Showing papers by "Jens Peter Bonde published in 2010"
TL;DR: Time has come where male reproductive toxicity should be addressed form entirely new angles including exposures very early in life, as new data show that environmental low-level exposure to biopersistent pollutants in the diet may pose a risk to people in all parts of the world.
Abstract: Male reproductive disorders that are of interest from an environmental point of view include sexual dysfunction, infertility, cryptorchidism, hypospadias and testicular cancer. Several reports suggest declining sperm counts and increase of these reproductive disorders in some areas during some time periods past 50 years. Except for testicular cancer this evidence is circumstantial and needs cautious interpretation. However, the male germ line is one of the most sensitive tissues to the damaging effects of ionizing radiation, radiant heat and a number of known toxicants. So far occupational hazards are the best documented risk factors for impaired male reproductive function and include physical exposures (radiant heat, ionizing radiation, high frequency electromagnetic radiation), chemical exposures (some solvents as carbon disulfide and ethylene glycol ethers, some pesticides as dibromochloropropane, ethylendibromide and DDT/DDE, some heavy metals as inorganic lead and mercury) and work processes such as metal welding. Improved working conditions in affluent countries have dramatically decreased known hazardous workplace exposures, but millions of workers in less affluent countries are at risk from reproductive toxicants. New data show that environmental low-level exposure to biopersistent pollutants in the diet may pose a risk to people in all parts of the world. For other toxicants the evidence is only suggestive and further evaluation is needed before conclusions can be drawn. Whether compounds as phthalates, bisphenol A and boron that are present in a large number of industrial and consumer products entails a risk remains to be established. The same applies to psychosocial stressors and use of mobile phones. Finally, there are data indicating a particular vulnerability of the fetal testis to toxicants—for instance maternal tobacco smoking. Time has come where male reproductive toxicity should be addressed form entirely new angles including exposures very early in life.
109 citations
TL;DR: The Rotterdam criteria for polycystic ovaries (PCO) should be revised, particularly to avoid misdiagnosis in this age group, as the number of follicles is higher at a younger age.
Abstract: background: According to the Rotterdam 2003 criteria, an ovary is defined as polycystic if 12 or more follicles of 2 –9 mm are present, when evaluating the ovary by ultrasonography on Days 3 –5 of the menstrual cycle in women not using hormonal contraceptives. The aim of this population-based study was to estimate the prevalence of polycystic ovaries (PCO) in a representative sample of young Danish women according to the Rotterdam criteria. methods: From a Danish pregnancy cohort established in 1988–1989, 267 (61%) young adult daughters agreed to participate in a clinical examination and 174 (40%) consented to vaginal ultrasound. Sufficient image quality in at least one ovary was obtained from 154 women. Both users and non-users of hormonal contraceptives were included and the examination was not restricted to a particular time of the menstrual cycle. results: The median (range) age was 20.1 (19.5 –21.0) years. The median follicle number per ovary was 14 (6 –30) and 12 or more follicles were counted in 104 of the 154 women. Thus, the prevalence was estimated to 68% [95% confidence interval (CI): 60– 74%]. PCO were present in 80% (95% CI: 65– 89%) of non-users (n ¼ 44) of hormonal contraceptives. Of the 104 women with PCO, 41% (95% CI: 32–51%) could be defined as having polycystic ovary syndrome. conclusions: A very large proportion of the young women had PCO according to the Rotterdam 2003 criteria. As the number of follicles is higher at a younger age, we believe the Rotterdam criteria should be revised, particularly to avoid misdiagnosis in this age group.
95 citations
TL;DR: This study supports the hypothesis that exposure to welding processed particles increases the risk for cardiovascular disease.
