Cardiovascular Disease Susceptibility and Resistance in Circumpolar Inuit Populations

Subarachnoid haemorrhage and intracranial aneurysms in Greenland in the period 2018-2021: incidence, outcome and familial disposition

Subarachnoid haemorrhages (SAH) caused by rupture of intracranial aneurysms (IA) are a severe condition. Earlier studies found a higher incidence of SAH in Greenlandic patients compared to Danish patients, with familial aggregation also higher in Greenland. However, updated data is lacking. To investigate the contemporary incidence, outcome, and familial disposition of SAH/IA in Greenlandic patients in 2018-2021. Greenlandic patients diagnosed with ruptured or unruptured IA (UIA) during 2018-2021 were included. Data was obtained from patient files, x-ray department, and discharge registry. Incidence rates were estimated as cases/100,000/year. Direct age-standardised incidence rates were calculated using WHO 2000-2025 as standards. Of 30 SAH patients, 20 (66.7%) were females, 10 (33.3%) males. Of 36 UIA patients, 27 (75.0%) were females, 9 (25.0%) males. For SAH, crude incidence was 13.4/100,000/year, age-standardised incidence was 10.8/100,000/year. Familial history was observed in 30.0% of SAH patients. 5 patients (16.7%) died before treatment, 28-day case-fatality rate (CFR) for all patients was 23.3%. Overall and age-standardised incidence rates were similar to previous studies but higher among females and compared to neighbouring countries. A high occurrence of familial history was reported. SAH remains a serious condition in Greenland, as evidenced by five fatalities before treatment was administered.

Trends in cardiovascular disease among Inuit in Greenland from 1994 to 2021

Background and aims

Cardiovascular disease (CVD) poses significant health challenges globally. While substantial data exists for most populations, the Arctic Inuit's CVD incidence rates remain understudied. This research aimed to change this by estimating CVD incidence and mortality rates in Greenland from 1994 to 2021.

Methods

Using nationwide registers, a retrospective observational study was conducted, focusing on individuals born in Greenland to Greenlandic-born parents. Data were sourced from the Greenlandic Hospital Discharge Register and the nationwide electronic medical record.

Results

A total of 65,824 individuals were included. the age- and sex-specific incidence rates (IR) of ischemic heart disease, stroke, and heart failure (HF) declined from 1994 to 2021, with the most substantial decline observed for HF among women. Conversely, the IR of atrial fibrillation/flutter increased in both men and women, while the IR of myocardial infarction rose among men. The IR for stroke was particularly elevated compared to other CVD subgroups. Mortality rates for those diagnosed with CVD were 2.4 times higher than those without. Men exhibited a 40 % elevated mortality risk relative to women.

Conclusion

The study provides pivotal insights into CVD trends within the Arctic Inuit population, highlighting both positive developments and areas of concern. Given the increasing elderly demographic in Greenland, proactive health strategies are crucial. Emphasizing primary prevention and addressing specific CVD risks, particularly the elevated stroke IR, is imperative for future public health efforts.

Overview of health research in Greenland from 2001 to 2020

AIMS

Health research in Greenlanders is challenged by a small population, few dedicated researchers and limited funding. Some research areas have proven impactful but gaps in knowledge are unknown. We aimed to quantify health research in Greenland, providing insights for researchers, policymakers and funding agencies to guide future research.

METHODS

We identified all peer-reviewed health research publications with the term 'Greenland***' in title or abstract from 2001 to 2020 through the platform entitled The Lens. Our bibliometric analysis included number of publications, publication rate, research types, research topics, citations and author affiliations, as well as funding.

RESULTS

From 2001 to 2020, a total of 640 health research publications concerning Greenland or Greenlanders were identified, with an average annual publication growth rate of 2.9%. The major health research topics studied in Greenland were infectious diseases, environmental health and general health. Several research fields, including rheumatology, nephrology and dermatology among others proved understudied at best. Three Danish universities contributed with 33% of all publications, with the International Journal of Circumpolar Health (N=176, 28%) being the top journal destination. The most productive author had 119 article authorships during the period.

CONCLUSION

During the past 20 years, Greenland's annual publication rate has been steadily increasing, with an average of 32 articles about health research published each year, which is a higher publication rate than world average. The health research in Greenland is primarily epidemiologic with infectious disease being the most studied research area. Most publications were anchored in Denmark and centred around a few highly productive authors.

