Associations between dietary macronutrient quality and asthenozoospermia risk: a hospital-based case-control study.

Background & aims: Macronutrients are the main part of the human diet and can affect multiple health outcomes. Nevertheless, associations between dietary macronutrient quality and asthenozoospermia risk have not been reported to date. Thus, this study aimed to be the first to explore the associations between macronutrient quality and asthenozoospermia risk using the novel multidimensional macronutrient quality index (MQI). Methods: A case-control study was conducted at infertility clinics of Shengjing Hospital of China Medical University during June and December 2020, including 552 asthenozoospermia cases and 585 normozoospermia controls. Data on diet were collected using a validated food frequency questionnaire. MQI was estimated according to the carbohydrate quality index (CQI), fat quality index (FQI), and protein quality index (PQI). Binary logistic regression models were performed to calculate the odds ratio (OR) with a 95% confidence interval (CI). Subgroup and interaction analyses were performed based on age, body mass index, physical activity, smoking, drinking, and education level. Dose-response relationships were evaluated by restricted cubic splines. Sensitivity analyses were performed in two ways. First, participants with a dietary change were excluded to lower potential reverse causation. Then, we used the healthy plate protein source quality index instead of PQI to redefine MQI. Results: No statistically significant association was observed between dietary MQI and asthenozoospermia risk (OR = 1.24, 95% CI: 0.88-1.73). The sub-indices of MQI, CQI, FQI, and PQI, failed to be identified as having a statistically significant association with asthenozoospermia risk (OR = 1.35, 95% CI: 0.92-1.97 for CQI; OR = 1.13, 95% CI: 0.84-1.53 for FQI; OR = 1.28, 95% CI: 0.92-1.78 for PQI). However, CQI showed a positive association with the risk of asthenozoospermia among non-drinkers (Ptrend < 0.05) and highly educated participants (OR = 1.82, 95% CI: 1.13-2.94; Ptrend < 0.05). Additionally, there was a multiplicative interaction between CQI and education level for asthenozoospermia risk (P < 0.05). Conclusions: Our findings demonstrated no association of MQI and its sub-indices with asthenozoospermia risk except for CQI. Although our findings are mostly non-significant, they contribute novel knowledge to this research field and lay the foundation for future studies.

ROS-induced oxidative stress is a major contributor to sperm cryoinjury.

