Wojciech Sobala

Human urinary phthalate metabolites level and main semen parameters, sperm chromatin structure, sperm aneuploidy and reproductive hormones

The aim of the study was to assess the association of phthalate metabolites levels in urine with semen parameters (sperm concentration, motility, morphology, CASA parameters), sperm chromatin structure, sperm aneuploidy and reproductive hormones. The study population consisted of 269 men who were attending an infertility clinic and had normal semen concentration (20-300mln/ml) or slight oligozoospermia (15-20mln/ml). Participants were interviewed and provided a semen sample. The phthalate metabolites were analysed in the urine using a procedure based on the LC-MS/MS method. Urinary phthalate metabolites levels were significantly associated with a decrease in sperm motility (5OH MEHP, MEHP, MINP), CASA parameters (MBP), testosterone level (MEHP) and an increase sperm DNA damage (MBP) and sperm aneuploidy (MBzP, MBP, MEHP, MEP). In view of the importance of human reproductive health and the widespread usage of phthalates, it is important to further investigate these correlations.

Lifestyle and semen quality: role of modifiable risk factors

Abstract The relationship between exposure to lifestyle factors and adverse effects on human reproductive health is debated in the scientific literature and these controversies have increased public and regulatory attention. The aim of the study was to examine the association between modifiable lifestyle factors and main semen parameters, sperm morphology, and sperm chromatin structure. The study population consisted of 344 men who were attending an infertility clinic for diagnostic purposes with normal semen concentration of 20–300 M/ml or with slight oligozoospermia (semen total concentration of 15–20 M/ml) [WHO 1999]. Participants were interviewed and provided semen samples. The interview included questions about demographics, socio-economic status, medical history, lifestyle factors (consumption of alcohol, tobacco, coffee intake, cell phone and sauna usage), and physical activity. The results of the study suggest that lifestyle factors may affect semen quality. A negative association was found between increased body mass index (BMI) and semen volume (p = 0.03). Leisure time activity was positively associated with sperm concentration (p = 0.04) and coffee drinking with the percentage of motile sperm cells, and the percentage of sperm head and neck abnormalities (p = 0.01, p = 0.05, and p = 0.03, respectively). Drinking red wine 1–3 times per week was negatively related to sperm neck abnormalities (p = 0.01). Additionally, using a cell phone more than 10 years decreased the percentage of motile sperm cells (p = 0.02). Men who wore boxer shorts had a lower percentage of sperm neck abnormalities (p = 0.002) and percentage of sperm with DNA damage (p = 0.02). These findings may have important implications for semen quality and lifestyle.

Phthalate exposure and child development: the Polish Mother and Child Cohort Study.

BACKGROUND Widespread phthalate exposure has prompted investigations concerning their potential adverse health effects. AIM The objective of this study was to evaluate the impact of pre and early postnatal phthalate exposure on child psychomotor development based on the data from the prospective Polish Mother and Child Cohort Study (REPRO PL). STUDY DESIGN, SUBJECTS AND OUTCOME MEASURES Phthalate exposure was determined by measuring 11 phthalate metabolites (MEP, MiBP, MnBP, 3OH-MnBP, MBzP, MEHP, 5OH-MEHP, 5oxo-MEHP, OH-MiNP, oxo-MiNP, and MnOP) in the urine collected from mothers during the third trimester of pregnancy (prenatal exposure) and from their children at the 24th month of age (postnatal exposure). The analysis was performed by the HPLC-MS/MS method. Psychomotor development was assessed in children at the age of 2years by the Bayley Scales of Infant and Toddler Development. RESULTS Child motor development was inversely associated with natural log concentrations (μg/g creatinine) of 3OH-MnBP (β= -2.3; 95% CI -4.0 to -0.6), 5OH-MEHP (β= -1.2; 95% CI -2.2 to -0.3), 5oxo-MEHP (β= -1.8; 95% CI -3.3 to -0.2) and sum of DEHP metabolites (β= -2.2; 95% CI -3.6 to -0.8), DnBP metabolites (β= -1.9; 95% CI -3.4 to -0.4), and high molecular weight phthalates (β= -2.5; 95% CI -4.1 to -0.9) in the urine collected from mothers during pregnancy after adjustment for a variety of potential confounders. Additional adjustment for postnatal phthalate exposure did not change the results. Postnatal child exposure to phthalates was not associated with any of the measured scores of child psychomotor development. CONCLUSIONS The study findings add further support to the possibility that prenatal phthalate exposure may be detrimental to child neurodevelopment and underscore the importance of policies and public health interventions aiming at reduction of such exposure.

