

Effect of surgical repair on testosterone production in infertile men with varicocele: a meta-analysis

OBJECTIVES

To determine the effect of surgical varicocele repair in improving testicular Leydig cell function as shown by increased testosterone production.

METHODS

Eligible studies were searched in Medline and the Pubmed database, and cross-referenced as of 31 May 2011 using the terms "varicocele,""testosterone" and "surgery." The database search, quality assessment and data extraction were independently carried out by two reviewers. Only studies including patients with testosterone evaluation before and after surgery were considered for the analysis. A systematic review and meta-analysis was carried out for continues variables using random effect models.

RESULTS

Out of 125 studies, a total of nine were selected, including 814 patients. The combined analysis showed that mean serum testosterone levels after surgical treatment increased by 97.48 ng/dL (95% confidence interval 43.73-151.22, P=0.0004) compared with preoperative levels.

CONCLUSIONS

Surgical treatment of varicocele significantly increases testosterone production and improves testicular Leydig cell function.

Serum inhibin B levels before and after varicocelectomy in early adolescence

BACKGROUND

Whereas no clear relationship has been observed between varicocelectomy and serum inhibin B levels in men, in adolescents comparison between inhibin B levels before and after varicocelectomy is lacking.

AIM

To evaluate the effect of varicocele surgical treatment on inhibin B levels in adolescents at the beginning of puberty compared to a group of healthy adolescents.

SUBJECTS AND METHODS

We studied 28 adolescents in Tanner 2 pubertal stage with a grade III left-sided varicocele (patients) compared to 13 age and pubertal stage-matched healthy adolescents (controls). All patients underwent blood tests to determine serum inhibin B levels before and 6 months after varicocelectomy by Palomo procedure. For comparison we investigated inhibin B levels in controls and repeated this test 6 months later. Testicular ultrasound was performed for patients only.

RESULTS

Baseline inhibin B concentrations of patients and controls were 109.90 ± 40.26 and 109.33 ± 38.34 pg/ml, respectively. No significant changes were observed in patients' inhibin B concentrations after varicocelectomy (116.00 ± 42.65 pg/ml), or in controls during the 6 months' follow-up (99.12 ± 30.09 pg/ml). Doppler examination after treatment shows a complete resolution of varicocele in all the patients without alterations in testicular parenchyma.

CONCLUSIONS

Varicocelectomy performed on adolescents at T2 pubertal stage might be useful to avoid alteration in inhibin B production and consequently in testicular function. Further studies are necessary to confirm the prognostic value of inhibin B levels and the benefit of early varicocelectomy in preserving the fertility of these adolescents.

Varicocele-induced infertility: Newer insights into its pathophysiology

The association between varicoceles and male infertility has been known since the 1950s; however, the pathophysiology of the process remains uncertain. The primary proposed hypotheses involve hyperthermia, venous pressure, testicular blood flow, hormonal imbalance, toxic substances, and reactive oxygen species. It is difficult to identify a single or dominant factor, and it is likely that many of these factors contribute to the infertile phenotype seen in clinical practice. Moreover, patient lifestyle and genetic factors likely affect patient susceptibilities to the varicocele insult. While the current studies have weaknesses, they provide building blocks for futures studies into the pathophysiology of the varicocele.

Activation of adenosine A2A receptors by polydeoxyribonucleotide increases vascular endothelial growth factor and protects against testicular damage induced by experimental varicocele in rats

In rat experimental varicocele, polydeoxyribonucleotide (PDRN) induces vascular endothelial growth factor (VEGF) production, thereby enhancing testicular function. This may point to a new therapeutic approach in human varicocele.

Inhibin B and anti-Müllerian hormone in spermatic vein of subfertile men with varicocele

INTRODUCTION

The pathophysiology of subfertility in men with varicocele remains unclear as well as the role of inhibin B (Inh-B) and anti-Müllerian hormone (AMH). The aim of this study was to evaluate Inh-B and AMH concentrations in the spermatic vein of subfertile men with varicocele.

PATIENTS AND METHODS

A total of 61 subfertile men with varicocele and 31 fertile controls underwent standard andrological evaluation. All subfertile men underwent varicocelectomy, during which blood samples were obtained from the spermatic vein to evaluate Inh-B and AMH concentrations.

