Semen Quality and Reproductive Hormones in Faroese Men – a Cross-sectional Population-based Study of 481 Men

Objectives: To determine semen quality and reproductive hormone levels in young Faroese men. Design: Descriptive cross-sectional study of Faroese men compared with Danish men. Setting: Faroese one-centre study. Participants: 481 men born from 1981 to 1987 and investigated from 2007 to 2010. Outcome measures: Sperm concentration, semen volume, total sperm count, sperm motility, sperm morphology and reproductive hormone levels. Results: Sperm concentrations for the Faroese men were lower than for the Danish men (crude median 40 vs 48 mill/ml, p<0.0005). Semen volume was higher, and thus the total sperm counts did not differ (159 vs 151 mill, p=0.2). Motility and morphology did not differ between the Faroese and Danes. The inhibin B/follicle-stimulating hormone ratios for the Faroese men were lower than for the Danes (64 vs 76, p=0.001). Similarly, lower total testosterone/luteinising hormone (LH) ratio (4.6 vs 6.0, p<0.0005) and lower calculated free-testosterone/LH ratio (94 vs 134, p<0.0005) were detected for the Faroese men. Conclusions: Semen quality among the Faroese men is at the same low level as reported for Danish men, and the reproductive hormone levels furthermore indicated a lower Leydig cell capacity for testosterone production. The influence of environmental exposure and genetic factors on semen quality has to be studied further

Shorter duration of breastfeeding at elevated exposures to perfluoroalkyl substances

The aim of this study was to determine whether maternal exposure to persistent perfluoroalkyl substances (PFASs) affect the capability to breastfeed. In two Faroese birth cohorts (N=1,130), concentrations of five PFASs were measured in maternal serum during pregnancy or two weeks after term. Duration of breastfeeding was assessed by questionnaire and clinical interview. In adjusted linear regression models, a doubling of maternal serum PFASs was associated with a reduction in duration of both total and exclusive breastfeeding, most pronounced for perfluorooctane sulfonic acid (PFOS) where a doubling was associated with a reduction in total breastfeeding of 1.4 (95% CI: 0.6; 2.1) months and perfluorooctanoic acid (PFOA) where a doubling was associated with a reduction in exclusive breastfeeding of 0.5 (0.3; 0.7) months. The associations were evident among both primiparous and multiparous women, and thus cannot be explained by confounding from previous breastfeeding

Sperm Aneuploidy in Faroese Men with Lifetime Exposure to Dichlorodiphenyldichloroethylene (DDE) and Polychlorinated Biphenyl (PCB) Pollutants.

Background: Although it is known that sperm aneuploidy contributes to early pregnancy losses and congenital abnormalities, the causes are unknown and environmental contaminants are suspected. Objectives: Our goal was to evaluate associations between lifetime exposure to organochlorines, specifically dichlorodiphenyldicholorethylene (p,p´-DDE) and polychlorinated biphenyls (PCBs), and sperm aneuploidy in men from the general population of the Faroe Islands, a population with a known history of organochlorine exposures. Methods: Serum and semen samples from men (n = 90) 22–44 years old who participated in Faroe Islands health studies were analyzed for p,p´-DDE and PCBs 118, 138, 153, and 180 and adjusted for total lipids. Cord blood and age-14 serum were available for a subgroup (n = 40) and were also analyzed for p,p´-DDE and PCBs. Sperm fluorescence in situhybridization (FISH) for chromosomes X, Y, and 18 was used to determine rates of XX18, XY18, YY18, and total disomy. Multivariable adjusted Poisson models were used to estimate the relationship between organochlorine exposure and sperm disomy outcomes. Results: Adult p,p´-DDE and total PCB serum concentrations were both associated with significantly increased rates of XX18, XY18, and total disomy. Age-14 p,p´-DDE and PCB concentrations were both associated with significantly increased rates of XX, XY, and total disomy in adulthood. Associations between cord blood concentrations of p,p´-DDE and PCBs and sperm disomy in adulthood were not consistently significant. Conclusions: Organochlorine exposures measured at age 14 and in adulthood were associated with sperm disomy in this sample of high-exposure men, suggesting that the impacts of persistent pollutants on testicular maturation and function require further investigation

Health effects associated with measured levels of contaminants in the Arctic

Published version. Source at http://dx.doi.org/10.3402/ijch.v75.33805 The Human Health Assessment Group has over the past decade recommended that effect studies be conducted in the circumpolar area. Such studies examine the association between contaminant exposure in the Arctic populations and health effects. Because foetuses and young children are the most vulnerable, effect studies are often prospective child cohort studies. The emphasis in this article is on a description of the effects associated with contaminant exposure in the Arctic. The main topics addressed are neurobehavioural, immunological, reproductive, cardiovascular, endocrine and carcinogenic effect. For each topic, the association between exposure and effects is described, and some results are reported for similar studies outside the Arctic

Involuntary Thumb Flexion on Neurological Examination: An Unusual Form of Upper Limb Dystonia in the Faroe Islands