Case-Control Study of the Association between Single Nucleotide Polymorphisms of Genes Involved in Xenobiotic Detoxification and Antioxidant Protection with the Long-Term Influence of Organochlorine Pesticides on the Population of the Almaty Region

The association of genetic polymorphisms with the individual sensitivity of humans to the action of pesticide pollution is being actively studied in the world. The aim of this study was a molecular epidemiological analysis of candidate polymorphisms of genes involved in pesticide metabolism, detoxification, and antioxidant protection. Some of the selected polymorphisms also relate to susceptibility to cancer and cardiovascular, respiratory, and immune system diseases in individuals exposed to pesticides for a long time. For a case-control study of a unique cohort of people exposed to organochlorine pesticides for 10 years or more were chosen, a control cohort was selected that matched with the experimental group by the main population characteristics. PCR-PRLF and genome-wide microarray genotyping (GWAS) methods were used. We identified 17 polymorphisms of xenobiotic detoxification genes and 27 polymorphisms of antioxidant defense genes, which had a significantly high statistical association with the negative impact of chronic pesticide intoxication on human health. We also found 17 polymorphisms of xenobiotic detoxification genes and 12 polymorphisms of antioxidant defense genes that have a protective effect. Data obtained added to the list of potential polymorphisms that define a group at high risk or resistant to the negative effects of pesticides.

Individual Risk Assessment for Population Living on the Territories Long-Term Polluted by Organochlorine Pesticides

The long-term storage of unutilized pesticides raised new problems of long-term environmental contamination. The study presents the results of surveying 151 individuals in 7 villages living close to pesticide-contaminated localities. All individuals have been surveyed concerning their consumption habits and lifestyle characteristics. An assessment of the general exposure risks of the local population was carried out using the analysis of pollutants in food products and the average levels of their consumption in the region. The cohort risk evaluation revealed that the greatest risk was associated with the regular consumption of cucumbers, pears, bell peppers, meat, and milk. The new model to estimate individual risks of long-term pesticide pollution was proposed as a calculation of the combined action of 9 risk factors, including individual genotypes, age, lifestyle, and personal pesticide consumption rates. The analysis of the predictive ability of this model showed that the final score for individual health risks corresponded to the development of chronic diseases. A high level of chromosomal aberrations was evidenced for individual genetic risk manifestations. The combined influence of all risk factors revealed contributions of 24.7% for health status and 14.2% for genetic status, while other impacts go to all unaccounted factors.

Dyslipidemia and the preventive potential in the Greenlandic population

Background

Low-density lipoprotein cholesterol (LDL-C) is a well-established risk factor for development of cardiovascular diseases. Based on available clinical data, we aimed to investigate the plasma lipid profile in the Greenlandic population, the proportion on cholesterol-lowering treatment and the adherence to local indications for cholesterol-lowering therapy.

Methods

This is an observational cross-sectional study of the adult (≥21 years) Greenlandic population with focus on clinically determined lipid levels from 2017 to early 2022. We investigated levels of dyslipidemia and assessed cholesterol-lowering medication usage in individuals with an indication according to current Greenlandic guidelines, which include a) LDL-C >5 mmol/l, b) diabetes, c) diagnosed atherosclerotic disease and 4) a SCORE2 >7.5%.

Results

In the adult Greenlandic population of 40,565 individuals a lipid profile was available in 13,895 with a mean LDL-C of 3.0 mmol/L and 976 (7%) had a LDL-C >5 mmol/l. One or more indications for cholesterol-lowering medication was present in 3988 individuals and a total of 5464 adult Greenlanders either fulfilled local criteria for statin therapy or received a statin (some without current indication) and among these, 2232 (41%) individuals received no statin.

Conclusion

These findings indicate that clinically significant dyslipidemia is common in the adult Greenlandic population and that the cardiovascular preventive potential of cholesterol-lowering therapy is currently underutilized.

An LDLR missense variant poses high risk of familial hypercholesterolemia in 30% of Greenlanders and offers potential of early cardiovascular disease intervention

The common Arctic-specific LDLR p.G137S variant was recently shown to be associated with elevated lipid levels. Motivated by this, we aimed to investigate the effect of p.G137S on metabolic health and cardiovascular disease risk among Greenlanders to quantify its impact on the population. In a population-based Greenlandic cohort (n = 5,063), we tested for associations between the p.G137S variant and metabolic health traits as well as cardiovascular disease risk based on registry data. In addition, we explored the variant’s impact on plasma NMR measured lipoprotein concentration and composition in another Greenlandic cohort (n = 1,629); 29.5% of the individuals in the cohort carried at least one copy of the p.G137S risk allele. Furthermore, 25.4% of the heterozygous and 54.7% of the homozygous carriers had high levels (>4.9 mmol/L) of serum LDL cholesterol, which is above the diagnostic level for familial hypercholesterolemia (FH). Moreover, p.G137S was associated with an overall atherosclerotic lipid profile, and increased risk of ischemic heart disease (HR [95% CI], 1.51 [1.18–1.92], p = 0.00096), peripheral artery disease (1.69 [1.01–2.82], p = 0.046), and coronary operations (1.78 [1.21–2.62], p = 0.0035). Due to its high frequency and large effect sizes, p.G137S has a marked population-level impact, increasing the risk of FH and cardiovascular disease for up to 30% of the Greenlandic population. Thus, p.G137S is a potential marker for early intervention in Arctic populations.

