Association between male Infertility and seminal plasma levels of growth hormone and insulin‐like growth factor‐1

Growth hormone (GH) and insulin‐like growth factor 1 (IGF‐1) have been proposed to play a pivotal role in male infertility due to their anabolic effects. The aim of this study was to investigate possible associations between seminal plasma levels of GH and IGF‐1 and sperm parameters. Fifty men participated in this study. Semen analysis was performed, while cell‐free seminal plasma was collected following sperm centrifugation. Seminal plasma concentrations of IGF‐1 and GH were determined by enzyme‐linked immunosorbent assay (ELISA). Due to the presence of asthenozoospermia in all participants who presented with abnormal sperm parameters, the participants were further subdivided into normal (group A), asthenozoospermic (group B) and asthenozoospermic plus at least one additional abnormal parameter (group C). A marginally nonsignificant statistical difference (p = 0.063) was revealed between the GH levels corresponding to the asthenozoospermic and the normal group with the latter presenting with higher GH levels. A statistically significant positive correlation (p < 0.05) was noted between levels of GH and IGF‐1 in group C. The above relationship has also been observed in men with low sperm concentration, vitality, volume and abnormal morphology. These novel findings require further investigation in order for the biological significance of those associations to be clarified.     

Metabonomic analysis of fatty acids in seminal plasma between healthy and asthenozoospermic men based on gas chromatography mass spectrometry

The mechanism of asthenozoospermia remains unclear. The knowledge of the metabolism of fatty acids in seminal plasma is important and meaningful for the pathological study of asthenozoospermia. We present an optimised assay of extraction and derivatisation followed by GC/MS to analyse metabolites, especially fatty acids, in seminal plasma from healthy and asthenozoospermic men. Eighty‐nine peaks including 17 kinds of fatty acids were analysed and identified in the chromatogram. The GC/MS data were analysed using t test, fold change and partial least squares discriminant analysis to explore the potential biomarkers of asthenozoospermia. Seven metabolites in asthenozoospermic group were found to be significantly different from those in the normal group (with p < .05, fold change >1.2 and variable importance for projection >1). Of which, high levels of oleic acid and palmitic acid in seminal plasma from asthenozoospermic men may indicate a membrane metabolism disorder in spermatozoa and the lack of valine in the asthenozoospermic group may contribute to poor sperm motility. The results may facilitate the understanding of the role of fatty acids and amino acids in asthenozoospermia and provide solid foundation for further pathological study of asthenozoospermia.     

Nutrient patterns and asthenozoospermia: a case–control study

The association of dietary nutrient patterns and sperm motility is not yet well elucidated, and previous studies have just focused on the isolated nutrients. This case–control study examined the association of nutrient patterns with asthenozoospermia among Iranian men. In total, 107 incident asthenozoospermic men and 235 age‐matched controls were interviewed through the infertility clinics in Tehran, Iran, from January 2012 to November 2013. Semen quality data were analysed according to the fifth edition of WHO guideline. Nutrient patterns were identified using principal component analysis based on semiquantitative 168‐item food frequency questionnaires. All nutrient intakes were energy‐adjusted by the residual method. In principal component analysis, three dietary patterns emerged. The first pattern, which was high in vitamin E, vitamin D, vitamin C, zinc, folate, total fibre, selenium and polyunsaturated fatty acids, was significantly associated with lower risk of asthenozoospermia. After adjustment for potential confounders, participants in the highest tertile of the first pattern scores had 51% lower risk of asthenozoospermia compared with those in the lowest (p‐trend: .004). Our findings suggest that adherence to the pattern comprising mainly of antioxidant nutrients may be inversely associated with asthenozoospermia.     

