Male Infertility and Future Cardiometabolic Health: Does the Association Vary by Sociodemographic Factors?

Vascular health of fathers with history of intracytoplasmic sperm injection

OBJECTIVE

Studies suggest that men who undergo assisted reproductive technologies (ART) may have a higher risk of cardiovascular disease; however, limited data on this matter is available. This observational pilot study aimed to investigate the overall vascular health of fathers with history of intracytoplasmic sperm injection (ICSI) compared to fathers whose partners conceived spontaneously.

METHODS

Diet quality, physical activity, sedentary behavior as well as overall vascular function including the assessment of pulse wave analysis, intima-media thickness (cIMT), arterial stiffness of the common carotid artery (CCA) and blood lipids, were evaluated.

RESULTS

A total of 34 fathers with history of ICSI and 29 controls (48.49 [46.32 - 57.09] years vs. 47.19 [40.62 - 55.18] years, p = 0.061) were included. After adjusting for age, no significantly increased cardiovascular risk was detected regarding vascular function.

CONCLUSIONS

The results suggest an unaltered cardiovascular risk profile in fathers with history of ICSI. In the future, prospective multicenter studies are required to validate these preliminary results.

Diabetes and male fertility disorders

Couple infertility is a common condition, defined as being unable to conceive after 12 months of regular unprotected sexual intercourse. Male Factor Infertility (MFI) is responsible, alone or in combination with female factors, for about half of the overall cases of couple infertility. MFI is gradually increasing in prevalence, with a notable decline in semen parameters over the last decades. The aetiologies behind the finding of decreasing sperm counts are difficult to pinpoint but might be due in part to increasing rates of overweight and obesity in men of childbearing age. Diabetes mellitus (DM) is a common and chronic metabolic disease, whose prevalence is also gradually increasing, rising up to 10% of the population. The International Diabetes Federation estimates that there are currently more than 500 million people living with DM worldwide, the vast majority of whom suffering from type 2 DM (T2DM). There is growing awareness of the relationship between unhealthy lifestyle, in particular unhealthy diet, and MFI. Starting from all these premises, the aim of this narrative review is to describe the current evidence on the link between DM and MFI, both in terms of DM as a cause of/a risk factor for MFI and of MFI as a possible predictive marker for T2DM. Finally, we will discuss the risk of DM as a consequence of the therapy of MFI or assisted reproductive techniques.

Obesity, Dietary Patterns, and Hormonal Balance Modulation: Gender-Specific Impacts

Understanding the intricate relationship between nutrition, hormonal balance, and gender-specific factors is crucial for developing targeted interventions to mitigate obesity-related endocrine disruptions and improve metabolic health. This narrative review examines the impact of various dietary patterns on hormonal regulation in both men and women, focusing on their effects on hormonal balance and metabolic health in the context of obesity. Calorie restriction, the Western diet, high-fat diets, low-CHO diets, plant-based diets, and the Mediterranean diet are analyzed in relation to their influence on obesity-related endocrine disruptions and metabolic health. Future research directions include investigating the specific mechanisms underlying dietary influences on hormonal regulation, addressing the gender-specific metabolic differences and body fat distribution, and exploring the dietary needs of individuals undergoing gender transition. Personalized dietary interventions tailored to individual metabolic and hormonal profiles are essential for optimizing health outcomes across the gender spectrum. By integrating gender-specific considerations into dietary recommendations, healthcare professionals can better support individuals in achieving optimal metabolic health and hormonal balance.

Syringin alleviates bisphenol A-induced spermatogenic defects and testicular injury by suppressing oxidative stress and inflammation in male zebrafish

Syringin (SRG) is a bioactive principle possessing extensive activities including scavenging of free radicals, inhibition of apoptosis, and anti-inflammatory properties. However, its effects on spermatogenic defects and testicular injury as well as the underlying mechanisms are still unclear. This study aims to investigate the protective effect of SRG on testis damage in zebrafish and explore its potential molecular events. Zebrafish testicular injury was induced by exposure to bisphenol A (BPA) (3000 μg/L) for two weeks. Fish were treated with intraperitoneal injection of SRG at different doses (5 and 50 mg/kg bodyweight) for two more weeks under BPA induction. Subsequently, the testis and sperm were collected for morphological, histological, biochemical and gene expression examination. It was found that the administration of SRG resulted in a significant protection from BPA-caused impact on sperm concentration, morphology, motility, fertility rate, testosterone level, spermatogenic dysfunction and resulted in increased apoptotic and reactive oxygen species' levels. Furthermore, testicular transcriptional profiling alterations revealed that the regulation of inflammatory response and oxidative stress were generally enriched in differentially expressed genes (DEGs) after SRG treatment. Additionally, it was identified that SRG prevented BPA-induced zebrafish testis injury through upregulation of fn1a, krt17, fabp10a, serpina1l and ctss2. These results indicate that SRG alleviated spermatogenic defects and testicular injury by suppressing oxidative stress and inflammation in male zebrafish.