Heart disease among Greenlandic children and young adults: a nationwide cohort study

BACKGROUND

The incidences of heart disease (HD) and congenital heart disease (CHD) among Inuit in Greenland (GL) and Denmark (DK) are unknown. This study aims to estimate incidence rates (IRs) of HD and CHD among the young Inuit populations in Greenland and Denmark compared with rates among young non-Inuit populations in the same countries.

METHODS

A register-based nationwide cohort including all individuals living in Greenland and Denmark from birth to age <40 years through 1989-2014 was formed. Ethnicity was considered Inuit/mixed if at least one parent was registered as being born in Greenland. Information on HD and CHD hospitalization was obtained from national inpatient registers using ICD-8 and ICD-10 codes.

RESULTS

HD IR was lower among individuals living in Greenland compared with those living in Denmark, [73.35GL (95% confidence interval (CI) 68.07 to 79.03)] vs [88.07DK (95% CI 87.38 to 88.76)], whereas CHD IRs were almost similar in the two countries [IR 34.44GL (95% CI 30.89 to 38.40) vs IR 34.67DK (95% CI 34.24 to 35.10)]. Being of Inuit/mixed ethnicity was associated with an increased risk of both HD and CHD compared with non-Inuit in Greenland and Denmark [adjusted hazard ratio HD 2.07GL (95% CI 1.25 to 3.42)] and CHD [2.92GL (95% CI 1.34 to 6.38)].

CONCLUSION

HD IR was lower in individuals living in Greenland compared with individuals living in Denmark, whereas the CHD IRs were almost the same for both countries. However, the risk of HD including CHD was higher among individuals of Inuit/mixed ethnicity compared with non-Inuit in both countries, suggesting a role of ethnicity among children and younger adults.

Food Reward after a Traditional Inuit or a Westernised Diet in an Inuit Population in Greenland

The food availability and dietary behaviours in Greenland have changed with increasing Westernisation. Food reward is an important driver of food choice and intake, which has not previously been explored in the Arctic population. The aim of this study was to explore differences in food reward after a four-week intervention period with a traditional Inuit diet (TID) or Westernised diet (WD) in Inuit populations in Northern and Western Greenland. This cross-sectional analysis included 44 adults (n = 20 after TID and n = 24 after WD). We assessed the food reward components, explicit liking and implicit wanting, using the Leeds Food Preference Questionnaire under standardised conditions 60 min after drinking a glucose drink as part of an oral glucose tolerance test after four weeks following a TID or WD. The food intake was assessed using food frequency questionnaires. The intervention groups differed only in implicit wanting for high-fat sweet foods, with higher implicit wanting among the participants following TID compared to WD. Both groups had lower explicit liking and implicit wanting for sweet relative to savoury foods and for high-fat relative to low-fat foods. This exploratory study can guide future studies in Inuit populations to include measures of food reward to better understand food intake in the Arctic.

Metabolic features of adiposity and glucose homoeostasis among school-aged inuit children from Nunavik (Northern Quebec, Canada)

In contrast to most Indigenous people in Canada, Inuit appeared until recently to have been protected from type 2 diabetes (T2D) related to obesity. We assessed the associations of metabolites (amino acids, acylcarnitines) with adiposity and biomarkers of T2D in school-aged Inuit children of Nunavik (Canada). Concentrations of metabolite were measured in plasma samples from a cross-sectional analysis of 248 children (mean age = 10.8 years). We assessed associations of plasma metabolites with adiposity measures (BMI, skinfold thicknesses) and T2D markers (insulin, glucose, adiponectin). Plasma concentrations of valine and tyrosine were higher in obese and overweight children compared to those of normal weight children (P < 0.05). An increment of 1-SD in BMI (SD = 3.3 kg/m²) was statistically associated with an increment of 0.21 (95% CI: 0.08, 0.33) for valine, 0.15 (95% CI: 0.02, 0.27) for isoleucine and 0.17 (95% CI: 0.04, 0.29) for tyrosine. Insulin concentration increased with concentrations of all amino acids (P < 0.05) except methionine. None of the acylcarnitines measured were statistically significantly associated with adiposity or T2D biomarkers A signature of metabolites, particularly higher levels of branched-chain amino acids, might allow for early detection of T2D among school-aged Inuit children.