4,977-bp human mitochondrial DNA deletion is associated with asthenozoospermic infertility in Jordan

Male infertility is commonly associated with sperm abnormalities including asthenozoospermia. The molecular basis of asthenozoospermia was linked to mitochondrial DNA (mtDNA) mutations. The 4,977-bp human mtDNA deletion is one of the most common mutations of spermatozoa and results in loss of about 33% of the mitochondrial genome. In this preliminary study, we aimed to investigate the presence of 4,977-bp mtDNA deletion in asthenozoospermic infertile men in Jordan. Semen specimens of 120 asthenozoospermic infertile men and 80 normozoospermic individuals were collected at the in vitro fertilization unit. MtDNA was extracted after the enrichment of spermatozoa; then, polymerase chain reaction was performed using 4,977-bp mtDNA deletion-specific primers. The deletion of 4,977-bp mtDNA was detected in 79.2% of asthenozoospermic patients compared to 10% in normozoospermic controls. The results showed a significant association between the presence of 4,977-bp mtDNA deletion and the asthenozoospermia and infertility (OR = 34.2000, 95% CI = 14.57–80.26, p-value < .001). In conclusion, our findings underscored a strong association between 4,977-bp mtDNA deletion and asthenozoospermia in the Jordanian population.     

Seminal plasma vitamin B6 levels in men with asthenozoospermia and men with normal sperm motility,a measurement using liquid chromatography with tandem mass spectrometry

There is growing evidence that vitamin B₆ has a valuable contribution in maintaining normal sperm parameters; however, this contribution has not yet well-identified. Here, we aimed to measure the level of seminal plasma vitamin B₆ in men with asthenozoospermia compared to men with normal sperm motility. Ninety-seven human males with asthenozoospermia and eighty-eight human males with normal sperm motility (control) were recruited in this study. Collected semen samples were assessed for sperm motility, sperm count and semen volume. Liquid chromatography with tandem mass spectrometry was used to measure seminal plasma vitamin B₆ concentrations. A highly significant difference (p < .0001) in concentrations of seminal plasma vitamin B₆ was found between asthenozoospermic and control groups. Besides, no statistical correlations were found between seminal plasma vitamin B₆ level and sperm motility, sperm count, semen volume and men age in both tested groups. In conclusion, men with asthenozoospermia have lower seminal plasma vitamin B₆ level compared to men with normal sperm motility. Also, seminal plasma vitamin B₆ was found not to be correlated with sperm motility and count, semen volume and men age in both tested groups. These results may provide new contribution in the management of male infertility.     

Seminal plasma nitric oxide concentration in oligo- and/or asthenozoospermic subjects with/without varicocele

There is an inverse correlation between seminal plasma nitric oxide (NO) concentration and sperm parameters (motility and concentration) in patients with varicocele. This study investigated whether this occurs in patients with oligo- and/or asthenozoospermia due to causes other than varicocele. A total of 69 (19 with varicocele and oligo- and/or asthenozoospermia [group 1], 30 from oligo- and/or asthenozoospermic ones without varicocele [group 2], and 20 from healthy subjects [control group]) semen samples were analyzed. While group 1 had a significantly higher NO concentration in the seminal plasma compared to both the control group and group 2, there was no significant difference between group 2 and the control group (p >.05). In group 1, but not in the other groups, there was an inverse correlation between the seminal plasma NO concentration and sperm motility and concentration. NO production could be specifically related to the varicocele, since NO production in oligo- and/or asthenozoospermia cases without varicocele is not increased.     

Relationship between Zinc Concentrations in Seminal Plasma and Various Sperm Parameters

The zinc concentration in seminal plasma from 98 infertile male patients and 8 fertile males was measured. The zinc concentration of the seminal plasma in azoospermic and oligoasthenozoospermic patients was significantly lower than that in the other groups (each, p<0.05). The seminal plasma zinc concentration in asthenozoospermic males was significantly higher than that in any other group (p<0.05). There was a positive correlation of zinc concentration with sperm concentration (r=0.33, p<0.05) and with sperm motility (r=0.22, p<0.05), while there was no correlation with sperm morphology. A correlation between zinc concentration and plasma testosterone concentration was observed (r=0.24, p<0.05). It is concluded that excessively high zinc concentration is apparently related to defective motility in asthenozoospermic patients, even though adequate seminal plasma content of the element is required for normal sperm function.     

