Effect of cumulus cells and sperm concentration on fertilization and development of pig oocytes

Effect of sperm concentrations and cumulus cells (CCs) on porcine IVF was re-evaluated using current improved IVM and IVC system. Our results showed that both CCs and sperm concentration had significant effect on penetration rate, frequency of polyspermy and embryonic development. The best IVF results were obtained with oocytes with CCs fertilized with 0.5 × 10⁵ sperm/ml. Such an IVP system works on both sow and gilt oocytes.

Discharge diagnoses of liver diseases in Nuuk Greenland compared to a Danish county hospital

BACKGROUND

It is a frequently held notion that Inuits/Greenlanders are less prone to develop chronic liver disease than Europeans. High alcohol consumption and chronic viral infection are more frequent in Greenland than in Denmark.

STUDY DESIGN

A cross-sectional study to examine the incidence and prevalence of liver discharge diagnosis with focus on cirrhosis among hospital-admitted patients in Greenland and Denmark.

METHODS

Register-based ICD-10 discharge diagnoses from Queen Ingrid's Hospital, Greenland, (n = 1072) and Randers Central Hospital, Denmark, (n = 4599) were used to compare the incidence and prevalence of cirrhosis in hospitalised patients during 1998.

RESULTS

Five patients (0.47%) in Greenland and 36 (0.78%) in Denmark had a liver discharge diagnosis (OR = 0.67, 95% CI: 0.26-1.72). Two patients (0.19%) in Greenland compared to 25 (0.54%) in Denmark had a cirrhosis associated discharge liver diagnosis (OR = 0.34, 95% CI: 0.08-1.45). The number of newly diagnosed discharged patients was smaller in Greenland, 2 (0.19%), vs. Denmark, 14 (0.30%), (OR = 0.61, 95% CI: 0.14-2.70).

CONCLUSION

Discharge liver diagnoses were not more frequent in Greenland than in Denmark--if anything, the hospital prevalence and incidence of liver discharge diagnoses were lower. This may reflect fewer cirrhosis cases in Greenland, and/or a shorter survival time, or lack of follow up.

Very high concentrations of n-3 fatty acids in peri-and postmenopausal Inuit women from Greenland

OBJECTIVES

The objectives of this study were to examine the profile of relative concentrations in plasma phospholipids of n-3 fatty acids among peri- and postmenopausal Inuit women living in Greenland and to verify their relationships with ischemic heart disease risk factors and more particularly, with concentrations of plasma triacylglycerols.

STUDY DESIGN

This study was part of a survey conducted in 2000, which aimed to assess the prevalence of osteoporosis and the associated risk factors among peri- and postmenopausal Greenland Inuit women.

METHODS

The study population consisted of 153 women aged 49-69 years (mean +/- SD: 55.3 +/- 4.4 y) randomly selected. Data were obtained through an interview (questionnaire on lifestyle habits, medical history etc) and a clinical session (physiologic and anthropologic measurements). Plasma samples were used to measure the fatty acid composition of plasma phospholipids.

RESULTS

The mean body mass index of women was 27.9 +/- 6.1. Seventy-five percent were smokers and 9% were currently on hormone replacement therapy. Relative concentrations of total n-3 fatty acids were very high (13.8%, 95% CI: 13.1-14.6), with docosahexanoic and eicosapentanoic acids accounting for 4.7% and 7.2%, respectively. The ratio of n-3:n-6 fatty acids was 0.67. n-3 fatty acids were inversely correlated to triacylglycerols.

CONCLUSION

These data show that peri- and post-menopausal Greenland Inuit women have very high plasma concentrations of n-3 fatty acids that protect them from ischemic heart disease.

Increasing overweight in Greenland: social, demographic, dietary and other life-style factors

OBJECTIVES

In several Arctic countries, weight gain is very evident among the local populations and the percentages of overweight and obese persons are increasing rapidly. Since the development of overweight among the Arctic populations seems to coincide with the westernization of their diet and other life-style factors, it is tempting to hypothesize that the transition to carbohydrate- and fat-rich western food causes the weight gain. The high relative content of (n-3) fatty acids in traditional foods presumably provides some protection against cardiovascular diseases, type 2 diabetes and various other diseases of affluent industrialized societies. In the present study, we have investigated the recent weight gain in Greenland and have tried to relate it to social factors, present dietary habits and other life-styles.

STUDY DESIGN

The cross-sectional study, which was part of the Arctic Monitoring and Assess Programme, included 410 men and women (18-49 years) from 5 districts in Greenland. It was based upon questionnaires including a dietary survey, anthropometric measurements and blood lipid analyses.

RESULTS

Obesity (Body Mass Index (BMI) > 30 kg/m2, corresponding to about 19% of the participants) increased with age, was most prevalent among higher household economic levels, and correlated with neither local, nor imported food intake.

CONCLUSION

Overweight was not found to be correlated with either western, or traditional food composition. Obesity had adverse effects on several health indicators, serum triglyceride, HDL and the cardiovascular risk index, (Chol-HDL)/HDL and TG/HDL, counteracting the positive effects of (n-3) fatty acids and should be considered as a serious health risk for the Greenlandic population.

Exposure to persistent organic pollutants and sperm DNA methylation changes in Arctic and European populations

Persistent organic pollutants (POPs), such as PCBs (polychlorinated biphenyls) and DDT [1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane], are environmental contaminants with potential endocrine disrupting activity. DNA methylation levels in peripheral blood lymphocytes have been associated with serum concentrations of POPs in Greenland Inuit and Korean populations. Greenland Inuits are characterized by the highest worldwide POP levels. In this cross-sectional study we evaluated the relationship between serum POP concentrations and DNA methylation levels in sperm of non-occupationally exposed fertile men from Greenland, Warsaw (Poland), and Kharkiv (Ukraine). Serum levels of PCB-153 [1,2,4-trichloro-5-(2,4,5-trichlorophenyl)benzene], as a proxy of the total PCBs body burden, and of p,p'-DDE [1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene], the main metabolite of DDT were measured. Sperm DNA methylation level was assessed globally by flow cytometric (FCM) immunodetection of 5-methyl-cytosines and at specific repetitive DNA sequences (Alu, LINE-1, Satα) by PCR-pyrosequencing after bisulfite conversion. Multivariate linear regression analysis was applied to investigate correlations between serum POP concentrations and DNA methylation. No consistent associations between exposure to POPs and sperm DNA methylation at repetitive DNA sequences were detected. A statistically significant global decrease in methylation was associated with exposure to either POP by FCM analysis. This is the first study to investigate environmental exposure to POPs and DNA methylation levels considering sperm as the target cells. Although POP exposure appears to have a limited negative impact on sperm DNA methylation levels in adult males, the global hypomethylation detected by one of the methods applied suggests that further investigation is warranted.

Lifestyle, reproductive factors and food intake in Greenlandic pregnant women: the ACCEPT - sub-study

Background

In the past decades, Greenland has changed from a hunter society to a more western lifestyle, causing less intake of traditional food, such as marine mammals, fish and seabirds. These changes in the living conditions and food habits might impact the maternal health in Greenland.

Objectives

To describe lifestyle, reproductive factors and food intake in Greenlandic pregnant women, and to assess possible age and geographical differences.

Design

Cross-sectional study of 189 Greenlandic pregnant women. Inclusion criteria were ≥18 years and lived >50% of their life in Greenland. Data were collected in 2010–2011, and information was obtained from lifestyle and food frequency questionnaires. Two age groups for comparison were given for the pregnant women (<27 years vs. ≥27 years) with regard to the median age. Region groups for comparison were West, Disko Bay, South, North and East.

Results

Population characteristics showed that 43.3% had pre-pregnancy body mass index (BMI) >25.0 kg/m², 46.3% were current smokers in the beginning of their pregnancy and few participants consumed alcohol during pregnancy. Women <27 years were more in doubt regarding planned breastfeeding period and consumed more dried fish and fast food. A trend for higher alcohol intake during pregnancy was found for women ≥27 years. The regional differences showed that women living >50% in North, South and West had a higher alcohol intake during pregnancy. Women in North had the fewest breastfeeding plans. Women in Disko Bay had the lowest intake of terrestrial species. No significant geographical differences were found for intake of marine mammals or seabirds.

Conclusions

The present study found relatively high BMI level and high smoking frequency in Greenlandic pregnant women. Age and region differences were found for alcohol consumption, breastfeeding plans and food intake profile. Further research is needed to implement relevant maternal health intervention programs in Greenland.