Association of Rotating Night Shift Work with BMI and Abdominal Obesity among Nurses and Midwives.

Background Mounting epidemiological evidence suggests that night shift work may contribute to the etiology of increased body weight. The present study aimed to examine association between rotating night shift work and body mass index (BMI), and abdominal adiposity respectively among nurses and midwives. Methods A cross-sectional study was conducted among 724 female nurses and midwives, aged 40-60 years (354 rotating night shift and 370 daytime workers) in Łódź, Poland, between 2008 and 2011. Information about occupational history and potential confounders was collected during personal interviews. Anthropometric measurements of body weight, height, waist (WC) and hip (HC) circumference were made, and body mass index (BMI), waist to hip ratio (WHR) and waist to height ratio (WHtR) were calculated. GLM regression models and multinomial logit regression models were fitted to explore the association between night shift work and anthropometric parameters, with adjustment for age, body silhouette at age 20, current smoking status, packyears, marital status, and menopausal hormone therapy use. Results Cumulative night shift work showed significant associations with BMI, WC, HC and WHtR, with BMI increasing by 0.477 kg/m2 per 1000 night duties and by 0.432 kg/m2 per 10000 night shift hours, WC increasing respectively by 1.089 cm and 0.99 cm, and HC by 0.72 cm and WHtR by 0.007 cm for both metrics. Both current and cumulative night work was associated with obesity (BMI≥30kg/m2), with OR=3.9 (95%CI:1.5-9.9), in women reporting eight or more night shifts per month. Conclusion The results of the study support the previously reported relations between night shift work and development of obesity.

Decreased proinflammatory cytokines in cervicovaginal fluid, as measured in midgestation, are associated with preterm delivery.

The main aim of this study was to investigate the relationship between selected proinflammatory cytokines [interleukin IL‐1 alpha (IL‐1α), IL‐1 beta (IL‐1β), IL‐6 and IL‐8] concentrations in cervicovaginal fluid, as measured in midgestation, and the risk of subsequent preterm delivery.

Polish mother and child cohort study — defining the problem, the aim of the study and methodological assumptions

OBJECTIVES Exposures during prenatal period have implications for pregnancy outcome as well as for childrens health, morbidity and mortality. Prospective cohort study design allows for the identification of exposures that may influence pregnancy outcome and childrens health, verification of such exposures by biomarker measurements and notification of any changes in exposure level. MATERIALS AND METHODS Polish Mother and Child Cohort Study (REPRO_PL) is multicenter prospective cohort study conducted in 8 different regions of Poland. The final cohort is intended to comprise 1300 mother-child pairs to be recruited within 4-year period (2007-2011). The recruitment and all scheduled visits are conducted in maternity units or clinics in the districts included in the study. The women are followed-up 3 times in pregnancy (once in each trimester) and after delivery for the notification of pregnancy outcome. During each visit, detailed questionnaire and biological samples are collected including saliva, urine, hair, maternal blood and cord blood. About 6 weeks postpartum, breast milk from part of the women is collected. The study concentrates on the identification and evaluation of the effects of prenatal environmental exposure on pregnancy outcome and childrens health. Specific research hypotheses refer to the role of heavy metals, exposure to polycyclic aromatic hydrocarbons (PAHs) and environmental tobacco smoke (ETS) in the aetiology of small-for-gestational-age (SGA) and preterm delivery (PD). The role of oxidative stress putative mechanism and pregnant women nutritional status will be investigated. Based on questionnaire data, the impact of occupational exposures and stressful situations will be evaluated. RESULTS The results of the study will become available within the next few years and will help to determine levels of child prenatal exposure in several areas of Poland and its impact on course and outcome of pregnancy.

Night shift work characteristics and 6-sulfatoxymelatonin (MT6s) in rotating night shift nurses and midwives

Objectives Synthesis of melatonin follows a circadian cycle, with high melatonin levels during the night and low levels during the day. Light exposure at night has been hypothesised as one of potential mechanisms of breast carcinogenesis in the night shift workers through inhibition of melatonin synthesis. The aim of the study was to examine a number of determinants for night shift work in relation to 6-sulfatoxymelatonin (MT6s), primary melatonin metabolite. Methods The cross-sectional study included 354 nurses and midwives (aged 40–60 years) currently working on rotating night shifts and 370 working days only. Data from questionnaires and 1-week diaries were used to characterise current job and total occupational history. Associations between rotating night shift work characteristics and MT6s (creatinine adjusted) in spot morning urine were tested in multiple linear regression models. Results No significant differences were found for MT6s concentrations between women currently working on rotating night shifts and those working only day shifts (means 47.2 vs 45.7 ng/mg Cr, respectively). The adjusted means among rotating night shift nurses and midwives varied depending on the department of employment, from 35.1 ng/mg Cr in neonatology to 68.2 ng/mg Cr in the orthopaedics department. Women working eight or more night shifts per month had significantly lower MT6s levels than those having fewer night shifts per month (37.9 vs 47.4 ng/mg Cr, respectively). Total night shift work history was not associated with MT6s. Conclusions The results of this study indicate that working eight or more night shifts per month may disrupt the synthesis of melatonin.

