The impact of diabetes mellitus type 1 on male fertility: Systematic review and meta-analysis

Semen quality and metabolic profile in people with type 1 diabetes with and without erectile dysfunction: a cross-sectional study

PURPOSE

The aim of the present study is to evaluate the association of metabolic and glycemic variables with semen parameters in patients with type 1 diabetes (T1D) with and without erectile dysfunction (ED).

METHODS

The study population included 88 adults with T1D using a continuous glucose monitoring, of whom 28 with ED (ED group) and 60 without it (NO ED group). All men completed the International Index of Erectile Function (IIEF-5) and underwent body composition analysis (BIA) and semen analysis.

RESULTS

ED group showed worse HbA1c levels [median (IQR), 8.4 (7.7, 9.9) vs 7.4 (7, 8.2) %, P < 0.001)], higher insulin dose [60 (51, 65) vs 45 (38, 56) UI/die, P = 0.004)] and a higher total body water and intracellular water as compared with ED group. Men in the ED group presented higher semen volume [2.8 (2.6, 4.2) vs 2.5 (2.2, 2.7) mL, P < 0.001] and sperm concentration [24 (19, 29) vs 20 (12, 23) mil/mL, P = 0.010], but reduced sperm progressive motility [28 (25, 35) vs 35 (25, 36) %, P = 0.011], higher rate of non-progressive motility [15 (10, 15) vs 10 (5, 10) %, P < 0.001] and higher rate of typical morphology [7(5, 8) vs 5 (4, 5) %, P = 0.001]. Based on multivariate logistic regression analysis performed to assess the association between clinical variables and ED, intracellular water (OR 3.829, 95% CI 1.205, 12.163, P = 0.023) resulted as the only independent predictor of ED.

CONCLUSION

Men with T1D and ED showed worse metabolic profile which is associated with poor semen quality, as compared with those without ED.

Type 1 diabetes mellitus and sperm quality: A case-control study

BACKGROUND

The potential impact of diabetes mellitus type 1 (DM1) on male fertility is currently poorly defined. Hyperglycaemia and insulin deficiency may affect spermatogenesis. Some evidence suggests that men with DM1 have a significant reduction in progressive sperm motility, sperm morphology and semen volume, without significant changes in sperm concentration and count, but definite data are lacking.

OBJECTIVES

To evaluate the impact of DM1 on clinical parameters related to male fertility and semen analysis.

MATERIALS AND METHODS

We compared a court of 42 male DM1 patients with 43 nondiabetic subjects overlapping in age and remaining clinical data in an observational case-control study. All subjects underwent a comprehensive andrological reproductive evaluation, including medical history, physical examination, and semen analysis. We collected biochemical data in all patients with DM1, while diabetic patients with any alteration in semen parameters underwent sperm culture and scrotal ultrasound. In addition, all men completed the IIEF-5 questionnaire (International Index of Erectile Function-5) and the AMS (Aging Male Symptom score) questionnaire.

RESULTS

Patients with DM1 had a higher prevalence of infertility, erectile dysfunction and worse semen parameters compared with controls. In particular, semen volume, total sperm count, and total and progressive sperm motility were significantly lower (p < 0.001, p = 0.003, p = 0.048, and p = 0.022 respectively). In addition, the rate of semen anti-sperm antibody positivity, the AMS score and FSH levels were higher.

DISCUSSION AND CONCLUSION

Several mechanisms may contribute to these semen alterations in DM1 patients, such as oxidative damage to spermatogenesis, seminal infections and pelvic neurological changes. These data suggest that patients with DM1 should be counselled from an andrological-reproductive point of view.