Hazard quotient profiles used as a risk assessment tool for PFOS and PFOA serum levels in three distinctive European populations

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) blood levels are commonly used as biomarkers of human environmental exposure to these compounds. Many biomonitoring studies indicate 100% detection for PFOS and PFOA thus justifying a concern of possible risk for the most exposed individuals. This study addresses the predictive value of hazard quotients (HQs) calculated on the basis of serum PFOS and PFOA in male and female populations of reproductive age in Greenland, Poland and Ukraine. Overall, 2026 results of PFOS and PFOA serum concentrations (589 males, 1437 females) were obtained from the INUENDO database. HQs were calculated from the actual biomonitoring results and literature-based animal data linking toxicological outcomes and critical PFOS/PFOA serum levels. HQs for serum PFOS were calculated based on Points of Departure (PoD) at 13μgmL(-1) (cynomolgus monkeys, 183days, changes in THS and T3) and for PFOA at 7.1μgmL(-1) serum (male rats, 90days, hepatocellular necrosis, increased liver weight). Uncertainty factors were applied to reflect interspecies differences and human variability. Serum HQs were expressed as a ratio relative to the point of departure for each PFOS and PFOA. Only in the three cases of males in Greenland were there serum PFOS levels showing HQ values exceeding 1, so indicating that such serum levels may be of concern. The mean serum concentration of PFOS was significantly higher in male than in female populations. Despite significant differences between HQ profiles for PFOS and PFOA in donors from Greenland, Poland and Ukraine, the concentrations of these perfluoroalkylated compounds do not indicate a cause for concern, except for the three aforementioned cases from Greenland. This study demonstrates that the HQ approach can help to interpret human biomonitoring data and thus serve as a valuable tool in further risk assessment priority settings and may also be used as a basis for taking decisions in risk management.

Impact of moderate interval exercise versus supine rest on the pharmacokinetics and pharmacodynamic profiles of subcutaneously administered growth hormone in adult growth hormone deficient patients

BACKGROUND

Diurnal variation in serum growth hormone (s-GH) levels after exogenous GH delivery has previously been reported in patients with no endogenous GH secretion. Changes in postural position or physical activity, leading to changes in blood flow and/or lymphatic drainage may be underlying explanations.

PRIMARY OBJECTIVES

The primary aim of this study is to study a possible impact of exercise and supine rest on pharmacokinetics (PK) and day-to-day variation of subcutaneously (s.c.) administered GH in adult GH deficient (AGHD) patients.

SECONDARY OBJECTIVE

The secondary aim of this study is to compare s-IGF-I, s-insulin, and plasma (p)-glucose profiles after a carbohydrate rich breakfast following s.c. GH injection vs. continuous infusion.

DESIGN AND METHODS

During supine rest eight AGHD males (59.8±8 years, BMI 29.7±4.9 kg/m(2)) were treated with one daily s.c. GH injections of 3 mg/24 h for 48 h (treatment sessions A, B) or a continuous s.c. GH infusion of 3 mg/24 h for 60 h (treatment sessions C, D). Exercise comprised 1 h bicycling with 50 W load on two consecutive days during treatment sessions B and D.

RESULTS

Administration of GH as a bolus injection, but not as a continuous GH infusion, resulted in about 32% higher s-GH levels during exercise (60 min) as well as 30 min after (s-GH logAUC(B-A) difference was 0.28; 95% CI: 0.14-0.4; p<0.001). However, the total s-GH(AUC 0-24 h) (p=0.75) and s-IGF-I(AUC0-48 h) levels (p=0.51) remained unchanged between the two occasions. P-glucose and insulin profiles were significantly higher after carbohydrate rich breakfast before first and second dosing both following s.c. GH injection and continuous infusion (p<0.05).

CONCLUSIONS

Moderate exercise intermittently increased s-GH levels. These changes seem to have no clinical short-term relevance, since total s-GH(24 h) and s-IGF-I(48 h) levels were unaffected.

Exposure to perfluoroalkyl substances and sperm DNA global methylation in Arctic and European populations

Perfluoroalkyl substances (PFASs) are widely used in a variety of industrial processes and products, and have been detected globally in humans and wildlife. PFASs are suspected to interfere with endocrine signaling and to adversely affect human reproductive health. The aim of the present study was to investigate the associations between exposure to PFASs and sperm global methylation levels in a population of non-occupationally exposed fertile men. Measurements of PFASs in serum from 262 partners of pregnant women from Greenland, Poland and Ukraine, were also carried out by liquid chromatography tandem mass spectrometry. Perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) were detected in 97% of the blood samples. Two surrogate markers were used to assess DNA global methylation levels in semen samples from the same men: (a) average DNA methylation level in repetitive DNA sequences (Alu, LINE-1, Satα) quantified by PCR-pyrosequencing after bisulfite conversion; (b) flow cytometric immunodetection of 5-methyl-cytosines. After multivariate linear regression analysis, no major consistent associations between PFASs exposure and sperm DNA global methylation endpoints could be detected. However, since weak but statistically significant associations of different PFASs with DNA hypo- and hyper-methylation were found in some of the studied populations, effects of PFASs on sperm epigenetic processes cannot be completely excluded, and this issue warrants further investigation.

Serum concentrations of polybrominated diphenyl ethers (PBDEs) and a polybrominated biphenyl (PBB) in men from Greenland, Poland and Ukraine

Many brominated flame retardants (BFRs)-including polybrominated diphenyl ethers (PBDEs)-have been shown to persist in the environment, and some have been associated with adverse health effects. The aim of the present study was to quantify serum concentrations of common brominated flame retardants in Inuit men from across Greenland, and in men from Warsaw, Poland and Kharkiv, Ukraine. Serum was sampled between 2002 and 2004 from men 19 to 50years of age. 299 samples were analyzed for BDE-28, 47, 99, 100, 153, 154 and 183 and the brominated biphenyl BB-153 using gas chromatography-high resolution mass spectrometry. BDE-47 and BDE-153 were detected in more than 95% of samples from all three populations. All other congeners, except BDE-154, were detected in more than 70% of samples from Greenland; lower detection frequencies were observed in Polish and Ukrainian samples. Concentrations of individual congeners were 2.7 to 15 fold higher in Greenlandic relative to Polish and Ukrainian men. Geometric mean concentrations of the sum of the most abundant PBDEs of the Penta-BDE commercial mixture (BDE-47, 99, 100, 153 and 154) were 6.1, 1.7 and 0.87ng/g lipids in the Greenlandic, Polish and Ukrainian men, respectively. Furthermore, significant geographical differences in BFR concentrations were observed within Greenland. Principal component analysis revealed distinct clustering of samples by country of origin. The associations between ΣPBDEs and age were inconsistent, varying from no association in Greenlandic and Polish study populations to a U-shaped relationship in Ukrainians. We report BFR levels for three populations for which sparse biomonitoring data exists.

Polyunsaturated fatty acids and calcaneal ultrasound parameters among Inuit women from Nuuk (Greenland): a longitudinal study

BACKGROUND

The traditional diet of Inuit people comprises large amounts of fish and marine mammals that are rich in omega-3 polyunsaturated fatty acids (PUFAs). Results from in vitro studies, laboratory animal experiments and population studies suggest that omega-3 PUFA intake and a high omega-3/omega-6 ratio exert a positive effect on bone health.

OBJECTIVE

This longitudinal study was conducted to examine the relationship between omega-3 and omega-6 PUFA status and quantitative ultrasound (QUS) parameters in Greenlandic Inuit women.

METHODS

The study included 118 Inuit women from Nuuk (Greenland), aged 49-64 years, whose QUS parameters measured at baseline (year 2000), along with PUFA status and covariates, and follow-up QUS measurements 2 years later (year 2002). QUS parameters [speed of sound (SOS); broadband ultrasound attenuation (BUA)] were measured at the right calcaneus with a water-bath Lunar Achilles instrument. Omega-3 and omega-6 PUFA contents of erythrocyte membrane phospholipids were measured after transmethylation by gas chromatography coupled with a flame ionization detector. Relationships between QUS parameters and different PUFAs were studied in multiple linear regression models.

RESULTS

Increasing values of EPA, DHA and the omega-3/omega-6 PUFA ratio were associated with increased BUA values measured at follow-up (year 2002). These associations were still present in models adjusted for several confounders and covariates. We found little evidence of associations between PUFAs and SOS values.

CONCLUSION

The omega-3 PUFA intake from marine food consumption seems to have a positive effect on bone intrinsic quality and strength, as revealed by higher BUA values in this group of Greenlandic Inuit women.