RESULTS

Peripheral vein Inh-B concentrations in men with varicocele were lower as compared to controls (52.9 [8.3-136.0) vs 116±9.7 ng/dL, P = .001). There was no difference in AMH concentrations (10.2 [4.4-45.4]) vs 10.4±0.8 pg/dL, P = 0.9). Spermatic vein Inh-B concentrations in men with varicocele were higher compared to those of peripheral vein (87.6±4.4 vs 52.9 [8.3-136.0] ng/dL, P = .001). On the contrary, spermatic vein AMH concentrations were lower compared to those from peripheral vein (8.84 [3.9-47.7] vs 10.2 [4.4-45.4] pg/dL, P = .013).

CONCLUSIONS

Inh-B constitutes a reliable marker of Sertoli cell function as well as spermatogenesis. On the contrary, the clinical significance of AMH in men with varicocele remains to be elucidated.

INHIBIN B LEVELS IN PERIPHERAL VEIN DO NOT CORRELATE WITH INHIBIN B LEVELS IN THE SPERMATIC VEIN IN ADOLESCENTS WITH VARICOCELE

This study was conducted to evaluate the inhibin B with FSH and LH levels on spermatogenesis in varicocele patients. The study group consisted of 10 adolescent with left idiopathic varicocele of grade II and III. Blood specimens were obtained from dilated spermatic vein and peripheral vein simultaneously. Peripheral samples were also collected from 7 healthy children as controls. Inhibin B was measured with ELISA inhibin B kits. FSH and LH were analyzed by radioimmunoassay techniques. The results were analyzed using Mann-Whitney U and Spearman's rank tests. A value of p < 0.05 was considered significant. Peripheral FSH, LH and inhibin B levels were the same in the study and control group (p > 0.05). Mean inbibin B levels of spermatic vein were significantly higher than the control and peripheral blood of the study groups (p < 0.05). FSH, LH, and inhibin B levels correlated poorly each other (p > 0.05). Preoperative serum inhibin B concentration could not reliably predict a response to varicocelectomy, but the increase in inhibin B levels after treatment might suggest an improvement in testicular function.

VARICOCELE LIGATION ON FREE TESTOSTERONE LEVELS IN INFERTILE MEN WITH VARICOCELE

We have analyzed the effects of varicocele ligation on free testosterone levels, and investigated the interrelationships between free testosterone and fertility. The records were retrospectively evaluated for 42 infertile patients who underwent varicocele ligation, with serum free testosterone levels, follicle stimulating hormone (FSH), lutenizing hormone (LH), testosterone, estradiol, prolactin, ejaculated volume, sperm concentration and motility before and after surgery. Serum free testosterone levels increased from 12.97+/-4.16 to 13.59+/-3.93 pg/mL, but the difference was insignificant. The differences before and after surgery of patients in sperm concentration and motility were also insignificant. However, in free testosterone increasing group, the sperm concentration and motility increased significantly, from 4.05+/-4.35 to 7.90+/-8.19 million/mL (P=0.01) and from 30.64+/-21.87% to 41.00+/-22.00%, respectively (P=0.03). The increase in serum free testosterone level by varicocele ligation results in a significant improvement in sperm concentration and motility.

Varicocele sclerotherapy improves serum inhibin B levels and seminal parameters

The usefulness of treating varicocele in order to improve fertility is still a matter of debate. The aim of this study was to evaluate variations in seminal parameters and inhibin B concentrations in a group of males affected by varicocele and treated by percutaneous retrograde sclerotherapy in comparison with a group of patients who did not undergo varicocele treatment. Thirty-eight patients with left varicocele underwent spermatic vein phlebography and percutaneous retrograde sclerotherapy with hydroxy-polyaethoxy-dodecanol. Serum inhibin B, follicle-stimulating hormone (FSH), testosterone levels and seminal parameters (sperm concentration, motility and morphology) were performed before and 6 months after sclerotherapy. Forty patients with left varicocele who did not undergo sclerotherapy were studied as controls. A significant increase (p < 0.01) in serum inhibin B levels and a significant decrease (p < 0.05) in FSH levels were observed 6 months after treatment. Semen analysis showed a significant improvement in sperm concentration (p < 0.05) and progressive motility (p < 0.01) after treatment. In control group no significant variations in hormonal and seminal parameters were observed 6 months after the basal examination. Six months after the basal evaluation, inhibin B levels were significantly higher in treated subjects than in controls (p < 0.05) whereas FSH levels were significantly lower (p < 0.05). Sperm concentration and progressive motility were significantly increased (p < 0.05 and p < 0.001, respectively) in treated subjects in comparison with controls. In conclusion, varicocele sclerotherapy improves inhibin B levels and seminal parameters, confirming the positive effect of this treatment on spermatogenesis and Sertoli cell function.

