Relationships between total testicular volume, reproductive parameters and surrogate measures of adiposity in men presenting for couple's infertility

Undiagnosed RASopathies in infertile men

RASopathies are syndromes caused by congenital defects in the Ras/mitogen-activated protein kinase (MAPK) pathway genes, with a population prevalence of 1 in 1,000. Patients are typically identified in childhood based on diverse characteristic features, including cryptorchidism (CR) in >50% of affected men. As CR predisposes to spermatogenic failure (SPGF; total sperm count per ejaculate 0-39 million), we hypothesized that men seeking infertility management include cases with undiagnosed RASopathies. Likely pathogenic or pathogenic (LP/P) variants in 22 RASopathy-linked genes were screened in 521 idiopathic SPGF patients (including 155 CR cases) and 323 normozoospermic controls using exome sequencing. All 844 men were recruited to the ESTonian ANDrology (ESTAND) cohort and underwent identical andrological phenotyping. RASopathy-specific variant interpretation guidelines were used for pathogenicity assessment. LP/P variants were identified in PTPN11 (two), SOS1 (three), SOS2 (one), LZTR1 (one), SPRED1 (one), NF1 (one), and MAP2K1 (one). The findings affected six of 155 cases with CR and SPGF, three of 366 men with SPGF only, and one (of 323) normozoospermic subfertile man. The subgroup "CR and SPGF" had over 13-fold enrichment of findings compared to controls (3.9% vs. 0.3%; Fisher's exact test, p = 5.5 × 10-3). All ESTAND subjects with LP/P variants in the Ras/MAPK pathway genes presented congenital genitourinary anomalies, skeletal and joint conditions, and other RASopathy-linked health concerns. Rare forms of malignancies (schwannomatosis and pancreatic and testicular cancer) were reported on four occasions. The Genetics of Male Infertility Initiative (GEMINI) cohort (1,416 SPGF cases and 317 fertile men) was used to validate the outcome. LP/P variants in PTPN11 (three), LZTR1 (three), and MRAS (one) were identified in six SPGF cases (including 4/31 GEMINI cases with CR) and one normozoospermic man. Undiagnosed RASopathies were detected in total for 17 ESTAND and GEMINI subjects, 15 SPGF patients (10 with CR), and two fertile men. Affected RASopathy genes showed high expression in spermatogenic and testicular somatic cells. In conclusion, congenital defects in the Ras/MAPK pathway genes represent a new congenital etiology of syndromic male infertility. Undiagnosed RASopathies were especially enriched among patients with a history of cryptorchidism. Given the relationship between RASopathies and other conditions, infertile men found to have this molecular diagnosis should be evaluated for known RASopathy-linked health concerns, including specific rare malignancies.

Association between central obesity and semen quality: A cross-sectional study in 4513 Chinese sperm donation volunteers

BACKGROUND

General obesity classified by body mass index has been linked to a reduction in semen quality; however, evidence on the adverse effect of central obesity on semen quality remains limited.

OBJECTIVES

To investigate the association between central obesity and semen quality.

MATERIALS AND METHODS

We conducted a cross-sectional study of 4513 sperm donation volunteers in Guangdong Provincial Human Sperm Bank during 2018-2021. Three central obesity indicators, including waist circumference, waist-to-hip ratio, and waist-to-height ratio, were measured using a multi-frequency bioelectrical impedance analysis for each subject. Semen analysis was conducted according to the World Health Organization laboratory manual for the examination and processing of human semen 5th edition. Linear regression models and unconditional logistic regression models were used to quantify the association between central obesity and semen parameters.