Role of seminal osmolarity in the reduction of human sperm motility

Mammalian sperm at ejaculation are suspended in the seminal plasma, a heterogeneous mixture deriving from the testicular/epididymal fluid and from secretions of seminal vesicles, prostate and bulbourethral glands. Biochemical characteristics of seminal fluid change along the male reproductive tract when considering its inorganic and organic composition and pH but it is known that in each region of the male genital tract seminal osmolarity is higher than that of serum. It has been previously demonstrated that in invertebrate and vertebrate sperm, seminal plasma osmolarity influences sperm motility and activity, and human sperm have been shown to possess osmosensitive calcium entry pathway that controls important functions such as acrosome reaction and oocyte penetration. In the present study, we have determined seminal plasma osmolarity in a large number of normozoospermic fertile and asthenozoospermic infertile subjects correlating it with sperm motility percentages and kinematic characteristics determined utilizing a computerized motion analysis system. Our results confirm that seminal plasma osmolarity is higher than that of serum (336.1 +/- 20.2 vs. 291.1 +/- 6.9 mOsm/L, respectively). Normozoospermic subjects show seminal osmolarity values that are significantly lower with respect to asthenozoospermic patients (317.8 +/- 12.2 vs. 345.2 +/- 22.6 mOsm/L, p<0.001), irrespective of the cause of asthenozoospermia. Seminal plasma osmolarity negatively correlates with sperm progressive motility percentages and kinetic characteristics (curvilinear velocity, linear velocity, linear coefficient and lateral displacements of sperm head). Furthermore, when sperm from fertile subjects were suspended in medium with an osmolarity increasing from 300 to 600 mOsm, sperm motility percentages and kinetics characteristics were progressively reduced and nearly abolished when medium osmolarity was 600 mOsm. On the contrary, when sperm from asthenozoospermic subjects with high semen osmolarity were resuspended in medium with lower osmolarity, sperm motility parameters improved significantly. Sperm motility parameters did not correlate with seminal plasma concentrations of sodium, potassium, chloride with a weak correlation only with seminal calcium concentration. No correlations are present between seminal plasma osmolarity and ionic composition.In conclusion, the present study confirms and extends the knowledge that, in human, seminal plasma osmolarity is higher than that of serum and demonstrates that seminal osmolarity influences sperm motility characteristics and then it may contribute to the pathogenesis of some forms of asthenozoospermia and male infertility.     

弱精子症、少弱精子症患者血清、精浆和精子锌含量分析

目的:检测弱精子症和少弱精子症患者血清、精浆和精子锌的含量,分析锌含量的变化与精子密度和精子运动之间的关系。方法:按照WHO《人类精液及精子-宫颈粘液相互作用实验室检验手册》第四版的标准进行精液质量分析,随机筛选出90例弱精子症、60例少弱精子症患者以及20例精液质量正常的生育者作为研究对象,利用原子吸收光谱法检测其血清、精浆、精子的锌含量并进行统计学分析。结果:3组间血清锌含量没有显著差异;弱精子症、少弱精子症患者精浆锌含量均显著低于正常生育者(P<0.05);少弱精子症患者精子锌含量显著高于弱精子症患者和正常生育者(P<0.01)。结论:弱精子症、少弱精子症患者精子的发生及运动功能下降可能与精浆锌含量的低下呈正相关;但过高的精子锌含量与精子的发生和运动功能的关系尚不十分明了,有待进一步研究。     

Zinc levels in seminal plasma of fertile and infertile men

Zinc levels were measured in seminal plasma from 78 men classified on the basis of spermogram analyses into five groups: normo-, oligo-, astheno-, oligoastheno- and azoospermia. Higher zinc levels were found in seminal plasma from the group of asthenozoospermia men in comparison to normo-, oligoastheno- (p less than 0.001), oligo- and azoospermia men (p less than 0.01), while no significant differences appeared when other group pairs were compared. Seminal plasma zinc levels were positively correlated with sperm density (r = 0.6358, p less than 0.01) in asthenozoospermia men, whereas a significant negative correlation was seen in all groups between percentage forms showing normal progressive motility and zinc concentration in seminal plasma. Although zinc is required in seminal plasma for normal spermatozoon functionality, excessively high levels of this ion may be related with defective motility in asthenozoospermia samples.     

