Alberto M. Torres-Cantero

Food intake and its relationship with semen quality: a case-control study

OBJECTIVE To compare dietary habits in normospermic and oligoasthenoteratospermic patients attending a reproductive assisted clinic. DESIGN An observational, analytical case-control study. SETTING Private fertility clinics. PATIENT(S) Thirty men with poor semen quality (cases) and 31 normospermic control couples attending our fertility clinics. INTERVENTION(S) We recorded dietary habits and food consumption using a food frequency questionnaire adapted to meet specific study objectives. Analysis of semen parameters, hormone levels, Y microdeletions, and karyotypes were also carried out. MAIN OUTCOME MEASURE(S) Frequency of intake food items were registered in a scale with nine categories ranging from no consumption to repeated daily consumption. RESULT(S) Controls had a higher intake of skimmed milk, shellfish, tomatoes, and lettuce, and cases consumed more yogurt, meat products, and potatoes. In the logistic regression model cases had lower intake of lettuce and tomatoes, fruits (apricots and peaches), and significantly higher intake of dairy and meat processed products. CONCLUSION(S) Frequent intake of lipophilic foods like meat products or milk may negatively affect semen quality in humans, whereas some fruits or vegetables may maintain or improve semen quality.

A low intake of antioxidant nutrients is associated with poor semen quality in patients attending fertility clinics

OBJECTIVE To compare specific nutrient intake between normospermic and oligoasthenoteratospermic patients attending infertility clinics in two Mediterranean provinces of Spain. DESIGN Case-control study. SETTING Private fertility clinics in southeastern Spain. PATIENT(S) Thirty men with poor semen quality (case subjects) and 31 normospermic control subjects of couples attending our fertility clinics. INTERVENTION(S) We recorded dietary habits and nutrient consumption using a food frequency questionnaire adapted to meet specific study objectives. MAIN OUTCOME MEASURE(S) We calculated nutrient intakes by multiplying the frequency of use for each food by the nutrient composition of the portion size specified on the food frequency questionnaire and by addition across all foods to obtain a total nutrient intake for each individual. Semen quality was assessed by measuring volume, concentration, motility, and morphology. Hormones levels were also analyzed in case and control subjects. RESULT(S) In the logistic regression, control subjects had a significantly higher intake of carbohydrates, fiber, folate, vitamin C, and lycopene and lower intakes of proteins and total fat. CONCLUSION(S) A low intake of antioxidant nutrients was associated with a poor semen quality in this case-control study of Spanish men attending infertility clinics.

Relationships between heavy metal concentrations in three different body fluids and male reproductive parameters: a pilot study

BackgroundAnimal studies have shown the reproductive toxicity of a number of heavy metals. Very few human observational studies have analyzed the relationship between male reproductive function and heavy metal concentrations in diverse biological fluids.MethodsThe current study assessed the associations between seminal and hormonal parameters and the concentration of the 3 most frequent heavy metal toxicants (lead, cadmium and mercury) in three different body fluids. Sixty one men attending infertility clinics that participated in a case-control study to explore the role of environmental toxins and lifestyles on male infertility were analyzed. Concentration of lead, cadmium and mercury were measured in blood and seminal plasma and whole blood using anodic stripping voltammetry and atomic absorption spectrophotometry. Serum samples were analyzed for follicle-stimulating hormone, luteinizing hormone and testosterone. Semen analyses were performed according to World Health Organization criteria. Mann-Whitney test and Spearmans rank correlations were used for unadjusted analyses. Multiple linear regression models were performed controlling for age, body mass index and number of cigarettes per day.ResultsThere were no significant differences between cases and controls in the concentrations of heavy metals in any of the three body fluids. In multivariate analyses using all subjects no significant associations were found between serum hormone levels and metal concentrations. However there was a significant positive association between the percentage of immotile sperms and seminal plasma levels of lead and cadmium.ConclusionsOur results suggest that the presence of lead and cadmium in the reproductive tract of men may be related to a moderate alteration of their seminal parameters.

Anogenital distance is related to ovarian follicular number in young Spanish women: a cross-sectional study.

