Metabolic syndrome in White-European men presenting for secondary couple's infertility: an investigation of the clinical and reproductive burden

Using a Decision Tree Algorithm Predictive Model for Sperm Count Assessment and Risk Factors in Health Screening Population

Purpose

Approximately 20% of couples face infertility challenges and struggle to conceive naturally. Despite advances in artificial reproduction, its success hinges on sperm quality. Our previous study used five machine learning (ML) algorithms, random forest, stochastic gradient boosting, least absolute shrinkage and selection operator regression, ridge regression, and extreme gradient boosting, to model health data from 1375 Taiwanese males and identified ten risk factors affecting sperm count.

Methods

We employed the CART algorithm to generate decision trees using identified risk factors to predict healthy sperm counts. Four error metrics, SMAPE, RAE, RRSE, and RMSE, were used to evaluate the decision trees. We identified the top five decision trees based on their low errors and discussed in detail the tree with the least error.

Results

The decision tree featuring the least error, comprising BMI, UA, ST, T-Cho/HDL-C ratio, and BUN, corroborated the negative impacts of metabolic syndrome, particularly high BMI, on sperm count, while emphasizing the link between good sleep and male fertility. Our study also sheds light on the potentially significant influence of high BUN on spermatogenesis. Two novel risk factors, T-Cho/HDL-C and UA, warrant further investigation.

Conclusion

The ML algorithm established a predictive model for healthcare personnel to assess low sperm counts. Refinement of the model using additional data is crucial for improved precision. The risk factors identified offer avenues for future investigations.

How much obesity and diabetes do impair male fertility?

BACKGROUND

Subfertility in obese and diabetic men during the reproductive age is evident, but the mechanisms by which obesity and diabetes mellitus cause male infertility are not entirely understood. The current study aimed to evaluate the effects and potential mechanisms of obesity and diabetes on male fertility.

METHODS

We enrolled control = 40, obese = 40, Lean-DM = 35, and Obese-DM = 35 individuals. The obesity-associated markers, diabetic markers, hormonal and lipid profile, inflammatory indices, and semen analysis were assessed in four experimental groups.

RESULTS

Our finding showed that diabetic markers were significantly increased in two diabetic groups, while obesity indices were markedly increased in two obese groups. Conventional sperm parameters were significantly lower in three groups compared with the control. Serum levels of total testosterone and sex hormone-binding globulin were significantly lower in men with obesity and DM compared with the control. There was a significant difference in the concentration of high-sensitivity C-reactive protein among four experimental groups. Moreover, serum leptin was significantly increased in obese DM, lean DM, and obese groups. Serum insulin levels had a positive correlation with metabolic-associated indices and high-sensitivity C-reactive protein levels, whereas it had a negative correlation with count, motility, and morphology.

CONCLUSIONS

Our findings showed the metabolic changes, hormonal dysfunction and inflammatory disturbance might be suspected mechanisms of subfertility in obese and diabetic subfertile men.

High serum alpha-fetoprotein levels in primary infertile men

BACKGROUND

Alfa-fetoprotein (AFP) is a serum glycoprotein highly produced during fetal development. While AFP synthesis drops dramatically after birth, AFP production only persists or returns under specific pathological condition.

OBJECTIVE

We sought to investigate the rate of and the potential meaning of high AFP serum levels in men seeking first medical attention for couple's primary infertility.

MATERIALS AND METHODS

Socio-demographic and clinical data from 1803 non-Finnish, White-European primary infertile men were retrospectively analysed. AFP was routinely measured in each patient (high AFP was defined as >7 ng/ml). Men with history of liver diseases, testicular cancer, or other known causes of increased AFP levels were excluded from the final analysis. Semen analyses were based on the 2010 World Health Organization reference criteria. Descriptive statistics and logistic regression models tested the association between serum AFP and clinical variables. Possible nonlinear relationships were graphically explored with locally estimated scatterplot smoothing method.