The effect of diabetes and the common diabetogenic TBC1D4 p.Arg684Ter variant on cardiovascular risk in Inuit in Greenland

Cardiovascular disease (CVD) is a well-known complication of diabetes, but the association has not been studied among Inuit in Greenland. The aim was to examine the association between diabetes and incident CVD among Inuit in Greenland and determine if the common diabetogenic TBC1D4 variant confers increased risk of CVD. We followed an initial study population of 4127 adults in Greenland who had participated in at least one population-based health survey, in national registers. We used Poisson regression to calculate incidence rate ratios (IRR) of cardiovascular endpoints, comparing participants with and without diabetes and comparing homozygous TBC1D4 carriers with heterozygous carriers and non-carriers combined. Close to 10% had diabetes and age range was 18–96 years (45% male). Of the 3924 participants without prior CVD, 362 (~ 9%) had CVD events during a median follow-up of 10 years. Multivariate IRR for the effect of diabetes on CVD was 1.12 (95% CI: 0.80, 1.57) p = 0.50. Using a recessive genetic model, we compared homozygous TBC1D4 carriers with wildtype and heterozygous carriers combined, with a multivariate IRR of 1.20 (95% CI: 0.69, 2.11) p = 0.52. Neither diabetes nor the TBC1D4 variant significantly increased CVD risk among Inuit in Greenland in adjusted models.

Abdominal visceral and subcutaneous adipose tissue and associations with cardiometabolic risk in Inuit, Africans and Europeans: a cross-sectional study

OBJECTIVES

Abdominal fat has been identified as a risk marker of cardiometabolic disease independent of overall adiposity. However, it is not clear whether there are ethnic disparities in this risk. We investigated the associations of visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue (SAT) with cardiometabolic risk factors in three ethnic diverse populations of Inuit, Africans and Europeans.

DESIGN

Cross-sectional pooled study.

SETTING

Greenland, Kenya and Denmark.

METHODS

A total of 5113 participants (2933 Inuit, 1397 Africans and 783 Europeans) from three studies in Greenland, Kenya and Denmark were included. Measurements included abdominal fat distribution assessed by ultrasound, oral glucose tolerance test, hepatic insulin resistance, blood pressure and lipids. The associations were analysed using multiple linear regressions.

RESULTS

Across ethnic group and gender, an increase in VAT of 1 SD was associated with higher levels of hepatic insulin resistance (ranging from 14% to 28%), triglycerides (8% to 16%) and lower high-density lipoprotein cholesterol (HDL-C, -1.0 to -0.05 mmol/L) independent of body mass index. VAT showed positive associations with most of the other cardiometabolic risk factors in Inuit and Europeans, but not in Africans. In contrast, SAT was mainly associated with the outcomes in Inuit and Africans. Of notice was that higher SAT was associated with higher HDL-C in African men (0.11 mmol/L, 95% CI: 0.03 to 0.18) and with lower HDL-C in Inuit (-0.07 mmol/L, 95% CI: -0.12 to -0.02), but not in European men (-0.02 mmol/L, 95% CI: -0.09 to 0.05). Generally weaker associations were observed for women. Furthermore, the absolute levels of several of the cardiometabolic outcomes differed between the ethnic groups.

CONCLUSIONS

VAT and SAT were associated with several of the cardiometabolic risk factors beyond overall adiposity. Some of these associations were specific to ethnicity, suggesting that ethnicity plays a role in the pathway from abdominal fat to selected cardiometabolic risk factors.

A descriptive study of ten-year longitudinal changes in weight and waist circumference in the multi-ethnic rural Northern Norway. The SAMINOR Study, 2003-2014

The obesity epidemic is dynamic with varying secular trends and differences between countries and ethnic groups. The objective of this study was to describe the age- and sex-specific longitudinal changes in weight and waist circumference in a rural Norwegian population with a high proportion of the indigenous Sami population. Based on two population-based surveys, SAMINOR 1 (2003-2004) and SAMINOR 2 (2012-2014), we present longitudinal changes in weight and waist circumference according to age at baseline in the SAMINOR 1 Survey and sex during the 10-year period. The analyses included 1538 men and 1958 women aged 36 to 69 at baseline (birth year 1934 to 1967). Forty-one percent of the population were Sami. Both weight and waist circumference were measured. The mean weight increased 0.8 kg (95% confidence interval: 0.5, 1.1) in men and 0.3 kg (95% confidence interval: 0, 0.5) in women. In both men and women, younger individuals gained significantly more weight during the 10-year follow-up than older participants (p < 0.001). The mean weight showed a statistically significant increase in men aged 36-54 and women aged 36-49 at baseline and was statistically significantly reduced in men and women aged 60-69. The mean waist circumference increased by 6.3 cm (95% confidence interval: 6.0, 6.6) in men and 8.4 cm (95% confidence interval 8.1, 8.8) in women. The mean waist circumference increased statistically significantly from SAMINOR 1 to SAMINOR 2 in all age groups, and there was an inverse relationship between age at baseline and change in waist circumference (p < 0.001). Waist circumference increased more than can be explained by changes in weight and age during the 10-year period. The inverse relationships between age at baseline in SAMINOR 1 and the 10-year change in weight and waist circumference were found in both Sami and non-Sami participants. The findings underline the need for prevention of obesity, particularly in younger people, as it is difficult to achieve permanent weight loss.

