Insulin-like Factor 3, Basal and Human Chorionic Gonadotropin-Stimulated Testosterone as Biomarkers to Predict the Effect of Testosterone Replacement in Testicular Cancer Survivors With Mild Leydig Cell Insufficiency

INTRODUCTION

Mild Leydig cell insufficiency affects a substantial proportion of testicular cancer survivors. Previous studies have not shown a beneficial effect of testosterone replacement therapy, however, with a pronounced interindividual effect. Thus, biomarkers identifying the subgroups that might benefit are wanted. We aimed to determine if insulin-like factor 3 (INSL3), basal and human chorionic gonadotropin (hCG)-stimulated testosterone can predict the effect of testosterone replacement therapy in testicular cancer survivors with mild Leydig cell insufficiency.

PATIENTS AND METHODS

We randomized adult testicular cancer survivors with mild Leydig cell insufficiency 1:1 to 12 months of transdermal testosterone replacement therapy (Tostran gel 2%) or placebo. INSL3, basal, and hCG-stimulated testosterone were measured at baseline. Outcomes (glucose, insulin, HbA1C, lipids, blood pressure, and body composition) were measured at baseline, 6 and 12 months. We applied a linear mixed-effect model comparing patients receiving testosterone with placebo in subgroups by biomarker.

RESULTS

We included and randomized 69 patients between October 2016 and February 2018. Patients with INSL3 and hCG-stimulated testosterone concentrations below the median had a -1.7 kg (95% CI: -3.1, -0.4) and -2.0 kg (95% CI: -3.5, -0.6) change in fat mass after 12 months of testosterone replacement therapy compared with placebo. This was not the case in patients with INSL3 and hCG-stimulated testosterone above the median. We did not find any effect of these biomarkers on glucose, insulin, HbA1c, or lipids.

CONCLUSION

Patients with INSL3 and hCG-stimulated testosterone concentrations below the median had decreased fat mass after 12 months of testosterone replacement therapy compared with placebo. It should be evaluated in larger trials if these biomarkers can be used as predictive markers identifying testicular cancer patients with mild Leydig cell insufficiency who might benefit from testosterone substitution.

Testicular function is associated with cardiometabolic health markers: A cross-sectional study of 2289 young men

BACKGROUND

Testicular function, including compensated Leydig cell function, has been indicated to be an early marker of morbidity.

OBJECTIVE

To study the association of testicular function and markers of metabolic and cardiovascular health in a population of young men.

MATERIALS AND METHODS

A cross-sectional study of 2289 men (median age 19 years, 5-95 percentile 18.4-22.2) from the general population examined between 2012 and 2019. Participants answered a questionnaire, had a blood sample drawn for assessment of reproductive hormone levels and health markers (lipids, glycosylated hemoglobin), delivered a semen sample, underwent physical examination including blood pressure measurements, and dual-energy X-ray absorptiometry scan for assessment of body composition. Associations were assessed in both crude and adjusted linear regression analyses.

RESULTS

The men were within the normal reference intervals of their age for reproductive and health biomarkers. Compared to the lowest quartile, having luteinizing hormone levels in the highest quartile was associated with higher mean arterial pressure (1.6 [95% confidence interval: 0.8; 2.5] mmHg), cholesterol (0.1 [95% confidence interval: 0.02; 0.18] mmol/L), and total body fat percentage (1.1 [95% confidence interval: 0.4; 1.8] %-points). Higher serum testosterone levels were associated with more advantageous cardiometabolic health markers and higher total sperm count with a healthier body composition and lower glycosylated hemoglobin.

DISCUSSION AND CONCLUSION

In this study of young men, unselected regarding reproductive hormones and semen quality, higher luteinizing hormone was associated with cardiovascular risk factors. Higher testosterone and total sperm count were associated with more favorable cardiometabolic indices. Thus, serum reproductive hormones and semen quality may be early appearing biomarkers of cardiovascular health even among young healthy men, which could potentially be useful for preventive initiatives to reduce the excess mortality and morbidity risk among infertile men. However, our study was cross-sectional and cannot determine causation. Future longitudinal studies of reproductive health in young men are warranted.