RESULTS

Overall, high serum AFP level was found in 29 (1.7%) patients. Normal versus high AFP levels patients were comparable in terms of body mass index (BMI), Charlson Comorbidity Index, waist circumference, smoking habits, history of cryptorchidism, testicular volume, and serum hormones (i.e., follicle-stimulating hormone, luteinizing hormone, and total testosterone). Conversely, men with higher AFP levels were older (p = 0.02), had lower sperm concentration (p = 0.003), and were more frequently oligozoospermic and azoospermic (all p ≤ 0.03). At multivariate analysis, high AFP levels were independently associated with oligozoospermia (OR 3.79; p = 0.033) and azoospermia (OR 3.29; p = 0.006). Likewise, if AFP levels increase, patients were found to be older, with higher BMI and to have more comorbidities (all p < 0.05).

DISCUSSION

Unexplained high AFP levels account for almost 2% of cases in primary infertile patients without a previous history of associated disorders. Higher serum AFP levels are linked with aberrant sperm counts, older age, obesity, and a greater amount of comorbid conditions.

CONCLUSION

Despite the need for additional validation, these data suggest that serum AFP measurement might have a multifaceted role over the diagnostic work-up of males presenting for couple's infertility.

Metabolic Syndrome and Male Fertility: Beyond Heart Consequences of a Complex Cardiometabolic Endocrinopathy

Metabolic syndrome (MetS) is a highly prevalent condition among adult males, affecting up to 41% of men in Europe. It is characterized by the association of obesity, hypertension, and atherogenic dyslipidemia, which lead to premature morbidity and mortality due to cardiovascular disease (CVD). Male infertility is another common condition which accounts for about 50% of cases of couple infertility worldwide. Interestingly, male infertility and MetS shares several risk factors (e.g., smoking, ageing, physical inactivity, and excessive alcohol consumption), leading to reactive oxygen species (ROS) production and increased oxidative stress (OS), and resulting in endothelial dysfunction and altered semen quality. Thus, the present narrative review aims to discuss the pathophysiological mechanisms which link male infertility and MetS and to investigate the latest available evidence on the reproductive consequences of MetS.

Impact of metabolic syndrome on the viability of human spermatozoa: a cross-sectional descriptive study in men from infertile couples

Background

A direct association between metabolic syndrome (MetS) and sperm production/function has been proposed. In this cross-sectional study, we aimed to determine the impact of MetS on sperm survival. Men from infertile couples treated at Hue University Hospital, Vietnam, were enrolled in this study, which spanned the October 2018 to October 2020 period. The general characteristics of the patients, including body mass index (BMI), waist-to-hip ratio (WHR), the levels of different biochemicals, and semen parameters were determined, and sperm survival tests (SSTs) were performed. The modified National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III for the Asian population was used for MetS diagnosis.

Results

Men with an abnormal waist circumference (≥ 90 cm) showed a higher rate of abnormal SST results (30.1% vs. 16.7%, p = 0.012). The frequency of abnormal SST results in patients with MetS (72.3%) was significantly higher than that in individuals without MetS (53.4%) (p = 0.02). Furthermore, the percentage of abnormal SST results in patients with MetS and with BMI ≥ 23 was significantly higher than those in individuals without MetS (77.1% vs. 55.2%, p = 0.03). Weak negative correlations were also observed between the patients’ age and the SST results.

Conclusion

Sperm viability was lower in men with MetS. We also observed that age and BMI were independent factors associated with abnormal SST.

Metabolic Syndrome and Reproduction

Metabolic syndrome (MetS) and infertility are two afflictions with a high prevalence in the general population. MetS is a global health problem increasing worldwide, while infertility affects up to 12% of men. Despite the high prevalence of these conditions, the possible impact of MetS on male fertility has been investigated by a few authors only in the last decade. In addition, underlying mechanism(s) connecting the two conditions have been investigated in few preclinical studies. The aim of this review is to summarize and critically discuss available clinical and preclinical studies on the role of MetS (and its treatment) in male fertility. An extensive Medline search was performed identifying studies in the English language. While several studies support an association between MetS and hypogonadism, contrasting results have been reported on the relationship between MetS and semen parameters/male infertility, and the available studies considered heterogeneous MetS definitions and populations. So far, only two meta-analyses in clinical and preclinical studies, respectively, evaluated this topic, reporting a negative association between MetS and sperm parameters, testosterone and FSH levels, advocating, however, larger prospective investigations. In conclusion, a possible negative impact of MetS on male reproductive potential was reported; however, larger studies are needed.