Sperm mitochondrial DNA deletion in Iranian infertiles with asthenozoospermia

Asthenozoospermia is an important cause of male infertility. The mutations in sperm mitochondrial DNA (mtDNA) result in either functionless or malfunctioning some proteins, subsequently affecting sperm motility leading to asthenozoospermia. The purpose of this study was to investigate sperm mtDNA 4,977‐bp deletion in infertile men with low sperm motility/immotile spermatozoa compared to healthy subjects with high sperm motility. Semen samples of 256 asthenozoospermic infertiles and 200 controls from northern Iran were collected. After extraction of spermatozoa total DNA, Gap‐polymerase chain reaction (Gap‐PCR) was performed. The deletion was observed in 85.93% of patients with asthenozoospermia compared with 14% in controls [OR = 37.5397, 95% confidence interval = 12.937–108.9276, p < .0001]. It is concluded that there is a strong association between sperm mtDNA 4,977‐bp deletion and asthenozoospermia‐induced infertility in the population examined. Large‐scale mtDNA deletions in spermatozoa may induce bioenergetic disorders. Nevertheless, to validate our results broader research may be needed.     

精浆和血清生殖激素与精液质量的关系

目的为了评估精液质量不同的男性精浆和血清生殖激素的浓度与精子浓度及活动力的关系,探索精浆与血清生殖激素的关系。方法对301名男性进行精液检查,按照精液的质量参数将受试对象分成4组:精液正常组(n=176),弱精子症组(n=66),少精子症组(n=40)和非梗阻性无精子症组(n=19)。采用电化学发光免疫法测定各组受试对象血清卵泡刺激素(FSH)、黄体生成素(LH)、泌乳素(PRL)、孕酮(P)、睾酮(T)和雌二醇(E2)六项生殖激素和精浆PRL、T、P和E2四项生殖激素的浓度,比较组间差异并进行相关性分析。结果精液正常组和弱精子症组血清FSH和E2的浓度显著低于少精子症组和非梗阻性无精子症组(P0.05),精液正常组血清LH和P的浓度显著低于弱精子症、少精子症和非梗阻性无精子症的人群(P0.05);而精液正常、弱精子症和少精子症三组精浆PRL的浓度则高于非梗阻性无精子症组(P0.05)。除了非梗阻性无精子症组,受试者血清FSH的浓度与其精子浓度呈负相关(r分别为-0.350、-0.273和-0.448,P0.05)。精液正常组精浆PRL的浓度和精子的浓度之间呈正相关(r=0.269,P0.05);在少精子症组中,亦有相同趋势的相关性(r=0.432,P0.05)。结论精浆PRL及血清FSH的浓度能够反映精子浓度或活动力,在男性不育的病因分析中具有一定的指导价值。     

Oxidative stress markers in seminal plasma of idiopathic infertile men may be associated with glutathione S-transferase M1 and T1 null genotypes

This study aimed to investigate the association between glutathione S-transferase (GST) M1 and T1 null genotypes and thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC) and nitric oxide (NO) levels in male infertility. For this purpose, semen samples were collected from fertile and infertile subjects, and then they were genotyped for GSTT1 and GSTM1 genes using multiplex-PCR. The TBARS, TAC and NO levels in seminal plasma were then measured via the ferric-reducing ability of plasma (FRAP). A significant association was observed between GSTT1 null genotype and oligozoospermia, asthenozoospermia and teratozoospermia. But, the GSTM1 null genotype was merely associated with teratozoospermia. Moreover, the GSTT1−/GSTM1+ combined genotype was associated with all subgroups of male infertility. Besides, an association was observed between GSTT1−/GSTM1− genotype and asthenozoospermia and teratozoospermia. Further analysis showed that the GSTT1 null genotype was associated with increased NO in asthenozoospermia. Also, the GSTT1 null genotype was associated with increased TBARS in oligozoospermia and asthenozoospermia. As well, GSTM1 null genotype was associated with decreased TAC and increased NO in asthenozoospermia respectively. As a preliminary conclusion, the GSTM1 and GSTT1 null genotypes could be considered as genetic risk factors for male infertility, interfering with some oxidative stress markers in infertile men.     