BackgroundIn animals, anogenital distance (AGD) at birth reflects androgen levels during pregnancy and predicts adult AGD. Little is known about AGD in relation to female reproductive characteristics in humans, a question this study was designed to explore.MethodsWe used multiple linear and logistic regression analyses to model the relationships between adult female reproductive system characteristics (e.g. ovarian morphology, menstrual cycle) and two measures of AGD [anus-fourchette (AGDAF) and anus-clitoris (AGDAC)] in 100 college-age volunteers in Spain. Ovarian morphology was classified as having < 6 or ≥ 6 follicles per ovary.ResultsBoth AGD measures were positively associated with ovarian follicle number, with AGDAF being more strongly associated. Women in the upper tertile of the AGDAF and AGDAC distributions were more likely to have ≥ 6 ovarian follicles [OR: 6.0 (95% CI 2.0, 17.6) and 3.0 (95% CI 1.1, 8.6), respectively] compared to women in the lowest tertile.ConclusionsIncreased follicular recruitment has been related to excess androgen exposure in utero in toxicological studies. Our results suggest that the androgenic environment during early fetal life may influence reproductive system development, including AGD, in human females.

Sperm counts may have declined in young university students in Southern Spain

Several studies have investigated temporal trends in semen quality in Northern Europe, but none has examined this question in Southern Europe. A prior study conducted in Almeria Province (Southern Spain) reported higher sperm count and concentration among Spanish young men recruited from 2001 to 2002 compared with young men from Northern Europe. The aim of this new study was to examine whether semen quality has changed among Spanish young men in the last decade. In this cross‐sectional study, questionnaires and semen samples were collected from 215 healthy young university students from Murcia Region between 2010 and 2011. The 273 men from the Almeria study previously studied were included in a trend analysis of the two populations from Southern Spain. Descriptive statistics were calculated for the Murcia study population and these and semen variables for the Murcia and Almeria study populations were compared. Study methods and population characteristics were similar across the two studies. Therefore, we used multiple linear regression analyses on the combined population (controlling for study centre, age, ejaculation abstinence time, season, smoking, medication during the last 3 months, Body mass index (BMI), presence of varicocoele and prenatal exposure to tobacco) to look for a birth‐cohort effect over the combined study period (2001–2011). Sperm concentration and total sperm count declined significantly with year of birth in the pooled analysis (β = −0.04 and β = −0.06, respectively, both p < 0.01). Sperm counts were significantly lower in Murcia study subjects than in the Almeria participants; sperm concentration median (5th–95th) = 44.0 (8.9–129) million/mL vs. 51.0 (5.0–206) million/mL; p < 0.01 and total sperm count = 121 (17.8–400) million vs. 149 (8.0–599) million; p < 0.01. Other semen variables did not differ significantly between the two studies. Our study suggests that total sperm count and sperm concentration may have declined in young Spanish men over the last decade.

Dietary intake of antioxidant nutrients is associated with semen quality in young university students

STUDY QUESTION What are the associations between the dietary intake of antioxidant nutrients and semen parameters in young men? SUMMARY ANSWER Our study suggests that some sperm parameters are sensitive to dietary intake of antioxidant nutrients. WHAT IS KNOWN ALREADY A few reports have suggested that some dietary factors might be related to semen quality. However, the relationship between the intake of antioxidant nutrients and semen quality in young men remains unexplored. STUDY DESIGN, SIZE, DURATION In this cross-sectional study, 215 young men were included between October 2010 and November 2011. PARTICIPANTS/MATERIALS, SETTING, METHODS Healthy university students with complete dietary and semen quality data were analyzed. Dietary intake was recorded using a validated food frequency questionnaire. The associations between the energy-adjusted nutrient intake of antioxidants in quartiles and the semen volume, sperm concentration, sperm motility, sperm morphology, total sperm count and total motile sperm count were assessed using multivariate linear regression. MAIN RESULTS AND THE ROLE OF CHANCE Out of 240 students who contacted us, 223 (92.9%) were eligible to participate in this study, and 215 attended the clinical appointment. In the multivariate adjusted linear regression models, there was a positive association between dietary intakes of cryptoxanthin (P(trend) = 0.03), vitamin C (P(trend) = 0.04), lycopene (P(trend) = 0.03) and β-carotene (P(trend) = 0.04) and total motile sperm count. The semen volume increased with higher intakes of vitamin C (P(trend) = 0.04). LIMITATIONS, REASONS FOR CAUTION Only one sample of semen was taken for each subject. However, there are indications that one semen sample may be sufficient to characterize the semen quality of the individuals in epidemiological studies. Bias due to measurement errors may also occur since there is no perfect method to assess diet. However, any bias due to measurement error would be non-differential and would reduce, not increase, the strength of the associations. Although selection bias in cross-sectional studies might not always be ruled out, our subjects were university student volunteers who were rewarded for their participation and the study was not advertised as a fertility study. WIDER IMPLICATIONS OF THE FINDINGS Previous articles in this area have focused mainly on men attending fertility clinics, thus our study brings generalizability to young men of the general population with unknown or untested fertility. Some of our results are in agreement with the previously reported papers.