STUDY QUESTION: What is the mechanism behind cryoinjury in human sperm, particularly concerning the interplay between reactive oxygen species (ROS) and autophagy, and how does it subsequently affect sperm fate? SUMMARY ANSWER: The freeze-thaw operation induces oxidative stress by generating abundant ROS, which impairs sperm motility and activates autophagy, ultimately guiding the sperm toward programmed cell death such as apoptosis and necrosis, as well as triggering premature capacitation. WHAT IS KNOWN ALREADY: Both ROS-induced oxidative stress and autophagy are thought to exert an influence on the quality of frozen-thawed sperm. STUDY DESIGN, SIZE, DURATION: Overall, 84 semen specimens were collected from young healthy fertile males, with careful quality evaluation. The specimens were split into three groups to investigate the ROS-induced cryoinjury: normal control without any treatment, sperm treated with 0.5 mM hydrogen peroxide (H2O2) for 1 h, and sperm thawed following cryopreservation. Samples from 48 individuals underwent computer-assisted human sperm analysis (CASA) to evaluate sperm quality in response to the treatments. Semen samples from three donors were analyzed for changes in the sperm proteome after H2O2 treatment, and another set of samples from three donors were analyzed for changes following the freeze-thaw process. The other 30 samples were used for fluorescence-staining and western blotting. PARTICIPANTS/MATERIALS, SETTING, METHODS: Sperm motility parameters, including progressive motility (PR %) and total motility (PR + NP %), were evaluated using the CASA system on a minimum of 200 spermatozoa. The proteomic profiles were determined with label-free mass spectrometry (MS/MS) and protein identification was performed via ion search against the NCBI human database. Subsequently, comprehensive bioinformatics was applied to detect significant proteomic changes and functional enrichment. Fluorescence-staining and western blot analyses were also conducted to confirm the proteomic changes on selected key proteins. The ROS level was measured using 2',7'-dichlorodihydrofluorescein diacetate labeling and the abundance of bioactive mitochondria was determined by evaluating the inner mitochondrial membrane potential (MMP) level. Molecular behaviors of sequestosome-1 (p62 or SQSTM1) and microtubule-associated proteins 1A/1B light chain 3 (LC3) were monitored to evaluate the state of apoptosis in human sperm. Fluorescent probes oxazole yellow (YO-PRO-1) and propidium iodide (PI) were utilized to monitor programmed cell death, namely apoptosis and necrosis. Additionally, gradient concentrations of antioxidant coenzyme Q10 (CoQ10) were introduced to suppress ROS impacts on sperm. MAIN RESULTS AND THE ROLE OF CHANCE: The CASA analysis revealed a significant decrease in sperm motility for both the H2O2-treatment and freeze-thaw groups. Fluorescence staining showed that high ROS levels were produced in the treated sperm and the MMPs were largely reduced. The introduction of CoQ10 at concentrations of 20 and 30 µM resulted in a significant rescue of progressive motility (P < 0.05). The result suggested that excessive ROS could be the major cause of sperm motility impairment, likely by damaging mitochondrial energy generation. Autophagy was significantly activated in sperm when they were under oxidative stress, as evidenced by the upregulation of p62 and the increased conversion of LC3 as well as the upregulation of several autophagy-related proteins, such as charged multivesicular body protein 2a, mitochondrial import receptor subunit TOM22 homolog, and WD repeat domain phosphoinositide-interacting protein 2. Additionally, fluorescent staining indicated the occurrence of apoptosis and necrosis in both H2O2-treated sperm and post-thaw sperm. The cell death process can be suppressed when CoQ10 is introduced, which consolidates the view that ROS could be the major contributor to sperm cryoinjury. The freeze-thaw process could also initiate sperm premature capacitation, demonstrated by the prominent increase in tyrosine phosphorylated proteins, verified with anti-phosphotyrosine antibody and immunofluorescence assays. The upregulation of capacitation-related proteins, such as hyaluronidase 3 and Folate receptor alpha, supported this finding. LARGE SCALE DATA: The data underlying this article are available in the article and its online supplementary material. LIMITATIONS, REASONS FOR CAUTION: The semen samples were obtained exclusively from young, healthy, and fertile males with progressive motility exceeding 60%, which might overemphasize the positive effects while possibly neglecting the negative impacts of cryoinjury. Additionally, the H2O2 treatment conditions in this study may not precisely mimic the oxidative stress experienced by sperm after thawing from cryopreservation, potentially resulting in the omission of certain molecular alterations. WIDER IMPLICATIONS OF THE FINDINGS: This study provides substantial proteomic data for a comprehensive and deeper understanding of the impact of cryopreservation on sperm quality. It will facilitate the design of optimal protocols for utilizing cryopreserved sperm to improve applications, such as ART, and help resolve various adverse situations caused by chemotherapy, radiotherapy, and surgery. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by grants from the Major Innovation Project of Research Institute of National Health Commission (#2022GJZD01-3) and the National Key R&D Program of China (#2018YFC1003600). All authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Association between dietary total antioxidant capacity and semen quality among men attending an infertility clinic: a cross-sectional study.

STUDY QUESTION: Is dietary non-enzymatic antioxidant capacity related to semen quality? SUMMARY ANSWER: The only statistically significant association of semen quality parameters with dietary total antioxidant capacity (DTAC) detected was an inverse association between DTAC and ejaculate volume. WHAT IS KNOWN ALREADY: Growing interest exists regarding the role of diet in influencing semen quality. While DTAC is linked to favorable health outcomes, its association with semen quality, especially among men attending infertility clinics, remains understudied. STUDY DESIGN SIZE DURATION: This cross-sectional study was carried out between June and December of 2020. In total, 1715 participants were included in the final analysis. PARTICIPANTS/MATERIALS SETTING METHODS: Men who attended an infertility clinic in China were enrolled. Experienced clinical technicians performed the semen analysis. The DTAC indices included the ferric-reducing ability of plasma, oxygen radical absorbance capacity, total reactive antioxidant potential, and Trolox equivalent antioxidant capacity. The quantile regression model was used for multivariate analysis. MAIN RESULTS AND THE ROLE OF CHANCE: After adjustment for a variety of confounding variables, a significant inverse association was identified between DTAC and ejaculate volume (ßcontinuous FRAP = -0.015, 95% CI = -0.023, -0.006, ßT3 vs T1 = -0.193, 95% CI = -0.379, -0.006, Ptrend = 0.007; ßcontinuous TRAP = -0.019, 95% CI = -0.041, 0.002, ßT3 vs T1 = -0.291, 95% CI = -0.469, -0.112, Ptrend = 0.002). The majority of DTAC indices have no statistically significant association with semen quality parameters. LIMITATIONS REASONS FOR CAUTION: We cannot infer causality because of the nature of the cross-sectional study design. The robustness of the conclusion may be compromised by the exactness of non-enzymatic antioxidant capacity estimation. WIDER IMPLICATIONS OF THE FINDINGS: Our findings demonstrated no association between DTAC indices and semen quality parameters among men attending an infertility clinic, except for ejaculate volume. Even though our findings are mostly non-significant, they contribute novel knowledge to the field of study while also laying the groundwork for future well-designed studies. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the JieBangGuaShuai Project of Liaoning Province [grant number 2021JH1/10400050], the Clinical Research Cultivation Project of Shengjing Hospital [grant number M1590], and the Outstanding Scientific Fund of Shengjing Hospital [grant number M1150]. The sponsors had no role in study design, or in the collection, analysis, and interpretation of data, or in the writing of the report, or in the decision to submit the article for publication. There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Dietary fat and fatty acid consumptions and the odds of asthenozoospermia: a case-control study in China.