Different Factors Are Associated With Sex Hormones and Leydig Cell Function in Israelis and Palestinians in Jerusalem

Total testosterone (TT) is known to influence health and virility in men. Among men from United States and Europe, numerous sociodemographic and lifestyle factors were reported to be associated with TT. However, associations with TT and Leydig cell function in the Middle East are poorly described. A cross-sectional, population-based sample had a structured interview, physical examinations, and blood tests in two hospitals in Jerusalem, Israel. A subsample (25- to 44-year-old men, n = 286: 124 Israelis, 162 Palestinians) had sex hormone measurements. The primary outcomes were TT and free testosterone/luteinizing hormone (FT/LH) ratio, representing Leydig cell function. Associations with sociodemographic and lifestyle factors, body mass index (BMI), and physical activity (PA) were evaluated using multivariable linear regression. Compared with Palestinians, Israelis had similar TT (4.81 vs. 5.09 ng/mL, p = .405) and higher FT/LH (31.2 vs. 25.8 ng/IU, p = .002). In ln-transformed values, marital status had a stronger association in Palestinians (P for interaction = 0.03). Age, BMI, and PA had a stronger association with TT in Israelis with significant interactions with ethnicity. BMI <25 and a higher PA quartile were associated with a higher TT (p < .001). Among Israelis, age (p = .007), married marital status (p = .007), and BMI <25 were significantly associated with FT/LH. No associations of any factors were identified among Palestinians. Associations with several modifiable factors identified in Western samples were replicated in Israelis and to a lesser degree in Palestinians. Different relationships of several factors with TT and FT/LH could result from ethnically diverse genetic, sociodemographic, and behavioral characteristics that warrant further research.

Diabetes Type 1 Negatively Influences Leydig Cell Function in Rats, Which is Partially Reversible By Insulin Treatment

Type 1 diabetes mellitus (T1DM) is associated with impaired spermatogenesis and lower testosterone levels and epididymal weight. However, the underlying processes in the testis are unknown and remain to be elucidated. Therefore, the present study focused on the effects of T1DM on testicular function in a spontaneously diabetic rat model. BB/OKL rats after diabetes manifestation were divided into 3 groups: those without insulin treatment and insulin treatment for a duration of 2 and of 6 weeks. Anthropometrical data, circulating levels of gonadotrophins, testosterone, and inhibin B were measured. Intratesticular testosterone, oxidative stress, inflammation, and apoptosis were analyzed. Key enzymes of steroidogenesis were evaluated in the testis. Untreated diabetic rats had significantly lower serum follicle-stimulating hormone and luteinizing hormone levels. Serum and intratesticular testosterone levels significantly decreased in untreated diabetic rats compared to healthy controls. Key markers of Leydig cell function were significantly downregulated at the RNA level: insulin-like factor 3 (Insl3) by 53% (P = .006), Star by 51% (P = .004), Cyp11A1 by 80% (P = .003), 3Beta-Hsd2 by 61% (P = .005), and Pbr by 52% (P = .002). In the insulin-treated group, only Cyp11A1 and 3Beta-Hsd2 transcripts were significantly lower. Interestingly, the long-term insulin-treated group showed significant upregulation of most steroidogenic enzymes without affecting testosterone levels. Tumor necrosis factor α and apoptosis were significantly increased in the long-term insulin-treated rats. In conclusion T1DM, with a severe lack of insulin, has an adverse action on Leydig cell function. This is partially reversible with well-compensated blood glucose control. Long-term T1DM adversely affects Leydig cell function because of the process of inflammation and apoptosis.

Acute primary testicular failure due to radiotherapy increases risk of severe postoperative adverse events in rectal cancer patients

AIM

The aim of this study is to analyze postoperative adverse events (AE) in relation to acute primary testicular failure after radiotherapy (RT) for rectal cancer.

METHOD

This relation was assessed in 104 men, included in a previous prospective cohort study of men treated with surgical resection of the rectum for rectal cancer stage I-III. Postoperative AE were graded according to Clavien-Dindo (2004). Grade 3 or more was set as cut-off for severe postoperative AE. The impact of primary testicular failure on postoperative AE was related to the cumulative mean testicular dose (TD) and the change in Testosterone (T) and Luteinizing hormone (LH) sampled at baseline and after RT.

RESULTS

Twenty-six study participants (25%) had severe postoperative AE. Baseline characteristics and endocrine testicular function did not differ significantly between groups with (AE+) and without severe postoperative AE (AE-). After RT, the LH/T-ratio was higher in AE+, 0.603 (0.2-2.5) vs 0.452 (0.127-5.926) (p = 0.035). The longitudinal regression analysis showed that preoperative change in T (OR 0.844, 95% CI 0.720-0.990, p = 0.034), LH/T-ratio (OR 2.020, 95% CI 1.010-4.039, p = 0.047) and low T (<8 nmol/L, OR 2.605, 95 CI 0.951-7.139, p = 0.063) were related to severe postoperative AE.

CONCLUSION

Preoperative decline in T due to primary testicular failure induced by preoperative RT could be a risk factor regarding short-term outcome of surgery in men with rectal cancer.