Effects of empagliflozin on gonadal functions of hyperglycemic male wistar rats

Empagliflozin (EMPA) showed antiapoptotic, oxidative and anti-inflammatory potential effect. EMPA attenuates the inflammation and oxidative stress biomarkers in patients with heart failure while significantly decreases the malondialdehyde (a lipid peroxidation marker) levels in the plasma of diabetic patients. The present study examined the effects of moderate hyperglycemia on reproductive function. Sixty male Wister rats ‎ were divided and randomly allocated into four groups of 15 animals each‎‎. Diabetes was induced by a single intraperitoneal injection of a prepared solution containing STZ diluted in 0.1 M sodium citrate buffer (pH 4.5) at a dosage of 40 mg/kg body weight in selected in groups II and III for seven days before starting the treatment with EMPA. The current study revealed that EMPA for eight weeks prevented testicular high glucose-induced oxidative stress markers such as penile nitric oxide (NO), glutathione peroxidase (GPX) and total anti-oxidant capacity (TAC) in STZ-induced hyperglycemia in a rat model. In addition, EMPA ameliorated the high levels of endogenous Interleukin-6 (IL-6) present in gonads in response to an acute inflammatory found in the hyperglycemic STZ-induced rats. The present study further suggested the protective effects of EMPA and how it has a beneficial role and can effectively attenuate hyperglycemia-induced testicular oxidative damage and inflammatory markers as well as androgen dependent testicular enzymes activity as a protective role against the consequences of hyperglycemia and male sub-infertility.

Causal relationship between genetically predicted type 2 diabetes mellitus and male infertility

Background

Diabetes mellitus (DM) stands as the most prevalent endocrine abnormality affecting the physiological systems and organs and impairing the male reproductive functions. Type 2 Diabetes Mellitus (T2DM), accounting for about 90-95% of DM, is closely associated with male infertility. However, the magnitude of the causal relationships between T2DM and male infertility remains unclear. The current investigation was to explore the causal relationship between T2DM and male infertility utilizing the Mendelian Randomization (MR) analysis.

Methods

A two-sample MR (2SMR) analysis was conducted to investigate the causal relationship between T2DM and male infertility in the European population from the genome-wide association study (GWAS) summary data that was publicly accessible. GWAS for T2DM and male infertility were extracted from the IEU Open GWAS Project database, with the resulting data encompassing 680 cases and 72,799 controls as the outcome data. Five MR methods were employed for the 2SMR analyses, namely the MR-Egger, weighted median estimation (WME), weighted mode (WM), inverse-variance weighted (IVW), and simple mode. The primary analytical technique utilized in this study was the IVW method, and a multivariate MR analysis was executed to examine the potential mediating influences of T2DM on male infertility.

Results

Following were the odds ratios (ORs) and associated 95% CIs derived from IVW (fixed effects), MR-Egger, WM, WME, and simple mode approaches: 0.824 (95% CI 0.703-0.966), 0.726 (95% CI 0.527-1.001), 0.827 (95% CI 0.596-1.150), 0.841 (95% CI 0.654-1.082), and 0.875 (95% CI 0.544-1.405), respectively. The outcomes of the heterogeneity tests were P=0.378 and P=0.384, respectively, implying no heterogeneity. Egger-intercept outcomes were P=0.374, highlighting the absence of pleiotropy. The stability of the results was affirmed through the leave-one-out analysis. Notably, all F-values surpassed 10, indicating the absence of weak bias attributed to instrument variables(IVs).

Conclusions

This research furnishes evidence supporting a causal association between T2DM and male infertility. These insights offer a foundation for future investigations aiming to establish the association between genetically predicted T2DM and male infertility. These outcomes suggest the significance of active monitoring and proactive measures for preventing infertility in male individuals with T2DM. Furthermore, careful consideration is required for individuals of reproductive age to prevent and treat T2DM.