Abstract: Objectives To study welding fume particles in relation to cardiovascular diseases. Methods In 1986, 10 059 male metal workers in 75 welding companies were sent a questionnaire about their welding experience and lifestyle (83.3% response rate). Of these, 5866 were available for analysis and had ever welded at baseline. Information on exposure to welding fumes after 1986 was obtained by individual linkage to the National Pension Fund. Lifelong exposure to welding fume particles was estimated from a job–exposure matrix based on more than 1000 welding-specific measures of fume particles. Hospital contacts for cardiovascular disease were obtained from the Danish National Patient Registry by individual linkage. The nine disease outcomes considered were acute myocardial infarct (AMI), angina pectoris, other acute ischaemic heart diseases, chronic ischaemic heart disease (CHD), cardiac arrythmias, cardiac arrest, heart failure, cerebral infarct, arterial embolism and thrombosis. The cohort was followed up from baseline until the end of 2006. Results When the incidence of each of the nine cardiovascular outcomes among welders was compared with 5-year age- and calendar year-specific male national rates, the number of observed cases significantly exceeded that expected for AMI (standardised incidence ratio, 95% CI) (1.12, 1.01 to 1.24), angina pectoris (1.11, 1.01 to 1.22), CHD (1.17, 1.05 to 1.31) and cerebral infarct (1.24, 1.06 to 1.44). Internal comparisons of the cohort with adjustment for tobacco smoking, alcohol and hypertension medicines showed a significantly increasing hazard rate ratio for CHD and non-significant increases for AMI, angina pectoris and cerebral infarct with increasing exposure to particles. Conclusions This study supports the hypothesis that exposure to welding processed particles increases the risk for cardiovascular disease.
71 citations
TL;DR: The findings strongly support that the intrauterine environment and maternal inheritance are contributing to the occurrence of cryptorchidism.
64 citations
TL;DR: There was no significant association between CB-153 and p,p'-DDE concentrations and risk of preterm birth however, in all cohorts the odds ratio was above 1.0 and new insights as to why results vary across studies were not apparent.
Abstract: Background
Epidemiological studies on the association between maternal exposure to persistent organic pollutants (POPs) and fetal growth alteration report inconsistent findings which weights in favor of additional studies.
63 citations
TL;DR: The results do not indicate an effect of childhood BMI, birth weight, or adult BMI on semen quality, but the exposure contrast in the study was limited.
61 citations
TL;DR: There is no clear evidence of male reproductive effects attributable to boron in studies of highly exposed workers, and there were no statistically significant differences in semen characteristics between exposure groups, including in the highly exposed subset.
59 citations
TL;DR: Working in a dissatisfying psychosocial environment increases the risk of subsequent mental health disorders, and randomised, controlled intervention trials may help in resolving whether this association is causal.
Abstract: Background The aim of this study was to examine if dissatisfaction with psychosocial work climate predicts psychiatrically diagnosed depressive, anxiety and substance abuse disorders. Methods In Aarhus County, Denmark, 13 423 public service employees at 683 workplace units answered a questionnaire survey assessing psychosocial work environment. An average workplace unit score of overall satisfaction with psychosocial working conditions, rated on a scale from 0–10 with 10 being most satisfied, was computed and assigned to the individual employees at each work unit. Aggregated satisfaction scores were divided into three levels, according to the 25–75 percentiles. Data on hospitalisations and outpatient treatments for depressive, anxiety and substance abuse disorders was obtained from the Danish Central Psychiatric Research Register. HRs and 95% CIs were computed for first onset of studied disorders, starting from the baseline survey at 1 January 2002 through to 30 April 2008. Risk estimates were adjusted for sociodemographic variables. Results A low satisfaction with psychosocial working conditions was associated with an increased risk of any mental health disorder, HR adj 1.71, 95% CI 1.04 to 2.82. The lower the satisfaction level, the higher was the risk of mental health disorders. Moreover, substance abuse disorders were more frequent among men dissatisfied with work climate, HR adj 3.53, 95% CI 1.55 to 8.03. Conclusion Working in a dissatisfying psychosocial environment increases the risk of subsequent mental health disorders. Randomised, controlled intervention trials may help in resolving whether this association is causal.
32 citations
TL;DR: The study showed that floor layers spent a high percentage of time in knee-straining work positions, particularly gluing and crawling, and highlights the need for prevention by minimizing the amount of kneeling work positions among floor layers.
31 citations
TL;DR: Pregnant women who worked with patients or children or food products had an excess risk of sick leave during pregnancy for more than three days and most of negative reproductive outcomes were not increased in these occupations, but the prevalence of congenital anomalies (CAs) was slightly higher in children of women who work with patients.