A Systematic Review and Meta-analysis on the Impact of Infertility on Men's General Health

CONTEXT

Male infertility has been associated with increased morbidity and mortality.

OBJECTIVE

To perform a systematic review and meta-analysis to provide the most critical evidence on the association between infertility and the risk of incident comorbidities in males.

EVIDENCE ACQUISITION

A systematic review and meta-analysis was performed according to the Meta-analysis of Observational Studies in Epidemiology and Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, and registered on PROSPERO. All published studies on infertile versus fertile men regarding overall mortality and risks of cancer, diabetes, and cardiovascular events were selected from a database search on PubMed, EMBASE, Google Scholar, and Cochrane. Forest plot and quasi-individual patient data meta-analysis were used for pooled analyses. A risk of bias was assessed using the ROBINS-E tool.

EVIDENCE SYNTHESIS

Overall, an increased risk of death from any cause was found for infertile men (hazard risk [HR] 1.37, [95% confidence interval {CI} 1.04-1.81], p = 0.027), and a 30-yr survival probability of 91.0% (95% CI 89.6-92.4%) was found for infertile versus 95.9% (95% CI 95.3-96.4%) for fertile men (p < 0.001). An increased risk emerged of being diagnosed with testis cancer (relative risk [RR] 1.86 [95% CI 1.41-2.45], p < 0.001), melanoma (RR 1.30 [95% CI 1.08-1.56], p = 0.006), and prostate cancer (RR 1.66 [95% CI 1.06-2.61], p < 0.001). As well, an increased risk of diabetes (HR 1.39 [95% CI 1.09-1.71], p = 0.008), with a 30-yr probability of diabetes of 25.0% (95% CI 21.1-26.9%) for infertile versus 17.1% (95% CI 16.1-18.1%) for fertile men (p < 0.001), and an increased risk of cardiovascular events (HR 1.20 [95% CI 1.00-1.44], p = 0.049), with a probability of major cardiovascular events of 13.9% (95% CI 13.3-14.6%) for fertile versus 15.7% (95% CI 14.3-16.9%) for infertile men (p = 0.008), emerged.

CONCLUSIONS

There is statistical evidence that a diagnosis of male infertility is associated with increased risks of death and incident comorbidities. Owing to the overall high risk of bias, results should be interpreted carefully.

PATIENT SUMMARY

Male fertility is a proxy of general men's health and as such should be seen as an opportunity to improve preventive strategies for overall men's health beyond the immediate reproductive goals.

Reproduction as a window for health in men

Male factor infertility is widely considered a harbinger for a man's general health. Failure of reproduction often accompanies other underlying processes, with growing evidence suggesting that a diagnosis of infertility increases the likelihood of developing future cardiac, metabolic, and oncologic diseases. The goal of this review is to provide a comprehensive overview of the research on male fertility as a marker for current and future health. A multidisciplinary approach is essential, and there is growing consensus that the male fertility evaluation offers an opportunity to better men's wellness beyond their immediate reproductive ambitions.

Counseling for the man with severe male infertility

PURPOSE OF REVIEW

This review summarize the proper counseling for men with severe male factor infertility.

RECENT FINDINGS

Men who are experiencing infertility should have a semen analysis, the results of which may imply additional investigations, including genetic and hormonal. Moreover, possible modifiable factors that may harm men's reproductive health should be carefully evaluated. Finally, different treatment options are available.

SUMMARY

Approximately 15% of couples struggle with infertility. Complete evaluations of both men and women are required to determine the etiology of infertility and determine appropriate treatment.

