Azoospermia is the complete absence of spermatozoa in the ejaculate in two or more semen analyses after centrifugation. Nonobstructive azoospermia (NOA) represents the most severe form of male factor infertility accounting for 10%-15% of cases and stems from an impairment to spermatogenesis. Understanding of the hypothalamic-pituitary-testicular axis has allowed NOA to be subcategorized by anatomic and/or pathophysiologic level. The etiologies of NOA, and therefore, the differential diagnoses when considering NOA as a cause of male factor infertility, can be subcategorized and condensed into several distinct classifications. Etiologies of NOA include primary hypogonadism, secondary hypogonadism, defects in androgen synthesis and/or response, defective spermatogenesis and sperm maturation, or a mixed picture thereof. This review includes up-to-date clinical, diagnostic, cellular, and histologic features pertaining to the multitude of NOA etiologies. This in turn will provide a framework by which physicians practicing infertility can augment their clinical decision-making, patient counseling, thereby improving upon the management of men with NOA.
Humans ; Azoospermia/diagnosis* ; Male ; Spermatogenesis/physiology* ; Hypogonadism/complications* ; Infertility, Male/etiology* ; Testis/pathology*

Hypogonadotropic hypogonadism (HH) represents a relatively rare cause of nonobstructive azoospermia (NOA), but its knowledge is crucial for the clinical andrologists, as it represents a condition that can be corrected with medical therapy in 3 quarters of cases. There are forms of congenital HH, whether or not associated with an absent sense of smell (anosmic HH or Kallmann syndrome, and normosmic HH, respectively), and forms of acquired HH. In congenital HH, complete absence of pubertal development is characteristic. On the other hand, if the deficit occurs after the time of pubertal development, as in acquired HH patients, infertility and typical symptoms of late-onset hypogonadism are the main reasons for seeking medical assistance. Gonadotropin-releasing hormone (GnRH) or gonadotropin replacement therapy is the mainstay of drug therapy and offers excellent results, although a small but significant proportion of patients do not achieve sufficient responses.
Humans ; Hypogonadism/drug therapy* ; Male ; Azoospermia/drug therapy* ; Gonadotropin-Releasing Hormone/therapeutic use* ; Kallmann Syndrome/drug therapy* ; Hormone Replacement Therapy

Except in cases of hypogonadotropic hypogonadism, the use of medical therapy before microsurgical testicular sperm extraction (micro-TESE) is controversial. In some studies, hormone therapy has been shown to improve the possibility of sperm retrieval during micro-TESE and even lead to the presence of sperm in the ejaculate in some cases, thereby obviating the need for micro-TESE. However, their routine use before micro-TESE in cases of nonobstructive azoospermia (NOA) being associated with hypergonadotropic hypogonadism and eugonadism (normogonadotropic condition) has not been supported with robust evidence. In this review, we discuss different types of medical therapy used before micro-TESE for NOA, their risks and benefits, and the available evidence surrounding their use in this setting.
Humans ; Male ; Azoospermia/therapy* ; Sperm Retrieval ; Hypogonadism/complications* ; Microsurgery

Testosterone affects several organs in the body and is very important for male well-being. Aging men with late-onset hypogonadism (LOH) experience physiologic, psychiatric, and sexual symptoms related to a decline in the serum concentration of testosterone with age. However, it is well-known that the extent of the decline in testosterone concentration does not correlate with the severity of LOH-related symptoms. Therefore, it is difficult to diagnose and treat patients with LOH. In addition, the symptoms, response to testosterone replacement therapy (TRT), and medical insurance coverage differ among ethnicities and countries. The evaluation of testosterone is essential for the diagnosis and treatment of LOH. The effects of testosterone are determined not only by the serum testosterone concentration but also by the androgen receptor sensitivity. A low number of glutamine repeats is indicative of high androgenic activity, and the number shows ethnicity-related differences (fewer in African American than in Caucasian people and more in East Asian people). The diagnosis of LOH is typically made using subjective symptoms and the serum testosterone concentration. The Aging Male Symptoms scale is widely used to evaluate the symptoms. The normal range of total testosterone concentration varies around the world; therefore, clinicians should follow the guidelines of their regional academic society. The principal treatment for LOH is TRT. There are many types of TRT and other treatment strategies are also available. Thus, physicians should treat LOH according to each patient's situation, considering related disorders, such as diabetes, osteoporosis, metabolic syndrome, and depression.
Humans ; Male ; Hypogonadism/drug therapy* ; Testosterone/blood* ; Hormone Replacement Therapy/methods* ; Japan ; Age of Onset ; Aging ; Aged ; Androgens/therapeutic use*