Non-linear association between androgen receptor CAG and GGN repeat lengths and reproductive parameters in fertile European and Inuit men

Recently the dogma that there is an inverse linear association between androgen receptor (AR) CAG and GGN polymorphisms and receptor activity has been challenged. We analysed the pattern of association between 21 male reproductive phenotypes and AR CAG/GGN repeat lengths in 557 proven-fertile men. A linear association was only found between sperm DNA fragmentation index (DFI) and CAG length, and between inhibin B and GGN length. Men with longer CAG then the reference (22-24), had higher oestradiol levels, whereas men with shorter CAG stretches had a higher DFI and a higher proportion of Fas-positive germ cells. Subjects with either short or long CAG had increased seminal levels of prostate-specific antigen and neutral α-glucosidase activity. Compared to men with the median GGN length of 23, those with shorter GGN repeats had higher levels of inhibin B, higher proportions of normal and progressive sperm, and a higher fraction of Fas-positive sperm, while men with longer GGN had higher oestradiol levels. These data indicate that at least for some markers of male reproductive function the association with CAG or GGN repeat length is curvilinear.

Serum levels of perfluorinated compounds and sperm Y:X chromosome ratio in two European populations and in Inuit from Greenland

This study investigated whether perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS), which exhibit reproductive toxicity in experimental animals, affect sperm sex chromosome ratio. The Y:X ratio was determined by fluorescence in situ hybridization. Serum concentrations of PFOA and PFOS were measured in 607 men from Greenland, Poland and Ukraine using liquid chromatography-tandem mass spectrometry. Data was analyzed by linear and nonlinear regression. We observed no associations between PFOA and Y:X ratio (p=0.845 in a linear model, p=0.296 in a nonlinear model). A positive nonlinear association between PFOS and Y:X ratio was observed (p=0.016), with no association in a linear model (p=0.118). Analyzing the populations separately, a negative trend between categorized PFOS exposure and Y:X ratio was observed for the Inuit (B=-0.002, p=0.044). In conclusion, there was a negative trend between Y:X ratio and PFOS in the Inuit, while there was no association between PFOA and the Y:X ratio in adult men.

Blood serum concentrations of perfluorinated compounds in men from Greenlandic Inuit and European populations

Perfluorinated compounds (PFCs), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are used in large quantities. They are persistent and found in measurable levels in human serum around the world. They have been associated with developmental, hepatic, and carcinogenic effects in animal studies. The aim of the present study was to describe levels of PFCs in serum among Inuits from Greenland and inhabitants from Warsaw, Poland and Kharkiv, Ukraine. Furthermore, the aim was to define social- and lifestyle related determinants of exposure for these compounds. Serum levels of seven PFCs were analyzed by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The concentrations of PFOS and PFOA were the highest of all PFCs in all three populations with a total amount of almost 90% of the PFCs. The mean levels of PFOS and PFOA were in the Greenlandic Inuits 52 and 4.8 ng mL(-1), in Poland 19 and 5.2 ng mL(-1), and in Ukraine 8.1 and 1.9 ng mL(-1), respectively. Thus, levels of PFCs in the serum of Inuits on Greenland were among the highest described in a general population whereas the levels in Poland were similar to other industrialized countries. The exposure in Ukraine was rather low. In the Greenlandic Inuit population, intake of seafood, tea, age and area of living were significant determinants of PFOS concentrations and explained about 22% of the variation. For the other populations no strong determinants were found.

Association of maternal serum concentrations of 2,2', 4,4'5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) levels with birth weight, gestational age and preterm births in Inuit and European populations

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.

METHODS

Blood samples were collected from interviewed pregnant women in Greenland (572), Kharkiv (611) and Warsaw (258) and were analyzed for CB-153 and p,p'-DDE by gas chromatography-mass spectrometry. Data on birth weight, gestational age and preterm birth were obtained for 1322 singleton live births. We examined the association between natural log-transformed serum POPs concentration and birth weight and gestational age using multiple linear regression and the association with prematurity using logistic regression controlling for potential confounding factors.

RESULTS

The median serum concentrations of CB-153 and p,p'-DDE were for Inuit mothers 105.6 and 298.9, for Kharkiv mothers 27.0 and 645.4 and for Warsaw mothers 10.7 and 365.2 ng/g lipids, respectively. Increase in CB-153 concentration by one unit on the log scale in Inuit mothers serum was associated with significant decrease in infant birth weight of -59 g and gestational age by -0.2 week. Decreases observed in the cohorts in Kharkiv (-10 g and -0.1 week) and in Warsaw (-49 g and -0.2 week) were not statistically significant. Increase in p,p'-DDE concentration by one unit on the log scale was associated with a statistically significant decrease in infant birth weight of -39.4 g and -104.3 g and shortening of gestational age of -0.2 week and -0.6 week in the Inuit and Warsaw cohorts, respectively. In the Kharkiv cohort decrease in birth weight (-30.5 g) was not significant, however a shortening of gestational age of -0.2 week per increase in p,p'-DDE concentration by one unit on the log scale was of the borderline significance. 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.

CONCLUSIONS

In utero exposure to POPs may reduce birth weight and gestational age of newborns however, new insights as to why results vary across studies were not apparent.

Fetal loss and maternal serum levels of 2,2',4,4',5,5'-hexachlorbiphenyl (CB-153) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) exposure: a cohort study in Greenland and two European populations

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.

Semen quality in relation to xenohormone and dioxin-like serum activity among Inuits and three European populations

BACKGROUND

Semen quality in humans may be influenced by exposure to endocrine-disrupting compounds.

OBJECTIVES

We analyzed associations between semen characteristics and serum xenoestrogen receptor (XER), xenoandrogen receptor (XAR), and aryl hydrocarbon receptor (AhR) transactivity. XER and XAR activity were measured in serum samples cleared for endogenous steroid hormones and AhR activity in raw lipophilic serum extracts free of proteins.

RESULTS

All together, 319 men from Warsaw (Poland), Greenland, Kharkiv (Ukraine), and Sweden provided semen and blood samples. No strong and consistent associations between xenobiotic activity and semen quality measures were observed in the four populations. However, when the data were combined across populations sperm concentration increased 40% per unit increase in XER activity [95% confidence interval (CI), 1-79%] in the subgroup with XER activity below the reference level. Among subjects with XER activity above the reference level an increase of 14% (95% CI, 2-28%) was found. Furthermore, an increase of 10% motile sperm per unit increase in XER activity below reference level (95% CI, 0.2-20) was found. We are unable to exclude that the associations are chance findings.

CONCLUSION

Alteration of XER, XAR, or AhR transactivity within the range found in serum from the general European and Inuit population seems not to markedly deteriorate sperm cell concentration, motility, or morphology in adult men.

Xenoandrogenic activity in serum differs across European and Inuit populations

BACKGROUND

Animal and in vitro studies have indicated that human male reproductive disorders can arise as a result of disrupted androgen receptor (AR) signalling by persistent organic pollutants (POPs). Our aim in the present study was to compare serum xenoandrogenic activity between study groups with different POP exposures and to evaluate correlations to the POP proxy markers 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p'-DDE).

METHODS

We determined xenoandrogenic activity in the serum fraction containing the lipophilic POPs but free of endogenous hormones. Adult male serum (n = 261) from Greenland, Sweden, Warsaw (Poland), and Kharkiv (Ukraine) was analyzed. Xenoandrogenic activity was determined as the effect of serum extract alone (XAR) and in the presence of the synthetic AR agonist R1881 (XARcomp) on AR transactivated luciferase activity.

RESULTS

The study groups differed significantly with respect to XARcomp activity, which was increased in the Inuits and decreased in the European study groups; we observed no difference for XAR activity. We found the highest level of the AR antagonist p,p'-DDE in Kharkiv, and accordingly, this study group showed the highest percent of serum samples with decreased XARcomp activities. Furthermore, the percentage of serum samples with decreased XARcomp activities followed the p,p'-DDE serum level for the European study groups. No correlations between serum XAR or XARcomp activities and the two POP markers were revealed.

CONCLUSIONS

The differences in XARcomp serum activity between the study groups suggest differences in chemical exposure profiles, genetics, and/or lifestyle factors.

Androgen receptor gene CAG repeat length as a modifier of the association between persistent organohalogen pollutant exposure markers and semen characteristics

OBJECTIVES

Exposure to persistent organohalogen pollutants was suggested to impair male reproductive function. A gene-environment interaction has been proposed. No genes modifying the effect of persistent organohalogen pollutants on reproductive organs have yet been identified. We aimed to investigate whether the CAG and GGN polymorphisms in the androgen receptor gene modify the effect of persistent organohalogen pollutant exposure on human sperm characteristics.

METHODS

Semen and blood from 680 men [mean (SD) age 34 (10) years] from Greenland, Sweden, Warsaw (Poland) and Kharkiv (Ukraine) were collected. Persistent organohalogen pollutant exposure was assessed by measuring serum levels of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and dichlorodiphenyl dichloroethene (p,p'-DDE). Semen characteristics (volume, sperm concentration, total count, proportion of progressively motile and morphology) and DNA fragmentation index (DFI) were determined. CAG and GGN repeat lengths were determined by direct sequencing of leukocyte DNA.