Abstract: Background: Exposure to infectious pathogens is a frequent occupational hazard for women who work with patients, children, animals or animal products. The purpose of the present study is to investigate if women working in occupations where exposure to infections agents is common have a high risk of infections and adverse pregnancy outcomes. Methods: We used data from the Danish National Birth Cohort, a population-based cohort study and studied the risk of Infection and adverse outcomes in pregnant women working with patients, with children, with food products or with animals. The regression analysis were adjusted for the following covariates: maternal age, parity, history of miscarriage, socio-occupational status, pre-pregnancy body mass index, smoking habit, alcohol consumption. Results: Pregnant women who worked with patients or children or food products had an excess risk of sick leave during pregnancy for more than three days. Most of negative reproductive outcomes were not increased in these occupations but the prevalence of congenital anomalies (CAs) was slightly higher in children of women who worked with patients. The prevalence of small for gestational age infants was higher among women who worked with food products. There was no association between occupation infections during pregnancy and the risk of reproductive failures in the exposed groups. However, the prevalence of CAs was slightly higher among children of women who suffered some infection during pregnancy but the numbers were small. Conclusion: Despite preventive strategies, working in specific jobs during pregnancy may impose a higher risk of infections, and working in some of these occupations may impose a slightly higher risk of CAs in their offspring. Most other reproductive failures were not increased in these occupations.
30 citations
TL;DR: In this article, the authors examined the risk of fetal loss related to environmental 2,2',4,4, 4,5, 5,5'-hexachlorobiphenyl (CB-153) or 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) exposure.
Abstract: Background
In the present study, the aim is to examine the risk of fetal loss related to environmental 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) or 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) exposure.
TL;DR: In this article, the authors found that the intervention had medium effects on self-reported sleep and cognitive errors, with an effect size of d 0.57, CI [0.90, −0.24], favoring the intervention.
Abstract: Work-related stress is a major occupational health problem. Prominent symptoms are impaired sleep and cognitive ability. Participants (N 102) were randomized to either an intervention or a wait-list control group. Outcomes, measured at baseline, 3, 6, and 9 months, were the Basic Nordic Sleep Questionnaire, Cognitive Failures Questionnaire, and Digit Span test. Data were analyzed using repeated measures analyses of variance. Selfreported quality of sleep improved in the intervention group. Relative to the control group, an effect size of d 0.64, CI [1.05, – 0.24], was found. For cognitive failures, an effect size of d 0.57, CI [0.90, – 0.24], was found, favoring the intervention. Gains were maintained at follow-up. Digit Span scores did not differ between groups. In conclusion, the intervention had medium effects on self-reported sleep and cognitive errors.
TL;DR: A critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function and other aspects of gene-environment interaction specifically associated with the issue of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage are presented.
Abstract: As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between and within populations, genetic variants might be important determinants of the individual susceptibility to the adverse effects of environment or lifestyle. Although the possible mechanisms of such interplay in relation to the reproductive system are largely unknown, some recent studies have indicated that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism, but the number of studies is still limited. This type of interaction studies may improve our understanding of normal physiology and help us to identify the risk factors to male reproductive malfunction. We also shortly discuss other aspects of gene-environment interaction specifically associated with the issue of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage. It remains to be investigated to what extent such genetic changes, by natural conception or through the use of assisted reproductive techniques, are transmitted to the next generation, thereby causing increased morbidity in the offspring.
TL;DR: Whether reference values for semen characteristics will help to resolve the intensely debated data indicating temporal and geographical shifts in sperm counts and hypotheses that anthropogenic activities that result in the release of chemicals into the environment are detrimental to male reproductive health are considered.
Abstract: The fifth edition of the World Health Organization (WHO) manual for semen analysis includes for the first time reference values for human semen characteristics. This paper considers whether such values will help to resolve the intensely debated data indicating temporal and geographical shifts in sperm counts and hypotheses that anthropogenic activities that result in the release of chemicals into the environment are detrimental to male reproductive health. The reasons that these reference values will not fulfil these purposes are also explained. Although established reference values for semen characteristics are of limited value in analytical epidemiologic research, the WHO guidelines are of utmost importance for supporting the development of appropriate research protocols. Moreover, in spite of its limitations, semen analysis is still a useful research tool in epidemiological research, and no superior alternatives are on the horizon.
TL;DR: In Denmark, breast cancer has been recognised as an occupational disease since the International Agency for Research on Cancer (IARC) decided in 2007 that shift work involving circadian disruption is probably carcinogenic to humans.
