Does air pollution exposure affect semen quality? Evidence from a systematic review and meta-analysis of 93,996 Chinese men.

Background: Air pollution may impair male fertility, but it remains controversial whether air pollution affects semen quality until now. Objectives: We undertake a meta-analysis to explore potential impacts of six pollutants exposure during the entire window (0-90 days prior to ejaculation) and critical windows (0-9, 10-14, and 70-90 days prior to ejaculation) on semen quality. Methods: Seven databases were retrieved for original studies on the effects of six pollutants exposure for 90 days prior to ejaculation on semen quality. The search process does not limit the language and search date. We only included original studies that reported regression coefficients (ß) with 95% confidence intervals (CIs). The ß and 95% CIs were pooled using the DerSimonian-Laird random effect models. Results: PM2.5 exposure was related with decreased total sperm number (10-14 lag days) and total motility (10-14, 70-90, and 0-90 lag days). PM10 exposure was related with reduced total sperm number (70-90 and 0-90 lag days) and total motility (0-90 lag days). NO2 exposure was related with reduced total sperm number (70-90 and 0-90 lag days). SO2 exposure was related with declined total motility (0-9, 10-14, 0-90 lag days) and total sperm number (0-90 lag days). Conclusion: Air pollution affects semen quality making it necessary to limit exposure to air pollution for Chinese men. When implementing protective measures, it is necessary to consider the key period of sperm development.

Analysis of the screening results of 24040 potential sperm donors in a human sperm bank in Henan Province, China: a 14-year retrospective cohort study.

STUDY QUESTION: Is there a relation between the characteristics of potential sperm donors and the acceptance rate of these potential donors? SUMMARY ANSWER: A relatively higher acceptance rate was observed for potential sperm donors who were aged ≤ 35 years, were married, had children, and who had received higher education, and acceptance rates were also higher during spring and winter than summer and autumn. WHAT IS KNOWN ALREADY: Recruiting donors to a sperm bank program is difficult and slow owing to the high rates of rejection and dropout. STUDY DESIGN, SIZE, DURATION: A total of 24040 potential sperm donors were screened by the Henan Human Sperm Bank from 2006 to 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS: Potential sperm donors were recruited using the following baseline requirement: height of 168 cm or taller; age 22-45 years; currently attending or had graduated from high school or above. Men who met the criteria for age, height, and education level were invited for semen quality screening. The acceptable criteria for semen samples included liquefaction time < 60min, volume ≥ 2mL, sperm concentration ≥ 60 × 106/mL, progressive motility ≥ 60%, post-thaw motility ≥ 40%, pre-freezing total motile sperm per vial > 30 × 106/mL, post-thaw total motile sperm per vial > 12 × 106/mL, and freeze-thaw survival rate ≥ 60%. Any potential sperm donors meeting the minimum criteria for acceptable semen quality on two consecutive semen samples were scheduled for clinical assessment, physical examination, and laboratory tests. The reasons for sperm donor rejection were analyzed. The characteristics of accepted and rejected donors were compared using the chi-square test, and multivariate logistic regression analyses were conducted to identify factors associated with the acceptance rate of potential sperm donors and the positive rate of sexually transmitted diseases (STDs). MAIN RESULTS AND THE ROLE OF CHANCE: Only 23.38% (5620/24040) of potential sperm donors were accepted. The top four reasons for rejection were suboptimal semen quality (90.27%), STDs (6.26%), dropped out (2.65%), and chromosomal abnormalities (0.35%). The most common reason for the rejection of donors with an STD was a positive test for mycoplasmas (49.05%), followed by hepatitis B virus (27.56%), Chlamydia trachomatis (4.68%), and Escherichia coli (3.03%). n this study, the acceptance rate for men aged ≤ 35 years was significantly higher than that for men aged >35 years (P < 0.05). The acceptance rates were also significantly higher for men with a higher education than for men with lower education, married men than unmarried men, and men with children than men without children (P < 0.05). Moreover, acceptance rates were significantly higher during spring and winter than during summer (P <0.05) but were not significantly higher during autumn than during summer (P >0.05). LIMITATIONS, REASONS FOR CAUTION: This study was not performed to analyze the effect of lifestyle habits, such as alcohol consumption and cigarette smoking, on the acceptance rate of potential sperm donors. WIDER IMPLICATIONS OF THE FINDINGS: Only a small proportion of potential sperm donors were accepted in this anonymous sperm donor program. New strategies for sperm donor recruitment may be required to improve the acceptance rate. In the future, we may have to target potential sperm donors who are aged ≤ 35 years and who received higher education in order to improve the acceptance rate. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Joint Construction Project of Henan Medical Science and Technology Research Plan under grant number LHGJ20190389. The authors report no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Effect of somatometric parameters on the prevalence and severity of varicocele: a systematic review and meta-analysis.