eNOS gene T786C,G894T and 4a4b polymorphisms and male infertility susceptibility: a meta‐analysis

The association between polymorphism of eNOS and male infertility in several studies was controversial. To explore a more precise estimation of the association, a meta‐analysis of eight case–control studies, including 1,968 cases and 1,539 controls, were selected. The meta‐analysis was conducted by calculating the pooled odds ratio (OR) with a 95% confidence interval (95% CI). Overall, the association between T786C and risk of male infertility was obvious (TC vs. TT: OR, 1.20; 95% CI, 1.01–1.42; CC vs. TT: OR, 3.37; 95% CI, 1.65–6.87; TC/CC vs. TT: OR, 1.47; 95% CI, 1.25–1.73; CC vs. TT/TC: OR, 3.18; 95% CI, 1.54–6.56; TC vs. TT: OR, 1.65; 95% CI, 1.27–2.03). However, no overall association was observed between the other two polymorphisms of eNOS (G894T and 4a4b) and male infertility. Stratified analysis showed that significantly strong association between T786C polymorphism and semen quality was present in all three types of male infertility (azoospermia, oligozoospermia and asthenozoospermia). In the subgroup analysis based on ethnicity, both T786C and 4a4b could influence the risk of male infertility in Asian and Caucasian. Further studies of polymorphisms of eNOS with their biological functions are needed to understand the role in the development of male infertility.     

Seminal mast cells in infertile asthenozoospermic males

This work aimed to assess the possible association between the presence of seminal mast cells and asthenozoospermia. One hundred and seventy-six male subjects were investigated: group (Gr)1 (n=46) normozoospermic fertile controls, Gr2 (n=62) idiopathic asthenozoospermia, Gr3 (n=32) asthenozoospermia with scrotal varicocele and Gr4 (n=36) asthenozoospermia with leucocytospermia. Four smear slides were prepared for each semen sample to be stained with toluidine blue-pyronin to detect mast cells. A significant increase was shown in mast cell-positive samples among varicocele-associated and idiopathic asthenozoospermic patients in comparison with fertile controls. Seminal mast cells were also detected at higher frequency among smokers and in age group over 40 years. It is concluded that mast cells and their products may play a pivotal role in the pathogenesis of asthenozoospermia, possibly proposing a new goal for medical treatment of infertile males to pursue. In addition, this concept may in a way detain smoking as a cause of male infertility considering the clear abundance of mast cells in semen samples of smokers.     

Analysis of lipid peroxidative levels in seminal plasma of infertile men by high-performance liquid chromatography

For the purpose to evaluate the significance of lipid peroxidative products on male infertility, the levels of malondialdehyde (MDA), which is one of the final products of lipid peroxidation in seminal plasma, were determined. Ninety-three male infertile patients were divided into obstructive azoospermic group (12 cases), non-obstructive azoospermic group (15 cases), oligozoospermic group (21 cases), asthenozoospermic group (19 cases), oligoasthenozoospermic group (16 cases) and oligoasthenoteratozoospermic group (10 cases). Eighteen fertile males were included in the control group. MDA concentrations of seminal plasma in the fertile and infertile men were detected by high-performance liquid chromatography (HPLC). The results showed that the concentration of MDA in seminal plasma differed significantly between the control group and all the infertile groups (P < 0.01) except the obstructive azoospermic group, between the oligoasthenozoospermic group and the oligozoospermic and asthenozoospermic groups (P < 0.01), and between the oligoasthenoteratozoospermic group and the oligozoospermic and asthenozoospermic groups (P < 0.01). MDA concentration of seminal plasma in the oligoasthenoteratozoospermic group differed significantly from that in the oligoasthenozoospermic group (P <0.05). The results suggested that detection of MDA concentrations in seminal plasma by HPLC has an indicative value on the diagnosis of male infertility induced by overproduction of reactive oxygen species in male reproductive system.     