The Prevalence and Components of Metabolic Syndrome in Men from Infertile Couples and Its Relation on Semen Analysis

PURPOSE

Metabolic syndrome (MetS) has been reported as a deleterious factor in male fertility potential, associated with hypogonadism, impaired spermatogenesis, decreased sperm concentration and motility, and increased sperm DNA damage. This study aimed to determine the prevalence of MetS in men from infertile couples and evaluate its effect on semen analysis (SA).

PARTICIPANTS AND METHODS

A cross-sectional descriptive study was performed in men from infertile couples diagnosed based on the World Health Organization 2010 criteria and treated at the Hue Center for Reproductive Endocrinology and Infertility, Vietnam. General information included medical history, lifestyle, MetS factors, SA, and sperm DNA fragmentation test were collected. Based on the diagnostic criteria of the American Heart Association and the National Heart, Lung, and Blood Institute for Asian men, the study population was divided into two groups: MetS and non-MetS groups. The outcomes were analyzed for any relationship between MetS and the SA index and the DNA fragmentation index (DFI).

RESULTS

A total of 534 men from infertile couples were included in this study. The prevalence of MetS was 23.4%, and abnormal semen analysis accounted for 93.8%. Age, body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), hepatitis B and total cholesterol were related to the occurrence of MetS in infertile men (p <0.05). MetS did not reveal any impact on the parameters of SA. There was a positive correlation between waist circumference (WC), WHR, WHtR, and systolic blood pressure (BP) with abnormal sperm head and DFI (p <0.05).

CONCLUSION

Although the prevalence of MetS was remarkable in men from infertile couples, there was no association between MetS and semen quality. However, WC, WHR, WHtR, and systolic BP were found to be significantly associated with abnormal sperm head and DFI.

Impact of metabolic syndrome on sex hormones and reproductive function: a meta-analysis of 2923 cases and 14062 controls

Current evidence is inconsistent regarding the impact of metabolic syndrome (MetS) on sex hormones and reproductive function, and this meta-analysis aimed to illuminate the association. A literature search was conducted in public databases to identify all relevant studies, and study-specific standardized mean differences (SMD) and 95% confidence intervals (CI) were pooled using a random-effects model. Finally, 21 studies were identified with a total of 2923 MetS cases and 14062 controls. In males, MetS cases had a lower level of testosterone, inhibin B, total sperm count, sperm concentration, sperm normal morphology, sperm total motility, sperm progressive motility and sperm vitality, and a higher level of DNA fragmentation and mitochondrial membrane potential. In females, MetS cases had a higher level of testosterone. No significant difference was detected for follicle-stimulating hormone, luteinizing hormone, oestradiol, prolactin, anti-Müllerian hormone and semen volume in males, and for oestradiol, follicle-stimulating hormone, luteinizing hormone and progesterone in females. In conclusion, this meta-analysis indicated the impact of MetS on sex hormones and reproductive function, and MetS cases had a potential risk of infertility.

The impact of metabolically healthy obesity in primary infertile men: Results from a cross-sectional study

BACKGROUND

A number of studies showed that obesity may negatively impact on sperm quality and consequently couple's fertility. Recently, specific attention was given to a clinical condition known as metabolically healthy obesity (MHO).

OBJECTIVES

To evaluate the effects of MHO on semen and hormonal parameters of men presenting for primary couple's infertility associated with pure male factor infertility (MFI).

MATERIALS AND METHODS

Data from a homogenous cohort of 512 white-European primary infertile men belonging to couples with pure MFI have been cross-sectionally analyzed. Semen analysis was based on 2010 WHO reference criteria. Patients were segregated into eugonadal, secondary hypogonadal, primary hypogonadal, and compensated hypogonadal. The Harmonized International Diabetes Federation criteria were used to define metabolic syndrome (MetS). Based on BMI and MetS, patients were further segregated into the following: (a) metabolically healthy non-obese (MHNO); (b) metabolically unhealthy non-obese (MUNO) (c) metabolically healthy obesity (MHO); and, (d) metabolically unhealthy obesity (MUHO). Main outcome measures were the prevalence of MHO and the impact of MHO on semen and hormonal parameters in this cohort of MFI primary infertile men.