Altered serum inhibin b levels in adolescents with varicocele

BACKGROUND/PURPOSE

Different studies have evaluated testicular hormonal dysfunction in adolescent varicocele but with variable results. Recently, inhibin B has been proposed as a marker for spermatogenesis and Sertoli cell function. The aim of the present study was to study in a homogeneous cohort of adolescents inhibin B and other hormones to detect whether untreated varicocele may be associated with any modifications of these factors.

METHODS

Sixteen adolescents (mean age, 14.5 +/- 1.0 years), at Tanner stages 4 to 5 with grade II or III left-sided varicocele, underwent hormonal evaluation of inhibin B, basal testosterone, and both baseline and GnRH stimulated FSH and LH levels. Thirteen unaffected adolescents of age-matched and pubertal development were used as controls.

RESULTS

Patients with varicocele showed a significant reduction in the testicular volume of the affected side (13.3 +/- 4.1 vs 15.8 +/- 4.8 mL; P = .002) and significant reduced levels of inhibin B compared with controls (271.9 +/- 70.2 vs 327.1 +/- 34.9 pg/mL; P = .042). Inhibin B levels were significantly correlated with testes volume (r = 0.62; P = .0097). Other hormonal parameters were similar in both varicocele and control groups.

CONCLUSION

Inhibin B is reduced in adolescents with untreated varicocele, and it is positively correlated with testicular volume. This could be an early marker for Sertoli cell damage, with possible implications for spermatogenesis and could represent a new indication for varicocele repair.

Inhibin B is a better marker of spermatogenesis than other hormones in the evaluation of male factor infertility

OBJECTIVE

To assess the role of inhibin B in the evaluation of male factor infertility.

DESIGN

Prospective study.

SETTING

Reproductive endocrinology clinic.

PATIENT(S)

Seventy-five patients with infertility problems (mean age 31.2 +/- 7.5 years) and 12 controls (32.1 +/- 8.8 years) with proven fertility.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen analysis was performed according to World Health Organization guidelines. Testicular volume was assessed with the Prader's orchidometer. Serum levels of inhibin B (pg/mL), LH (mIU/mL), FSH (mIU/mL), prolactin (micro IU/mL), and testosterone (nmol/L) were assessed.

RESULT(S)

The mean +/- SEM inhibin B and testosterone levels were significantly lower in the patients than in the controls (inhibin B: 116.4 +/- 11.7 vs. 181.2 +/- 20.9, P=.008; testosterone: 13.6 +/- 0.9 vs. 25.1 +/- 2.9, P=.008). In general, sperm count and testicular volume in the patients were significantly and positively correlated with inhibin B (sperm count: r = 0.476, P<.0001; testicular volume, right: r = 0.57, P=.0001; left: r = 0.53, P=.0001); the inhibin B-FSH index was negatively correlated with FSH. Inhibin B was more strongly correlated with testicular volume and semen parameters than FSH. Inhibin B in the patients was negatively correlated with FSH (r = -0.723, P=.0001) and LH (r = -0.52, P=.0001) and was positively correlated with testosterone (r = 0.4, P=.0013).

CONCLUSION(S)

Inhibin B measurement is a better marker of fertility status than FSH and LH. Concentration of inhibin B in patients with infertility may provide useful information on spermatogenesis and possibly serve as a more direct marker of spermatogenesis than FSH.

Significance of inhibin in reproductive pathophysiology and current clinical applications

The human reproductive process is regulated by complex mechanisms that involve many organs, including the brain, gonads and endocrine system. It has been more than 70 years since the name 'inhibin' was used to describe a substance produced in the gonads that negatively regulates pituitary secretion. Inhibin B controls FSH secretion via a negative feedback mechanism. It is a glycoprotein hormone secreted by the Sertoli cells of the testis and granulosa and theca cells of the ovary. Serum inhibin B concentrations are positively related to testicular volume and sperm counts. Current understanding of inhibin physiology and pathology in the human suggests that inhibin B may be of importance as a marker of Sertoli cell function in men with infertility and as a prognostic indicator in women undergoing ovulation induction therapy. Inhibin concentrations are elevated in patients with granulosa cell tumours and in post-menopausal women with mucinous ovarian cancers. Immunoreactivity against the inhibin alpha-subunit was identified in all cases of adrenal cortical adenoma and carcinoma, and levels are suppressed in the malignant prostate disease. This article discusses the structure, regulation and clinical use of inhibin and other related substances.