RESULTS

A statistically significant interaction was found between the CB-153 group and CAG repeat category in relation to sperm concentration and total sperm count (P=0.03 and 0.01, respectively). For p,p'-DDE, in the European cohorts a significant interaction was found in relation to DFI (P=0.01). For CAG<20, sperm concentration and total sperm count were 35 and 42% lower, respectively, when the group with CB-153 exposure above median was compared with that below the median. DFI was 40% higher in the high p,p'-DDE exposure group for CAG<or=21.

CONCLUSIONS

This study indicated that the androgen receptor CAG repeat length might modify the susceptibility of an individual to the adverse effects of persistent organohalogen pollutant exposure on semen quality. Other studies regarding this matter are warranted.

Relationships between sperm DNA fragmentation, sperm apoptotic markers and serum levels of CB-153 and p,p′-DDE in European and Inuit populations

Persistent organochlorine pollutants (POPs) are suspected to interfere with hormone activity and the normal homeostasis of spermatogenesis. We investigated the relationships between sperm DNA fragmentation, apoptotic markers identified on ejaculated spermatozoa and POP levels in the blood of 652 adult males (200 Inuits from Greenland, 166 Swedish, 134 Polish and 152 Ukrainian). Serum levels of 2, 2′, 4, 4′, 5, 5′-hexachlorobiphenyl (CB-153), as a proxy of the total POP burden, and of 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p′-DDE), as a proxy of the total DDT exposure were determined. Sperm DNA fragmentation was measured by using the TUNEL assay, whereas immunofluorescence methods were utilized for detecting pro-apoptotic (Fas) and anti-apoptotic (Bcl-xL) markers. Both TUNEL assay and apoptotic markers were statistically differed across the four populations. No correlation between neither sperm DNA fragmentation nor apoptotic sperm parameters and the large variations in POPs exposure was observed for the separate study groups. However, considering the European populations taken together, we showed that both %TUNEL positivity and Bcl-xL were related to CB-153 serum levels, whereas our study failed to demonstrate any relations between DDE and %TUNEL positivity and apoptotic sperm biomarkers (Fas and Bcl-xL) in any region or overall regions. These results suggest that CB-153 and related chemicals might alter sperm DNA integrity and Bcl-xL levels in European adult males, but not in the highly exposed Inuit men. Additional issues (genetic background, lifestyle habits and characterization of total xeno-hormonal activities) need to be investigated in order to fully assess the population variations observed.

Reproductive hormone levels in men exposed to persistent organohalogen pollutants: a study of inuit and three European cohorts

OBJECTIVE

Persistent organohalogen pollutant (POP) exposure may have a negative impact on reproductive function. The objective of this study was to assess the impact of POP exposure on the male hypothalamo-pituitary-gonadal axis.

PARTICIPANTS

Participants included 184 Swedish fishermen and spouses of pregnant women from Greenland (n = 258), Warsaw, Poland (n = 113) , and Kharkiv, Ukraine (n = 194).

EVALUATIONS/MEASUREMENTS

Serum levels of 2,2,4,4,5,5-hexachlorobiphenyl (CB-153) and dichlorodiphenyl dichloroethene (p,p -DDE) were determined in the four populations, showing different exposure patterns: Swedish fishermen, high CB-153/low p,p -DDE; Greenland, high CB-153/high p,p -DDE; Warsaw, low CB-153/moderate p,p -DDE; Kharkiv, low CB-153/high p,p -DDE. Serum was also analyzed for testosterone, estradiol, sex hormone-binding globulin (SHBG) , inhibin B, luteinizing hormone (LH) , and follicle-stimulating hormone (FSH) . Free testosterone levels were calculated based on testosterone and SHBG.

RESULTS

We found significant center-to-center variations in the associations between exposure and the outcomes. The most pronounced effects were observed in Kharkiv, where statistically significant positive associations were found between the levels of both CB-153 and p,p -DDE and SHBG, as well as LH. In Greenland, there was a positive association between CB-153 exposure and LH. In the pooled data set from all four centers, there was positive association between p,p -DDE and FSH levels [beta = 1.1 IU/L; 95% confidence interval (CI), 1.0-1.1 IU/L]. The association between CB-153 levels and SHBG was of borderline statistical significance (beta = 0.90 nmol/L; 95% CI, -0.04 to 1.9 nmol/L).

CONCLUSIONS

Gonadotropin levels and SHBG seem to be affected by POP exposure, but the pattern of endocrine response is the subject of considerable geographic variation.

Remarkably low incidence of hypospadias in Greenland despite high exposure to endocrine disrupters; possible protective effect of androgen receptor genotype

Endocrine disrupters, such as persistent organohalogen pollutants (POPs) may cause hypospadias, which is a common congenital anomaly in males, affecting 0.2-0.7%. We hypothesized that hypospadias incidence would be high among Greenlanders, who are one of the most POP exposed populations on earth through consumption of contaminated sea mammals. Interestingly, among the 11 076 boys born in Greenland 1982-2002, only two cases of hypospadias were noted (incidence 0.02%; 95% CI: 0.002-0.06). Normal male sexual differentiation is dependent on the androgen receptor (AR). AR function is regulated by polymorphic repeats of CAG and GGN trinucleotide bases. In Greenland 85% were carriers of GGN=23, which in a previous report was less frequent in patients with hypospadias than in the general population. This finding indicates that AR genotype could contribute to a genetic predisposition in Greenlanders, who despite one of the worlds highest body burden of POPs, seem to be protected from hypospadias.

Association between exposure to persistent organohalogen pollutants and epididymal and accessory sex gland function: multicentre study in Inuit and European populations

Exposure to persistent organochlorine pollutants (POPs) may have negative impact on male reproductive function. We, therefore, investigated the association between serum levels of POPs and epididymal and accessory sex gland function. Serum levels of CB-153, p,p'-DDE and seminal markers of epididymal [neutral-alpha glucosidase (NAG)], prostatic [prostate specific-antigen (PSA)] and zinc, and seminal vesicle function (fructose) were measured from 135 Swedish fishermen and fertile men from Greenland (n=163), Warsaw, Poland (n=167) and Kharkiv, Ukraine (n=158). Multiple linear regression analyses, adjusting for potential confounders, were employed using both continuous and categorized exposure variables. Both exposure and outcome variables were log transformed. Considering the consistency between models with either continuous or categorized CB-153 levels, negative associations with the activity of NAG were found among Greenlandic men (mean difference 7.0 mU/ejaculate, 95% CI 3.0, 34), and in the aggregated cohort (mean difference 4.0 mU/ejaculate, 95% CI -0.2, 8.0). A positive association was observed between CB-153 and PSA as well as zinc among Kharkiv men. In the Swedish cohort, a negative association was found between CB-153 and fructose. In conclusion, the negative effects of POP on sperm motility, observed in the same study population might partly be caused by post-testicular mechanisms, involving a decreased epididymal function.

Semen Quality and Exposure to Persistent Organochlorine Pollutants

BACKGROUND

Inconsistent results have been found in previous human studies on male reproductive toxicity of persistent organochlorine pollutants. The majority of studies have been conducted among selected populations of infertility clients or among occupational cohorts including a limited number of participants.

METHODS

We conducted a cross-sectional study of semen quality and serum concentration of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) among 763 men. We included men from all regions in Greenland (n = 194), fishermen from Sweden (n = 185), inhabitants of the city of Kharkiv, Ukraine (n = 195), and inhabitants of the city of Warsaw, Poland (n = 189). Blood samples were analyzed for CB-153 and p,p'-DDE using gas chromatography-mass spectrometry and adjusted for serum lipids.

RESULTS

Sperm concentration was not impaired with increasing serum CB-153 or p,p'-DDE levels in any of the separate groups or overall. Similarly, the proportion of morphologically normal sperm was not associated with either CB-153 or p,p'-DDE blood concentration. However, sperm motility was inversely related to CB-153 concentration in Greenland and the Swedish fishermen population. Across all 4 regions, the sperm motility decreased on average by 3.6% (95% confidence interval = 1.7% to 5.6%) per one-unit increase in the log of blood CB-153 (ng/g lipid). The concentration of p,p'-DDE was negatively associated with sperm motility in the Greenlandic population and in the compiled dataset.

CONCLUSION

Adult exposure to persistent organochlorine pollutants within the ranges observed in the present study is not likely to cause reduction in sperm concentration or morphology. However, higher exposure may be associated with impaired sperm motility.

Dioxin-like activities in serum across European and Inuit populations

BACKGROUND

Persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins/furans, polychlorinated biphenyls (PCBs) and organochlorine pesticides can cause a series of adverse effects on e.g. reproduction in animals and humans, many of which involve the aryl hydrocarbon receptor (AhR). The aim of the present study was to compare the integrated serum level of AhR mediated activity among European and Inuit populations, and evaluate whether the activity was associated to the selected POP markers, 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p'-DDE).