RESULTS

Overall, MHNO, MUNO, MHO, and MUHO were found in 462 (90%), 13 (2.5%), 27 (5.2%), and 10 (1.9%) men, respectively. MHO patients had lower total testosterone and SHBG levels (all P < .05) but higher E₂ values (P < .005) compared with MHNO men. Groups did not differ in terms of semen parameters. At multivariable logistic regression, analysis MHO was associated with an increased risk of primary and secondary hypogonadism (all P ≤ .02) compared with MHNO, after accounting for age and comorbid conditions.

DISCUSSION AND CONCLUSIONS

Metabolically healthy obesity is threefold more prevalent than unhealthy obesity in primary infertile men. Despite semen parameters are comparable among groups, MHO patients show worse endocrine parameters and a higher risk of primary and secondary hypogonadism compared with metabolically healthy normal infertile men.

Effect of clomiphene citrate treatment on the Sertoli cells of dysmetabolic obese men with low testosterone levels

BACKGROUND

Clomiphene citrate (CC) has been shown to restore the hypothalamic-pituitary-gonadal (HPG) axis by increasing testosterone (T) levels to physiological levels in patients with dysmetabolic conditions such as obesity, metabolic syndrome and type 2 diabetes mellitus (T2DM). However, the data are unclear regarding the effects on Sertoli cell (SC) function.

AIM

To study SC function by assessing Inhibin B (IB) and anti-Mullerian hormone (AMH) levels at baseline and after 3 months of CC treatment.

MATERIALS AND METHODS

This is an ancillary study of a cross-over, randomised, double-blind, placebo-controlled trial performed to evaluate androgen response to CC treatment in dysmetabolic obese subjects with low T levels treated with metformin. We evaluated SC function by assessing IB and AMH levels at baseline and after 3 months of each treatment in ten dysmetabolic obese subjects with low T levels. In all subjects, the influence of the clinical characteristics, metabolic and hormonal baseline parameters on SC and Leydig (LC) function, evaluated respectively with AMH, IB, follicle-stimulating hormone (FSH) and T levels, was tested.

RESULTS

No significant changes were observed for IB and AMH concentrations after each treatment period. Whereas T and oestradiol (E2) levels were shown to be significantly higher in the CC plus metformin phase (CC/Met) only. No clinical, metabolic or hormonal parameters showed significant effects on serum AMH at baseline or after treatments. However, baseline T, dihydrotestosterone (DHT) and E2 positively affected IB levels during CC/Met therapy (P = .003, P = .038 and P = .049, respectively). Baseline leptin and FSH had a negative (P = 031) and positive (P = .048) respectively role on T levels during CC/Met, as they were statistically significant compared to the placebo period (Plac/Met).

CONCLUSION

Unlike the LC activity, CC was unable to influence SC function, as shown by the lack of IB and AMH serum modifications, thus suggesting an intrinsic nonreversible defect of SC cells in patients with dysmetabolic conditions.

Effects of Metabolic Syndrome on Semen Quality and Circulating Sex Hormones: A Systematic Review and Meta-Analysis

Previous studies were controversial in the effects of metabolic syndrome (MetS) on semen quality and circulating sex hormones, and thus we conducted a systematic review and meta-analysis to clarify the association. A systematic search was conducted in public databases to identify all relevant studies, and study-specific standardized mean differences (SMD) and 95% confidence intervals (CI) were pooled using a random-effects model. Finally, 11 studies were identified with a total of 1,731 MetS cases and 11,740 controls. Compared with the controls, MetS cases had a statistically significant decrease of sperm total count (SMD: -0.96, 95% CI: -1.58 to -0.31), sperm concentration (SMD: -1.13, 95% CI: -1.85 to -0.41), sperm normal morphology (SMD: -0.61, 95% CI: -1.01 to -0.21), sperm progressive motility (SMD: -0.58, 95% CI: -1.00 to -0.17), sperm vitality (SMD: -0.83, 95% CI: -1.11 to -0.54), circulating follicle-stimulating hormone (SMD: -0.87, 95% CI: -1.53 to -0.21), testosterone (SMD: -5.61, 95% CI: -10.90 to -0.31), and inhibin B (SMD: -2.42, 95% CI: -4.52 to -0.32), and a statistically significant increase of sperm DNA fragmentation (SMD: 0.76, 95% CI: 0.45 to 1.06) and mitochondrial membrane potential (SMD: 0.89, 95% CI: 0.49 to 1.28). No significant difference was found in semen volume, sperm total motility, circulating luteinizing hormone (LH), estradiol, prolactin and anti-Müllerian hormone (AMH) (P > 0.05). In conclusion, this meta-analysis demonstrated the effects of MetS on almost all the semen parameters and part of the circulating sex hormones, and MetS tended to be a risk factor for male infertility. Further larger-scale prospective designed studies were needed to confirm our findings.