Background: The prevalence of dystonia varies worldwide. A prior report suggested a high prevalence of focal dystonia in the Faroese population, possibly reflecting a founder effect. During standardized neurological examination as part of an ongoing neuroepidemiologic study in the Faroe Islands, we noted an unusual phenomenon of thumb flexion during repetitive hand movements in a subset of subjects and sought to define its phenomenology. Methods: We requested commentary from a panel of dystonia experts regarding the phenomenology of the movements. These experts reviewed the videotaped neurological examination. Results: Among the experts, dystonia was the leading diagnosis. Alternate causes were considered, but deemed less likely. Discussion: Diagnosis of dystonia requires careful clinical assessment and consideration of associated features. We report a novel form of dystonia, not previously described to our knowledge, in this isolated population. Further studies of dystonia prevalence in the Faroe Islands are merited to characterize its burden in this population and its specific clinical characteristics. Keywords: Dystonia, focal dystonia, Faroe Islands, thumb flexion, phenomenolog

Overview of ongoing cohort and dietary studies in the Arctic

Published version. Source at http://dx.doi.org/10.3402/ijch.v75.33803 This article gives an overview of the ongoing cohort and dietary studies underlying the assessment of population health in the Arctic. The emphasis here is on a description of the material, methods and results or preliminary results for each study. Detailed exposure information is available in an article in this journal, whereas another paper describes the effects associated with contaminant exposure in the Arctic. The cohort descriptions have been arranged geographically, beginning in Norway and moving east to Finland, Sweden, Russia and the other Arctic countries and ultimately to the Faroe Islands. No cohort studies have been reported for Alaska or Iceland

Association between perfluoroalkyl substance exposure and asthma and allergic disease in children as modified by MMR vaccination

Perfluoroalkyl substances (PFAS) are highly persistent chemicals that might be associated with asthma and allergy, but the associations remain unclear. Therefore, this study examined whether pre- and post-natal PFAS exposure was associated with childhood asthma and allergy. Measles, mumps and rubella (MMR) vaccination in early life may have a protective effect against asthma and allergy and is therefore taken into account when evaluating these associations. In a cohort of Faroese children whose mothers were recruited during pregnancy, serum concentrations of five PFAS were measured: Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) at three timepoints (maternal serum in pregnancy week 34-36 and child serum at ages 5 and 13 years) and determined their association with immunoglobulin E (IgE) (cord blood and at age 7 years) and asthma/allergic diseases (questionnaires at ages 5 and 13 years and skin prick test at age 13 years). A total of 559 children were included in the analyses. Interactions with MMR vaccination were evaluated. Among 22 MMR-unvaccinated children, higher levels of the five PFAS at age 5 years were associated with increased odds of asthma at ages 5 and 13. The associations were reversed among MMR-vaccinated children. Pre-natal PFAS exposure was not associated with childhood asthma or allergic diseases regardless of MMR vaccination status. In conclusion, PFAS exposure at age 5 was associated with increased risk of asthma among a small subgroup of MMR-unvaccinated children but not among MMR-vaccinated children. While PFAS exposure may impact immune system functions, this study suggests that MMR vaccination might be a potential effect-modifier

Methylmercury Exposure and Adverse Cardiovascular Effects in Faroese Whaling Men

Background: Methylmercury (MeHg), a worldwide contaminant found in fish and seafood, has been linked to an increased risk of cardiovascular mortality. Objective: We examined 42 Faroese whaling men (30–70 years of age) to assess possible adverse effects within a wide range of MeHg exposures from consumption of pilot whale meat. Methods: We assessed exposure levels from mercury analysis of toenails and whole blood (obtained at the time of clinical examination), and a hair sample collected 7 years previously. Outcome measures included heart rate variability (HRV), blood pressure (BP), common carotid intima-media thickness (IMT), and brainstem auditory evoked potentials (BAEP). We carried out multiple regression and structural equation model (SEM) analyses to determine the confounder-adjusted effect of mercury exposure. Taking into account correlations among related measures, we categorized exposure and outcomes in groups to derive latent exposure and response variables in SEMs. We used multiple regression analysis to compare the predictive validity of individual exposure biomarkers and the latent exposure variable on individual and latent outcomes. Results: The toenail mercury concentrations varied widely and had a geometric mean of 2.0 μg/g; hair concentrations averaged about 3-fold higher. Mercury exposure was significantly associated with increased BP and IMT. This effect was reflected by SEMs, but mercury in toenails tended to be the best effect predictor. Conclusions: The results support the notion that increased MeHg exposure promotes the development of cardiovascular disease

Birth Weight and Prenatal Exposure to Polychlorinated Biphenyls (PCBs) and Dichlorodiphenyldichloroethylene (DDE): A Meta-analysis within 12 European Birth Cohorts

Objectives: Exposure to high concentrations of persistent organochlorines may cause fetal toxicity, but the evidence at low exposure levels is limited. Large studies with substantial exposure contrasts and appropriate exposure assessment are warranted. Within the framework of the EU (European Union) ENRIECO (ENvironmental Health RIsks in European Birth Cohorts) and EU OBELIX (OBesogenic Endocrine disrupting chemicals: LInking prenatal eXposure to the development of obesity later in life) projects, we examined the hypothesis that the combination of polychlorinated biphenyls (PCBs) and dichlorodiphenyldichloroethylene (DDE) adversely affects birth weight