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.

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.

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.

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.

[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.