Effects of Insulin on Porcine Neonatal Sertoli Cell Responsiveness to FSH In Vitro

There is ongoing debate as to whether the decline of sperm production in recent times may be related to a parallel increase in the rate of obesity and diabetes. Lower anti-Müllerian hormone (AMH) and inhibin B secretion have been observed in young hyperinsulinemic patients compared to healthy controls, suggesting a Sertoli cell (SC) dysfunction. The pathophysiological mechanisms underlying SC dysfunction in these patients are poorly understood. To the best of our knowledge, no evidence is available on the effects of insulin on SC function. Therefore, this study was undertaken to assess the effects of insulin on basal and follicle-stimulating hormone (FSH)-stimulated SC function in vitro. To accomplish this, we evaluated the expression of AMH, inhibin B and FSHR genes, the secretion of AMH and inhibin B and the phosphorylation of AKT473 and SC proliferation on neonatal porcine SC after incubation with FSH and/or insulin. We found that similar to FSH, the expression and secretion of AMH is suppressed by insulin. Co-incubation with FSH and insulin decreased AMH secretion significantly more than with FSH alone. Insulin had no effect on the expression and secretion of the inhibin B gene, but co-incubation with FSH and insulin had a lower effect on inhibin B secretion than that found with FSH alone. FSH and/or insulin increased AKT473 phosphorylation and SC proliferation. In conclusion, the results of this study showed that insulin modulates SC function. We hypothesize that hyperinsulinemia may therefore influence testicular function even before puberty begins. Therefore, particular care should be taken to avoid the onset of hyperinsulinemia in children to prevent a future deleterious effect on fertility.

Risk of metabolic disorders in childless men: a population-based cohort study

OBJECTIVE

To study whether male childlessness is associated with an increased risk of metabolic disorders such as metabolic syndrome (MetS) and diabetes.

DESIGN

A population-based cohort study.

SETTING

Not applicable.

PARTICIPANTS

2572 men from the population-based Malmö Diet and Cancer Cardiovascular Cohort.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

From cross-sectional analyses, main outcome measures were ORs and 95% CIs for MetS and diabetes among childless men. In prospective analyses, HRs and 95% CI for diabetes among childless men.

RESULTS

At baseline, in men with a mean age of 57 years, the prevalence of MetS was 26% and 22% among childless men and fathers, respectively. Similarly, we observed a higher prevalence of diabetes of 11% among childless men compared with 5% among fathers. In the cross-sectional adjusted analyses, childless men had a higher risk of MetS and diabetes, with ORs of 1.22 (95% CI 0.87 to 1.72) and 2.12 (95% CI 1.34 to 3.36) compared with fathers. In the prospective analysis, during a mean follow-up of 18.3 years, we did not see any increase in diabetes risk among childless men (HR 1.02 (0.76 to 1.37)).

CONCLUSION

This study provides evidence of an association between male childlessness and a higher risk of MetS and diabetes. However, as these associations were found in cross-sectional analyses, reverse causation cannot be excluded.

High Blood Pressure Is a Highly Prevalent but Unrecognised Condition in Primary Infertile Men: Results of a Cross-sectional Study

BACKGROUND

Although most of the components related to metabolic syndrome were shown to have a detrimental effect on male fertility, the effects of high blood pressure (HBP) have been partially analysed.

OBJECTIVE

To investigate the prevalence and impact of hypertension on clinical and semen parameters in a cohort of white European men presenting for couple's infertility at a single tertiary referral academic centre.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional study was performed including analysis of data from 2185 primary infertile men. Comorbidities were scored with Charlson Comorbidity Index (CCI; categorised 0 vs ≥1). HBP was defined as blood pressure ≥140/90mmHg. Semen analyses followed the 2010 World Health Organization reference criteria.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Descriptive statistics and logistic regression analyses tested the association among semen parameters, clinical characteristics, and HBP.

