Paweł Kałużny

Estimation of saliva cotinine cut-off points for active and passive smoking during pregnancy—polish mother and child cohort (REPRO_PL)

A reliable assessment of smoking status has significant public health implications and is essential for research purposes. The aim of this study was to determine optimal saliva cotinine cut-off values for smoking during pregnancy. The analyses were based on data from 1771 women from the Polish Mother and Child Cohort. Saliva cotinine concentrations were assessed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-ESI + MS/MS). The saliva cotinine cut-off value for active smoking was established at 10 ng/mL (sensitivity 96%, specificity 95%) and for passive smoking at 1.5 ng/mL (sensitivity 63%, specificity 71%). About 5% of the self-reported non-smoking women were classified as smokers based on the cotinine cut-off value. Significantly more younger, single, and less educated self-reported non-smokers had a cotinine concentration higher than 10 ng/mL compared to those who were older, married, and who had a university degree. Close to 30% of the non-smokers who indicated that smoking was not allowed in their home could be classified as exposed to passive smoking based on the cut-off value. The study suggests that self-reported smoking status is a valid measure of active smoking, whereas in the case of passive smoking, a combination of questionnaire data and biomarker verification may be required.

Circadian gene methylation in rotating-shift nurses: a cross-sectional study

ABSTRACT Investigating the methylation status of the circadian genes may contribute to a better understanding of the shift work-related circadian disruption in individuals exposed to artificial light at night. In the present study, we determined the methylation status of the circadian genes associated with a shift work pattern among nurses and midwives participating in a cross-sectional study in Lodz, Poland. Quantitative methylation polymerase chain reaction assays were used to assess promoter CpG methylation in PER1, PER2, PER3, CRY1, CRY2, BMAL1, CLOCK, and NPAS2 in genomic DNA from whole blood of 347 women having a rotating-shift work schedule and 363 women working days only. The percentage of methylated reference (PMR) was assessed using fluorescent probes for PER1, PER2, PER3, CRY1, and NPAS2, and the percentage of gene methylation, as the methylation index (MI), using two sets of primers for BMAL1, CLOCK, and CRY2. We tested the possible association between current and lifetime rotating night-shift work characteristics and circadian gene methylation by using proportional odds regression model with blood DNA methylation, categorized into tertiles, and adjusted for age, current smoking status, folate intake and blood collection time. The findings indicated that CpG methylation in PER2 promoter was significantly decreased (P < 0.004) among nurses and midwives currently working rotating shifts, as compared with day-working nurses and midwives. The lower percentage of PER2 methylation was associated with a higher monthly frequency of current night duties (2–7 night shifts, and eight or more night shifts per month) (P = 0.012) and was associated at borderline significance (P = 0.092) with the lifetime duration of shift work (>10 ≤ 20 years and >20 ≤ 43 years of rotating-shift work) among nurses and midwives (N = 710). Moreover, women with a longer lifetime duration of shift work presented a lower status of PER1 methylation (P = 0.040) than did the women with up to 10 years of rotating-shift work. Long lifetime duration of shift work (> 10 years) among current rotating night-shift workers (N = 347) was associated with BMAL1 hypomethylation (P = 0.013). Among eight of the investigated circadian genes, only PER1, PER2, and BMAL1 showed differential methylation attributable to the rotating-shift work of nurses and midwives. The findings on blood-based DNA methylation in the circadian genes may provide a better insight into the mechanistic principles underlying the possible health effects of night-shift work but these should be verified in further studies recruiting larger populations of shift workers.

Human Semen Quality, Sperm Dna Damage, and the Level of Reproductive Hormones in Relation to Urinary Concentrations of Parabens

Objective: The aim of this study was to evaluate the association between environmental exposure to parabens and semen quality parameters [main semen parameters, computer-aided semen analysis (CASA parameters], sperm chromatin structure, and the level of reproductive hormones in men [follicle-stimulating hormone (FSH), testosterone, estradiol]. Methods: Urine samples collected from 315 men who attended the infertility clinic for diagnostic purposes with normal semen concentration of 15 to 300 mln/mL were analyzed for five parabens concentrations using a validated gas chromatography ion-tap mass spectrometry method. Participants were interviewed and also provided a semen, saliva, and blood samples. Results: Urinary parabens concentrations were significantly associated with an increase in the percentage of sperm with abnormal morphology, in sperm with high DNA stainability and a decrease in the percentage of motility and testosterone level. Conclusions: This is one of the first study on this topic, so the observation of the relationship between parabens and semen quality warrants further investigation.

Environmental exposure to parabens and sperm chromosome disomy

Abstract Parabens are widely used as antimicrobial preservatives in cosmetics, pharmaceuticals, food and beverage processing due to their board spectrum of activity, inertness, and low cost. The study population consisted of 156 men under 45 years of age who attended the infertility clinic for diagnostic purposes with normal semen concentration of 15–300 mln/ml. Participants were interviewed and provided a semen sample. The parabens concentrations: ethyl paraben (EP), butyl paraben (BP), methyl paraben (MP), and iso-butyl paraben (iBuP) were analyzed in the urine using a validated gas chromatography ion-tap mass spectrometry method. The positive association was found between urinary level of BP and XY18 disomy (p = 0.045) and PP and disomy of chromosome 13 (p = 0.007). This is the first study to examine these relationships, and replication of our findings is needed before the association between parabens concentration in urine and aneuploidy can be fully defined. These findings may be of concern due to increased parabens use.