Protective Effect of Black Rice Cyanidin-3-Glucoside on Testicular Damage in STZ-Induced Type 1 Diabetic Rats

Diabetic testicular damage is quite a common and significant complication in diabetic men, which could result in infertility. The natural fertility rate of type 1 diabetes men is only 50% because of testicular damage. This research first aimed to explore the intervention effect of C3G on testicular tissue damage induced by diabetes. Here, a streptozotocin-induced type 1 diabetic rat model was established, and then C3G was administered. After 8 weeks of C3G supplementation, the symptoms of diabetes (e.g., high blood glucose, lower body weight, polydipsia, polyphagia) were relieved, and at the same time that sperm motility and viability increased, sperm abnormality decreased in C3G-treated diabetic rats. Furthermore, the pathological structure of testis was restored; the fibrosis of the testicular interstitial tissue was inhibited; and the LH, FSH, and testosterone levels were all increased in the C3G-treated groups. Testicular oxidative stress was relieved; serum and testicular inflammatory cytokines levels were significantly decreased in C3G-treated groups; levels of Bax, Caspase-3, TGF-β1 and Smad2/3 protein in testis decreased; and the level of Bcl-2 was up-regulated in the C3G-treated groups. A possible mechanism might be that C3G improved antioxidant capacity, relieved oxidative stress, increased anti-inflammatory cytokine expression, and inhibited the apoptosis of spermatogenic cells and testicular fibrosis, thus promoting the production of testosterone and repair of testicular function. In conclusion, this study is the first to reveal that testicular damage could be mitigated by C3G in type 1 diabetic rats. Our results provide a theoretical basis for the application of C3G in male reproductive injury caused by diabetes.

Semen quality and metabolic profile in people with type 1 diabetes with and without erectile dysfunction: a cross-sectional study

Purpose

The aim of the present study is to evaluate the association of metabolic and glycemic variables with semen parameters in patients with type 1 diabetes (T1D) with and without erectile dysfunction (ED).

Methods

The study population included 88 adults with T1D using a continuous glucose monitoring, of whom 28 with ED (ED group) and 60 without it (NO ED group). All men completed the International Index of Erectile Function (IIEF-5) and underwent body composition analysis (BIA) and semen analysis.

Results

ED group showed worse HbA1c levels [median (IQR), 8.4 (7.7, 9.9) vs 7.4 (7, 8.2) %, P < 0.001)], higher insulin dose [60 (51, 65) vs 45 (38, 56) UI/die, P = 0.004)] and a higher total body water and intracellular water as compared with ED group. Men in the ED group presented higher semen volume [2.8 (2.6, 4.2) vs 2.5 (2.2, 2.7) mL, P < 0.001] and sperm concentration [24 (19, 29) vs 20 (12, 23) mil/mL, P = 0.010], but reduced sperm progressive motility [28 (25, 35) vs 35 (25, 36) %, P = 0.011], higher rate of non-progressive motility [15 (10, 15) vs 10 (5, 10) %, P < 0.001] and higher rate of typical morphology [7(5, 8) vs 5 (4, 5) %, P = 0.001]. Based on multivariate logistic regression analysis performed to assess the association between clinical variables and ED, intracellular water (OR 3.829, 95% CI 1.205, 12.163, P = 0.023) resulted as the only independent predictor of ED.

Conclusion

Men with T1D and ED showed worse metabolic profile which is associated with poor semen quality, as compared with those without ED.

The protective effects of icariin against testicular dysfunction in type 1 diabetic mice Via AMPK-mediated Nrf2 activation and NF-κB p65 inhibition

BACKGROUND

Owing to the early suffering age and the rising incidence of type 1 diabetes (T1D), the resulting male reproductive dysfunction and fertility decline have become a disturbing reality worldwide, with no effective strategy being available. Icariin (ICA), a flavonoid extracted from Herba Epimedium, has been proved its promising application in improving diabetes-related complications including diabetic nephropathy, endothelial dysfunction and erectile dysfunction. Ensuring the future reproductive health of children and adolescents with T1D is crucial to improve global fertility. However, its roles in the treatment of T1D-induced testicular dysfunction and the potential mechanisms remain elusive.

PURPOSE

The purpose of this present study was to investigate whether ICA ameliorates T1D-induced testicular dysfunction as well as its potential mechanisms.

METHODS

T1D murine model was established by intraperitoneal injection of STZ with or without treated with ICA for eleven weeks. Morphological, pathological and serological experiments were used to determine the efficacy of ICA on male reproductive function of T1D mice. Western blotting, Immunohistochemistry analysis, qRT-PCR and kit determination were performed to investigated the underlying mechanisms.