RESULTS

With adjustment for age, race, education level, marital status, fertility status, occupation, year of semen collection, abstinence period, ambient temperature, and relative humidity, central obesity defined as waist circumference ≥90 cm, waist-to-hip ratio ≥0.9, or waist-to-height ratio ≥0.5 was significantly associated with a 0.27 (95% confidence interval: 0.15, 0.38) mL, 14.47 (3.60, 25.34) × 106 , 7.06 (0.46, 13.76) × 106 , and 6.80 (0.42, 13.18) × 106 reduction in semen volume, total sperm number, total motile sperm number, and total progressive motile sperm number, respectively, and a 53% (10%, 112%) increase in odds of below the World Health Organization 2010 reference value for semen volume. These associations did not significantly vary across age. Similar results were observed for central obesity defined using each of the three indicators, except that subjects with a waist circumference ≥90 cm had a slightly higher total motility (estimated change: 1.30%; 95% confidence interval: 0.27%, 2.34%) and progressive motility (estimated change: 1.27%; 95% confidence interval: 0.23%, 2.31%).

DISCUSSION AND CONCLUSION

We found that central obesity was significantly associated with a reduction in semen volume, total sperm number, total motile sperm number, and total progressive motile sperm number. Future studies are warranted to confirm our results in other regions and populations.

Morphological and ultrasonographic characterization of the three zones of supratesticular region of testicular artery in Assaf rams

To fully understand the histological, morphometrical and heamodynamic variations of different supratesticular artery regions, 20 mature and healthy Assaf rams were examined through ultrasound and morphological studies. The testicular artery images of the spermatic cord as shown by B-mode analysis indicated a tortuous pattern along its course toward the testis, although it tends to be less tortuous close to the inguinal ring. Doppler velocimetric values showed a progressive decline in flow velocity, in addition to pulsatility and vessel resistivity when entering the testis, where there were significant differences in the Doppler indices and velocities among the different regions. The peak systolic velocity, pulsatility index and resistive index were higher in the proximal supratesticular artery region, followed by middle and distal ones, while the end diastolic velocity was higher in the distal supratesticular region. The total arterial blood flow and total arterial blood flow rate reported a progressive and significant increase along the testicular cord until entering the testis. Histological examination revealed presence of vasa vasorum in the tunica adventitia, with their diameter is higher in the proximal supratesticular zone than middle and distal ones. Morphometrically, the thickness of the supratesticular artery wall showed a significant decline downward toward the testis; meanwhile, the outer arterial diameter and inner luminal diameter displayed a significant increase distally. The expression of alpha smooth muscle actin and vimentin was higher in the tunica media of the proximal supratesticular artery zone than in middle and distal ones.

Prediction Models for Successful Sperm Retrieval in Patients with Non-Obstructive Azoospermia Undergoing Microdissection Testicular Sperm Extraction: Is There Any Room for Further Studies?

Several prediction models for successful sperm retrieval (SSR) in patients with azoospermia due to spermatogenic dysfunction (also termed non-obstructive azoospermia—NOA) have been developed and published in the past years, however their resulting prediction accuracy has never been strong enough to translate their results in the clinical practice. This notwithstanding, the number of prediction models being proposed in this field is growing. We have reviewed the available evidence and found that, although patients with complete AZFc deletion or a history of cryptorchidism may have better probability of SSR compared to those with idiopathic NOA, no clinical or laboratory marker is able to determine whether a patient with NOA should or should not undergo microdissection testicular sperm extraction (mTESE) to have his testicular sperm retrieved. Further research is warranted to confirm the utility of evaluating the expression of noncoding RNAs in the seminal plasma, to individuate patients with NOA with higher probability of SSR.

Testicular volume and clinical correlates of hypothalamic-pituitary-testicular function: A cross-sectional study in obese men