Sleep quality and methylation status of core circadian rhythm genes among nurses and midwives

ABSTARCT Poor sleep quality or sleep restriction is associated with sleepiness and concentration problems. Moreover, chronic sleep restriction may affect metabolism, hormone secretion patterns and inflammatory responses. Limited recent reports suggest a potential link between sleep deprivation and epigenetic effects such as changes in DNA methylation profiles. The aim of the present study was to assess the potential association between poor sleep quality or sleep duration and the levels of 5-methylcytosine in the promoter regions of PER1, PER2, PER3, BMAL1, CLOCK, CRY1 CRY2 and NPAS2 genes, taking into account rotating night work and chronotype as potential confounders or modifiers. A cross-sectional study was conducted on 710 nurses and midwives (347 working on rotating nights and 363 working only during the day) aged 40–60 years. Data from in-person interviews about sleep quality, chronotype and potential confounders were used. Sleep quality and chronotype were assessed using Pittsburgh Sleep Quality Questionnaire (PSQI) and Morningness–Eveningness Questionnaire (MEQ), respectively. Morning blood samples were collected. The methylation status of the circadian rhythm genes was determined via quantitative methylation-specific real-time PCR assays (qMSP) reactions using DNA samples derived from leucocytes. The proportional odds regression model was fitted to quantify the relationship between methylation index (MI) as the dependent variable and sleep quality or sleep duration as the explanatory variable. Analyses were carried out for the total population as well as for subgroups of women stratified by the current system of work (rotating night shift/day work) and chronotype (morning type/intermediate type/evening type). A potential modifying effect of the system of work or the chronotype was examined using the likelihood ratio test. No significant findings were observed in the total study population. Subgroup analyses revealed two statistically significant associations between a shorter sleep duration and 1) methylation level in PER2 among day workers, especially those with the morning chronotype (OR = 2.31, 95%CI:1.24–4.33), and 2) methylation level in CRY2 among subjects with the intermediate chronotype, particularly among day workers (OR = 0.52, 95%CI:0.28–0.96). The study results demonstrated a positive association between average sleep duration of less than 6 hours and the methylation level of PER2 among morning chronotype subjects, and an inverse association for CRY2 among intermediate chronotype subjects, but only among day workers. Both the system of work and the chronotype turned out to be important confounders and modifiers in a number of analyses, making it necessary to consider them as potential covariates in future research on sleep deficiency outcomes. Further studies are warranted to explore this under-investigated topic.

Is it possible to improve compliance in hypertension and reduce therapeutic inertia of physicians by mandatory periodical examinations of workers

BACKGROUND Due to high prevalence, insufficient recognition, and ineffective treatment, hypertension (HT) still remains a major medical and socio-economic problem. There is a real necessity to develop effective prophylaxis for cardiovascular disorders (CVD), based on strategies that support compliance during long-term therapy. The Polish scheme of occupational health services with mandatory periodical employee check-ups creates a unique opportunity for effective HT prophylaxis. As a result, visiting a doctor is required not only due to health ailments but also by law, which is especially important for those feeling well. It enables an improvement in tertiary prevention, including actions taken not only by the doctors of the occupa-tional health services, but also by the physicians in charge of treating the patients. AIM Evaluation of the usefulness of mandatory health check-ups of employees concerning frequency of diagnosis and im-provement of treatment outcomes of HT. METHODS The study group comprised 1010 Polish workers referred by their employers for mandatory medical examinations. All of the study participants filled in a questionnaire focused on self-assessment of their health, current blood pressure (BP) mea-surements, and in cases where HT had been previously detected - compliance with medical recommendations. Then in the doctors office BP measurements were taken twice. Workers who fulfilled a criterion indicating a need for intervention were educated on optimal diet, physical activity, and risk factors for CVD. They also received medical instructions for three-step action. The first recommendation: measure BP three times a day for one week and record the results. The second: visit a gen-eral practitioner (GP) for a professional assessment of those results. The third: re-visit the occupational health physician within three months. The criterion for intervention was prior HT and a mean of two BP measurements ≥ 180/110 mmHg - in each case, or ≥ 140/90 mmHg - in the case of occupational exposure to risk factors for CVD. RESULTS The mean age of the study participants was 41.7 years (similar in both genders). A previous diagnosis of HT was declared by 20.1% of patients. 11% of patients involved in the intervention did not comply with medical advice. The current HT therapy of all of the subjects with HT (100% of those with abnormal BP, who visited their GP) was modified. CONCLUSIONS Prophylactic medical check-ups of workers gives improved compliance and medical surveillance of HT in patients with an uncontrolled clinical course of this disease. Obligations and periodic examinations encourage both patients and physicians to improve compliance and reduce the risk of therapeutic inertia.