RESULTS AND LIMITATIONS

Overall, HBP was found in 6.8% of infertile patients and in 3.6% of age-comparable men without known fertility problems. Of 148 patients, 85 (58%) were either unaware of their HBP or not adequately medically-controlled. +HBP men were older (median age [interquartile range], 37 [33-40] vs 39 [36-44] yr; p<0.001), had higher CCI scores (X₂=25.6; p<0.001), higher BMI (25.1 [23.3-27.3] vs 26.8 [24.9-29.4]; p<0.001), and a waist circumference >102cm in a greater proportion of individuals (41% vs 23%; X₂=4.68 p<0.05) than -HBP men. Hypertensive and normotensive men did not differ in terms of hormonal milieu and semen parameters. Patients did not differ in terms of HPB rates according to oligozoospermia, asthenozoospermia, and teratozoospermia status. The lack of a real control group represents the main limitation of the study.

CONCLUSIONS

Hypertension and unrecognised or not adequately controlled HBP are highly prevalent among white European primary infertile men. Hypertension per se did not have an impact on hormonal and semen parameters.

PATIENT SUMMARY

Because of its effects in terms of overall prospective men's health, high blood pressure must be comprehensively considered over the basic work-up of every infertile man in the outpatient clinic setting.

Sexual dysfunction and male infertility

Infertility affects up to 12% of all men, and sexual dysfunction occurs frequently in men of reproductive age, causing infertility in some instances. In infertile men, hypoactive sexual desire and lack of sexual satisfaction are the most prevalent types of sexual dysfunction, ranging from 8.9% to 68.7%. Erectile dysfunction and/or premature ejaculation, evaluated with validated tools, have a prevalence of one in six infertile men, and orgasmic dysfunction has a prevalence of one in ten infertile men. In addition, infertile men can experience a heavy psychological burden. Infertility and its associated psychological concerns can underlie sexual dysfunction. Furthermore, general health perturbations can lead to male infertility and/or sexual dysfunction. Erectile dysfunction and male infertility are considered proxies for general health, the former underlying cardiovascular disorders and the latter cancerous and noncancerous conditions. The concept that erectile dysfunction in infertile men might be an early marker of poor general health is emerging. Finally, medications used for general health problems can cause sperm abnormalities and sexual dysfunction. The treatment of some causes of male infertility might improve semen quality and reverse infertility-related sexual dysfunction. In infertile men, an investigation of sexual, general, and psychological health status is advisable to improve reproductive problems and general health.

Association of sex hormones with metabolic syndrome among Egyptian males

BACKGROUND

Studies have shown that testosterone and estradiol (E2) are associated with metabolic syndrome (MetS). To our knowledge, few studies, if any about the association of endogenous sex hormones with MetS have been done in Egypt.

AIM

To study the relation between endogenous sex hormones and MetS among Egyptian males.

SUBJECTS AND METHOD

For the study, 80 Egyptian males were enrolled: 40 males with MetS and 40 healthy age-matched males. Anthropometric measurements and blood pressure were taken for both groups. FBG, TC, HDL-C, TG, testosterone, and E2 levels were determined; LDL-C was calculated.

RESULTS

Males with MetS had significantly lower testosterone levels and significantly higher E2 levels compared to those without MetS (p value 0.0001). The lowest quartile of testosterone was most prevalent among males with MetS (19/40 males, 47.5%) compared to those without MetS (0/40 males, 0%, p value 0.011). Estradiol in the third quartile was most prevalent among males with MetS (19/40 males, 47.5%) compared to those without MetS (1/40 males, 2.5%, p value 0.0001). Serum testosterone and E2 levels were independent predictors of MetS with optimum cut off value (≤2.37ng/ml) for testosterone and (>16.78pg/ml) for E2.

CONCLUSION

Endogenous testosterone and estradiol are independently associated with MetS with potential utility as predictors of MetS.

The sixth vital sign: what reproduction tells us about overall health. Proceedings from a NICHD/CDC workshop

STUDY QUESTION

Does the fertility status of an individual act as a biomarker for their future health?