The circadian clock is an important internal time regulatory system for a range of physiological and behavioral rhythms within living organisms. Testosterone, as one of the most critical sex hormones, is essential for the development of the reproductive system, maintenance of reproductive function, and the overall health of males. The secretion of testosterone in mammals is characterized by distinct circadian rhythms and is closely associated with the regulation of circadian clock genes. Here we review the central and peripheral regulatory mechanisms underlying the influence of circadian clock genes upon testosterone synthesis. We also examined the specific effects of these genes on the occurrence, development, and treatment of common male diseases, including late-onset hypogonadism, erectile dysfunction, male infertility, and prostate cancer.
Testosterone/metabolism* ; Humans ; Male ; Circadian Clocks/genetics* ; Circadian Rhythm Signaling Peptides and Proteins/metabolism* ; Circadian Rhythm/physiology* ; Hypogonadism/metabolism* ; Erectile Dysfunction/metabolism* ; Infertility, Male/metabolism* ; Prostatic Neoplasms/metabolism* ; Men's Health

Non-obstructive azoospermia is a common condition associated with significant health risks, including increased mortality, cancer, and chronic diseases such as metabolic and cardiovascular disorders. This review aims to highlight the potential health challenges faced by men with this condition compared to fertile counterparts. Through a comprehensive bibliographic search on PubMed, using the following algorithm: ("infertility, male" [MeSH Terms] OR "azoospermia" [MeSH Terms]) AND ("mortality" [MeSH Terms] OR "neoplasms" [MeSH Terms] OR "chronic disease" [MeSH Terms] OR "diabetes mellitus" [MeSH Terms] OR "heart diseases" [MeSH Terms]), we analyzed existing literature to explore the associations between infertility, specifically azoospermia, and adverse health outcomes. Findings indicate that infertile men are at a higher risk of death, various cancers (particularly testicular cancer), metabolic syndrome, diabetes, hypogonadism, and cardiovascular disease. Although research specifically addressing azoospermia is limited, available studies support the notion that men with this condition may experience heightened health vulnerabilities. Given these risks, it is imperative for healthcare professionals, especially urologists, to conduct thorough health assessments for men diagnosed with azoospermia. Informing patients of these potential health issues and integrating comprehensive evaluations into their care can facilitate early detection and intervention for life-threatening conditions. Ultimately, men with azoospermia should receive ongoing monitoring to address their specific health concerns, thus improving their long-term health outcomes.
Humans ; Male ; Azoospermia/epidemiology* ; Cardiovascular Diseases/etiology* ; Metabolic Syndrome/epidemiology* ; Infertility, Male/complications* ; Testicular Neoplasms/epidemiology* ; Hypogonadism/epidemiology* ; Diabetes Mellitus/epidemiology* ; Risk Factors ; Neoplasms/epidemiology*