Human Chorionic Gonadotropin Test: Old Uncertainties, New Perspectives, and Value in 46,XY Disorders of Sex Development

The human chorionic gonadotropin (hCG) test represents a key step in assessing Leydig cell function in prepubertal males, but differences in terms of hCG doses, number of injections, and sequence of blood drawing are published in the literature, showing poor standardization. The few available data in healthy boys are summarized here. A recombinant hCG (rhCG) formulation might permit overcoming some controversies as well as avoid the potential biological risk related to the injection of extractive hormones. Studies in humans are scarce, but they indicate that 250 µg rhCG in a single dose may represent a useful scheme for the dynamic evaluation of Leydig cell function in children as well as in adults. The main indication for hCG testing in childhood is the investigation of 46,XY disorders of sex differentiation. The test must also be considered in order to investigate the presence of functional testicular tissue when gonadal peptide hormones cannot be measured.

INSL3 and AMH in patients with previously congenital or acquired undescended testes

BACKGROUND

In previous reports no differences in Leydig and Sertoli cell function were found between congenital undescended testis (CUDT) and acquired UDT (AUDT) on the basis of serum levels of LH, testosterone, FSH or inhibin B. This study tried to detect differences in Leydig and Sertoli cell function between CUDT and AUDT using insulin-like peptide 3 (INSL3) and anti-Müllerian hormone (AMH).

METHOD

118 men with a history of UDT (CUDT N=55 (6/55 bilateral), AUDT N=63 (15/63 bilateral)) were investigated. Differences between CUDT and AUDT, influence of age at surgery in CUDT, and effect of spontaneous descent or orchiopexy in AUDT were evaluated.

RESULTS

For INSL3, no significant differences were found. AMH levels in bilateral CUDT were significantly lower compared with bilateral AUDT (6.4 (1.7-11.4) vs 13.2 (6.1-30.1) μg/l, p=0.02). AMH levels in unilateral CUDT were significantly higher than in bilateral CUDT (12.1 (2.4-43.7) vs. 6.4 (1.7-11.4) μg/l, p=0.02).

CONCLUSION

No differences in Leydig cell function on the basis of INSL3 levels between the different UDT groups were found. Sertoli cell function evaluated by AMH, was more negatively affected in bilateral CUDT in comparison with bilateral AUDT and unilateral CUDT.

LEVEL OF EVIDENCE RATING

Level III Treatment Study.

Longitudinal Changes in Serum Levels of Testosterone and Luteinizing Hormone in Testicular Cancer Patients after Orchiectomy Alone or Bleomycin, Etoposide, and Cisplatin

BACKGROUND

Controversy exists whether Leydig cells recover after testicular cancer (TC) treatment or whether premature hormonal aging will occur.

OBJECTIVE

Evaluate serial changes in total testosterone (TT) and luteinizing hormone (LH) in patients treated with orchiectomy alone (Stage I) or combination chemotherapy with bleomycin, etoposide, and cisplatin (BEP).

DESIGN, SETTINGS, AND PARTICIPANTS

Changes in TT and LH were investigated during 5-yr follow-up (Stage I: n=75, BEP: n=81). A selected group of TC patients with mild Leydig cell dysfunction (LH ≥ 8 IU/l) were followed for a longer period (Stage I: n=20, BEP: n=23). An age-matched control group of 839 healthy men served as controls for TT and LH levels.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Changes in age-adjusted TT and LH were evaluated separately in each treatment group with univariate linear regression analysis. The proportion of patients initiating testosterone substitution during follow-up was calculated.

RESULTS AND LIMITATIONS

In the 75 Stage I patients there were no significant changes in LH and TT, while in the 81 BEP treated patients there was a significant decline in LH during follow-up (-24.2 percentage point/yr, 95% confidence interval: -38.5 to -9.9, p=0.001). In total, 11% of Stage I patients and 15% of BEP-treated patients initiated testosterone substitution. In the 23 BEP-treated patients with mild Leydig cell dysfunction there was a significant decline in age-adjusted TT (-0.9 percentage point/yr, 95% confidence interval: -1.8 to -0.04, p=0.04), while in the 20 Stage I patients there were no significant changes in age-adjusted LH and TT. Limitations include the retrospective study design.

CONCLUSIONS

TT remained stable during 5-yr follow-up in TC patients treated with orchiectomy alone or BEP. BEP-treated patients with mild Leydig cell dysfunction during follow-up were at risk of long-term testicular failure and evaluation of Leydig cell function beyond follow-up should be considered in this group of patients.

PATIENT SUMMARY

This study shows that the majority of testicular cancer survivors had stable testosterone levels after treatment for testicular cancer. However, 11-15% of patients needed testosterone substitution after treatment.