SUMMARY ANSWER

Data support an association between reproductive health and overall health for men and women.

WHAT IS ALREADY KNOWN

Various chronic conditions, such as diabetes, obesity and cancer, can compromise fertility, but there are limited data for the converse situation, in which fertility status can influence or act as a marker for future health. Data reveal an association between infertility and incident cardiovascular disease and cancer in both men and women.

STUDY DESIGN SIZE AND DURATION

A National Institute of Child Health and Human Development-Centers for Disease Control and Prevention workshop in April 2016 was convened that brought together experts in both somatic diseases and conditions, and reproductive health. Goals of the workshop included obtaining information about the current state of the science linking fertility status and overall health, identifying potential gaps and barriers limiting progress in the field, and outlining the highest priorities to move the field forward.

PARTICIPANTS/MATERIALS SETTING AND METHODS

Approximately 40 experts participated in the workshop.

MAIN RESULTS AND THE ROLE OF CHANCE

While the etiology remains uncertain for infertility, there is evidence for an association between male and female infertility and later health. The current body of evidence suggests four main categories for considering biological explanations: genetic factors, hormonal factors, in utero factors, and lifestyle/health factors. These categories would be key to include in future studies to develop a comprehensive and possibly standardized look at fertility status and overall health. Several themes emerged from the group discussion including strategies for maximizing use of existing resources and databases, the need for additional epidemiologic studies and public health surveillance, development of strategies to frame research so results could ultimately influence clinical practice, and the identification of short and long-term goals and the best means to achieve them.

LIMITATIONS REASONS FOR CAUTION

Further research may not indicate an association between fertility status and overall health.

WIDER IMPLICATIONS OF THE FINDINGS

Currently medical care is compartmentalized. Reproductive medicine physicians treat patients for a short period of time before they transition to others for future care. Going forward, it is critical to take an interdisciplinary patient care approach that would involve experts in a broad range of medical specialties in order to more fully understand the complex interrelationships between fertility and overall health. If infertility is confirmed as an early marker of chronic disease then screening practices could be adjusted, as they are for patients with a family history of malignancy.

STUDY FUNDING/COMPETING INTERESTS

Funding for the workshop was provided by the Fertility and Infertility Branch, National Institute of Child Health and Human Development, National Institutes of Health and the Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control. There are no conflicts of interest to declare. The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention or the National Institutes of Health.

TRIAL REGISTRATION NUMBER

Not applicable.

Primary, secondary and compensated hypogonadism: a novel risk stratification for infertile men

Recently, the cohort of men from the European Male Ageing Study has been stratified into different categories distinguishing primary, secondary and compensated hypogonadism. A similar classification has not yet been applied to the infertile population. We performed a cross-sectional study enrolling 786 consecutive Caucasian-European infertile men segregated into eugonadal [normal serum total testosterone (≥3.03 ng/mL) and normal luteinizing hormone (≤9.4 mU/mL)], secondary (low total testosterone, low/normal luteinizing hormone), primary (low total testosterone, elevated luteinizing hormone) and compensated hypogonadism (normal total testosterone; elevated luteinizing hormone). In this cross-sectional study, logistic regression models tested the association between semen parameters, clinical characteristics and the defined gonadal status. Eugonadism, secondary, primary and compensated hypogonadism were found in 80, 15, 2, and 3% of men respectively. Secondary hypogonadal men were at highest risk for obesity [OR (95% CI): 3.48 (1.98-6.01)]. Primary hypogonadal men were those at highest risk for azoospermia [24.54 (6.39-161.39)] and testicular volume <15 mL [12.80 (3.40-83.26)]. Compensated had a similar profile to primary hypogonadal men, while their risk of azoospermia [5.31 (2.25-13.10)] and small testicular volume [8.04 (3.17-24.66)] was lower. The risk of small testicular volume [1.52 (1.01-2.33)] and azoospermia [1.76 (1.09-2.82)] was increased, although in a milder fashion, in secondary hypogonadal men as well. Overall, primary and compensated hypogonadism depicted the worst clinical picture in terms of impaired fertility. Although not specifically designed for infertile men, European Male Ageing Study categories might serve as a clinical stratification tool even in this setting.