The aim of this study was to determine whether testicular volume is correlated with clinical and biochemical markers of hypothalamic–pituitary–testicular (HPT) axis function. This was a cross-sectional substudy of a larger randomized controlled trial including obese men, body mass index (BMI) ≥30 kg m⁻², with a total testosterone level <12 nmol l⁻¹. Testicular volume was measured by orchidometer, testosterone by liquid chromatography/tandem mass spectrometry, and body composition by dual-energy X-ray absorptiometry. Men completed the Aging Males' Symptoms (AMS) score, International Index of Erectile Function-5 (IIEF-5), physical function, and handgrip dynamometer testing. Eighty-nine men participated with a median (interquartile range [IQR]) age of 53.1 (47.6, 59.2) years, BMI of 37.0 (34.6, 40.5) kg m⁻², and a total testosterone of 7.0 (6.1, 7.9) nmol l⁻¹. Median testicular volume was 18 (IQR: 10, 20) ml. Testicular volume was negatively correlated with BMI (τ = −0.1952, P = 0.010) and total fat mass (τ = −0.2115, P = 0.005) independent of age and testosterone. When BMI, testosterone, sex hormone-binding globulin (SHBG), and luteinizing hormone (LH) were present in a multivariable model, only BMI (-0.38 ml change in testicular volume per 1 kg m^-2 BMI; 95% CI: −0.74, −0.02; P = 0.04) and LH (-0.92 ml change in testicular volume per 1 IU l^-1 LH; 95% CI: −1.75, −0.095; P = 0.03) remained independent significant predictors of testicular volume. Testicular volume was positively correlated with IIEF-5 (τ = 0.2092, P = 0.021), but not related to handgrip strength, physical function tests, or AMS. In obese men, testicular volume is inversely and independently associated with measures of adiposity, but not with most clinical or biochemical markers of HPT axis action. From a clinical perspective, this suggests that obesity might compromise the reliability of reduced testicular volume as a sign of androgen deficiency in men.

Testicular shear wave elastography in oligo-astheno-teratozoospermic individuals: a prospective case-control study

Purpose

The primary objective of this study was to evaluate the testicular stiffness by ultrasound shear wave elastography (SWE) both in men with oligo-astheno-teratozospermia (OAT) and in control group. The secondary objective was to identify a possible correlation between semen quality with testicular stiffness.

Methods

This was a prospective case-control study. We divided the sample in two groups; Group A (case group) included men with OAT, and Group B (control group) men with normal sperm parameters. All participants had at last two semen analysis in the past 180 days (at last 90 days apart), using performed ultrasound and SWE elastography.

Results

We analyzed 100 participants, 50 patients in Group A and 50 controls in Group B. There were statistically significant differences in term of testicular volume and testicular stiffness between two groups. Men with OAT had the testicular stiffness value higher than the controls in both sides (left testicular stiffness 21.4 ± 5.4 kPa vs 9.9 ± 1.6 kPa, p < 0.0001; right testicular stiffness 22.9 ± 4.8 kPa vs 9.5 ± 2.4 kPa, p < 0.0001). Men with abnormal semen parameters showed an inverse correlation between the mean value of testicular stiffness and total sperm count (22.15 ± 3.38 kPa, r = − 0.387, p = 0.005), sperm concentration (22.15 ± 3.38 kPa, r = − 0.244, p = 0.04), and progressive motility (22.15 ± 3.38 kPa, r = − 0.336, p = 0.01), while the correlation was not evident in controls group.

Conclusion

SWE is able to differentiate between testicles with spermatogenic changes from a healthy testicle. For this reason, it could be used to evaluate, in a non-invasive way, the tissue alterations of the organ.

The impact of body mass index on reproductive hormones, testosterone/estradiol ratio and semen parameters

Introduction

The aim of this study was to evaluate the relationship between body mass index (BMI) and sperm parameters and reproductive hormone levels in patients with no known risk factors for infertility.

Material and methods

Four hundred patients who met the study's inclusion criteria were divided into three groups according to their BMI values as normal weight (BMI: 18.5-24.9 kg/m²), overweight (BMI 25-29.9 kg/m²), and obese (BMI ≥30 kg/m²). Semen parameters, reproductive hormone levels and testosterone/estradiol ratio were compared retrospectively between the groups.

Results

There was no significant difference between the groups in terms of age and infertility period. The mean BMI of all the patients was 26.6 ±4.08, and the BMI in the normal, overweight and obese groups were 22.6 ±1.7, 27.4 ±1.3, and 33.4 ±2.9, respectively (p <0.001). There was no significant difference between the groups in terms of serum follicle stimulating hormone, luteinizing hormone, estradiol, prolactin, semen volume, sperm concentration, total sperm count, and progressive and total motility. Serum testosterone (T) level and testosterone/estradiol (T/E2) ratio were significantly higher in the normal BMI group (p <0.001).