BACKGROUND: Published studies have shown contradictory results regarding the relationship between somatometric parameters and varicoceles. We performed a systematic review and meta-analysis to investigate the possible effects of age, height, weight, and body mass index (BMI) on the presence and severity of varicoceles. METHODS: Databases including EMBASE, MEDLINE, PubMed, Cochrane Library, China National Knowledge Infrastructure (CNKI), Web of Science, and Google Scholar were systematically searched to identify relevant articles published up to March 2020. Two researchers independently identified eligible articles and extracted data. Cochran's Q statistic and I2 statistics were used to assess heterogeneity. Meta-analysis was performed using StataSE 12.0 software (StataCorp LP, USA). Random-effects models were used to obtain the weighted mean differences (WMDs) and 95% confidence intervals (CIs). Publication bias was assessed using Begg's funnel plot and Egger's regression test. RESULTS: The search strategy produced 272 articles, of which 18 articles were eligible according to the inclusion/exclusion criteria. A total of 56,325 patients with varicocele and 1,334,694 patients without varicocele were included in the meta-analysis to evaluate the effect of somatometric parameters on the presence and severity of varicocele. The overall results demonstrated that the presence of varicoceles was significantly associated with height (WMD = 1.41, 95% CI = 1.07 to 1.74, P < 0.001) and inversely correlated with BMI (WMD = - 1.35, 95% CI = -1.67 to - 1.03, P < 0.001) but not with age (WMD = -0.93, 95% CI = -2.19 to 0.33, P = 0.149) or weight (WMD = 0.24, 95% CI = -2.24 to 2.72, P = 0.850). The severity of varicocele was inversely correlated with increased BMI but not with age. CONCLUSION: The presence of varicoceles was significantly associated with height and inversely correlated with BMI.

[Bacterial culture of donor semen: Analysis of results from 2008 to 2018].

OBJECTIVE: To investigate the distribution of pathogenic bacteria in donor semen and the effect of bacterial infection on semen quality. METHODS: We performed bacterial culture on and counted the bacterial colonies (BC) in the semen samples collected from 4 897 sperm donors from 2008 to 2018 and divided them into groups A (BC <104 cfu/ml, n = 4 229), B (BC ≥104 cfu/ml, n = 150) and C (BC = 0 cfu/ml, n = 518). Using the biochemical reaction system of the French Biological Merry Emmanuel Company, we identified the bacterial species in group B, subjected all the semen samples to SCA computer assisted semen analysis, and compared the semen quality among different groups. RESULTS: In the 4 897 semen samples, hybrid bacterial contamination was found in 6 (0.12%) and non-hybrid bacteria in 4 379 (89.42%), including 150 (3.43%) in group B. In the semen samples with BC ≥104 cfu/ml, Gram-negative (G－) bacteria were observed in 104 (69.33%), mainly including Escherichia coli, followed by Proteusbacillus vulgaris and Enterobacteria, Gram-positive cocci (G+) in 39 (26.00%), G－ bacteria in 4 (2.67%) and Neisseria gonorrhoeae in 3 (2.00%). Compared with group C, groups A and B showed remarkably reduced total sperm count (P < 0.05) and percentage of progressively motile sperm (P < 0.05) but no statistically significant differences in the semen liquefaction time, semen PH value, total sperm motility or the percentage of morphologically normal sperm (P > 0.05). CONCLUSIONS: Bacterial culture of donor semen revealed a positive rate of 89.42% and varied the bacterial species, mainly including G－ bacteria. And the semen quality decreased with the increase of bacterial colonies.

A longitudinal study of semen quality among Chinese sperm donor candidates during the past 11 years.

Studies suggest that semen quality is declining globally, however, the debate remains open due to the possible effects of ethnic and geographical differences. This study aimed to explore whether semen quality of sperm donor candidates has changed in Henan Province, China from 2009 to 2019. In this retrospective study, we included 23,936 sperm donor candidates who were recruited by the Henan Human Sperm Bank of China between 2009 and 2019. To minimize intra-individual bias, we included only the first ejaculate provided by each sperm donor candidate. The following parameters were measured: volume, sperm concentration, total sperm count, progressive motility, and total motility. After adjustment for age, body mass index (BMI), and sexual abstinence duration, we evaluated changes in main semen parameters over time using multiple linear regression analyses. The sperm concentration decreased from 62.0 million/mL in 2009 to 32.0 million/mL in 2019 (P < 0.001), with an average annual rate of 3.9%. The total sperm count decreased from 160.0 million in 2009 to 80.0 million in 2019 (P < 0.001), with an average annual rate of 4.2%. The progressive motility decreased from 54.0% in 2009 to 40.0% in 2019 (P < 0.001), with an average annual rate of 2.5%. The total motility decreased from 60.0% in 2009 to 46.0% in 2019 (P < 0.001), with an average annual rate of 1.9%. Our results indicated that semen quality among sperm donor candidates had decreased during the study period in Henan Province, China.