STUDY QUESTION: Are dietary fat and fatty acid (FA) intakes related to the odds of asthenozoospermia? SUMMARY ANSWER: Plant-based fat consumption was associated with decreased asthenozoospermia odds, while the consumption of animal-based monounsaturated fatty acid (MUFA) was positively related to asthenozoospermia odds. WHAT IS KNOWN ALREADY: Dietary fat and FA are significant ingredients of a daily diet, which have been demonstrated to be correlated to the reproductive health of men. However, to date, evidence on fat and FA associations with the odds of asthenozoospermia is unclear. STUDY DESIGN SIZE DURATION: The hospital-based case-control study was performed in an infertility clinic from June 2020 to December 2020. Briefly, 549 asthenozoospermia cases and 581 controls with normozoospermia were available for final analyses. PARTICIPANTS/MATERIALS SETTING METHODS: We collected dietary data through a verified food frequency questionnaire of 110 food items. Asthenozoospermia cases were ascertained according to the World Health Organization guidelines. To investigate the correlations of dietary fat and FA consumptions with the odds of asthenozoospermia, we calculated the odds ratios (ORs) and corresponding 95% CIs through unconditional logistic regression models. MAIN RESULTS AND THE ROLE OF CHANCE: Relative to the lowest tertile of consumption, the highest tertile of plant-based fat intake was inversely correlated to the odds of asthenozoospermia (OR = 0.68, 95% CI = 0.50-0.91), with a significant dose-response relation (OR = 0.85, 95% CI = 0.75-0.97, per standard deviation increment). Inversely, animal-based MUFA intake (OR = 1.49, 95% CI = 1.04-2.14) was significantly correlated to increased odds of asthenozoospermia, and an evident dose-response relation was also detected (OR = 1.24, 95% CI = 1.05-1.45, per standard deviation increment). Subgroup analyses showed similar patterns of associations to those of the primary results. Moreover, we observed significant interactions on both multiplicative and additive scales between animal-based MUFA and cigarette smoking. LIMITATIONS REASONS FOR CAUTION: Selection bias and recall bias were unavoidable in any of the observational studies. As we failed to obtain the information of trans-fatty acid (TFA) consumption, the relation of TFA intake and asthenozoospermia odds was unclear. WIDER IMPLICATIONS OF THE FINDINGS: This study indicated that different sources of fat and FAs might exert different effects on the etiology of asthenozoospermia, and cigarette smoking could exacerbate the adverse effect of high animal-based MUFA intake on asthenozoospermia. Our findings provide novel evidence pertaining to the fields of prevention of asthenozoospermia through decreasing animal-derived fat and FA consumptions and smoking cessation. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the JieBangGuaShuai Project of Liaoning Province, Natural Science Foundation of Liaoning Province, Clinical Research Cultivation Project of Shengjing Hospital, and Outstanding Scientific Fund of Shengjing Hospital. All authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Phytochemical consumption and the risk of teratozoospermia: findings from a hospital-based case-control study in China.