Changes in conventional cardiovascular risk factors and the estimated 10-year risk of acute myocardial infarction or cerebral stroke in Sami and non-Sami populations in two population-based cross-sectional surveys: the SAMINOR Study

OBJECTIVE

To describe changes in cardiovascular risk factors and in the estimated 10-year risk of acute myocardial infarction (AMI) or cerebral stroke (CS) between SAMINOR 1 (2003-2004) and SAMINOR 2 (2012-2014), and explore if these changes differed between Sami and non-Sami.

DESIGN

Two cross-sectional surveys.

SETTING

Inhabitants of rural Northern Norway.

PARTICIPANTS

Participants were aged 40-79 years and participated in SAMINOR 1 (n=6417) and/or SAMINOR 2 (n=5956).

PRIMARY OUTCOME MEASURES

Generalised estimating equation regressions with an interaction term were used to estimate and compare changes in cardiovascular risk factors and 10-year risk of AMI or CS between the two surveys and by ethnicity.

RESULTS

Mean cholesterol declined by 0.50, 0.43 and 0.60 mmol/L in women, Sami men and non-Sami men, respectively (all p<0.001). Sami men had a small decline in mean high-density lipoprotein (HDL) cholesterol and an increase in mean triglycerides (both p<0.001), whereas non-Sami showed no change in these variables. Non-Sami women had an increase in mean HDL cholesterol (p<0.001) whereas Sami women had no change. Triglycerides did not change in non-Sami and Sami women. Systolic and diastolic blood pressure declined by 3.6 and 1.0 mm Hg in women, and 3.1 and 0.7 in men, respectively (all p<0.01). Mean waist circumference increased by 6.7 and 5.9 cm in women and men, respectively (both p<0.001). The odds of being a smoker declined by 35% in women and 46% in men (both p<0.001). Estimated 10-year risk of AMI or CS decreased in all strata of sex and ethnicity (p<0.001), however, Sami women had a smaller decline than non-Sami did.

CONCLUSIONS

Independent of ethnicity, there was a decline in mean cholesterol, blood pressure, smoking, hypertension (women only) and 10-year risk of AMI or CS, but waist circumference increased. Relatively minor ethnic differences were found in changes of cardiovascular risk factors.

Validation of cardiovascular diagnoses in the Greenlandic Hospital Discharge Register for epidemiological use

Cardiovascular disease (CVD) is one of the leading causes of death worldwide. In Greenland, valid estimates of prevalence and incidence of CVD do not exist and can only be calculated if diagnoses of CVD in the Greenlandic Hospital Discharge Register (GHDR) are correct. Diagnoses of CVD in GHDR have not previously been validated specifically. The objective of the study was to validate diagnoses of CVD in GHDR. The study was conducted as a validation study with primary investigator comparing information in GHDR with information in medical records. Diagnoses in GHDR were considered correct and thus valid if they matched the diagnoses or the medical information in the medical records. A total of 432 online accessible medical records with a cardiovascular diagnosis according to GHDR from Queen Ingrid's Hospital from 2001 to 2013 (n=291) and from local health care centres from 2007 to 2013 (n=141) were reviewed. Ninety-nine and ninety-two percent of discharge diagnosis in GHDR from Queen Ingrid's Hospital and local health care centres were correct in comparison with diagnoses in the medical record indicating valid registration practice. The correctness of cardiovascular diagnoses in GHDR was considered high in terms of acceptable agreement between medical records and diagnoses in GHDR. Cardiovascular diagnoses are valid for epidemiological use.

Genetics of metabolic traits in Greenlanders: lessons from an isolated population

In this review, we describe the extraordinary population of Greenland, which differs from large outbred populations of Europe and Asia, both in terms of population history and living conditions. Many years in isolation, small population size and an extreme environment have shaped the genetic composition of the Greenlandic population. The unique genetic background combined with the transition from a traditional Inuit lifestyle and diet, to a more Westernized lifestyle, has led to an increase in the prevalence of metabolic conditions like obesity, where the prevalence from 1993 to 2010 has increased from 16.4% to 19.4% among men, and from 13.0% to 25.4% among women, type 2 diabetes and cardiovascular diseases. The genetic susceptibility to metabolic conditions has been explored in Greenlanders, as well as other isolated populations, taking advantage of population-genetic properties of these populations. During the last 10 years, these studies have provided examples of loci showing evidence of positive selection, due to adaption to Arctic climate and Inuit diet, including TBC1D4 and FADS/CPT1A, and have facilitated the discovery of several loci associated with metabolic phenotypes. Most recently, the c.2433-1G>A loss-of-function variant in ADCY3 associated with obesity and type 2 diabetes was described. This locus has provided novel biological insights, as it has been shown that reduced ADCY3 function causes obesity through disrupted function in primary cilia. Future studies of isolated populations will likely provide further genetic as well as biological insights.