Age-specific and sex-specific reference intervals for non-fasting lipids and apolipoproteins in 7260 healthy Chinese children and adolescents measured with an Olympus AU5400 analyser: a cross-sectional study.

AIMS: Ethnic, demographic, lifestyle, genetic and environmental factors influence lipids and apolipoproteins. The aim of this study was to establish age-specific and gender-specific reference intervals for non-fasting lipids and apolipoproteins in healthy Chinese children and adolescents. METHODS: This study followed the Clinical and Laboratory Standards Institute EP28-A3c guidelines. Non-fasting samples were collected from 7260 healthy Chinese children and adolescents, and they were analysed using the Olympus AU5400 analyser for: triglycerides, total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1 and apolipoprotein B (ApoB). The age-related and gender-related reference intervals were partitioned using the Harris-Boyd method. The non-parametric method was used to establish the lower limit (2.5th percentile) and the upper limit (97.5th percentile) for the reference intervals. The 90% CIs for the lower and upper limits were also calculated. RESULTS: Based on the Harris-Boyd method, gender partitions were required for TC, LDL-C and ApoB. Age differences were observed for all analytes. Paediatric reference intervals were established for non-fasting lipids and apolipoproteins based on a large population of healthy children and adolescents. CONCLUSIONS: Previously used reference intervals did not take age and gender into account. These age-specific and gender-specific reference intervals established in this study may contribute to improved management and assessment of paediatric diseases.

Paediatric reference intervals for common coagulation assays in Chinese children as performed on the STA-R coagulation analyzer.

INTRODUCTION: In order to correctly manage the paediatric patients affected with haemostatic disorders, age-appropriate reference intervals should be used. The purpose of this study was to establish age-specific reference intervals for prothrombin time (PT), thrombin time (TT), activated partial thromboplastin time (aPTT) and fibrinogen (Fg). METHODS: In this study, a total of 34 234 apparently healthy children and adolescents aged 0-15 years were chosen as reference individuals. PT, TT, aPTT and Fg were performed on the STA-R coagulation analyzer. Outliers were eliminated using the Dixon D/R ratio rule. Partitioning by age was achieved using Harris and Boyd's standard normal deviate test. The lower (2.5th percentiles) and upper (97.5 percentiles) reference intervals were established using the nonparametric method. RESULTS: Compared with the adult group, the median time of PT was significantly different in the groups consisting of children aged 0-15 days, 15 days-1 month, 1-6 months and 11-15 years. The median time of APTT and TT was significantly prolonged in all paediatric age groups than in the adult group (P < .05). Compared with the adult group, the median values of Fg were significantly different in the groups consisting of children aged 0-15 days and 2-15 years. Our results showed that all coagulation assays required partitioning by age. CONCLUSION: Our results suggest that results of coagulation assays are highly dependent on age, and that age-specific reference intervals must be used to ensure proper evaluation of paediatric coagulation assays.

Pediatric reference intervals of liver and renal function tests from birth to adolescence in Chinese children as performed on the Olympus AU5400.

BACKGROUND: The growth and development of children and adolescents influence values of liver and renal function tests. The purpose of this study was to determine age- and gender-specific reference intervals for liver and renal function tests in apparently healthy Chinese children and adolescents. METHODS: A total of 63,086 apparently healthy children and adolescents (0-15 y) were chosen as reference individuals in this study. The 15 biochemical analytes relating to liver and renal function were measured using an Olympus AU5400 analyzer. Reference intervals were partitioned according to age and/or gender subgroups using the Harris and Boyd's method and established using non-parametric methods. RESULTS: Our results showed that all analytes except for cholinesterase (ChE) and α1-microglobulin (α1-MG) required partitioning by age. Gender partitions were also required for alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), creatinine (Cre), and uric acid (UA). Age- and gender-appropriate reference intervals for liver and renal function tests were established for apparently healthy Chinese children and adolescents. CONCLUSIONS: When establishing pediatric reference intervals, partitioning by age and/or gender is essential. Those reference intervals can be adopted in other clinical laboratories after appropriate validation.