RESULTS

We found that replenishment of ICA alleviated testicular damage, promoted testosterone production and spermatogenesis, ameliorated apoptosis and blood testis barrier impairment in streptozotocin-induced T1D mice. Functionally, ICA treatment triggered adenosine monophosphate protein kinase (AMPK) activation, which in turn inhibited the nuclear translocation of nuclear factor kappa B p65 (NF-κB p65) to reduce inflammatory responses in the testis and activated nuclear factor erythroid 2-related factor 2(Nrf2), thereby enhancing testicular antioxidant capacity. Further studies revealed that supplementation with the AMPK antagonist Compound C or depletion of Nrf2 weakened the beneficial effects of ICA on testicular dysfunction of T1D mice.

CONCLUSION

Collectively, these results demonstrate the feasibility of ICA in the treatment of T1D-induced testicular dysfunction, and reveal the important role of AMPK-mediated Nrf2 activation and NF-κB p65 inhibition in ICA-associated testicular protection during T1D.

The Molecular Basis of Male Infertility in Obesity: A Literature Review

The rising incidence of obesity has coincided with rising levels of poor reproductive outcomes. The molecular basis for the association of infertility in obese males is now being explained through various mechanisms. Insulin resistance, hyperglycemia, and changes in serum and gonadal concentrations of adipokines, like leptin, adiponectin, resistin, and ghrelin have been implicated as causes of male infertility in obese males. The effects of obesity and hypogonadism form a vicious cycle whereby dysregulation of the hypothalamic-pituitary-testicular axis-due to the effect of the release of multiple mediators, thus decreasing GnRH release from the hypothalamus-causes decreases in LH and FSH levels. This leads to lower levels of testosterone, which further increases adiposity because of increased lipogenesis. Cytokines such as TNF-α and interleukins, sirtuins, and other inflammatory mediators like reactive oxygen species are known to affect fertility in obese male adults. There is evidence that parental obesity can be transferred through subsequent generations to offspring through epigenetic marks. Thus, negative expressions like obesity and infertility have been linked to epigenetic marks being altered in previous generations. The interesting aspect is that these epigenetic expressions can be reverted by removing the triggering factors. These positive modifications are also transmitted to subsequent generations.

Adverse effect of environmental androgenic compounds Galaxolide and Irgacure 369 on the male reproductive system

Our recent study has found that two environmental chemicals, Galaxolide (HHCB, a raw material for synthesizing musk) and Irgacure 369 (IC-369, a photoinitiator used in packaging) are agonists for the androgen receptor in vitro and in vivo. This study aims to reveal the subchronic reproductive toxicity of these two compounds in mature male rats. The results showed that compared with the control group, HHCB and IC-369 reduced the sperm concentration and motility, increased the sperm deformity, and caused the atrophy of the seminiferous tubules in the testicles. Exposure to HHCB and IC-369 reduced testosterone level, and induced luteinizing hormone, and follicle-stimulating hormone levels in rat serum. Compared with the control group, the levels of oxidative stress markers in the serum and testicular tissue increased. HHCB and IC-369 also inhibited expression of the genes involved in androgen synthesis in testicle. The above results indicated that HHCB and IC-369 could affect the levels of sex hormones, alter gene expression profiles and induce histological damage in reproductive organs, resulting in decreased sperm quality. Therefore, HHCB and IC-369 have endocrine disruptors with prominent reproductive toxicity in males.