STUDY QUESTION: Are dietary phytochemicals associated with the risk of teratozoospermia? SUMMARY ANSWER: Dietary intake of carotene, including total carotene, α-carotene, ß-carotene as well as retinol equivalent, and lutein + zeaxanthin, were inversely correlated with the risk of teratozoospermia. WHAT IS KNOWN ALREADY: Phytochemicals are natural plant derived bioactive compounds, which have been reported to be potentially associated with male reproductive health. To date, no study has investigated the association between phytochemical intake and the risk of teratozoospermia. STUDY DESIGN SIZE DURATION: This hospital-based case-control study, which included 146 newly diagnosed teratozoospermia cases and 581 controls with normozoospermia from infertile couples, was conducted in a hospital-based infertility clinic in China, from June 2020 to December 2020. PARTICIPANTS/MATERIALS SETTING METHODS: Dietary information was collected using a validated semi-quantitative 110-item food frequency questionnaire. Unconditional logistic regression was applied to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between phytochemical (i.e. phytosterol, carotene, flavonoid, isoflavone, anthocyanidin, lutein + zeaxanthin, and resveratrol) intake and the risk of teratozoospermia. MAIN RESULTS AND THE ROLE OF CHANCE: We observed a decreased risk of teratozoospermia for the highest compared with the lowest tertile consumption of total carotene (OR = 0.40, 95% CI = 0.21-0.77), α-carotene (OR = 0.53, 95% CI = 0.30-0.93), ß-carotene (OR = 0.47, 95% CI = 0.25-0.88), retinol equivalent (OR = 0.47, 95% CI = 0.24-0.90), and lutein + zeaxanthin (OR = 0.35, 95% CI = 0.19-0.66), with all of the associations showing evident linear trends (all P trend <0.05). In addition, significant dose-response associations were observed between campestanol and α-carotene consumption and the risk of teratozoospermia. Moreover, there was a significant multiplicative interaction between BMI and lutein + zeaxanthin intake (P interaction <0.05). LIMITATIONS REASONS FOR CAUTION: The cases and controls were not a random sample of the entire target population, which could lead to admission rate bias. Nevertheless, the controls were enrolled from the same infertility clinic, which could reduce the bias caused by selection and increase the comparability. Furthermore, our study only included a Chinese population, therefore caution is required regarding generalization of our findings to other populations. WIDER IMPLICATIONS OF THE FINDINGS: Dietary phytochemicals, namely carotene, lutein, and zeaxanthin, might exert a positive effect on teratozoospermia. These phytochemicals are common in the daily diet and dietary supplements, and thus may provide a preventive intervention for teratozoospermia. STUDY FUNDING/COMPETING INTERESTS: This study was funded by Natural Science Foundation of Liaoning Province (No. 2022-MS-219 to X.B.W.), Outstanding Scientific Fund of Shengjing Hospital (No. M1150 to Q.J.W.), Clinical Research Cultivation Project of Shengjing Hospital (No. M0071 to B.C.P.), and JieBangGuaShuai Project of Liaoning Province (No. 2021JH1/1040050 to Y.H.Z.). All authors declared that there was no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Intake of ultra-processed foods and asthenozoospermia odds: A hospital-based case-control study.

Background: The intake of ultra-processed foods (UPFs) has increased rapidly in recent years. Evidence has suggested that UPFs has adverse effects on several health outcomes. This study aimed to first evaluate the association between the intake of UPFs and asthenozoospermia odds. Methods: A hospital-based case-control study including 549 cases and 581 controls was performed in the infertility clinics of Shengjing Hospital of China Medical University from June 2020 to December 2020. Dietary intake was assessed using a validated food frequency questionnaire. Food items were categorized by the NOVA classification system based on the degree of processing. Semen parameters were analyzed according to the World Health Organization guidelines. Results: The highest tertile of UPFs intake (% of total energy intake) was positively associated with the odds of asthenozoospermia (odds ratio [OR] = 1.53; 95% confidence interval [CI]: 1.12, 2.10; P for trend < 0.05), compared with the lowest tertile. Similar patterns were also found in subgroup analyses among participants with age ≥32 years (OR = 1.58; 95% CI: 1.04, 2.40), BMI ≥ 24 kg/m2 (OR = 1.52; 95% CI: 1.04, 2.22), ever cigarette smoking (OR = 1.78; 95% CI: 1.14, 2.79), and ever alcohol drinking (OR = 1.65; 95% CI: 1.01, 2.72), and in sensitivity analyses by using absolute amount (g/day) to calculate the intake of UPFs. Conclusion: Higher consumption of UPFs was positively associated with the odds of asthenozoospermia. More studies are needed to confirm our findings.

Associations between Meat and Vegetable Intake, Cooking Methods, and Asthenozoospermia: A Hospital-Based Case-Control Study in China.

Background: The role of meat and vegetable intake in the development of asthenozoospermia has been controversial, and the role of cooking methods for meat and vegetables in the association has yet to be determined. The present study aimed to illuminate the relationship between the consumption and cooking methods of meat and vegetables and the risk of asthenozoospermia. Methods: In this hospital-based case-control study, we enrolled 552 patients with asthenozoospermia and 585 healthy controls. Dietary information was assessed using a validated self-administered food frequency questionnaire. Asthenozoospermia was diagnosed according to the fifth edition of the WHO laboratory manual for the examination and processing of human semen. Results: Participants in the highest tertile of total meat and unprocessed meat intake had a 44% and 39% lower risk of asthenozoospermia than those in the lowest tertile (OR = 0.56, 95% CI: 0.37, 0.87 and OR = 0.61, 95% CI: 0.40, 0.93), respectively. Participants with the highest processed meat consumption showed higher risk (OR = 1.44, 95% CI: 1.01, 2.06). Raw vegetable consumption was negatively associated with the risk of asthenozoospermia (OR = 0.67, 95% CI: 0.45, 0.98). The stir-frying cooking method for meat was associated with increased risk of asthenozoospermia (OR = 1.58, 95% CI: 1.02, 2.46). Conclusions: Intake of total meat, unprocessed meat, and raw vegetable may reduce asthenozoospermia risk, while higher consumption of processed meat may increase the risk. Cooking methods may play a role in these associations. These findings need to be confirmed in large and prospective cohort studies.