Trans fatty acid intake is inversely related to total sperm count in young healthy men

STUDY QUESTION Is intake of fatty acids related to semen quality among young men? SUMMARY ANSWER The intake of trans fatty acids is inversely related to total sperm count in healthy young men. WHAT IS KNOWN ALREADY Spain has seen an increase in the proportion of calories consumed as fat over the same period that a downward trend in semen quality has been observed. In addition, rodent models suggest that trans fat intake may severely affect testicular function. STUDY DESIGN, SIZE, DURATION Cross-sectional study of 209 men recruited between October 2010 and November 2011. PARTICIPANTS/MATERIALS, SETTING, METHODS A group of 209 healthy young university students 18-23 years of age provided a semen sample and completed a previously validated food frequency questionnaire. The association between intake of fatty acids with semen quality parameters (sperm concentration, motility, morphology and total count) was assessed using multivariate linear regression. MAIN RESULTS AND THE ROLE OF THE CHANCE Trans fatty acid intake was inversely related to total sperm count after adjusting for potential confounders (P, trend = 0.03). The multivariate adjusted mean (95% confidence interval) total sperm count in increasing quartiles of trans fat intake was 144 (110-190), 113 (87-148), 100 (18-130) and 89 (69-117). There also was an inverse association between cholesterol intake and ejaculate volume (P, trend = 0.04). No other statistically significant relations were observed. LIMITATIONS, REASONS FOR CAUTION The cross-sectional design of the study limits causal inference, we cannot exclude the possibility of unmeasured confounding and there was insufficient statistical power to identify modest associations. WIDER IMPLICATIONS OF THE FINDINGS The results of this study, together with previous experimental work in rodents and biomarker studies among infertility patients, suggest that intake of trans fatty acids may be related to lower semen quality. Although the data provide further evidence that diet is a modifiable factor that could impact male fertility, it is not known whether the observed differences in sperm count translate into differences in fertility. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by The Seneca Foundation, Regional Agency of Science and Technology, grant no 00694/PI/04, Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III (FIS), grant no PI10/00985, and grant P30 DK46200 from the National Institutes of Health. The authors have no competing interests to declare.

Longer anogenital distance is associated with higher testosterone levels in women: a cross‐sectional study

Animal models have suggested that anogenital distance (AGD) at birth reflects androgen levels during in utero development and predicts adult AGD. A recent study showed an association between perineal length and androgen levels in men, suggesting that serum testosterone levels in adulthood will depend on factors involved during the fetal period. The aim of this study is to assess the relationship between AGD measures and reproductive hormone levels in women.

Exposure to environmental toxins in males seeking infertility treatment: a case-controlled study

This case-control study explored the role of environmental toxins in male infertility in patients attending an assisted reproduction clinic in southeastern Spain. Exposures were compared by questionnaire for 30 infertile oligoasthenoteratozoospermic males (cases) and 31 normozoospermic controls residing in the area. Odds ratios and 95% confidence intervals (CI) were used to estimate differences in lifestyle and chemical occupational exposures. More than two-thirds of the cases (23/30), compared with less than one-third of controls (10/31), had been exposed occupationally to at least one toxin or pollutant (OR = 6.9; 95% CI: 2.2-21.4) and were also more exposed to them currently (OR = 5.2; 95% CI: 1.6-17.2). Exposure to glues, solvents or silicones (OR = 22.9; 95% CI: 2.8-190.9), metals (OR = 8.8; 95% CI: 1.4-54.2) and physical agents (OR = 7.3; 95% CI: 1.4-36.7) in the past, as well as current exposure to glues, solvents or silicones (OR = 10.4; 95% CI: 2.6-42.5) and physical agents (OR = 4.7; 95% CI: 1.1-19.2), were significantly higher in cases than in controls. Average duration of exposure was also significantly higher in cases (P < 0.001). This study suggests that male infertility in patients attending infertility clinics may often be the result of occupational exposure.

Full breastfeeding and paediatric cancer

Aim:  It has been suggested that there is an inverse association between breastfeeding and the risk of childhood cancer. We investigated the association between full breastfeeding and paediatric cancer (PC) in a case control study in Spain.