New perspectives in functional hypogonadotropic hypogonadism: beyond late onset hypogonadism

Functional hypogonadotropic hypogonadism (FHH) is an increasingly frequent condition, whose pathological mechanisms are not yet fully clarified. The concept of FHH has now completely replaced that of late onset hypogonadism, that only concerned the ageing man. FHH is the result of an impairment of the hypothalamic-pituitary gonadal axis (HPG-A) function, resulting in decreased testosterone concentrations associated with low or inappropriately normal gonadotropin levels and infertility; it can be diagnosed once organic causes of hypogonadism are excluded. The growing occurrence of FHH derives from its association with widespread conditions, such as obesity and diabetes mellitus, but also to the increasing ease and frequency of use of several drugs, such as opioids, glucocorticoids, and sex steroids. Moreover, given the tendency of many subjects to excessive physical activity and drastic reduction in caloric intake, FHH may also be secondary to low energy availability. Finally, the association with HIV infection should not be overlooked. Therefore, there is an important variability in the diseases that can lead to FHH. Despite the heterogeneity of the underlying pathologies, the mechanisms leading to FHH would seem quite similar, with the initial event represented by the impairment at the HPG-A level. Nevertheless, many different biological pathways are involved in the pathogenesis of FHH, therefore the aim of the current paper is to provide an overview of the main relevant mechanisms, through a detailed analysis of the literature, focusing specifically on pathogenesis and clinical, diagnostic and therapeutic aspects.

Lauric acid improves hormonal profiles, antioxidant properties, sperm quality and histomorphometric changes in testis and epididymis of streptozotocin-induced diabetic infertility rats

Lauric acid, a 12‑carbon atom medium chain fatty acid (MCFA) has strong antioxidant and antidiabetic activities. However, whether lauric acid can ameliorate hyperglycaemia-induced male reproductive damage remains unclear. The study aimed to determine the optimal dose of lauric acid with glucose-lowering activity, antioxidant potential and tissue-protective effects on the testis and epididymis of streptozotocin (STZ)-induced diabetic rats. Hyperglycaemia was induced in Sprague Dawley rats by an intravenous injection of STZ at a dose of 40 mg/kg body weight (bwt). Lauric acid (25, 50 and 100 mg/kg bwt) was administered orally for eight weeks. Weekly fasting blood glucose (FBG), glucose tolerance and insulin sensitivity were examined. Hormonal profiles (insulin and testosterone), lipid peroxidation (MDA) and antioxidant enzyme (SOD and CAT) activities were measured in the serum, testis and epididymis. The reproductive analyses were evaluated based on sperm quality and histomorphometry. Lauric acid administration significantly improved FBG levels, glucose tolerance, hormones-related fertility and oxidant-antioxidant balance in the serum, testis and epididymis compared to untreated diabetic rats. Treatment with lauric acid preserved the testicular and epididymal histomorphometry, along with the significant improvements in sperm characteristics. It is shown for the first time that lauric acid treatment at 50 mg/kg bwt is the optimal dose for ameliorating hyperglycaemia-induced male reproductive complications. We conclude that lauric acid reduced hyperglycaemia by restoring insulin and glucose homeostasis, which attributes to the regeneration of tissue damage and sperm quality in STZ-induced diabetic rats. These findings support the correlation between oxidative stress and hyperglycaemia-induced male reproductive dysfunctions.

Productivity Index in Clinical Andrology: Research Directions on High-Impact Topics and in Particular on Male Infertility

PURPOSE

Andrological diseases have an important social and economic impact as they cause a serious impairment of the quality of life of the affected patient. Epidemiologically, the impact of these disorders is progressively increasing, as demonstrated by the ever-growing prevalence of male infertility. This evidence justifies the rapid development of research in andrology that the scientific community has undertaken in recent decades. This study aims to evaluate the productivity index of the main andrological topics studied and reported in the literature.

METHODS

The total number of published articles was extracted from the Scopus database by entering the following keywords and mesh terms: "Male Infertility", "Erectile Dysfunction", "Premature Ejaculation", "Male Hypogonadism", "Testicular Tumors", "Prostate Cancer", "Prostatic hyperplasia", "Prostate hyperplasia", "Prostatitis", "Prostate inflammation", and "Male Accessory Gland Infections". Furthermore, a list of the top 50 researchers sorted by productivity was created for each topic. For male infertility, a further search was performed by combining the search term "male infertility" with the above-mentioned terms. Thus, a list of the top 30 authors in order of productivity was also extracted. The graphs were created using Excel.