Diet Quality Scores and Asthenoteratozoospermia Risk: Finding From a Hospital-Based Case-Control Study in China.

Objective: We aimed to examine associations of diet quality scores, including the dietary approaches to stop hypertension (DASH), alternate Healthy Eating Index (AHEI), and Chinese Healthy Eating Index (CHEI) with asthenoteratozoospermia risk in China. Methods: Among 254 cases and 633 controls in a hospital-based case-control study in Shenyang, Liaoning Province, China, DASH, AHEI, and CHEI were calculated using a validated food frequency questionnaire. Asthenotetrazoospermia was evaluated according to World Health Organization guidelines. Unconditional multiple logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for the association between quality diet scores and asthenoteratozoospermia risk. Results: We found that the CHEI score was inversely associated with asthenoteratozoospermia risk, with ORs of 0.59 (95% CI 0.39, 0.88) and 0.59 (95% CI 0.39, 0.88) for the 2nd and 3rd tertiles vs. the 1st tertile, respectively (P trend < 0.05). In addition, our data indicated that each standard deviation increase in CHEI, AHEI-2010, and DASH score was associated with 19, 13, and 17% decreased risk of asthenoteratozoospermia, respectively. Conclusion: Our findings suggest that higher adherence to the CHEI, AHEI-2010, and DASH diet quality scores may reduce the risk of asthenoteratozoospermia, especially for younger participants.

[Extracellular vesicles: Their physiological functions related to sperm maturation, sperm motility and fertilization].

Extracellular vesicles are cell-to-cell communication tools that play important roles in sperm maturation, motility, and fertilization. Epididymosomes provide proteins, lipids, and genetic materials to sperm as the latter go through the epididymis, not only promoting sperm maturation, but also influencing sperm and offspring phenotypes at the epigenetic level. After ejaculation, prostasomes fuse with sperm, leading to changes in the composition of the sperm plasma membrane and the contents of sperm, which maintains the stability of the sperm plasma membrane and increases sperm motility as well. Uterosomes can enhance sperm capacitation and acrosome reaction. Oviductosomes participate in sperm capacitation and motility, provide non-coding RNA to sperm, and influence the development of embryos. However, studies on extracellular vesicles and spermatozoa are mostly based on animal experiments, and their applicability to humans remains to be further explored.

The Association Between Dairy Product Consumption and Asthenozoospermia Risk: A Hospital-Based Case-Control Study.

Background: Evidence of an association between dairy product and main related dairy nutrient intake, and the asthenozoospermia risk have been limited and controversial. Methods: A hospital-based case-control study including 549 men with asthenozoospermia and 581 normozoospermic controls was carried out in the infertility clinics of Shengjing Hospital of China Medical University between June, 2020 and December, 2020. Dietary intake was assessed with a validated food frequency questionnaire. According to the World Health Organization guidelines, semen parameters were collected through masturbation and were measured with WLJY9000 instrument and flow cytometry. The daily intake of dairy products and related nutrients was categorized into three groups according to control distribution, and the lowest tertile was used as the reference category. An unconditional multiple logistic regression was used to estimate the odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) for asthenozoospermia risk. Results: After adjustment for potential confounders, we found no statistically significant associations between the intake of total dairy products and asthenozoospermia risk (ORT3vs.T1 = 1.19, 95%CI = 0.85-1.67). Additionally, we generated null findings regarding the main related nutrients from dairy, including protein (ORT3vs.T1 = 1.19, 95%CI = 0.85-1.68), fat (ORT3vs.T1 = 1.28, 95%CI = 0.91-1.80), calcium (ORT3vs.T1 = 1.20, 95%CI = 0.85-1.68), saturated fatty acids (ORT3vs.T1 = 1.30, 95%CI = 0.92-1.83), and phosphorous (ORT3vs.T1 = 1.18, 95%CI = 0.84-1.67), and the asthenozoospermia risk. Of note, after stratification by body mass index (BMI), and the saturated fatty acids consumption from dairy was significantly associated with a higher asthenozoospermia risk (ORT3vs.T1 = 1.76, 95%CI = 1.01-3.09) among participants with a BMI below 25 kg/m2. Conclusion: This study provided limited evidence of an association between the intake of total dairy products and the main related dairy nutrients including protein, fat, calcium, saturated fatty acids, and phosphorus, and the asthenozoospermia risk. Further studies are warranted to confirm our findings in the future.

