Gert Mulvad

Exposure of Inuit in Greenland to Organochlorines Through the Marine Diet

High organochlorine concentrations have been found among the Inuit in eastern Canada and in Greenland. The present study was undertaken to assess the exposure to organochlorines in relation to age, sex, and diet in a general population sample of Inuit from Greenland. Survey data and plasma concentrations of 14 polychlorinated biphenyl (PCB) congeners and 16 pesticides, including 5 toxaphene congeners, were recorded in a random population survey of 408 adult indigenous Greenlanders. In a two-stage design, the survey response rate was 66%, and 90% of those randomly selected for blood testing participated. This was equivalent to an overall response rate of 59%. The median plasma concentration of the sum of PCB congeners was 13.3 µg/L; the lipid-adjusted value was 2109 µg/kg. The PCB concentration was twice as high as among the Inuit of Nunavik, Canada, 25 times higher than in a control group from southern Canada, and several times higher than the values found in European studies. Concentrations were similarly elevated for all PCB congeners and pesticides. The PCB congener pattern was similar to previous observations from the eastern Canadian Arctic and Greenland. Concentrations showed statistically significant positive associations with age, marine diet, and male sex in multiple linear regression analyses. The exceptionally high plasma concentrations of several organochlorines among the Inuit of Greenland are attributed to a lifelong high intake of seafood, in particular marine mammals. Concentrations of PCB adjusted for the consumption of marine food increased until approximately 40 yr of age, which is equivalent to the birth cohorts of the early 1950s. The age pattern indicates that bioaccumulation of PCB started in the 1950s, which is a likely date for the introduction of the compounds into the Arctic environment.

Perfluorinated compounds are related to breast cancer risk in greenlandic inuit: A case control study

BackgroundBreast cancer (BC) is the most common cancer for women in the western world. From very few cases an extraordinary increase in BC was observed in the Inuit population of Greenland and Canada although still lower than in western populations. Previous data suggest that exposure to persistent organic pollutants (POPs) might contribute to the risk of BC. Rat studies showed that perfluorinated compounds (PFCs) cause significantly increase in mammary fibroadenomas. This study aimed at evaluating the association between serum levels of POPs/PFCs in Greenlandic Inuit BC cases and their controls, and whether the combined POP related effect on nuclear hormone receptors affect BC risk.MethodsThirty-one BC cases and 115 controls were sampled during 2000-2003 from various Greenlandic districts. The serum levels of POPs, PFCs, some metals and the combined serum POP related effect on estrogen- (ER), androgen- (AR) and Ah-receptor (AhR) transactivity were determined. Independent student t-test was used to compare the differences and the odds ratios were estimated by unconditional logistic regression models.ResultsWe observed for the very first time a significant association between serum PFC levels and the risk of BC. The BC cases also showed a significantly higher concentration of polychlorinated biphenyls at the highest quartile. Also for the combined serum POP induced agonistic AR transactivity significant association to BC risk was found, and cases elicited a higher frequency of samples with significant POP related hormone-like agonistic ER transactivity. The AhR toxic equivalent was lowest in cases.ConclusionsThe level of serum POPs, particularly PFCs, might be risk factors in the development of BC in Inuit. Hormone disruption by the combined serum POP related xenoestrogenic and xenoandrogenic activities may contribute to the risk of developing breast cancer in Inuit. Further investigations are needed to document these study conclusions.

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.European Journal of Clinical Nutrition (2000) 54, 732–737

Mycoplasma genitalium presence, resistance and epidemiology in Greenland

Objectives . Greenland reports the highest rates of chlamydial infection and gonorrhea in the Arctic. Our objective was to determine the presence, and describe the basic epidemiology, of Mycoplasma genitalium for Greenland. Study design . Cross-sectional study. Methods . 314 residents from Nuuk and Sisimiut, between the ages of 15 and 65 years, participated in “Inuulluataarneq” (the Greenland Sexual Health Project) between July 2008 and November 2009. Participants provided self-collected samples for sexually transmitted infection (STI) testing and completed a sexual health survey. Descriptive statistics and logistic regression were used to summarize the basic characteristics of STI cases overall and M. genitalium and Chlamydia trachomatis specifically. Clinically relevant characteristics in each full model were gender (male or female), age (in years), age at sexual debut (in years), number of sexual partners in the past 3 months (continuous) and history of forced sex and community. Results . The overall prevalence of STIs was 19.0%, specifically: 9.8% for M. genitalium and 9.4% for C. trachomatis; 100% of M. genitalium-positive cases carried macrolide resistance determinants. Being female [OR = 3.2; 95% confidence interval (CI): 1.1–9.8] and younger age (OR = 0.9; 95% CI: 0.9–1.0) were associated with M. genitalium positivity. Age was also associated with C. trachomatis (OR = 0.9; 95% CI: 0.8–0.9) and STI positivity overall (OR = 0.9; 95% CI: 0.9–0.9). Conclusions . We observed a high prevalence of M. genitalium and macrolide resistance in this study. A better understanding of M. genitalium sequelae is needed to inform policy around testing, treatment, control and antibiotic use.

Plasma organochlorine concentrations and bone ultrasound measurements: a cross-sectional study in peri-and postmenopausal Inuit women from Greenland.