METHODS

The study included 338 males from Greenland (Inuit's), Sweden, Warsaw (Poland) and Kharkiv (Ukraine). The AhR transactivity of serum extracts alone (AhRag) and competitive AhR activity (AhRcomp) upon co-exposure with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were determined in the lipophilic serum fraction containing the POPs using the AhR mediated luciferase reporter Hepa1.12cR cell assay.

RESULTS

The European groups showed higher median level of AhR-TEQ (TCDD toxic equivalents) compared to the Inuit's, whereas higher incidence of Inuits sample further induced AhRcomp activity. Neither AhRag nor AhR-TEQ were correlated to CB-153 or p,p'-DDE for any of the study groups. Multiple regressions showed a significant heterogeneity of association between the CB-153 and the AhRcomp across the study groups, and accordingly a negative association between AhRcomp and CB-153 was found for the Kharkiv group.

CONCLUSION

No consistent correlation between AhR activities and two POP markers was found. Although the difference of AhRag between European and Inuit men could not be explained by CB-153 or p,p'-DDE levels alone, we believe that the variation of AhR serum activity reflects different pattern of POP exposure, genetics and/or life style factors.

Impact of PCB and p,p'-DDE contaminants on human sperm Y:X chromosome ratio: studies in three European populations and the Inuit population in Greenland

OBJECTIVE

Recent studies indicate that persistent organohalogen pollutants (POPs) may contribute to sex ratio changes in offspring of exposed populations. Our aim in the present study was to investigate whether exposure to 2,2 ,4,4 ,5,5 -hexachlorobiphenyl (PCB-153) and dichlorodiphenyldichloroethene (p,p -DDE) affects sperm Y:X chromosome distribution.

SUBJECTS AND METHODS

We obtained semen and blood for analysis of PCB-153 and p,p -DDE levels from 547 men from Sweden, Greenland, Poland (Warsaw), and Ukraine (Kharkiv), with regionally different levels of POP exposure. The proportion of Y- and X-chromosome-bearing sperm in the semen samples was determined by two-color fluorescence in situ hybridization analysis.

RESULTS

Swedish and Greenlandic men had on average significantly higher proportions of Y sperm (in both cohorts, 51.2%) and correspondingly higher lipid-adjusted concentrations of PCB-153 (260 ng/g and 350 ng/g, respectively) compared with men from Warsaw (50.3% and 22 ng/g) and Kharkiv (50.7% and 54 ng/g). In the Swedish cohort, log-transformed PCB-153 and log-transformed p,p -DDE variables were significantly positively associated with Y-chromosome fractions (p-values 0.04 and <0.001, respectively). On the contrary, in the Polish cohort PCB-153 correlated negatively with the proportion of Y-bearing fraction of spermatozoa (p=0.008).

CONCLUSIONS

The present study indicates that POP exposure might be involved in changing the proportion of ejaculated Y-bearing spermatozoa in human populations. Intercountry differences, with different exposure situations and doses, may contribute to varying Y:X chromosome ratios.

Rubidium content in autopsy liver tissue samples from Greenlandic Inuit and Danes measured by X-ray fluorescence spectrometry

BACKGROUND

The biological function of rubidium (Rb) is unknown, but this alkali metal probably has a normal biologic role.

OBJECTIVE

To measure the content of Rb in liver tissue samples from Greenlandic Inuit using X-ray fluorescence spectrometry, and compare the results with those obtained in liver samples from ethnic Danes.

STUDY DESIGN

Observational, descriptive survey on environmental pathology.

METHODS

The setting was related to forensic medicine and hospitalised care in Nuuk, Ilulissat and Copenhagen. Normal liver tissue was obtained at autopsy from 50 Greenlandic Inuit (27 men) with a median age of 61 years (range 23-83) and from 42 Danes (31 men) with a median age of 38 years (range 16-83).

RESULTS

Liver Rb content in Inuit was not significantly different compared with Danes. There was no significant gender difference in liver Rb content either in Inuit or in Danes. The content of Rb given as median (5-95 percentile) was 0.1837mmol/kg dry liver (0.1041-0.3147) in Inuit, and 0.1965mmol/kg dry liver (0.0799-0.2815) in Danes (p=0.6). There was an inverse correlation between liver Rb content and age in Inuit (r(s)=-0.45, p=0.002) but not in Danes. Median hepatic Rb index (Rb content in micromol/kg dry weight divided by age in years) in Inuit was 3.05 and in Danes 4.21 (p=0.02). The correlations between liver Rb and liver potassium content were: Inuit r(s)=0.28, p=0.07; Danes r(s)=0.25, p=0.08; combined series r(s)=0.34, p=0.01.

CONCLUSIONS

Inuit have liver Rb levels, which are quite similar to the levels found in Danes. In Inuit, liver Rb content appears to decrease with age.

Time to pregnancy as a function of male and female serum concentrations of 2,2'4,4'5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE)

BACKGROUND

Persistent organochlorine pollutants (POP) may affect both the female and male reproductive system in animals as well as in humans.

METHODS

Blood samples were collected from pregnant women and their partners from Greenland, Warsaw and Kharkiv, and from a cohort of Swedish fishermen's wives. Blood samples were analysed for 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE). Information on the participants' fertility, measured as time to pregnancy (TTP), was collected. In total, 778 men and 1505 women were included in the analyses.

RESULTS

The data from Warsaw, Kharkiv and the Swedish fishermen's wives indicated no effect of either male or female exposure to POP on TTP. However, among men and women from Greenland, there seemed to be an association between serum concentrations of CB-153 and p,p'-DDE and prolonged TTP. Due to the strong intra-individual correlation between CB-153 and p,p'-DDE in the Greenlandic population, it was not possible to determine whether the risk was associated with CB-153 or p, p'-DDE or was an interaction between the two compounds.

CONCLUSIONS

The overall results of the present study create a somewhat ambiguous pattern, but give some support to the idea that dietary POP exposure might be harmful for couple fertility.

Inter-population variations in concentrations, determinants of and correlations between 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE): a cross-sectional study of 3161 men and women from Inuit and European populations

BACKGROUND

The study is part of a collaborative project (Inuendo), aiming to assess the impact of dietary persistent organochlorine pollutants (POPs) on human fertility. The aims with the present study are to analyze inter-population variations in serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE), to assess inter-population variations in biomarker correlations, and to evaluate the relative impact of different determinants for the inter-individual variations in POP-biomarkers.

METHOD

In study populations of 3161 adults, comprising Greenlandic Inuits, Swedish fishermen and their wives, and inhabitants from Warsaw, Poland and Kharkiv, Ukraine, serum concentrations of CB-153 and p,p'-DDE, were analysed by gas chromatography-mass spectrometry.

RESULTS

The median serum concentrations of CB-153 were for male and female Inuits 200 and 110, for Swedish fishermen 190 and their wives 84, for Kharkiv men and women 44 and 27, and for Warsaw men and women 17 and 11 ng/g lipids, respectively. The median serum concentrations of p,p'-DDE were for Kharkiv men and women 930 and 650, for male and female Inuits 560 and 300, for Warsaw men and women 530 and 380, and for Swedish fishermen 240 and their wives 140 ng/g lipids, respectively. The correlation coefficients between CB-153 and p,p'-DDE varied between 0.19 and 0.92, with the highest correlation among Inuits and the lowest among men from Warsaw. Men had averagely higher serum concentrations of CB-153 and p,p'-DDE, and there were positive associations between age and the POP-biomarkers, whereas the associations with BMI and smoking were inconsistent. Dietary seafood was of importance only in the Inuit and Swedish populations.

CONCLUSION

CB-153 concentrations were much higher in Inuits and Swedish fishermen's populations than in the populations from Eastern Europe, whereas the pattern was different for p,p'-DDE showing highest concentrations in the Kharkiv population. The correlations between the POP-biomarkers varied considerably between the populations, underlining that exposure sources differ and that the choice of representative biomarkers of overall POP exposure has to be based on an analysis of the specific exposure situation for each population. Age and gender were consistent determinants of serum POPs; seafood was of importance only in the Inuit and Swedish populations.

Fatty acid compositions of serum phospholipids of postmenopausal women: a comparison between Greenland Inuit and Canadians before and after supplementation with fish oil

OBJECTIVES

We compared serum phospholipid fatty acid compositions, in particular the status of omega-3 polyunsaturated fatty acid (PUFA), of postmenopausal Greenland Inuit women and postmenopausal Canadian women at baseline and after supplementing the Canadian women with a fish-oil product.