Polyunsaturated Fatty Acids and Their Potential Therapeutic Role in Cardiovascular System Disorders-A Review

Cardiovascular diseases are described as the leading cause of morbidity and mortality in modern societies. Therefore, the importance of cardiovascular diseases prevention is widely reflected in the increasing number of reports on the topic among the key scientific research efforts of the recent period. The importance of essential fatty acids (EFAs) has been recognized in the fields of cardiac science and cardiac medicine, with the significant effects of various fatty acids having been confirmed by experimental studies. Polyunsaturated fatty acids are considered to be important versatile mediators for improving and maintaining human health over the entire lifespan, however, only the cardiac effect has been extensively documented. Recently, it has been shown that omega-3 fatty acids may play a beneficial role in several human pathologies, such as obesity and diabetes mellitus type 2, and are also associated with a reduced incidence of stroke and atherosclerosis, and decreased incidence of cardiovascular diseases. A reasonable diet and wise supplementation of omega-3 EFAs are essential in the prevention and treatment of cardiovascular diseases prevention and treatment.

Distribution of risk factors for cardiovascular disease and the estimated 10-year risk of acute myocardial infarction or cerebral stroke in Sami and non-Sami populations: The SAMINOR 2 Clinical Survey

Objective: This study aimed to assess and compare the distribution of cardiovascular risk factors and the estimated 10-year risk of fatal or non-fatal acute myocardial infarction (AMI) or cerebral stroke (CS) among the Sami and non-Sami populations of Northern Norway. Methods: The SAMINOR 2 Clinical Survey is a cross-sectional survey conducted in 10 municipalities in the counties of Finnmark, Troms and Nordland in rural Northern Norway in 2012–2014. All inhabitants aged 40–79 years were invited to participate, and 6004 (48.2%) accepted. The NORRISK 2 model was used to estimate the 10-year risk of fatal or non-fatal AMI or CS. Sex and age were included in the model, as well as the following risk factors for cardiovascular disease (CVD): serum total cholesterol, serum high-density lipoprotein cholesterol, systolic blood pressure, smoking habits and anti-hypertensive treatment. Results: Only minor ethnic differences were observed between Sami and non-Sami populations in a number of individual risk factors for CVDs. Overall, the NORRISK 2 model revealed no ethnic differences in the 10-year risk of AMI or CS. Conclusions:There were no differences in 10-year risk of AMI or CS between the Sami and non-Sami populations in 10 selected municipalities in Northern Norway.

Prevalence of pre-diabetes and type 2 diabetes mellitus among Sami and non-Sami men and women in Northern Norway - The SAMINOR 2 Clinical Survey

The aim of this study was to determine and compare the prevalence of pre-diabetes and type 2 diabetes mellitus (T2DM) among Sami and non-Sami men and women of rural districts in Northern Norway. The SAMINOR 2 Clinical Survey is a cross-sectional population-based study performed in 2012–2014 in 10 municipalities of Northern Norway. A total of 12,455 Sami and non-Sami inhabitants aged 40–79 years were invited to participate and 5878 were included in the analyses. Participants with self-reported T2DM and/or a glycated haemoglobin (HbA1c) result ≥6.5% were categorised as having T2DM. Those with 5.7%≤HbA1c<6.5% were categorised as pre-diabetics. In men, the total age-standardised prevalence of pre-diabetes (37.9% vs 31.4%) and T2DM (10.8% vs 9.5%) were higher in Sami compared with non-Sami; the ethnic difference was statistically significant for both pre-diabetes (OR 1.42, p < 0.001) and T2DM (OR 1.31, p = 0.042). In women, pre-diabetes (36.4% vs 33.5%) and T2DM (8.6% vs 7.0%) were also more common in Sami than non-Sami; the differences in both pre-diabetes (OR 1.20, p = 0.025) and T2DM (OR 1.38, p = 0.021) were also statistically significant. The observed ethnic difference in the waist-to-height ratio (WHtR) was a plausible explanation for the ethnic difference in the prevalence of pre-diabetes and T2DM.

Association of blood polychlorinated biphenyls and cholesterol levels among Canadian Inuit

BACKGROUND

It has generally been thought that Inuit populations have low risk of cardiovascular disease due to high consumption of omega-3 fatty acids found in traditional marine-based diets. However, results of recent surveys showed that Inuit populations are experiencing increasing rates of cardiovascular disease and related risk factors.