BackgroundInuit women are highly exposed through their traditional seafood based diet to organochlorine compounds, some of them displaying endocrine disrupting properties. We hypothesized that this exposure might be related to bone characteristics that are altered in osteoporosis, because hormone deficiency is a known risk factor for the disease.MethodsWe measured quantitative ultrasound parameters (QUS) at the right calcaneum of 153 peri- and postmenopausal Inuit women (49–64 year old) from Nuuk, Greenland, and investigated the relation between these parameters and plasma organochlorine concentrations. We used high-resolution gas chromatography with electron capture detection to analyze plasma samples for 14 polychlorinated biphenyls (PCB) congeners and 11 chlorinated pesticides and metabolites. We analysed morning urine samples for cadmium, a potential confounder, by atomic absorption spectrometry. We used a validated questionnaire to document dietary and lifestyle habits as well as reproductive and medical histories.ResultsConcentrations of PCB 153, a surrogate of exposure to most organochlorines present in plasma samples, were inversely correlated to QUS parameters in univariate analyses (p < 0.001). However, PCB 153 concentrations were not associated with QUS values in multivariate analyses that comprised potential confounding factors such as age, body weight, former oral contraceptive use and current hormone replacement therapy (HRT) use, which were all significant predictors of bone stiffness (total R2 = 0.39; p < 0.001).ConclusionOverall we found little evidence that organochlorines exposure is related to osteoporosis in Greenlandic Inuit women, but the hypothesis that exposure to dioxin-like compounds might be linked to decreased bone quality and osteoporosis deserves further attention.

Lead sources in human diet in Greenland

Although blood lead levels have declined in Greenland, they are still elevated despite the fact that lead levels in the Greenland environment are very low. Fragments of lead shot in game birds have been suggested as an important source of dietary exposure, and meals of sea birds, particularly eider, contain high concentrations of lead. In a cross-sectional population survey in Greenland in 1993–1994, blood lead adjusted for age and sex was found to be associated with the reported consumption of sea birds. Participants reporting less than weekly intake of sea birds had blood lead concentrations of approximately 75 μg/L, whereas those who reported eating sea birds several times a week had concentrations of approximately 110 μg/L, and those who reported daily intake had concentrations of 170 μg/L (p = 0.01). Blood lead was not associated with dietary exposure to other local or imported food items.

Decreasing overweight and central fat patterning with Westernization among the Inuit in Greenland and Inuit migrants.

OBJECTIVE: To analyse overweight, obesity and central fat patterning among the Inuit of Greenland and Inuit migrants in Denmark and their relation to Westernization.DESIGN: Cross-sectional, population-based epidemiological study.SUBJECTS: A total of 2046 adult Greenlanders (Inuit), 61% of those invited to participate, living in three areas of Greenland and in Denmark.MEASUREMENTS: Height, weight, waist and hip circumferences were measured and body mass index (BMI in kg/m2) and waist–hip ratio calculated. Sociocultural information was obtained by questionnaire and interview. Westernization was estimated by language and place of residence.RESULTS: The prevalence of obesity (≥30 kg/m2) was 16 and 22% among men and women in Greenland (P=0.004), and 12 and 11%, respectively, in Denmark (NS). Westernization was accompanied by a decrease in the proportion of obese people, in particular among women. Adjusted for BMI, age and Inuit heritage waist circumference decreased with Westernization (among women), while hip circumference did not change. The differences were particularly pronounced for migrants compared with residents of Greenland.CONCLUSION: BMI and central fat patterning decrease with Westernization among Greenland Inuit women contrary to most studies of migrants. The changes were less prominent among men. This suggests a reduced cardiovascular risk profile with Westernization among Greenland Inuit.

Sexual health and sexually transmitted infections in the North American Arctic.

STI rates reported for the Arctic are much higher than those reported for their southern counterparts.

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.

Blood pressure among the Inuit (Eskimo) populations in the Arctic.

Aims: Studies of blood pressure among various Inuit (Eskimo) populations in the Arctic have given inconsistent results. Most studies reported lower blood pressure among the Inuit as compared with the predominantly white national populations. This has been attributed to traditional subsistence practices and lifestyle. This study compared the blood pressure among the major Inuit population groups with other populations and examined the associations with factors like age, gender, obesity and smoking. Methods: The study comprised four Inuit populations from Alaska, Canada, and Greenland with participation rates ranging from 51% to 73%. In a cross-sectional design, 2,509 randomly selected adults from 31 villages were examined. Blood pressure, anthropometric measurements, smoking, and medication were recorded. Results: Mean systolic blood pressures ranged from 116 to 124 mm Hg among men and 110 to 118 among women in the four populations. Mean diastolic blood pressures ranged from 75 to 78 mm Hg among men and from 71 to 73 among women. Systolic blood pressure increased with age. Male gender, obesity, being a non-smoker, and being on anti-hypertensive treatment were associated with high systolic and diastolic blood pressure. Adjusted for age, body mass index, smoking, and anti-hypertensive treatment, blood pressure differed among the populations (p≤0.001). Mean systolic blood pressure was low among the Inuit compared with most European populations of the INTERSALT study, but higher than in several Asian populations and the Amazonian Indians. Conclusions: Inuit blood pressures rank intermediate on a global scale but low in comparison with most European populations. The Inuit population is not homogeneous, and this is reflected in blood pressure differences among the four regional subgroups. The role of the traditional diet, a rural lifestyle with a low level of psychosocial stress, and genetics must be further explored.