METHODS

Fasting serum samples were collected from 15 Inuit subjects from Greenland and 16 non-Inuit subjects from Canada. In addition, eight Canadian subjects provided fasting serum samples after completing a long-chain omega-3 PUFA intervention (2.4 g of eicosapentaenoic acid [EPA] plus 1.6 g of docosahexaenoic acid [DHA] per day) for 28 d. Fatty acid compositions of serum phospholipids of the samples were determined and compared by one-way analysis of variance.

RESULTS

In comparison with the Greenlanders, baseline Canadian women had 73% and 46% less EPA (20:5omega-3) and DHA (22:6omega-3), respectively, and 32% and 91% more linoleic acid (LA; 18:2omega-6) and arachidonic acid (AA; 20:4omega-6), respectively. The omega-3 supplementation in Canadian women increased DHA and decreased LA levels to approach those in Greenland Inuit and raised EPA levels to surpass (45% higher) those in Greenland women (P < 0.0001). In contrast, AA was only moderately lowered (by 16% overall) such that AA levels remained 62% higher in the supplemented Canadians than in the Greenlanders (P < 0.0001).

CONCLUSIONS

Short-term EPA plus DHA supplementation of postmenopausal North American women can mimic the high EPA and DHA levels and lower LA levels in corresponding Inuit women but not the markedly lower levels of AA. The present findings also support the hypothesis of genetically decreased Delta5-desaturase potential in the Greenland Inuit compared with Canadian postmenopausal women.

The (18)F-fluorodeoxyglucose lumped constant determined in human brain from extraction fractions of (18)F-fluorodeoxyglucose and glucose

Quantification of regional cerebral glucose metabolism (CMRglc) using positron emission tomography and 18F-fluorodeoxyglucose (PET-FDG) requires knowledge of the correction factor between FDG and glucose net clearance, the FDG lumped constant (LC). Because diverging values for LC have been obtained, the authors reevaluated LC by measuring the ratio of the cerebral net extraction fractions of FDG (E*) and glucose (E) from arteriovenous cerebral measurements. Thirty subjects were studied (mean age = 25 +/- 4 years): 12 during a programed infusion of FDG and 18 after a bolus injection of FDG. In the infusion study, LC was calculated as the ratio E*/E. In the bolus study, E* was calculated from the slope of a Patlak-Gjedde plot. Lumped constant was significantly smaller in the infusion study as compared with the bolus study (0.48 +/- 0.16 vs. 0.81 +/- 0.27, P < 0.001). In 4 subjects studied during continuous FDG infusion for 2.5 hours, LC decreased to 0.36 +/- 0.11. These results suggest that the "steady-state" method underestimates LC because E* continues to decline because of significant labeled product. Further, the authors provide evidence for resetting of LC toward a greater value. The subsequent resetting of CMRglc provides a physiologically more meaningful estimate and allows for comparison of CMRglc values between different methodologies.

Haemoglobin concentrations appear to be lower in indigenous Greenlanders than in Danes: assessment of haemoglobin in 234 Greenlanders and in 2804 Danes

OBJECTIVE

To compare haemoglobin concentrations in Greenlanders and Danes.

METHODS

Haemoglobin was measured in a population survey in 1993-1994 comprising 234 indigenous Greenlandic individuals (115 men) aged 19-82 yr. and in Copenhagen County 1983-1984 comprising 2804 Caucasian Danes (1444 men) aged 30-60 yr. The Greenlandic participants were residents in the capital Nuuk (n=70), the town Ilulissat (n=74), and four settlements in the Uummannaq district (n=90). The significance of differences was assessed by Student's t-test, and the xi2-test. Correlations were assessed by Spearman's correlation coefficient (rs).

RESULTS

Greenlanders: Haemoglobin levels were not correlated with age or consumption of traditional foods, and were not significantly different in the three residential areas. Mean haemoglobin was higher in men, 146+/-9.6 (SD) g/L, than in women, 132+/-9.6 g/L (p<0.0001). Mean haemoglobin in iron-replete men with serum ferritin >32 microg/L (n=104) was 146+/-9.3 g/L, and in iron-replete women (n=68) 133+/-10.4 g/L (p<0.0001). The 5th percentile for haemoglobin in iron-replete men was 133 g/L (8.3 mmol/L) and in women 118 g/L (7.3 mmol/L). The prevalence of iron deficiency anaemia (i.e. ferritin <13 microg/L and Hb <5th percentile for iron-replete men and women) was 0% in men, 2.78% in women < or =50 yr of age and 0% in women >50 yr of age. Danes: Mean haemoglobin in men was 154+/-10.0 g/L and in women 138+/-10.4 g/L (p<0.0001). Haemoglobin in iron-replete men (n=1379) (i.e. serum ferritin >32 microg/L) was 154+/-10.7 g/L, and in iron-replete women (n=1003) 140+/-9.6 g/L (p<0.0001). Mean haemoglobin was lower in premenopausal than in postmenopausal women (p<0.0001). The 5th percentile for haemoglobin in iron-replete men was 137 g/L (8.5 mmol/L) and in women 124 g/L (7.7 mmol/L). The prevalence of iron deficiency anaemia (i.e. ferritin <13 microg/L and Hb <5th percentile for iron replete men and women) was 0% in men, 1.92% in women < or =50 yr of age and 0% in women >50 yr of age.

CONCLUSION

Haemoglobin concentrations in Greenlanders were significantly lower than in Danes both in men (p<0.0001) and in women (p<0.0001). Delta(mean haemoglobin) in men was 8.0 g/L (0.5 mmol/L) and in women 6.2 g/L (0.4 mmol/L). Variations in haemoglobin levels may be due to genetic differences.

Arterial calcification as a marker for atherosclerosis in three Arctic populations

Accumulation of calcification in the arterial wall in the course of the atherogenic process is considered to be a manifestation of advanced atherosclerosis. In this study of autopsy specimens from Alaska non-Natives, Alaska Natives, and Greenland Natives, comparisons were made of the prevalence and extent of arterial calcification with that of all raised (advanced) lesions in the thoracic aorta, abdominal aorta, right coronary artery, and left anterior descending coronary artery, to determine the degree to which calcified lesions track the development of advanced lesions. Calcification was determined quantitatively from radiograph images of the fixed specimens; advanced lesion data on these specimens were available from prior studies. Findings show that the prevalence and extent of calcified lesions closely follows the pattern of prevalence and extent of advanced lesions among the groups. We conclude that calcification is a good marker for comparisons of the prevalence and may also provide a good measure of the extent of atherosclerosis in these populations.

Iron status markers in 224 indigenous Greenlanders: influence of age, residence and traditional foods

OBJECTIVE

To evaluate iron status in indigenous Greenlanders and its relationship to gender, age and intake of traditional Greenlandic foods.

METHODS

Serum ferritin, serum transferrin saturation and haemoglobin were evaluated in a population survey in 1993-1994 comprising 224 Greenlandic individuals (109 men) aged 19-82 yr. The participants were residents in the capital Nuuk (n=73) with a predominantly Western style of living, the town Ilulissat (n=60) with a mixture of Western and Greenlandic style of living, and the small town Uummannaq (n=91) with a predominantly Greenlandic style of living. Consumption of traditional foods was assessed by questionnaire.

RESULTS

Intake of traditional foods was more prevalent among elderly than among young individuals and more frequent in Uummannaq than in Ilulissat and Nuuk. Ferritin levels were higher in men than in women (p<0.0001). Median ferritin levels were lowest in Nuuk (men, 92 microg/L; women, 40 microg/L), higher in Ilulissat (men, 104 microg/L; women, 69 microg/L) and in Uummannaq (men, 118 microg/L; women, 46 microg/L) (p<0.001). The prevalence of iron load (ferritin >200 microg/L) was lowest in Nuuk (men: 13.8%, women: 2.3%) intermediate in Ilulissat (men, 11.1%; women, 9.1%) and highest in Uummannaq (men, 32.1%; women, 21.1%). The prevalence of iron depletion (ferritin <16 microg/L) was high in Nuuk (men, 0%; women, 20.5%), and lower in Ilulissat (men, 3.7%; women, 6.1%) and in Uummannaq (men, 0%; women, 10.5%). The prevalence of iron deficiency anaemia (ferritin <13 microg/L and Hb <5th percentile for iron-replete men and women) was 0.92% in men and 0.87% in women. Correlations between age and ferritin were lowest in Nuuk (men, r(s)=0.26, p=0.2; women, r(s)=0.50, p=0.001) intermediary in Ilulissat (men, r(s)=0.37, p=0.06; women, r(s)=0.73, p<0.0001) and highest in Uummannaq (men, r(s)=0.59, p<0.0001; women, rs=0.74, p<0.0001). Intake of traditional foods was correlated with ferritin in men (r(s)=0.29, p=0.01) and women (r(s)=0.40, p<0.0001).