Prevalence and Predictors of Anxiety and Depressive Symptoms Among International Medical Students in China During COVID-19 Pandemic.

Background: The rapid spread of Coronavirus Disease-19 (COVID-19) infection has been the most important public health crisis across the globe since the end of 2019. Anxiety and depression are the most common mental health problems among people during the pandemic, and many studies have reported anxiety and depressive symptoms in college students. However, information on the mental health status of international medical students during this critical period of time has been scarce, which hinders the efforts in making proper policy or strategies to help these students. The present study aims to explore the prevalence of anxiety and depressive symptoms in international medical students in China and to find out the factors that have potential predictive value for anxiety and depressive symptoms. Method: A cross-sectional study was carried out for international medical students during November 2020 at China Medical University in Shenyang, China. Five hundred and nineteen international students were interviewed with questionnaires containing demographic variables, Stressors in school, Generalized Anxiety Disorder Assessment (GAD-7), Patient Health Questionnaire-9 (PHQ-9), Simplified Coping Style Questionnaire (SCSQ), Perceived Stress Scale (PSS-10), the Multidimensional Scale of Perceived Social Support (MSPSS), Revised Life Orientation Test (LOT-R) and Resilience Scale-14 (RS-14). Univariate logistic regression and stepwise multiple logistic regression analyses were conducted where appropriate to explore the predictive factors of anxiety symptoms and depressive symptoms. Results: The prevalence of anxiety symptoms and depressive symptoms in the sample population was 28.5% (148/519) and 31.6% (164/519), respectively. Stressors in school (ß = 0.176, OR = 1.192, CI: 1.102-1.289), negative coping style (ß = 0.639, OR = 1.894, CI: 1.287-2.788) and perceived stress (ß = 0.230, OR = 1.258, CI: 1.184-1.337) were found to be the predictors of anxiety symptoms among the international medical students; while gender (ß = -0.594, OR = 0.552, CI: 0.315-0.968), stay up late (ß = 0.828, OR = 2.288, CI: 1.182-4.431), current place of residence (ß = 1.082, OR = 2.951, CI: 1.256-6.931), stressors in the school (ß = 0.303, OR = 1.354, CI: 1.266-1.496), negative coping style (ß = 0.866, OR = 2.377, CI: 1.516-3.725), perceived stress (ß = 0.233, OR = 1.262, CI: 1.180-1.351) were found to be predictors of depressive symptoms. Conclusion: The prevalence of anxiety symptoms and depressive symptoms was moderate among international medical students in China. The communal predictors of anxiety and depressive symptoms were stressors in school, negative coping style and perceived stress; while demographic factors such as gender (male), stay up late at night and current place of residence were found associated with depressive symptoms. These results suggest that proper stress management and specific interventions are needed to help students maintain their mental health during the COVID-19 pandemic period.

Dietary Inflammatory Index and Risk of Asthenozoospermia: A Hospital-Based Case-Controlled Study in China.

Background: Evidence of associations between a pro-inflammatory diet and asthenozoospermia risk is limited. We therefore performed a case-controlled study to investigate associations between pro-inflammatory diet using dietary inflammatory index (DII) scores and asthenozoospermia risk in China. Methods: Our hospital-based case-controlled study comprised 549 incident asthenozoospermia men and 581 healthy controls. All were interviewed at the infertility clinic in Shengjing Hospital of China Medical University from June 2020 to December 2020. DII scores were calculated based on dietary intake which were assessed using a validated food frequency questionnaire. Semen parameters were analyzed according to World Health Organization guidelines. An unconditional logistic regression model was used to estimate odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for asthenozoospermia risk. The lowest tertile served as the reference category for regression analyses. Results: After adjustment for age in the primary multivariable model, we failed to determine a significant negative association between DII and asthenozoospermia risk (for the highest tertile of DII scores compared to the lowest tertile) (OR = 0.77, 95% CI: 0.57-1.03). Similarly, non-significant associations were also identified in the multivariable model after adjusting for more potential confounders (OR = 0.86; 95% CI: 0.58-1.27). Additionally, in subgroup analyses stratified by age, body mass index, and smoking status, non-significant results were consistent with the main findings. Conclusions: To our knowledge, this is the first study exploring this particular topic. Our research does not support an association between DII scores and asthenozoospermia risk. Further prospective studies with more DII relevant foods and nutrients are warranted to confirm our findings.