Gestational age-specific reference intervals for 15 biochemical measurands during normal pregnancy in China.

Aims Physiological changes that occur during pregnancy can influence biochemical parameters. Therefore, using reference intervals based on specimens from non-pregnant women to interpret laboratory results during pregnancy may be inappropriate. This study aimed to establish the essential reference intervals for a range of analytes during pregnancy. Methods A cross-sectional study was performed in 13,656 healthy pregnant and 2634 non-pregnant women. Fifteen biochemical measurands relating to renal and hepatic function were analysed using an Olympus AU5400 analyzer (Olympus, Tokyo, Japan). All the laboratory results were checked for outliers using Dixon's test. Reference intervals were established using a non-parametric method. Results Alanine aminotransferase, aspartate aminotransferase, albumin, cholinesterase, creatinine, direct bilirubin, gamma-glutamyl transpeptidase, total bilirubin, total bile acid and total protein showed a decrease during the whole gestational period, while alkaline phosphatase and uric acid increased. Urea nitrogen, ß2-microglobulin and cystatin-C fell significantly during the first trimester and then remained relatively stable until third trimester. Reference intervals of all the measurands during normal pregnancy have been established. Conclusions The reference intervals established here can be adopted in other clinical laboratories after appropriate validation. We verified the importance, for some measurands, of partitioning by gestational age when establishing reference intervals during pregnancy.

[Expressions of SLC22A14 and SPAG6 proteins in the ejaculated sperm of idiopathic asthenozoospermia patients.]

OBJECTIVE: To investigate the expressions of solute carrier family 22 member 14 (SLC22A14) and sperm-associated antigen 6 (SPAG6) in the sperm of idiopathic asthenospermia men. METHODS: We collected semen samples from 50 idiopathic asthenozoospermia patients and another 50 normal sperm donors, purified the sperm by discontinuous density centrifugation on Percoll gradients, and then determined the mRNA and protein expressions of SLC22A14 and SPAG6 by RT-PCR and Western blot, respectively. RESULTS: Compared with the normal controls, the idiopathic asthenozoospermia patients showed significantly decreased mRNA expressions of SLC22A14 (0.77 ± 0.08 vs 0.53 ± 0.10, P<0.01) and SPAG6 (0.78 ± 0.09 vs0.52 ± 0.10 , P<0.01) and protein expressions of SLC22A14 (0.80 ± 0.09 vs 0.55 ± 0.10 , P<0.01) and SPAG6 (0.78 ± 0.09 vs 0.56 ± 0.09, P<0.01). CONCLUSIONS: T The expressions of SLC22A14 and SPAG6 are reduced in the sperm of the patients with idiopathic asthenospermia, which may be one of the important causes of asthenospermia.

Prevalence of Ureaplasma urealyticum, Mycoplasma hominis, Chlamydia trachomatis infections, and semen quality in infertile and fertile men in China.

OBJECTIVE: To study the prevalence of ureaplasma urealyticum (UU), mycoplasma hominis (MH), and chlamydia trachomatis (CT) infections among infertile and fertile men and to study the effects of these infections on semen quality. METHODS: A total of 621 infertile and 615 fertile men were enrolled in this study in our hospital between January 2011 and June 2013. Semen samples were obtained by masturbation after 3-5 days of sexual abstinence. Semen analysis was performed using the methods outlined by the World Health Organization. UU and MH were detected using culture, and CT was detected using polymerase chain reaction. RESULTS: There were no significant differences between infertile and fertile men in terms of the prevalences of UU, MH, and CT. The presence of UU was related, in infected compared with uninfected men, to lower mean sperm concentration and lower vitality. The differences in semen parameters associated with MH or CT between infected and uninfected men did not attain statistical significance. CONCLUSION: During the infertility assessment, the clinician should consider evaluating for the presence of UU in men with oligospermia or decreased sperm vitality.

[Expression of TEKT4 protein decreases in the ejaculated spermatozoa of idiopathic asthenozoospermic men].

OBJECTIVE: To investigate the role of the TEKT4 protein in the pathogenesis of idiopathic asthenozoospermia. METHODS: We separated and purified the ejaculated sperm from idiopathic asthenozoospermia patients and normozoospermic men by Percoll discontinuous density gradients, and detected the distribution and the expressions of TEKT4 mRNA and TEKT4 protein by RT-PCR and Western blot. RESULTS: RT-PCR revealed that the expression of TEKT4 mRNA was significantly lower in the sperm of the idiopathic asthenozoospermia patients than in those of the normozoospermic men (0.59 +/- 0.13 vs 0.75 +/- 0.15, t = 4.325, P < 0.05), and Western blot confirmed the results of RT-PCR (0.48 +/- 0.14 vs 0.69 +/- 0.13, t = 5.939, P < 0.05). CONCLUSION: The expression of TEKT4 is significantly decreased in the ejaculated sperm of idiopathic asthenozoospermia patients, which might be one of the causes of idiopathic asthenozoospermia.