CONCLUSION

The observed differences in estimated body iron stores in Greenlanders from the three residential areas can be explained by differences in the dietary intake of haem iron.

Elements in autopsy liver tissue samples from Greenlandic Inuit and Danes. III. Zinc measured by X-ray fluorescence spectrometry

The aim of the study was to measure the content of zinc (Zn) in liver tissue samples from Greenlandic Inuit using X-ray fluorescence spectrometry, and compare the results with those obtained in liver samples from Danes. Normal liver tissue samples was obtained at autopsy from 50 Greenlandic Inuit (27 men) with a median age of 61 years (range 23-83) and from 74 Danes (44 men) with a median age of 60 years (range 15-87). In the entire series, liver zinc content in Inuit was not significantly different compared with Danes. There was no significant gender difference in liver zinc content either in Inuit or in Danes. The content of zinc given as median (5-95 percentile) was in Inuit 3.809 mmol/kg dry liver (2.355-7.406), and in Danes 3.992 mmol/kg dry liver (2.499-8.645). There was a significant, positive correlation between liver zinc content and age in Danish women (r(s) = 0.43, p = 0.02), which could not be demonstrated in Danish men or in Inuit. Median hepatic zinc index (zinc content in mmol/kg dry weight divided by age in years) in Inuit was 0.073, and in Danes 0.080 (p = 0.3) without any significant difference between the two genders. In Inuit and Danes there was an inverse correlation between hepatic zinc index and age both in the two genders and in the entire series: Inuit: r(s) = -0.62, p < 0.0001; Danes: r(s) = -0.70, p < 0.0001. The results indicate that Inuit have liver zinc levels, which are similar to those found in Danes.

The associations of a marine diet with plasma lipids, blood glucose, blood pressure and obesity among the inuit in Greenland

OBJECTIVE

To analyse the associations between the intake of fish and marine mammals and risk factors for cardiovascular disease, ie lipid profile, fasting blood glucose, blood pressure and obesity, in a population whose average consumption of n-3 fatty acids is high compared with Western countries.

DESIGN

Information was obtained from a population survey in Greenland: interview data, clinical data and fasting blood samples were obtained from a random sample of Inuit from three towns and four villages.

SUBJECTS

Two-hundred and fifty-nine adult Inuit (74% of the sample).

RESULTS

Marine diet was positively associated with serum high-density lipoprotein (HDL) and blood glucose and inversely with very-low-density lipoprotein (VLDL) and triglyceride. Association with low-density lipoprotein (LDL), diastolic and systolic blood pressure, waist-hip ratio and body mass index were inconsistent and not statistically significant. The pattern was similar within groups with low, medium and high consumption of marine food.

CONCLUSIONS

There are statistically significant associations between the consumption of marine food and certain lipid fractions in the blood also in this population with a very high average intake of marine food. The observation that blood glucose is positively associated with marine diet in a population survey is new and should be repeated. There was good agreement between the results for the reported consumption of seal and those for the biomarkers.

SPONSORSHIP

The study was financially supported by the Greenland Home Rule, Directorate of Health and Research, the Commission for Scientific Research in Greenland, and the Danish Medical Research Council.

Concentration of organochlorines in human brain, liver, and adipose tissue autopsy samples from Greenland

Organochlorines are persistent lipophilic compounds that accumulate in Inuit people living in circumpolar countries. Organochlorines accumulate as a result of the Inuits' large consumption of sea mammal fat; however, available data are limited to blood lipids, milk fat, and adipose tissue. We report results of organochlorine determination in liver, brain, omental fat, and subcutaneous abdominal fat samples collected from deceased Greenlanders between 1992 and 1994. Eleven chlorinated pesticides and 14 polychlorinated biphenyl congeners were measured in tissue lipid extracts by high-resolution gas chromatography with electron capture detection. Mean concentrations of polychlorinated biphenyls, 2, 2'-bis(4-chlorophenyl)-1,1-dichloroethylene, ss-hexachlorocyclohexane, hexachlorobenzene, mirex, trans-nonachlor, and oxychlordane in adipose tissue samples from Greenlanders were 3-34-fold higher than those measured using the same analytical method in samples from Canadians in Quebec City, Quebec. Brain lipids contained lower concentrations of all organochlorines than lipids extracted from other tissues. Organochlorine residue levels in lipid extracts from liver, omental fat, and subcutaneous abdominal fat samples were similar, with the exception of ss-hexachlorocyclohexane, which reached a greater concentration in liver lipids than in lipids from both adipose tissues (4-fold; p < 0. 05). Comparisons with available international data on adipose tissue levels reveal that the organochlorine body burden in the Inuit population of Greenland is presently among the highest resulting from environmental exposure.

Concentration of organochlorines in human brain, liver, and adipose tissue autopsy samples from Greenland

Organochlorines are persistent lipophilic compounds that accumulate in Inuit people living in circumpolar countries. Organochlorines accumulate as a result of the Inuits' large consumption of sea mammal fat; however, available data are limited to blood lipids, milk fat, and adipose tissue. We report results of organochlorine determination in liver, brain, omental fat, and subcutaneous abdominal fat samples collected from deceased Greenlanders between 1992 and 1994. Eleven chlorinated pesticides and 14 polychlorinated biphenyl congeners were measured in tissue lipid extracts by high-resolution gas chromatography with electron capture detection. Mean concentrations of polychlorinated biphenyls, 2, 2'-bis(4-chlorophenyl)-1,1-dichloroethylene, ss-hexachlorocyclohexane, hexachlorobenzene, mirex, trans-nonachlor, and oxychlordane in adipose tissue samples from Greenlanders were 3-34-fold higher than those measured using the same analytical method in samples from Canadians in Quebec City, Quebec. Brain lipids contained lower concentrations of all organochlorines than lipids extracted from other tissues. Organochlorine residue levels in lipid extracts from liver, omental fat, and subcutaneous abdominal fat samples were similar, with the exception of ss-hexachlorocyclohexane, which reached a greater concentration in liver lipids than in lipids from both adipose tissues (4-fold; p < 0. 05). Comparisons with available international data on adipose tissue levels reveal that the organochlorine body burden in the Inuit population of Greenland is presently among the highest resulting from environmental exposure.

Factors predicting atracurium reversal time

BACKGROUND

To identify individual factors and combination of factors predictive of reversal time (defined as time from neostigmine administration to train-of-four (TOF) ratio 0.70) from atracurium-induced neuromuscular block, the present study tested the following variables as possible predictors of reversal time: 1) degree of block at the time of antagonism as quantified by first response to TOF or double-burst stimulation (DBS); 2) time from last supplemental dose of atracurium to administration of neostigmine (pre-reversal time); and 3) time from administration of initial atracurium dose to T1 (the magnitude of the first twitch in TOF) recovered to 10% (duration of action of the initial dose of atracurium).

METHODS

The study population comprised 83 female patients, ASA physical status 1 or 2, anaesthetized with fentanyl, thiopental, halothane and nitrous oxide. Initial and supplemental doses of atracurium were 0.5 mg x kg(-1) and 0.15 mg x kg(-1), respectively. Evoked responses to TOF or DBS were recorded mechanomyographically. Neuromuscular block was antagonized with neostigmine, 0.07 mg x kg(-1), at varying time intervals (6-50 min) after the final atracurium dose.

RESULTS

Multiple linear regression analyses testing T1, D1 (the magnitude of the first twitch in DBS), pre-reversal time and duration of action of the initial dose of atracurium, demonstrated that with superficial block, T1 >15%, T1 is the only significant predictor for reversal time. With moderate block, 0< T1 < or =15%, both T1 and duration of action of the initial atracurium dose are significant predictors for reversal time. With profound block, T1=0, duration of action of the initial dose and pre-reversal time are significant predictors for reversal time.

CONCLUSION

1) T1 is a more important predictor for reversal time from atracurium-induced neuromuscular block than D1; 2) predictors differ with the degree of block: with T1 > 15%, T1 is the only significant predictor; with 0< T1 < or =15%, the duration of action of the initial dose and T1 are predictors for reversal time; with T1=0, the duration of action of the initial dose and pre-reversal time predict reversal time.