Testicular ultrasound examination and hemodynamics of patients with azoospermia

The most difficult form of male infertility to treat is azoospermia. Azoospermia is defined as the complete absence of spermatozoa in the ejaculate. The age of the patients who underwent clinical and diagnostic studies varied between 22 and 45 years. Among 119 examined patients with azoospermia, 58.0% were diagnosed with secretory infertility. In 42.0% patients, the presence of spermatogenesis in excretory-obturational infertility was established. Among 69 patients with secretory infertility, 23 had azoospermia in the absence of spermatozoa and spermatogenic cells, which accounted for 33.3% of all patients with secretory infertility (in particular, 2 with leukocytospermia, which indicated damage to the tubular apparatus as a result of previous orchitis). In 66.6% patients, azoospermia was observed in the absence of spermatozoa, but in the presence of precursor cells of spermatogenesis. 11.5% patients out of 69 (group 1) were diagnosed with concomitant diseases. We see that arterial hypertension, diseases of the gastrointestinal tract, liver, and kidneys occur. Hereditary diseases were not detected in the examined patients. Pain of varying intensity was found in 6.7% of patients, varying degrees of testicular hypoplasia were found in 7.6%, dysuria in 13.4%, epididymitis in history 8.4%; history of epidemic mumps 6.7%; 12.6% had depression, restlessness, sleep disorders, and 21.0% had erectile dysfunction. According to clinical examination and ultrasound, chronic prostatitis is suspected in 19.2% of patients. An increase in the number of leukocytes in the blood was found in 13.2% patients. According to ultrasound, 60.5% of the patients with azoospermia had normal testicular sizes, and 39.5% had reduced testes. The volume of the testicles in the control group was 22.3 ± 2.1 cm³ on average, varying from 18.3 to 25.1 cm³. In the group with azoospermia, the volume of the testicles was on average 16.7 ± 1.7 cm³ and varied from 8.2 to 21.1 cm³, that is, the volume of the testicles in patients with azoospermia was on average 1.3 times smaller compared to normozoospermia. In the obstructive form of azoospermia, diffuse changes were detected in both testicles, probably obturational changes. Hypoplasia of the left testicle and increased echogenicity were observed in the non-obstructive form of azoospermia. The veins of the spermatic cord were moderately dilated. There was a normal amount of free fluid in the scrotum. According to elastography, the elasticity of the testicles was above normal. Obturational processes in the testicles were suspected. The hemodynamic parameters of testicular parenchymal blood flow in infertile men obtained by ultrasound dopplerography are of important diagnostic value. The average value of the linear blood flow velocity in the arteries of the parenchyma in men with normozoospermia was 0.107 ± 0.015 m/s on the right, and 0.103 ± 0.012 m/s on the left. With azoospermia, the average value of the linear velocity of blood flow on the right was 0.086 ± 0.012 m/s, and on the left – 0.084 ± 0.008 m/s. Thus, the hemodynamic indicators of the scrotum show that the most pronounced changes are found in men with azoospermia in the absence of spermatogenesis.

Association between male infertility and the risk of hypertension: A meta-analysis and literature review

To explore the association between male infertility and hypertension risk, a meta-analysis and systematic review was conducted. Observational studies were sought in Medline, PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure up to April 30, 2021. Two independent reviewers selected available studies and extracted the data. The association between male infertility and hypertension risk was estimated by calculating the relative risk (RR) and 95% confidence interval (95% CI) using Stata12.0 statistical software. A total of seven studies were included in this meta-analysis, including 102,152 patients and 636,645 healthy individuals. The results demonstrated that male infertility was significantly associated with increased hypertension incidence (RR = 1.08; 95% CI 1.02-1.14; p = 0.004), with moderate-quality evidence. A subgroup analysis based on region showed that a positive association was observed in Europe but not the United States or Asia. This positive association was further confirmed in a cohort study, but not in a case-control study. After adjusting for potential confounders, male infertility was still significantly associated with hypertension risk (RR = 1.06, 95% CI 1.03-1.09). In conclusion, our findings suggest that male infertility increases the risk of hypertension incidence. However, further studies are needed to provide more conclusive evidence.

Male Infertility Increases the Risk of Cardiovascular Diseases: A Nationwide Population-Based Cohort Study in Taiwan

PURPOSE

Some evidence suggests that male infertility increases the risk of cardiovascular diseases (CVDs). However, the evidence in Asian populations is relatively scarce. The aim of this study is to determine whether male infertility increases the risk of CVDs.

MATERIALS AND METHODS

We used inpatient and outpatient data for the years 2000 to 2015 from the Taiwanese Longitudinal Health Insurance Database. We enrolled 7,016 males over 18 years old and diagnosed with male infertility. Of these, 2,326 matched our inclusion criteria and were assigned to the study group. For each infertility patient, four comparison patients were frequency-matched by age and index date to form a control cohort comprising 9,304 patients. Cox proportional hazards analysis was used to estimate the association between male infertility and CVDs.