Abstract: In Denmark, breast cancer has been recognised as an occupational disease since the International Agency for Research on Cancer (IARC) decided in 2007 that shift work involving circadian disruption is probably carcinogenic to humans.1 Compensation has been given to 26 nurses, 12 nursing assistants, four physicians and 14 workers from other occupations who had worked night shifts for more than 20 years. This has caused public concern …
01 Jan 2010
TL;DR: The risk of fetal loss may increase at higher levels of CB-153 and p,p'-DDE exposure, although lack of dose response and inconsistencies between countries did not allow for firm conclusions.
Abstract: Background: In the present study, the aim is to examine the risk of fetal loss related to environmental 2,2',4,4',5,5'hexachlorobiphenyl (CB-153) or 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) exposure. Methods: We related LC/MS/MS measurements of CB-153 and p,p'-DDE in serum samples to interview-data on previous fetal loss in populations of pregnant women from Poland, Ukraine and Greenland. Results: In total, 1710 women were interviewed, and 678 of these had at least one previous pregnancy. The risk of ever experiencing a fetal loss increased at higher levels of CB-153 and p,p'-DDE exposure, with an adjusted odds ratio (OR) of 2.4; confidence interval (CI) (1.1-5.5) for CB-153>200 ng/g lipid compared to 0-25 ng CB-153/g lipid and OR of 2.5 CI (0.9-6.6) for p,p'-DDE>1500 ng/g lipid compared to 0-250 ng DDE/g lipid. However, no clear dose response associations were observed. The results further suggest that high level of organochlorine serum concentrations may be related to repeated loss. Conclusions: The risk of fetal loss may increase at higher levels of CB-153 and p,p'-DDE exposure, although lack of dose response and inconsistencies between countries did not allow for firm conclusions.
01 Jan 2010
TL;DR: In this article, anomalies of the sviluppo sessuale maschile, i.e., the difference between the sissuale and the fertilita maschili, are discussed.
Abstract: Il differenziamento sessuale e la fertilita maschili sono il risultato di una sequenza di segnali che comprende fattori cellulari, genetici ed endocrini. Le manifestazioni cliniche delle anomalie dello sviluppo sessuale maschile sono l’ipogonadismo, l’inversione sessuale e lo stato intersessuale. Esse possono essere dovute ad anomalie nella determinazione e nella differenziazione delle gonadi, a disturbi della regolazione ipotalamo-ipofisi-gonadi e della biosintesi degli ormoni steroidei, a sindromi da insensibilita agli ormoni e ad anomalie delle vie di escrezione. Dopo l’esame clinico, e necessaria una valutazione endocrinologica per distinguere l’ipogonadismo ipergonadotropo dall’insufficienza gonadica primaria e l’ipogonadismo ipogonadotropo dai disturbi pituitari e ipotalamici. La valutazione genetica comprende l’analisi dei cromosomi e, per un numero crescente di anomalie, oggi e possibile uno screening grazie alla genetica molecolare. In molti casi, in particolare in quelli di inversione sessuale e di stato intersessuale, e necessario un approccio interdisciplinare della diagnosi e del trattamento.
TL;DR: This study found no association between current caffeine exposure and semen quality and wrote that the study had information on only coffee and tea intakes, resulting in underestimation of caffeine intake due to appreciable amounts of cola drunk by many young men, which is not true.
Abstract: We read with interest the article by Jensen et al. (1) on the association between semen quality and caffeine intake among 2,554 young Danish men. They found a high intake of cola and/or caffeine products to be associated with reduced sperm concentration and total sperm count, but the association was statistically significant only for cola. Jensen et al. (1) cited a previous study conducted by our group (2), which analyzed the association between both prenatal coffee and current caffeine exposure and semen quality in 347 young Danish men. Our study does not exclude a small-tomoderate effect of prenatal coffee exposure on semen volume, but we found no association between current caffeine exposure and semen quality. Jensen et al. (1) wrote that our study had information on only coffee and tea intakes, resulting in underestimation of caffeine intake due to appreciable amounts of cola drunk by many young men, which is not true. As stated in the article, we did estimate the total caffeine intake for the young men by adding caffeine from coffee and cola (2), and cola accounted for approximately 29% of the total caffeine intake.