Can Periodical Examinations of Employees Be Useful in Detection of Glycaemia Impairment and Improving Patients’ Adherence to Medical Recommendations?

Worldwide epidemiological data indicates insufficient diagnosis of diabetes as an increasing public health problem. In the search for solutions to this disadvantageous situation, occupational medicine health services seem to open up a unique opportunity to recognize some abnormalities in the early stages, especially among the asymptomatic working-age population. 316 workers underwent obligatory prophylactic examinations. In patients with twice assayed FGL ≥ 126 mg/dL (7.0 mmol/L) an additional intervention was implemented, including further diagnostic processes and therapy in General Practice (GP), followed by examination by an occupational health specialist within 3 months. The diagnosis of previously unknown diabetes was established among 2.5% of examined workers. All patients referred to the GP due to detected glycaemia impairment visited their doctor and finished the diagnostic process, took up therapy constrained by the occupational health physician to show the effects of intervention within 3 months. Prophylactic medical check-ups allow improved compliance and medical surveillance over glycaemia impairment in patients with prediabetes states, unknown diabetes or uncontrolled clinical course of diabetes. Considering fasting glucose level during mandatory prophylactic examination helps effective prevention of diabetes and its complications and thus provides public health system benefits.

Sleep quality and methylation status of selected tumor suppressor genes among nurses and midwives

ABSTRACT Chronic sleep restriction may affect metabolism, hormone secretion patterns and inflammatory responses. Limited reports suggest also epigenetic effects, such as changes in DNA methylation profiles. The study aims to assess the potential association between poor sleep quality or sleep duration and the levels of 5-methylcytosine in the promoter regions of selected tumor suppressor genes. A cross-sectional study was conducted on 710 nurses and midwives aged 40–60 years. Data from interviews regarding sleep habits and potential confounders were used. The methylation status of tumor suppressor genes was determined via qMSP reactions using DNA samples derived from leucocytes. No significant findings were observed in the total study population or in the two subgroups of women stratified by the current system of work. A borderline significance association was observed between a shorter duration of sleep and an increased methylation level in CDKN2A among day working nurses and midwives. Further studies are warranted to explore this under-investigated topic.

Urinary Bisphenol A Levels and Male Fertility

Bisphenol A (BPA) is a high-production volume industrial chemical found in many consumer products. BPA is a suspected potent endocrine disruptor, with endocrine-disrupting properties demonstrated in animal studies. Few human studies have examined bisphenol A exposure in relation to male fertility and, results are divergent. The aim of the study is to examine the associations between urinary BPA concentration and male fertility. Bisphenol A urinary concentrations were measured using gas chromatography coupled with tandem mass spectrometry in 315 men under 45 years of age with normal sperm concentration (⩾15 mln/ml) recruited from a male reproductive health clinic. Participants were interviewed and provided a semen sample. BPA was detected in 98.10% of urine samples, with a median concentration of 1.87 µg/l (1.63 µg/ g creatinine). A multiple linear regression analysis identified a positive association between the urinary concentrations of bisphenol A 25th–50th percentile and total sperm sex chromosome disomy (p = .004). Also when modeled as continuous variable urinary BPA concentration increased total sperm sex chromosome disomy (p = .01). Urinary concentration of BPA also increase the percentage of immature sperm (HDS) (p = .018) and decrease motility (p = .03). The study provides evidence that exposure to BPA is associated with poorer semen quality. Future studies are needed to confirm these findings.

0295 Urinary cadmium concentration and mammographic volumetric density – preliminary results

Cadmium (Cd) is a heavy metal with widespread occurrence in the environment. Occupational exposure to cadmium occurs in many occupational settings, such as pigment and batteries production, galvanization and recycling of electric tools. Environmental contamination with Cd comes from industry and agriculture. The interest of the researchers and stakeholders in cadmium as potential risk factor for breast cancer has been increasing over the recent years. The objective of our ongoing project is to assess the association between Cd and mammographic density - a strong risk factor for breast cancer. Our research hypothesis assumes that Cd, as metalloestrogen, modifies mammographic density therefore affecting breast cancer risk. The cross sectional study will include, in total, 500 women undergoing screening mammography at the mammography centres in Lodz (Poland). The study procedures include personal interview, anthropometric measurements, blood and urine collection and mammography. Cd is determined in spot urine sample (by ICP-MS technique). Digital mammography is performed according to the standards for screening mammography and volumetric mammographic density is analysed by Volpara software. The potential associations are examined with linear regression model, age and BMI adjusted. During the first phase of the study we collected data from 200 women of mean age 54 years. The mean Cd concentration was 0.54 µg/L, and mean volumetric density 7.6% (left breast, cranio-caudal view). The preliminary analysis showed an inverse association of the volumetric density with age (p<0.01) and BMI (p<0.001). We did not observe association between cadmium concentration in urine and volumetric density.