RESULTS

After a 15-year follow-up, the incidence rate of CVDs was higher in the infertility group than the control group (1,460.23 and 1,073.70 per 100,000 person-years, respectively). The Cox proportional hazards regression analysis revealed that the adjusted HR for CVDs was 1.472 for the infertility group (95% CI, 1.288-1.683; p<0.001) relative to the control group. The Kaplan-Meier analysis of the cumulative incidence of CVDs in the two groups showed that the cumulative risk curve for CVDs was significantly higher for the infertility group than the control group.

CONCLUSIONS

This study shows that men with infertility have a higher risk of developing incident CVDs. In the future, healthcare providers should pay attention to these patients because of their higher health risks.

Oxidative Stress and Male Infertility: Evidence From a Research Perspective

Male fertility potential can be influenced by a variety of conditions that frequently coincide. Spermatozoa are particularly susceptible to oxidative damage due to their limited antioxidant capacity and cell membrane rich in polyunsaturated fatty acids (PUFAs). The role of oxidative stress (OS) in the etiology of male infertility has been the primary focus of our Stellenbosch University Reproductive Research Group (SURRG) over the last 10 years. This review aims to provide a novel insight into the impact of OS on spermatozoa and male reproductive function by reviewing the OS-related findings from a wide variety of studies conducted in our laboratory, along with those emerging from other investigators. We will provide a concise overview of the production of reactive oxygen species (ROS) and the development of OS in the male reproductive tract along with the physiological and pathological effects thereof on male reproductive functions. Recent advances in methods and techniques used for the assessment of OS will also be highlighted. We will furthermore consider the current evidence regarding the association between OS and ejaculatory abstinence period, as well as the potential mechanisms involved in the pathophysiology of various systemic diseases such as obesity, insulin resistance, hypertension, and certain mental health disorders which have been shown to cause OS induced male infertility. Finally, special emphasis will be placed on the potential for transferring and incorporating research findings emanating from different experimental studies into clinical practice.

Treatment With Cholecalciferol Leads to Increase Of Selected Semen Parameters in Young Infertile Males: Results of a 6-month Interventional Study

High incidence of infertility along with low vitamin D levels was detected in otherwise healthy young men. The aim is to observe the effect of vitamin D supplementation on semen parameters as assessed by semen analysis in infertile men. In total, 45 men (mean age 36.6 years) in consecutive order were included, of whom 34 finished the study. Subjects were supplemented by vitamin D (cholecalciferol) 2500 IU/day. Vitamin D levels were assessed by HPLC. Semen analysis was performed strictly following 2010 WHO guidelines. Study periods were baseline and month 6. During follow-up, 20 %, 7.4 %, 22 % and 0.7 % increase in serum vitamin D levels, progressive sperm motility, sperm concentration and sperm morphology, respectively, were observed (all p<0.05). At follow-up end, 9 patients (26 %) reached normal sperm parameters of whom 2 fertilized their partner. There was no correlation between vitamin D and semen parameters observed. This study proves that vitamin D supplementation is possibly a modulator of sperm parameters in vitamin D deficient, otherwise healthy men. Although a direct relationship between vitamin D and sperm parameters was not observed obtaining adequate vitamin D levels could likely play a role in the male factor of infertility.

Male fertility as a marker for health

Male reproduction is a complex biological process, and male factor infertility is increasingly recognized as a biomarker for overall male health. Emerging data suggest associations between male reproduction and medical disease (genetic, infectious, chronic comorbid conditions), psychological disease, environmental exposures, dietary habits, medications and substances of abuse, and even socioeconomic factors. There is also evidence that a diagnosis of male fertility is associated with future disease risk including cancer, metabolic disease and mortality. As such, there is a growing view that the male fertility evaluation is an opportunity to improve a man's health beyond his immediate reproductive goals, and also highlights the necessity of a multidisciplinary approach.

Defining critical factors in multi-country studies of assisted reproductive technologies (ART): data from the US and UK health systems

As the worldwide use of assisted reproductive technologies (ART) continues to grow, there is a critical need to assess the safety of these treatment parameters and the potential adverse health effects of their use in adults and their offspring. While key elements remain similar across nations, geographic variations both in treatments and populations make generalizability challenging. We describe and compare the demographic factors between the USA and the UK related to ART use and discuss implications for research. The USA and the UK share some common elements of ART practice and in how data are collected regarding long-term outcomes. However, the monitoring of ART in these two countries each brings strengths that complement each other's limitations.

Men Who Have Undergone Vasectomy are Healthier Than Non-sterilized Fertile Men: An Analysis of the Nation Survey for Family Growth

OBJECTIVE

To evaluate the health status of men who have undergone vasectomy versus nonsterilized fertile men.

METHODS

Using the National Survey for Family Growth from 2002 to 2017, univariate and multivariate analyses were performed on demographic and health data, including health status and health care utilization.