Comparison of zinc concentrations in blood and seminal plasma and the various sperm parameters between fertile and infertile men

The aim of the study was to examine the relationships between concentrations of zinc in blood and seminal plasma and sperm quality among infertile and fertile men. One hundred seven male (infertile group) partners of couples who were undergoing investigation for infertility with no known cause for the infertility and 103 men (fertile group) whose wives were pregnant at the time of the study were recruited. The subjects' blood and seminal plasma concentration of zinc were determined by atomic absorption spectroscopy. Except for semen volume, all the other semen parameters for the infertile men were significantly lower than those for the fertile group. The geometric means of the seminal plasma zinc concentration were significantly lower in the infertile group compared with those in the fertile group; 183.6 mg/L (range, 63-499) versus 274.6 mg/L (range, 55-420). There were no significant differences in the geometric means of the blood zinc concentration between the 2 groups. Seminal plasma zinc concentration was significantly correlated with sperm density (r = 0.341, P < .0001), motility (r = 0.253, P < .0001), and viability (r = 0.286, P < .0001). On the basis of the findings of this study and those of other reports, zinc may contribute to fertility through its positive effect on spermatogenesis.     

Association and meta‐analysis of HLA and non‐obstructive azoospermia in the Han Chinese population

The exact aetiology and pathogenesis of most non‐obstructive azoospermia (NOA) are still unknown. The previous two genomewide association studies (GWASs) have identified three different loci within the HLA region for NOA in the Han Chinese population, including rs3129878, rs498422 and rs7194. To further validate the risk of three GWAS‐linked loci for NOA, we conducted a case–control study of these three risk loci in an independent Han Chinese male population, with 603 NOA patients and 610 controls. Furthermore, we also performed a meta‐analysis of five studies on these three NOA‐risk loci. The case–control study strongly suggested a significant association between loci rs3129878, rs498422 and rs7194 and NOA (P = 6.75 × 10^?21 (OR = 2.2586), P = 0.0060 (OR = 1.4013) and P = 0.0128 (OR = 1.2626) respectively). Our meta‐analyses also supported the susceptibility of these three risk loci to NOA (P < 0.01). The risk variants within the HLA region potentially have a strong effect on males at risk of NOA, and may serve as diagnostic markers for male infertility. However, considering genetic difference between different populations, future validating studies in larger independent samples and animal experiments are suggested.     

The secretory activity of the seminal vesicles and its relationship to sperm motility: effects of infection in the male reproductive tract

In 146 males aged between 20 years and 40 years attending an infertility service, the secretory activity of the seminal vesicles was assessed by measurement of corrected seminal fructose concentration. This value was related to the presence of a positive semen culture, other evidence of inflammatory processes in the reproductive tract and sperm motility. Only 48% of subjects with a positive semen culture showed evidence of inflammation in the reproductive tract, as assessed by the presence of more than 20 white blood cells per high power field, and greater than 10% spermagglutination in the ejaculate. There was a relationship between the inflammatory process, hypofunction of the seminal vesicles and poor sperm motility. When the semen culture was positive but there was no evidence of inflammation neither seminal vesicle function nor sperm motility was affected. When the semen culture was negative, i.e. no evidence of inflammation and the subjects were asthenozoospermic, the corrected fructose levels were normal. It is proposed that in these conditions the cause of asthenozoospermia may be factors other than accessory sex organ dysfunction. In conclusion, there was no close relationship between the bacteriological results and evidence of inflammation of the accessory glands. A positive semen culture was related to lower levels of corrected fructose (hypofunction of the seminal vesicles) when the positive sperm culture was associated with inflammation of the reproductive tract and asthenozoospermia.