OBJECTIVE: To evaluate the clinical efficacy of "Shibao Decoction" in the management of late-onset hypogonadism (LOH) caused by deficiency of kidney essence. METHODS: Sixty male patients with late-onset hypogonadism of kidney essence deficiency type were randomly assigned to the treatment group and the control group, each with 30 cases. The patients in treatment group were treated with oral Shibao Decoction, while the control group was treated with oral Testosterone Undecanoate Capsules. The patients in both groups were treated for 12 weeks. The PADAM symptom score, TCM syndrome score, serum total testosterone (TT), serum free testosterone (FT), sex hormone binding globulin (SHBG), body mass index (BMI), total skeletal muscle mass index (SMI), appendicular skeletal muscle mass index (ASMI), FBG, FINS, and insulin resistance index (HOMA-IR) levels were compared between the two groups. RESULTS: After treatment, PADAM scores for each item and TCM symptoms score decreased, TT and FT increased in both groups, all with statistically significant differences from those of pre-treatment (P<0.05). The level of SHBG in the control group decreased (P<0.05), which had not changed significantly in the treatment group (P>0.05). After treatment, SMI and ASMI increased in both groups significantly (P<0.05). BMI decreased in the control group (P<0.05), which had not changed significantly in the treatment group (P>0.05). The level of FINS decreased in the control group (P<0.05), which had not changed significantly in the treatment group (P>0.05). FPG had not changed significantly in both groups (P>0.05), and the insulin resistance index (HOMA-IR) had significantly improved in both groups, all with statistically significant differences from those of pre-treatment (P<0.05). After treatment, the total effective rates of PADAM score and TCM syndrome score in the treatment group were 73.3% and 86.6% respectively, and the total effective rates in the control group were 66.7% and 76.6% respectively. The total effective rates of the two scores in the treatment group were slightly higher than those in the control group (P>0.05). There was no significant difference in the indicators between the two groups after treatment, and the treatment group is generally comparable with the control group in the therapeutic effects (P>0.05). And no adverse reactions occurred during treatment in both groups. CONCLUSION The "Shibao Decoction" has a remarkable therapeutic effect on late-onset hypogonadism caused by deficiency of kidney essence and has good safety. It can be used as an alternative to testosterone undecanoate and is worthy of clinical promotion and application.
Humans ; Hypogonadism/etiology* ; Drugs, Chinese Herbal/therapeutic use* ; Male ; Testosterone/therapeutic use* ; Treatment Outcome ; Sex Hormone-Binding Globulin ; Medicine, Chinese Traditional ; Middle Aged ; Adult ; Kidney

To investigate the factors affecting the sperm retrieval rate of microdissection testicular sperm extraction (micro-TESE) in patients with nonmosaic Klinefelter syndrome (KS), 64 patients with nonmosaic KS who underwent micro-TESE in the Center for Reproductive Medicine of Peking University Third Hospital (Beijing, China) between January 2016 and December 2017 were included in the study. Data on medical history, physical examination and laboratory examination results, and micro-TESE outcomes were collected. Patients were divided into two groups according to micro-TESE outcomes. The following factors were compared between the two groups by the Mann‒Whitney U test or Student's t-test based on the distribution (nonnormal or normal) of the factors: age, testicular size, follicle-stimulating hormone level, luteinizing hormone level, testosterone level, and anti-Müllerian hormone level. The overall success rate of sperm retrieval was 50.0%. Correlation analysis showed that testicular volume was positively correlated with testosterone level. Using a logistic regression model, age and anti-Müllerian hormone levels were found to be better predictors for the sperm retrieval rate than the other parameters.
Humans ; Male ; Sperm Retrieval ; Klinefelter Syndrome ; Microdissection ; Anti-Mullerian Hormone ; Semen ; Testis ; Spermatozoa ; Testosterone ; Azoospermia ; Retrospective Studies

Klinefelter syndrome (KS) is the most common genetic cause of human male infertility. However, the effect of the extra X chromosome on different testicular cell types remains poorly understood. Here, we profiled testicular single-cell transcriptomes from three KS patients and normal karyotype control individuals. Among the different somatic cells, Sertoli cells showed the greatest transcriptome changes in KS patients. Further analysis showed that X-inactive-specific transcript ( XIST ), a key factor that inactivates one X chromosome in female mammals, was widely expressed in each testicular somatic cell type but not in Sertoli cells. The loss of XIST in Sertoli cells leads to an increased level of X chromosome genes, and further disrupts their transcription pattern and cellular function. This phenomenon was not detected in other somatic cells such as Leydig cells and vascular endothelial cells. These results proposed a new mechanism to explain why testicular atrophy in KS patients is heterogeneous with loss of seminiferous tubules but interstitial hyperplasia. Our study provides a theoretical basis for subsequent research and related treatment of KS by identifying Sertoli cell-specific X chromosome inactivation failure.
Animals ; Humans ; Male ; Female ; Sertoli Cells/metabolism* ; Klinefelter Syndrome/genetics* ; Endothelial Cells ; Testis/metabolism* ; X Chromosome/metabolism* ; Mammals/genetics*

Child ; Humans ; Consensus ; Hypogonadism/drug therapy*