RESULTS

Men who have undergone vasectomy are more likely to be older, healthier, have more children, identify as non-Hispanic white, be married, have a higher level of education, earn a higher mean household income, and were more likely to be privately insured than non-sterilized fertile men. On multivariate analysis, men who underwent vasectomy had a better health status despite being older.

CONCLUSION

There are significant socioeconomic and health differences between men who elect vasectomy and non-sterilized fertile men. These differences should be considered when considering using sterilized men as a proxy for proven fertile men in epidemiological studies.

A comparison of metabolic health parameters in ICSI-conceived and naturally conceived adolescents

RESEARCH QUESTION

Are there differences in the cardiometabolic health of ICSI-conceived adolescents compared with a control group, taking parental risk factors into account?

DESIGN

ICSI-conceived adolescents (n = 272), their mothers (n = 273) and naturally conceived control adolescents (n = 273) and their mothers (n = 273) provided a blood test and answered a health-related questionnaire. The adolescents also attended a physical examination.

RESULTS

ICSI-conceived males showed significantly higher mean weight (72.6 ± 15.1 versus 67.7 ± 12.6 kg, P = 0.005), body mass index (BMI) (22.2 ± 3.7 versus 21.0 ± 3.2 kg/m², P = 0.007) and waist circumference (79.1 ± 11.6 versus 74.5 ± 8.7 cm, P < 0.001). The mean values for weight and BMI were also significantly higher in the ICSI parents. In the ICSI-conceived females significant differences in high-density lipoprotein cholesterol (1.5 ± 0.3 versus 1.6 ± 0.3 mmol/l, P = 0.033) and triglyceride values (1.1 ± 0.5 versus 1.0 ± 0.4 mmol/l, P = 0.013) were observed. ICSI mothers also had significantly higher triglycerides (P = 0.002), higher glutamate pyruvate transaminase/alanine aminotransferase (P < 0.001) and higher alkaline phosphatase values (P < 0.001).

CONCLUSIONS

Increased values for weight were found in the male and differences in lipid parameters in the female ICSI-conceived adolescents, which were reflected in the values of their parents. Adjustment for parental risk factors generally attenuated the differences between the ICSI and the control groups, but did not completely remove them. Whether these observed differences are clinically relevant for the future health of the participants requires further study. To increase knowledge in this area, future studies should also include parental data.

Clinical correlation among male infertility and overall male health: A systematic review of the literature

Purpose

Ongoing evidence has suggested the role of male factor infertility as a potential predictor of mortality and general health status. The aim of the present review is to update the current knowledge base regarding the association between male factor infertility and general health through a critical review of the literature.

Materials and Methods

A systematic review of the literature was carried out from inception to November 2019 in order to evaluate significant associations between male infertility and adverse health outcomes such as cardiovascular, oncologic, metabolic and autoimmune diseases as well as overall mortality.

Results

In all, 27 studies met inclusion criteria and were critically examined. Five studies examined male infertility and cardiovascular disease risk, 11 examined oncologic risk (e.g., overall cancer risk, testis and prostate cancer), 8 examined aggregate chronic medical diseases and 5 infertility related to incidence of mortality, for a total of 599,807 men diagnosed with any male factor infertility covering a period from 1916 to 2016.

Conclusions

A man's fertility and overall health appear to be interconnected. Therefore, a diagnosis of male infertility may allow a window into future comorbidity and/or mortality which may help guide clinical decisions and counseling. Several possible etiologies such as genetic, epigenetic, developmental, and lifestyle-based factors need to be further evaluated in order to establish the underlying mechanisms between male infertility and health.

New insights to guide patient care: the bidirectional relationship between male infertility and male health

Male reproduction is a complex process, and numerous medical conditions have the potential to alter spermatogenesis. In addition, male factor infertility may be a biomarker for future health. In the present review, we discuss the current literature regarding the association between systemic diseases and fertility, which may impact clinical outcomes or semen parameters. A number of conditions that have systemic consequences were identified, including genetic (e.g., cystic fibrosis, DNA mismatch repair alterations), obesity, psychological stress, exogenous testosterone, and a variety of common medications. As such, the infertility evaluation may offer an opportunity for health counseling beyond the discussion of reproductive goals. Moreover, male infertility has been suggested as a marker of future health, given that poor semen parameters and a diagnosis of male infertility are associated with an increased risk of hypogonadism, cardiometabolic disease, cancer, and even mortality. Therefore, male fertility requires multidisciplinary expertise for evaluation, treatment, and counseling.