OBJECTIVE

The purpose of this study was to investigate if blood polychlorinated biphenyls (PCBs) are associated with high cholesterol and related parameters in Canadian Inuit, known risk factors for cardiovascular disease.

METHODS

The Adult Inuit Health Survey (IHS, 2007-2008) included 2595 Inuit participants from three regions of the Canadian Arctic, of which 2191 could be classified as with or without high cholesterol. The high cholesterol outcome was defined by LDL-C > 3.36mmol/L or taking medication(s) that reduce cholesterol, and was examined in adjusted logistic regression models with individual blood levels of PCB congeners, sum of dioxin-like PCBs (∑DL-PCBs), or sum of non-dioxin-like PCBs (∑NDL-PCBs). Statistically significant covariates for high cholesterol were ranked in importance according to the proportion of the model log likelihood explained. Continuous clinical parameters of total cholesterol, triglycerides, LDL-C, and HDL-C were examined in multiple linear regression models with ∑DL-PCBs or ∑NDL-PCBs.

RESULTS

A total of 719 participants had high cholesterol (32.8%). PCBs were associated with increased risk of high cholesterol, and higher levels of serum triglycerides, total cholesterol, and LDL-C. No association was observed between PCBs and serum HDL-C. With respect to other statistically significant covariates for high cholesterol, the log likelihood ranking of PCBs generally fell between body mass index (BMI) and age.

CONCLUSION

Further work is needed to corroborate the associations observed with PCBs and lipids in Canadian Inuit and to examine if they are causal in the direction anticipated.

Associations between vitamin D status and atherosclerosis among Inuit in Greenland

BACKGROUND AND AIMS

Low levels of vitamin D are suspected to be a risk factor for cardiovascular disease and atherosclerosis. The aim of this study was to assess the prevalence of subclinical atherosclerosis among Inuit in Greenland, and to evaluate the association with vitamin D status. We hypothesized that low vitamin D status could be associated with higher carotid intima-media thickness (IMT) as a marker of atherosclerosis.

METHODS

756 adults from the Inuit Health in Transition (IHIT) study carried out in Greenland in the period 2005-2010 were included. A blood sample donated in 1987 was available for a sub-sample of 102 individuals. Serum 25(OH)D3 from the IHIT study and the 1987 survey was used as a measure of vitamin D status. IMT measurements were conducted by ultrasound scanning. The prevalence of atherosclerosis was estimated, and the association between serum 25(OH)D3 and IMT measurements was examined by linear regression.

RESULTS

The overall prevalence of subclinical atherosclerosis was 20.1% (n = 152). The linear regression analyses indicated a weak positive association between serum 25(OH)D3 level and IMT measurements from the IHIT study, though not statistically significant after adjustment for potential confounders (β = 0.35% per 10 nmoL/L 25(OH)D3, p = 0.06). Linear regression analyses of the association between serum 25(OH)D3 level in the 1987 survey and IMT measurements also indicated a positive, though not statistically significant, association after adjustment (β = 0.07% per 10 nmoL/L 25(OH)D3, p = 0.86).

CONCLUSIONS

Our findings did not support the hypothesis of an association between low vitamin D levels and risk of atherosclerosis.

Evaluation of epigenetic alterations (mir-126 and mir-155 expression levels) in Mexican children exposed to inorganic arsenic via drinking water

Recently, a great number of epidemiological studies have shown evidence that exposure to inorganic arsenic could have harmful effects on the cardiovascular system of humans. However, the underlying mechanisms through which arsenic induces cardiovascular toxic effects remain unclear. In this regard, epigenetic mechanisms have emerged as a probable connection between environment and disease phenotypes, including cardiovascular diseases. Therefore, this study aimed to evaluate epigenetic changes related to cardiotoxicity (miR-126 and miR-155 expression levels) in children from San Luis Potosi, Mexico exposed to inorganic arsenic. From 2014 to 2015, in a cross-sectional study, children (aged 6-12 years; n = 73) attending public schools at the studied sites were enrolled to take part in this study. Urinary arsenic was used as an exposure biomarker and analyzed by an atomic absorption spectrophotometry technique. On the other hand, miR-126 and miR-155 expression levels were evaluated by qRT-PCR. A mean urinary arsenic level of 30.5 ± 25.5 μg/g of creatinine was found. Moreover, the data showed a significant negative association (p < 0.05) between urinary arsenic concentrations and plasma miR-126 levels. However, an association between urinary arsenic concentrations and plasma miR-155 levels was not found (p > 0.05). In this regard, some investigations have shown an association between diminished plasma miR-126 levels and cardiovascular illnesses. The results found in this study are of concern. However, more similar studies including a larger sample size are necessary in order to clarify the real significance of the data.