Percutaneous epididymal sperm aspiration: a diagnostic tool for the prediction of complete spermatogenesis

The classification of azoospermia into obstructive or non-obstructive is largely based on medical history, physical examination and biochemical markers in serum and semen. However, the most accurate parameter for diagnosis is the testicular histology. The predictive value of the percutaneous epididymal sperm aspiration (PESA), FSH, LH, testosterone, inhibin-B and testicular volume was investigated for their accuracy to predict a complete spermatogenesis (Johnsen score > or =8) in order to replace the testicular histology. The specificity and sensitivity of FSH, inhibin-B, LH, testosterone, testicular volume, and the presence of sperm in a PESA procedure was evaluated in 147 azoospermic males attending the centre for infertility diagnosis. A positive PESA outcome presented the highest sensitivity and specificity to predict a Johnsen score > or =8 (93 and 94% respectively) compared with FSH (90 and 19%), inhibin-B (88 and 57%) and testicular volume (95 and 45%). Differences in clinical presentation were observed between patients with positive sperm retrieval with PESA, depending on the aetiology of obstruction. In conclusion, the presence of spermatozoa in the epididymis (PESA+) correlates with a Johnsen score > or =8 and is the most accurate parameter to predict complete spermatogenesis compared with clinical or biochemical parameters. Between obstructive azoospermic patients, the clinical parameters observed varied according to the aetiology.

Serum levels of dimeric and monomeric inhibins and the degree of seminal alteration in infertile men with varicocele

The aim of the present study was to establish the serum levels of inhibins and their relationship with the degree of seminal alteration in infertile men. Thirty-six patients with varicocele (Va) and seven non-obstructive azoospermic men (Az) were included. The Va group was divided into two subgroups: Va I (sperm concentration: >20 x 106; n = 21) and Va II (sperm concentration: < 20 x 106; n = 15). Twelve fertile men were included as a control group (Co). Semen analysis and serum follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), inhibin B and Pro-alphaC levels were determined. Serum inhibin B and T levels were significantly lower and FSH and LH significantly higher in group Az when compared with the Co. Inhibin B was unable to differentiate Va I from Va II groups. However, in Va II an increase in FSH levels was observed. An inverse correlation between inhibin B and FSH, a direct correlation between inhibin B and testosterone, sperm concentration, motility and morphology were found. No such correlations were seen when only the Va group was analysed. The lack of correlation between serum levels of inhibin B, gonadotrophins, sperm concentration and seminal parameters observed in Va, adds other factor to the complex pathophysiology of varicocele. Finally, further studies are needed to elucidate if oligozoospermic patients with varicocele have also an impaired negative feed-back mechanism that regulates FSH synthesis and secretion.

Inhibin B: a novel marker of spermatogenesis

Subfertility affects about 15% of all couples. Assessment of spermatogenesis has a central role in the evaluation of the subfertile couple. Classical markers of spermatogenesis, such as semen analysis, testicular biopsy and endocrine evaluation all have their diagnostic limitations. There is a clear need for accurate additional markers of spermatogenesis. Recently, the serum inhibin B level has emerged as a sensitive endocrine marker of spermatogenesis. This paper summarises the pros and cons of different markers of spermatogenesis, with specific focus on serum inhibin B. The serum inhibin B level has been shown to be associated with classical markers of spermatogenesis, particularly testicular histology, and to be the most accurate endocrine marker of spermatogenesis. A subnormal serum inhibin B level clearly reflects disturbed spermatogenesis. Before puberty, when no spermatogenesis takes place, inhibin B is a marker of testicular integrity. Clinical applications of serum inhibin B in childhood and adulthood are given, and a view on future directions and research is presented. The serum inhibin B level has proven to be valuable in the evaluation of spermatogenesis, and holds a promise for further research.

Serum levels of inhibin B in men and their relationship with gonadal hormones, testicular volume, testicular biopsy results and sperm parameters

Currently, serum inhibin B levels, indicating testicular function due directly to its testicular origin, has been used increasingly in assisted reproductive units. Our aim in this prospective study was to evaluate the biological significance of inhibin B in gonadal dysfunctional males and the usefulness of inhibin B for the detection of male reproductive dysfunction. We included 52 oligoazoospermic and 20 normospermic men in this study. In our study serum inhibin B levels had statistically significant negative correlation with serum FSH and LH levels (P < 0.001, r: 0.781) and statistically moderate positive correlation with oestradiol levels (P < 0.005, r: 0.292). Inhibin B levels had significantly positive correlation with sperm count (P < 1.005, r: 0.851) and with testicular volume (P < 0.001, r: 0.466). Consequently, serum inhibin B level determination is a useful and non-invasive method for the evaluation of male gonadal dysfunction, taking into account its correlation with history, clinical examination, hormonal parameters, testicular volume, spermiogram and testicular biopsy.