RESULTS AND CONCLUSIONS

As could be expected, we observed that prostate cancer and male infertility were the two most investigated topics, followed by benign prostatic hyperplasia and erectile dysfunction, whose prevalence is set to increase given the progressive aging of the population. Less investigated is the inflammation of the accessory sexual glands. In conclusion, this study provides a ranking of the main andrological topics investigated in the literature, also presenting the top list of the most productive authors for each one.

Is losartan a promising agent for the treatment of type 1 diabetes-induced testicular germ cell apoptosis in rats?

BACKGROUND

Diabetes mellitus (DM) is common metabolic disease that poses a major risk to public health and fertility. Previous studies indicate that DM may cause male infertility by triggering oxidative stress and germ cell apoptosis in the testis. Due to the undesirable effects of known antidiabetic drugs, scientists have begun to investigate the use of alternative drugs to control infertility complications observed in men. In this context, present study aimed to investigate the possible antiapoptotic effect of losartan against DM-induced testicular germ cell apoptosis.

METHODS AND RESULTS

Expreimental DM model was induced by intraperitoneal injection of streptozocin (STZ, 55 mg/kg) to 28 rats, which were then randomly assigned to 4 groups; 1 mL saline solution was given to DM + saline group by oral gavage, 5 mg/kg/day oral losartan was given to DM + low-dose losartan, 20 mg/kg/day oral losartan was given to DM + mid-dose losartan and, 80 mg/kg/day oral losartan was given to DM + high-dose losartan group for 4 weeks. Bax, Bcl-2 and cleaved-Caspase 3 immunoexpression, terminal-deoxynucleotidyl transferase dutp nick end labeling (TUNEL), Annexin-V and Real Time PCR analyses performed to evaluate antiapoptotic effects of losartan on diabetic rats' testis. In addition, biochemical analyzes carried out to evaluate change in oxidative stress.

CONCLUSION

The results showed that losartan may have dose-related antiapoptotic effects on rats' testis via decreasing oxidative stress.

Effects of diabetes mellitus on sperm quality and fertility outcomes: Clinical evidence

BACKGROUND

Diabetes mellitus is a global epidemic characterized by high morbidity and mortality. Diabetes mellitus can lead to acute and chronic systemic complications. Among them, a negative effect of diabetes mellitus on sperm quality and male/couple fertility has been suggested. However, available studies in diabetes mellitus men evaluated relatively small cohorts with discordant results.

OBJECTIVES

To evaluate the clinical evidences of the effects of diabetes mellitus on sperm quality and fertility outcomes.

METHODS

An extensive Medline search was performed identifying studies in the English language.

RESULTS

The prevalence of diabetes mellitus in infertile men ranges from 0.7% to 1.4%, while the prevalence of infertility in diabetes mellitus men, evaluated in a few studies, ranges from 35% to 51%. Male diabetes mellitus seems to play a negative effect on couple fecundity, while being childless or subfertile men might increase the risk of diabetes mellitus. Available cross-sectional studies investigating semen parameters and male sexual hormones in men with diabetes mellitus are heterogeneous, assessed relatively small cohorts, show often discordant results and frequently are not directly comparable to derive robust conclusions. Two meta-analyses support a negative effect of diabetes mellitus on sperm normal morphology and no effect on sperm total count, with contradictory results regarding other semen parameters. Considering only studies on type 1 diabetes mellitus men, meta-analyses support a negative effect of diabetes mellitus on sperm motility and no effect on sperm total count, with contradictory results regarding other semen parameters. The rate of children observed among type 1 diabetes mellitus men was lower than controls, especially in subjects with a longer diabetes mellitus duration. Couples with a diabetes mellitus male partner undergoing assisted reproduction techniques showed lower pregnancy rates than controls. No study evaluated the impact of diabetes mellitus treatment on semen quality and male fertility.

CONCLUSIONS

Overall, available data show that diabetes mellitus might impair male reproductive health and couple fertility. However, further larger and full of details studies are needed.