High awareness of diabetes in the health care system in Greenland measured as a proportion of population tested with glycated haemoglobin within 2 years

BACKGROUND

Sixty years ago diabetes was almost non-existent in Greenland and until the beginning of this century awareness of diabetes was quite minimal. A high prevalence of undiagnosed diabetes has been reported in repeated population surveys. Increased focus on diabetes has been made a priority within the health care system since 2008, and in 2010 glycated haemoglobin was introduced as a diagnostic tool to further facilitate the diagnosis of diabetes.

OBJECTIVE

The aim of this study was to estimate the age and gender specific use of glycated haemoglobin in 2014 and 2015, as an indicator of diagnostic activity and awareness of diabetes, and to estimate the prevalence of diagnosed pre-diabetes and diabetes among adults in Greenland aged 20-79 years of age.

METHODS

The study was performed as an observational, cross sectional register study based on information gleaned from the electronically laboratory system used in Greenland including all patients tested with glycated haemoglobin at least once in 2014 or 2015.

RESULTS

A total of 10,127 patients were tested with glycated haemoglobin in 2014 or 2015 corresponding to 18.1% of the whole population. Among adults aged 20-79 years 9506 patients were tested corresponding to 24.0% of the total adult population. More females (32.5%) than males (16.5%) aged 20-79 years old were tested (p < 0.001). The prevalence of diagnosed diabetes and high risk pre-diabetes among adults aged 20-79 years was 4.3 and 6.8% respectively.

CONCLUSION

In conclusion use of glycated haemoglobin is widely used in the health care system in Greenland indicating a high awareness of diabetes in the population and by the health care system. Still, awareness of undiagnosed diabetes remains an important issue and additional strategies targeting males under 70 years old must be considered.

Serum adipocyte-fatty acid binding protein (FABP4) levels in women from Mexico exposed to polycyclic aromatic hydrocarbons (PAHs)

Recent studies indicate that exposure to polycyclic aromatic hydrocarbons (PAHs) is a very important risk factor for the development of cardiovascular diseases (CVDs). Correspondingly, adipocyte-fatty acid binding protein (FABP4, also known as aP2 and AFABP) has been proposed as a new, meaningful and useful biomarker to predict metabolic and cardiovascular diseases. Therefore, the aim of this study was to evaluate serum FABP4 levels in Mexican women exposed to PAHs. Urinary 1-hydroxypyrene ((1-OHP), exposure biomarker for PAHs) levels were quantified using a high-performance liquid chromatography (HPLC) technique, and serum FABP4 concentrations were analyzed using a commercially available ELISA kit. The mean urinary 1-OHP level found in women participating in this study was 1.30 ± 1.10 μmol/mol creatinine (2.45 ± 2.10 μg/g creatinine). Regarding serum FABP4 concentrations, the levels ranged from 3.80 to 62.5 ng/mL in the assessed population. Moreover, a significant association (p < 0.001) was found between urinary 1-OHP levels and serum FABP4 concentrations in women after adjusting for potential confounding variables. The presented data in this study can be considered only as a starting point for further studies. Then, in order to elucidate whether FABP4 represents a risk factor for CVD disease in humans exposed to air contaminants (such as PAHs), large epidemiological studies are necessary.

Plasma asymmetric dimethylarginine (ADMA) levels in Mexican women exposed to polycyclic aromatic hydrocarbons (PAHs): A preliminary study

Recent studies indicate that exposure to environmental pollutants (as polycyclic aromatic hydrocarbons) is a very important risk factor for development of cardiovascular diseases (CVDs). Correspondingly, in recent times asymmetric dimethylarginine (ADMA) has been proposed as a new and meaningful biomarker predictor for the risk of CVDs. Therefore, the objective of this study was to evaluate plasma ADMA concentrations in Mexican women (n=155) exposed to polycyclic aromatic hydrocarbons (PAHs). Urinary 1-hydroxypyrene [(1-OHP), exposure biomarker for PAHs] levels were quantified using a high performance liquid chromatography (HPLC) technique and plasma ADMA concentrations were analyzed using a commercially available ELISA kit. Urinary 1-OHP levels in all women assessed ranged from <LOD to 8.80μmol/mol creatinine. Regarding plasma ADMA concentrations, the mean levels ranged from 0.66 to 1.00μmol/L. Moreover, a significantly relationship was found between plasma ADMA concentrations and urinary 1-OHP levels (p=0.005; r=0.390). In conclusion, the results showed in this study demonstrated that the urinary 1-OHP levels were significant predictors of plasma ADMA concentrations in Mexican women exposed to PAHs. Although with due caution regarding the low representativeness of the present screening, it can be considered as a preliminary work to perform prospective studies including greater number of individuals and focusing in a more complete characterization of the effects produced by PAHs exposure on cardiovascular health.