Heavy physical work during pregnancy — a risk factor for small‐for‐gestational‐age babies in Poland

BACKGROUND Heavy physical work is still considered one of the most prevalent risk factors of negative pregnancy outcome. The present study was undertaken to evaluate the impact of heavy physical work during pregnancy, based on subjective assessment of workload, on the risk of delivering a small-for-gestational-age (SGA) baby. METHODS Job characteristics were compiled for 1,064 working women from the Lódź region (8% population sample) based on questionnaire responses. Energy expenditure during daily work was estimated. SGA was diagnosed when the birth weight was below the 10th percentile of the standard curves for central Poland. The SGA group comprised 78 women who delivered SGA babies, while the non-SGA group consisted of 986 women with eutrophic newborns. RESULTS An excessive risk of SGA was found in the group reporting heavy physical effort at work. The physical effort perceived as heavy by pregnant women appeared to be a better predictor of SGA manifestation than the estimated energy expenditure at work. CONCLUSIONS The information obtained from a pregnant worker should constitute an essential decisive factor for determining the time of work cessation during pregnancy.

Exposure to inhalable dust and its cyclohexane soluble fraction since the 1970s in the rubber manufacturing industry in the European Union

Objectives: As exposures to airborne particulates in the European rubber industry might still be causing genotoxic risks, it is important to assess trends in levels of inhalable dust and its cyclohexane soluble fraction (CSF) between the 1970s and 2003. Methods: 13 380 inhalable and 816 respirable dust and 5657 CSF measurements, collected within the framework of the European Union Concerted Action EXASRUB, were analysed. Hierarchical mixed effects models were applied to assess exposure trends, taking into account between-factory, between-worker/location and day-to-day variances. Results: Geometric mean levels of inhalable dust and CSF exposure changed by −4 (range −5.8 to +2.9) and −3 (range −8.6 to 0) per year, respectively. Significant reductions in inhalable dust concentrations were found in all countries for handling of crude materials and mixing and milling (−7 to −4 per year), as well as for miscellaneous workers (−11 to −5 per year), while significant CSF exposure reductions were found in curing (−8.6 per year) and maintenance and engineering departments (−5.4 per year). Conclusion: These analyses suggest that on average exposure levels of inhalable dust and its CSF in the European rubber manufacturing industry have steadily declined. Most likely genotoxic risks have also lessened over time since exposure levels have decreased and the most toxic chemicals have been replaced. In addition to differences in exposure reductions and levels among various stages of the production process, large differences across countries were noted. These patterns should be taken into account in retrospective assessment of exposure for epidemiological studies assessing cancer risk in the rubber industry.

Exposure to ambient air pollution-does it affect semen quality and the level of reproductive hormones?

Abstract Background: Ambient air pollution has been associated with a variety of reproductive disorders. However, a limited amount of research has been conducted to examine the association between air pollution and male reproductive outcomes, specifically semen quality. Aim: The present study was designed to address the hypothesis that exposure to fluctuating levels of specific air pollutants adversely affects sperm parameters and the level of reproductive hormones. Subjects and methods: The study population consisted of 327 men who were attending an infertility clinic in Łodź, Poland for diagnostic purposes and who had normal semen concentration of 15–300 mln/ml. All participants were interviewed and provided a semen sample. Air quality data were obtained from AirBase database. Results: The statistically significant association was observed between abnormalities in sperm morphology and exposure to all examined air pollutants (PM10, PM2.5, SO2, NOX, CO). Exposure to air pollutants (PM10, PM2.5, CO, NOx) was also negatively associated with the level of testosterone. Additional exposure to PM2.5, PM10 increase the percentage of cells with immature chromatin (HDS). Conclusions: The present study provides suggestive evidence of an association between ambient air pollution and sperm quality. Further research is needed to explore this association in more detail. Individual precise exposure assessment would be needed for more detailed risk characterization.