Apolipoprotein E and atherosclerosis in Greenland Inuit

Arterial, liver, and serum specimens were collected from Greenland Inuit at autopsy and apolipoprotein E genotyping was done on 42 females (mean age = 61.3 years) and 56 males (mean age = 56.8 years). Estimates of the allele frequencies of the apo E, derived from the observed frequencies of the six common apolipoprotein E genotypes, are E2: 0.015+/-0.009; E3: 0.776+/-0.030; and E4: 0.209+/-0.029. No significant difference was found between these frequencies and those previously reported for Greenland Inuit, Canadian Inuit, or Alaska natives; however, differences were observed in comparison with frequencies reported for Japan, Norway, Sweden, USA-Blacks and USA-Whites. Anthropometric data (body mass index, panniculus adiposus thickness), blood analyte levels (total serum cholesterol, HDL-cholesterol, LDL + VLDL-cholesterol, and glycohemoglobin), and prevalence and extent of atherosclerotic lesions in the aorta and coronary arteries were analyzed for any associations with apolipoprotein E genotype. The occurrence of apolipoprotein E2 alleles are very rare and the E4 alleles are slightly more frequent in the Greenland Inuit population as compared to other populations. No significant association between apolipoprotein E genotypes and the extent of atherosclerotic lesions in the aorta and coronary arteries were found, and there does not appear to be any strong evidence for an association of either serum lipids, glycohemoglobin levels, or adiposity measurements to apolipoprotein E genotype in Greenland Inuit.

Mercury accumulations in brains from populations exposed to high and low dietary levels of methyl mercury. Concentration, chemical form and distribution of mercury in brain samples from autopsies

Autopsy samples from 17 Greenlanders and 12 Danes were analysed for total and organic mercury by atomic absorption spectrophotometry, and for cellular localisation by autometallography. The concentration of total mercury in the Greenlanders (median: 174 micrograms Hg/kg wet weight brain tissue, range 59-4782, highest in cerebellum: 492) was found to be significantly higher than in the Danish group (3.7 micrograms Hg/kg w.w., range 1.2-11.8). Furthermore, the total concentration of mercury was positively correlated to age (rho = 0.56, p < 0.05), and the fraction of methyl mercury was negatively correlated to age (rho = -0.66, p < 0.01) among the Greenlanders. This suggests an age dependent accumulation of total mercury and a slow transformation of methyl mercury to inorganic mercury in the brain. The autometallographically demonstrable mercury was primarily located in glia cells.

Effects of dietary seal oil on fat metabolism

In the 1970s, Bang and Dyerberg demonstrated that a high intake of n-3 acids in Greenland protected against ischemic heart disease. This started the interest in fish oil as a preventive component in cardiac disease. The fatty acid composition in Greenlandic diet is quite different from the one in the Danish diet, being lower in saturated fatty acids and polyunsaturated fatty acids (PUFAs) and higher in monounsatured fatty acids (MUFAs). During the last decade, evidence has suggested that the MUFA (18:1) is not a neutral dietary component but has a positive effect of its own. This paper reports on a current project undertaken to study the effect of marine MUFAs and PUFAs on atherosclerosis-related parameters and to evaluate their possible synergistic effect in the prevention of atherosclerosis. The project has recently started, so at the moment results cannot be presented. The study will be carried out as an intervention study on 50 healthy volunteers. Capsules of Greenlandic halibut oil (rich in MUFAs) and "Biomarin" (rich in n-3 PUFAs) will be tested against seal oil.

Communication about health and the risk effect of eating traditional food

Like other populations, the Arctic population has to deal with the fact that specialized information made available to them through environmental and medical research is often difficult to grasp. Not only are the data complicated, they are also often misconstrued through media distortion. Communication is more than just information. Experience with communication gained during a 1990s international autopsy study in Greenland will be presented. The study looked at the possible protective effect against atherosclerosis due to the special fatty acid composition in the traditional food and also the effect of exposure of the local people to heavy metal and organochlorine. "When I eat traditional food, I know who I am" (Inuk).

Regional variation in cardiovascular risk factors and ischemic heart disease mortality in Greenland

In a random sample of 264 indigenous Greenlanders, behavioral and biochemical risk factors for cardiovascular disease were compared between the capital, Nuuk, and the rest of the country ("the Coast") while the whole sample was compared with Denmark. In Nuuk consumption of marine food averaged 23 meals per month, compared with 38 on the Coast. N6/N3 ratio was higher in Nuuk but HDL concentrations were similar. There were fewer current smokers in Nuuk, but the prevalence of hypertension and mortality from ischemic heart disease (IHD) were similar. IHD mortality is lower in Greenland than in Denmark (352 and 434 per 100,000). This is in agreement with the dietary differences, and with the low N6/N3 ratio and the high HDL concentration in Greenland, but opposed to a high proportion of smokers and a high prevalence of hypertension in Greenland compared with Denmark. IHD mortality is apparently decreasing in Greenland concurrently with a Westernization of the lifestyle. This paradox may be due to the fact that societal changes are recent, and the situation may change in the future.

High serum coenzyme Q10, positively correlated with age, selenium and cholesterol, in Inuit of Greenland. A pilot study

Greenlanders (Eskimos) have low prevalence of ischaemic heart disease, partly explained by a lower extent of atherosclerosis and a low n-6/n-3 ratio of polyunsaturated fatty acids. As atherosclerosis is also a result of oxidative stress, the total antioxidative readiness could have a substantial impact. From a health survey we chose the subpopulation from the most remote area, where the traditional Greenlandic diet with high intake of sea mammals and fish predominates. The mean (SD) of S-CoQ10 in males was 1.495 (0.529) nmol/ml and 1.421 (0.629) nmol/ml in females, significantly higher (p < 0.001) compared to a Danish population. In a linear multiple regression model the S-CoQ10 level is significantly positively associated with age and S-selenium in males, and S-total cholesterol in females. The high level of CoQ10 in Greenlanders probably reflects diet, since no bioaccumulation takes place, and it could probably be a substantial part of the antioxidative defense.

EMLA patch for spinal puncture. A comparison of EMLA patch with lignocaine infiltration and placebo patch

We have prospectively assessed pain and anxiety of spinal puncture in 180 adult patients randomly allocated to one of three equal groups. On the morning of surgery group 1 had an EMLA patch, whereas group 2 and 3 had placebo patches. Group 2 also had infiltration analgesia with 2 ml lignocaine 2% with adrenaline, immediately before the block. Spinal anaesthesia was performed with 25 gauge sharp needles without introducer or 25,27 gauge blunt needles with 20,22 gauge introducers. Patients assessed the spinal puncture pain on a 10-cm visual analogue scale immediately after removal of the needle. Pain scores were significantly lower in group 1 (EMLA), median 0.75, than in group 2 (placebo, infiltration analgesia), median 1.75, and group 3 (placebo), median 1.80, p < 0.0001. Pain intensity was less than expected in more patients in the EMLA group than in the other two groups, p = 0.034. However, the decision to accept/reject spinal anaesthesia in the future was not influenced by the pain of lumbar puncture. We conclude that application of an EMLA patch is a simple and effective method to provide adequate analgesia for spinal puncture, which also helps to allay patients' fears of spinal anaesthesia.

New equipment for neuromuscular transmission monitoring: a comparison of the TOF-Guard with the Myograph 2000

OBJECTIVE

The present study is to clarify whether the bias and limits of agreement of the TOF-Guard and the mechanomyograph differ from those of two mechanomyographs on contra lateral arms. Previous studies of the bias and limits of agreement between acceleromyographical (TOF-Guard) and mechanomyographical measurements of neuromuscular transmission did not take the error introduced by using contra lateral arms into consideration.

METHODS

Fifty-two women undergoing gynecological surgery were anesthetized with midazolam, fentanyl, thiopental, halothane and nitrous oxide. Neuromuscular blockade was induced and maintained with atracurium. In 32 patients, neuromuscular monitoring was performed with a Myograph 2000 on one hand and a TOF-Guard at the other (M/T group). In 20 patients, monitoring was performed with a Myograph 2000 at both hands (M/M group). Train-of-four stimulations were applied to the ulnar nerve at the wrist in both groups. Bias and limits of agreement between the contra lateral hands in each group were calculated as proposed by Bland and Altman.

RESULTS

When the TOF ratio was 0.25, TOF ratio bias and limits of agreement in the M/T group were 0.86 and 17.58 to -15.85, respectively. Corresponding values in the M/M group were -1.75 and 12.3 to -8.8. Bias in the M/T group decreased significantly to -8.1 when TOF ratio increased to 0.70, resulting in limits of agreement of 12.1 to -28.4. The corresponding values in the M/M group were bias 2.0 and limits of agreement 10.7 to -6.7. TOF-Guard bias for onset time and time to 5% recovery of T1 (first twitch in TOF) were -19s and -1.5 min, respectively; both values differed significantly from zero (P < 0.05). Taken together with the changing TOF-ratio bias during recovery in the M/T group, these results indicate different onset and recovery curves for the two monitoring devices.

CONCLUSIONS

Due to wide limits of agreement and different recovery courses, acccleromyographic and mechanomyographic recordings of neuromuscular transmission cannot be used interchangeably. The substantial variation between simultaneous mechanomyographical recordings of neuromuscular transmission obtained in contra lateral arms suggests that this factor should be taken into account when studying new neuromuscular monitoring techniques using the two-arm technique.