Dairy Product Consumption and Oligo-Astheno-Teratozoospermia Risk: A Hospital-Based Case-Control Study in China.

Background: Researches on the association of dairy products consumption with Oligo-astheno-teratozoospermia (OAT) risk has been limited and controversial. Therefore, we aim to explore the aforementioned association among Chinese men. Methods: A hospital-based case-control study was conducted in men consisting of 106 cases of OAT and 581 controls. Intakes of dairy products and their related nutrients were collected using a semi-quantitative food frequency questionnaire and semen quality was analyzed according to the World Health Organization guidelines. The daily intake of dairy products and their related nutrients was categorized into three groups with the lowest tertile serving as the reference category. Odds ratios (ORs) and 95% confidence intervals (CIs) of association between dairy intake and OTA risk were calculated by the multivariable logistic regression models. Results: No significant association was found between total dairy (OR T3vs.T1 =1.53, 95% CI: 0.85-2.78), protein (OR T3vs.T1 =1.51, 95% CI: 0.84-2.75), or calcium (OR T3vs.T1 = 1.46, 95% CI: 0.81-2.66) and the OAT risk in the main findings. However, we observed a statistically significant positive association of dairy fat intake with OAT risk (OR T3vs.T1 =1.93, 95% CI: 1.06-3.58). The findings were consistent with the main results when we carried out subgroup analysis stratified by body mass index. Conclusion: A significant positive association was found between dairy fat intake and the risk of OAT. Further large-scale prospective studies are required to confirm this finding.

[Biosafety in andrology laboratories during the outbreak of COVID-19].

The novel coronavirus disease 2019 (COVID-19) broke out in December 2019 and has been rapidly escalating throughout the world. Clinical findings show that the patients with either symptomatic or asymptomatic COVID-19 can be a potential source of infection. Although respiratory droplets and close contact are considered to be the main routes of transmission, there is the possibility of aerosol transmission in a relatively closed environment. The nucleic acid of the novel coronavirus can be detected in nasopharyngeal swabs, sputum and other lower respiratory tract secretions, blood, feces, urine and so on, but whether it exists in the semen has not been confirmed. It is reported that the novel coronavirus may affect the testis that highly expresses angiotensin-converting enzyme 2 (ACE2) and theoretically the semen is a possible carrier of the virus considering the fact that it is discharged from the same channel as the urine. Andrology laboratorians are exposed to most of the specimens above, including semen, and some open operations in the laboratory increase the risk of aerosol generation. Therefore, corresponding protective procedures are necessitated in andrology laboratories to reduce the risk of infection during the outbreak of COVID-19. Based on the knowledge and experience available as regards the pandemic and the characteristics of the work in the andrology laboratory, we summarize some biosafety points for andrology laboratorians to attend to during the outbreak of COVID-19.

[Semen expulsion under the ureterocystoscope].

OBJECTIVE: To determine the exact location of the opening of the ejaculatory duct in men and provide some basic anatomical evidence for seminal vesiculoscopy and the treatment of ejaculatory duct obstruction. METHODS: We performed ureterocystoscopy for 21 male patients aged 26 - 47 years with hematuria (n = 12), hematospermia (n = 2), glandular cystitis (n = 6), and anejaculation after radical resection of rectal carcinoma (n = 1), and meanwhile, with the consent of the patients, massaged the prostate and ejaculatory duct and observed the outlet of the expelled fluid. Under the microscope, we described the fluid samples with sperm as the expulsion from the ejaculatory duct. RESULTS: Ureterocystoscopy showed that the exact anatomical sites of the expulsion of prostatic fluid and semen in the patients were the side and lower side of the prostatic utricle opening above the verumontanum and the ventral side of the verumontanum. Quantities of sperm were found in the expulsion fluid of 13 of the patients, and no expulsion, including semen, was seen from the prostatic utricle opening. CONCLUSION: Anatomically, the ejaculatory duct openings of males are located at the two sides of the verumontanum adjacent to the opening of the prostatic utricle, rather than in the prostatic utricle above the verumontanum.

[Oral tadalafil on alternate days for erectile dysfunction that fails to respond to on-demand sildenafil: a report of 15 cases].

OBJECTIVE: To sum up the experience in administering oral tadalafil on alternate days for the treatment of erectile dysfunction (ED) that fails to respond to on-demand medication. METHODS: We retrospectively analyzed the clinical data of 15 cases of ED treated with oral tadalafil on alternate days from September 2010 to March 2012. All the patients had failed to respond to on-demand medication of sildenafil previously. RESULTS: After 4 weeks of tadalafil treatment, 11 (73.3%) of the cases were remarkably improved, with significant difference in IIEF-5 scores before and after treatment (P < 0.05). Transient adverse reactions were observed in the other 4 cases, including mild headache in 2, slight backache in 1, and facial flush in 1. CONCLUSION: Oral tadalafil on alternate days is safe and effective in the treatment of ED that fails to respond to on-demand medication of sildenafil.