Conclusions

Adipose tissue increase was not significantly correlated with change in the semen parameters and it was negatively correlated with T levels and T/E2 ratio.

Quantification of testicular fat deposition in the evaluation of middle-aged overweight male infertility

OBJECTIVES

To measure the testicular volume and testicular fat deposition of middle-aged overweight men and to assess the utility of testicular fat deposition and testicular volume in determining and monitoring testicular infertility.

MATERIALS AND METHODS

Pelvic MRI with thin slice T2WI, T1WI and mDIXON Quant was performed on 30 middle-aged overweight patients in the treatment group and 30 middle-aged overweight men in the control group. Testicular volume and testicular fat deposition were measured separately based on thin slice T2WI and the fat fraction (FF) map of mDIXON Quant, and the testicular fat deposition observed with T1WI was used as a reference for qualitative diagnosis. Testicular volume and testicular fat deposition in middle-aged overweight individuals were compared using a t test with Bonferroni correction and receiver operating characteristic (ROC) curve.

RESULTS

The testicular volumes (10.6-17.9 cm³) of individuals in the treatment group were smaller than those (12.6-19.0 cm³) of individuals in the control group (p < 0.05), and the average FF value (2.2-4.6%) of the testes in the treatment group was higher than that (1.5-3.1%) in the control group (p < 0.05). The ROC analysis showed that the area under the curve (AUC) of testicular fat deposition (0.899) was higher than that of testicular volume (0.777), and biopsy and sperm count were used as references to diagnose infertility. The diagnostic sensitivity (90.00%) of testicular fat deposition of the mDIXON Quant sequence was higher than that (50.00%) of the T1W sequence (p < 0.05). Testicular fat deposition was decreased after 6 months of active treatment with exercise weight loss and drug treatment, and no significant change in testicular volume was observed 6 months later.

CONCLUSION

The findings suggest that the proton density fat fraction (mDIXON Quant sequence in this study) approach is a novel tool for the quantitative and objective evaluation of testicular fat deposition. Testicular fat deposition measurement is more specific than testicular volume measurement in the diagnosis of male infertility, and the mDIXON Quant is more sensitive than T1WI in the diagnosis of testicular fat deposition. Furthermore, our findings may facilitate a more accurate diagnosis and monitoring of testicular infertility, therapeutic effect, and prognosis by measuring testicular fat deposition.

Association between parental anthropometric measures and the outcomes of intracytoplasmic sperm injection cycles

PURPOSE

To study the association between body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR), and response to controlled ovarian stimulation, semen quality, and intracytoplasmic sperm injection (ICSI) outcomes.

METHODS

This prospective observational study included data from 402 couples undergoing ICSI between January/2010-September/2016. Participants had their weight, height, waist, and hip measured before ICSI treatment.

RESULTS

Gonadotropin dose was positively associated with maternal WHR. Maternal WC and WHR negatively influenced the estradiol level, number of follicles, oocytes, and mature oocytes. Maternal BMI negatively influenced oocyte yield. Semen volume was negatively influenced by male BMI. Sperm concentration was negatively associated with WHR and WHtR. Progressive sperm motility was negatively influenced by all anthropometric measures (AMs). The TMSC was negatively affected by all AM but WC. Significant differences were observed in all ICSI outcomes except pregnancy and miscarriage rates, favoring women with AM below the cut off values compared to women above the cut off. It was observed that men with AM below the cut off values showed significantly higher rates of fertilization, embryo and blastocyst development, implantation, and pregnancy than men above the cut off. When combined maternal and paternal AM were analyzed, significant differences were observed in fertilization, embryo and blastocyst development and implantation rates, favoring couples with normal BMI, WC, and WHR.

CONCLUSIONS

Lower AMs have a protective effect on fertility. Awareness and counseling on how to minimize its impact in both partners could improve ICSI outcomes.