[Expression of SEPT4 protein in the ejaculated sperm of idiopathic asthenozoospermic men].

OBJECTIVE: To investigate the role of the SEPT4 protein in the pathogenesis of idiopathic asthenozoospermia. METHODS: Samples of ejaculated sperm from idiopathic asthenozoospermia patients and normozoospermic men were separated and purified by Percoll discontinuous density gradients, the distribution and expression of SEPT4 in the sperm samples were determined by immunocytochemistry, and the expressions of SEPT4 mRNA and SEPT4 protein were detected by RT-PCR and Western blot. RESULTS: Immunocytochemistry showed that the expression of SEPT4, located in the annulus, was significantly reduced in the sperm of the idiopathic asthenozoospermia patients (t = 3.452, P < 0.01). RT-PCR revealed that the expression of SEPT4 mRNA was significantly lower in the sperm of the idiopathic asthenozoospermia patients than in those of the normozoospermic men (t = 3.521, P < 0.05). Western blot confirmed the results of RT-PCR (t = 5.872, P < 0.05). CONCLUSION: The expression of SEPT4 is significantly decreased in the ejaculated sperm of idiopathic asthenozoospermia patients, which might be one of the causes of idiopathic asthenozoospermia.

Sperm donation and its application in China: a 7-year multicenter retrospective study.

Sperm donation in China is different from that in other countries due to cultural, social and political factors. This research presents the current status of sperm donation in Mainland China and highlights some problems. Between January 2003 and December 2009, 19 471 sperm donors were screened totally and 6467 donors (33.2%) were recruited. The primary reasons for non-recruitment were either inadequate semen parameters (55.0%) or positive results for sexually transmitted diseases (7.9%). There were 327 (1.7%) qualified donors who withdrew from the program because of frustration related to failed semen parameters, participation merely for free medical tests or job transfer. A questionnaire investigating donor intention, as well as other concerns associated with sperm donation, was distributed to 516 potential donors. All potential donors indicated their primary motivation as altruism, while 90.9% mentioned monetary reward as a second motivating factor. Approximately 93.4% of donors expressed some apprehension about the risk of consanguineous mating and the protection of their identity. Over the past 7 years, 488 389 vials of donors' semen have been cryopreserved. In 36 438 artificial insemination with donor sperm (AID) cycles, the clinical pregnancy rate was 23.9% and the live birth rate was 16.6%. In 7148 in vitro fertilization cycles, the clinical pregnancy rate was 45.8% and the live birth rate was 35.2%. Human sperm banks have been strictly monitored to ensure that each sperm donor can only impregnate five women nationwide. There is still a large gap between the supply and demand for sperm donation which may be solved by updated guidelines.

[CatSper1 protein and idiopathic asthenozoospermia].

OBJECTIVE: To investigate the role of the cation channel of sperm 1 (CatSper1) protein in the pathogenesis of idiopathic asthenozoospermia. METHODS: Sperm samples from patients with idiopathic asthenozoospermia were separated by Percoll discontinuous density gradients, and the distribution and expression of the CatSper1 protein were determined by immunocytochemistry. Western blotting was used to detect the different expressions of CatSper1 in the ejaculated sperm from the normal control, mild asthenozoospermia, moderate asthenozoospermia and severe asthenozoospermia groups, followed by statistical analyses. RESULTS: The expression of CatSper1, located in the principle piece of the sperm tail, was reduced significantly in the samples from the idiopathic asthenozoospermia patients as compared with the normal controls (t = 2.188, P = 0.042). The relative contents of the CatSper1 protein in the sperm of the control, mild asthenozoospermia, moderate asthenozoospermia and severe asthenozoospermia groups were 0.806 +/- 0.266, 0.669 +/- 0.207, 0.505 +/- 0.214 and 0.295 +/- 0.162, respectively, significantly decreased in the asthenozoospermia patients in comparison with the normal controls (P <0.05). There was a positive correlation between the percentage of progressively motile sperm and the relative content of the CatSper1 protein (r = 0.633, P = 0.000). CONCLUSION: The decreased or abnormal expression of the CatSper1 protein may be a factor involved in the pathogenesis of idiopathic asthenozoospermia.