[Impact of male infertility on men's self-esteem and satisfaction with sexual relationship].

OBJECTIVE: To investigate the impact of infertility on men's self-esteem, self-confidence, sexual satisfaction and overall relationship with their spouses. METHODS: Using Self-Esteem and Relationship questionnaire (SEAR), we conducted an investigation among 253 infertile men and 52 fertile male controls. We divided the infertile men into four subgroups according to their perceived causes of infertility: male (M) factors, female (F) factors, both M and F factors, and unknown factors, and compared the SEAR scores among different groups. RESULTS: In the infertile men, the total SEAR score was significantly higher in those with < 3 years than in those with > or = 3 years of infertility duration (75.50 +/- 17.05 vs 68.66 +/- 17.19, P < 0.05) and so was it in those with above-high-school than in those with high-school or lower education background (81.42 +/- 13.99 vs 67.61 +/- 17. 8, P < 0.01), but showed no significant difference between the > or = 30- and < 30-year-olds (71.77 +/- 17.42 vs 72.74 +/- 18.38, P > 0.05). The total SEAR scores in the M factor, M & F factor, unknown factor and F factor groups were 65.69 +/- 18.68, 68.52 +/- 17.68, 74.85 +/- 15.19 and 83.21 +/- 12.61, respectively, with significant differences between the first two and the latter two groups (P < 0.05), as well as between the unknown factor and F factor groups (P < 0.05). In the fertile male controls, the total SEAR score and subdomain scores on sexual relationship, self-confidence, self-esteem and overall relationship were 90.04 +/- 9.85, 88.40 +/- 10.74, 92.23 +/- 9.41, 91.95 +/- 10.67 and 90.38 +/- 14.14, respectively, all remarkably higher than in the M factor, M&F factor and unknown factor groups of the infertile men after adjustment of their infertility duration and education levels (P < 0.05). CONCLUSION: Infertility reduces men's self-esteem, self-confidence, sexual satisfaction and relationship with their spouses, and the degree of its impact is correlated with the patients' infertility duration and education level.

[Impact of perceived male infertility factors on penile erectile function].

OBJECTIVE: To evaluate the impact of the factors of perceived male infertility on men's penile erectile function. METHODS: Using the 5-item version of the International Index of Erectile Function (IIEF-5), we investigated the penile erectile function among 245 infertile men (infertility group) and another 52 males having physical checkup for planned conception (checkup group), the former further divided into four subgroups according to the factors of infertility: male factor, female factor, bilateral factor, and unknown factor. We compared the total and item scores of IIEF-5 among different groups. RESULTS: Mild or mild-moderate ED was found in 50.61% of the infertile men, with a total IIEF-5 score of 21.24 +/- 2.58. The total and item scores of IIEF-5 were markedly higher in the male factor than in the female factor subgroup (P < 0.01), but with no significant difference between the male factor subgroup and the bilateral and unknown factor subgroups (P > 0.05), except the score on confidence. The scores were significantly lower in the bilateral and unknown factor subgroups than in the female factor subgroup (P < 0.05), with no remarkable difference between the former two. In the infertility group, the total and item scores of IIEF-5 were markedly higher in those with education above high school than in those with high school or lower education (P < 0.01), but not correlated with age and infertility duration. After adjustment for education background, the total IIEF-5 score and the scores on confidence and satisfaction were significantly lower in the infertility than in the checkup group (P < 0.05), and 15.38% of the men in the latter group had mild ED, dramatically lower than in the former (P < 0.01). CONCLUSION: Perceived infertility may cause ED in males, and a higher incidence rate is associated with lower education background of the men.

[Detection of the mutation of all the exons of the CFTR gene in Chinese men with congenital bilateral absence of the vas deferens].

OBJECTIVE: To assess the necessity of detecting the gene of cystic fibrosis transmembrane conductance regulator factor (CFTR) in Chinese men with congenital bilateral absence of the vas deferens (CBAVD). METHODS: We detected the mutation of all the 27 exons of the CFTR gene in 9 patients with CBAVD by DNA sequencing, and compared the results using NCBI and Cystic Fibrosis Mutation Database. RESULTS: Four novel missense mutations/variants were found in the CFTR gene of the CBAVD patients, which were submitted and accepted in the Cystic Fibrosis Mutation Database. CONCLUSION: There are mutations or variants in the CFTR gene in Chinese men with CBAVD, and the mutational distribution is different from that in Westerners.