High prevalence of markers of coronary heart disease among Greenland Inuit

High Prevalence of Atrial Fibrillation Found in the Capital of Greenland When Using Continuous Electrocardiogram Monitoring: A Cross-Sectional Study

Background

Atrial fibrillation (AF) increases the risk of conditions such as ischemic stroke, dementia, and heart failure, and early detection is crucial. In Greenland, ischemic strokes are common, and the prevalences of AF risk factors are increasing. Studies based on 30-second electrocardiograms (ECGs) and diagnosis codes so far have indicated either a low prevalence of AF or a prevalence comparable to that in other Western countries, such as Denmark. However, using short, single-point ECGs may underestimate the true prevalence, as especially paroxysmal AF can be missed. With this study, we aim to estimate the prevalence of AF using 3-5-day continuous Holter recordings among people in Nuuk, the capital of Greenland.

Methods

In this cross-sectional study, we estimated the prevalence of AF among the population aged ≥ 50 years in Greenland's capital, Nuuk. We used an ePatch to record continuous ECGs for 3-5 days, and questionnaires to assess demographic data, comorbidities, medication, symptoms, and risk factors for AF.

Results

Of 226 participants (62% women), 21 (33% women) had either self-reported AF, AF on the recording, or both, equivalent to a prevalence of 9.3% (confidence interval [CI] 5.8-13.9). The age-stratified prevalence was 7.2% (CI 2.7-15.1) among those aged 50-59 years; 8.8% (CI 4.1-16.1) among those aged 60-69 years; and 18.2% (CI 7.0-35.5) among those aged ≥ 70 years.

Conclusions

This study provides a novel insight into AF prevalence in Nuuk, emphasizing the potential underestimation in previous studies. Continuous ECG monitoring revealed a higher prevalence, especially among the younger age groups, urging a reevaluation of diagnostic practices in this unique population.

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.

Prevalence and clinical features of heart failure in Greenland

Heart Failure (HF) constitutes a significant burden for healthcare around the world. In Greenland, risk factors like smoking, diabetes, and obesity are prevalent. Yet, the prevalence of HF remains unexplored. This register-based cross-sectional study uses data from the national medical record in Greenland to estimate the age- and gender-specific prevalence of HF and to describe the characteristics of patients with HF in Greenland. A total of 507 patients (26% women) with a mean age of 65 years were included based on a diagnosis of HF. The overall prevalence was 1.1% and higher among men compared to women (1.6% vs. 0.6%, p < 0.05). The highest prevalence was among men above 84 years (11.1%). More than half (53%) had a body mass index above 30 kg/m2 and 43% were current daily smokers. The proportion diagnosed with ischaemic heart disease (IHD) was 33%. The overall prevalence of HF in Greenland is consistent with that in other high-income countries, yet high among men in some age groups, compared to Danish men. Almost half the patients were obese and/or smokers. A low prevalence of IHD was observed indicating that other factors may play a role in developing HF among Greenlanders.

The Greenland population health survey 2018 - methods of a prospective study of risk factors for lifestyle related diseases and social determinants of health amongst Inuit

Since 1993, regular population health surveys in Greenland have supported and monitored the public health strategy of Greenland and have monitored cardiometabolic and lung diseases. The most recent of these surveys included 2539 persons aged 15+ from 20 communities spread over the whole country. The survey instruments included personal interviews, self-administered questionnaires, blood sampling, anthropometric measurements, blood pressure, ECG, oral glucose test, pulmonary function, hand grip strength and chair stand test. Blood samples were analysed for glucose, glycated haemoglobin (HbA1c), insulin, incretin hormones, cholesterol, kidney function, fatty acids in erythrocyte membranes and mercury, urine for albumin-creatinine ratio, and aliquots were stored at -80°C for future use. Data were furthermore collected for studies of the gut microbiome and diabetes complications. Survey participants were followed up with register data. The potential of the study is to contribute to the continued monitoring of risk factors and health conditions as part of Greenland's public health strategy and to study the epidemiology of cardiometabolic diseases and other chronic diseases and behavioural risk factors. The next population health survey is planned for 2024. The emphasis of the article is on the methods of the study and results will be presented in other publications.

The prevalence of atrial fibrillation in Greenland: a register-based cross-sectional study based on disease classifications and prescriptions of oral anticoagulants

   Previous studies of the prevalence of atrial fibrillation (AF) in Greenland are based on either single-point electrocardiograms (ECGs) or patients admitted with stroke. This study estimates the prevalence of AF based on disease classifications in the electronic medical record system (EMR) and prescriptions of oral anticoagulants (OACs). Patients given a diagnose classification code for AF or atrial flutter or prescribed the vitamin K antagonist Warfarin or the direct-acting oral anticoagulant Rivaroxaban were identified in the EMR. Descriptive data and selected laboratory values were extracted, and a minimum CHA₂DS₂-VASc score was calculated for the 790 patients identified in the EMR (66% men). A total prevalence of AF of 1.4% was found in the general population (1.8% among men and 1.0% among women), with a significantly lower prevalence among women younger than 70 years. There was a significant increase in AF-prevalence with advancing age (p<0.001) for both men and women. A minimum CHA₂DS₂-VASc was estimated and app. 10% of the patients may be undertreated with OACs. The prevalence of AF found in this study is higher than that found in previous studies in Greenland and comparable to the prevalence found in other Western countries, indicating that AF is common in Greenland.

Diet and physical activity in Greenland: genetic interactions and associations with obesity and diabetes

The Inuit in Greenland have gone through dramatic lifestyle changes during the last half century. More time is spent being sedentary and imported foods replaces traditional foods like seal and whale. The population has also experienced a rapid growth in obesity and metabolic disturbances and diabetes is today common despite being almost unknown few decades ago. In this paper, we describe and discuss the role of lifestyle changes and genetics for Inuit metabolic health. Novelty: Cardiometabolic disease risk has increased in Greenland. Lifestyle changes and possibly gene-lifestyle interactions play a role.

The role of a traditional and western diet on glucose homeostasis in Greenlandic Inuit carriers and non-carriers of type 2 diabetes variant in the TBC1D4 gene: A protocol for a randomized clinical trial

INTRODUCTION

The lifestyle of Inuit in Greenland and worldwide is undergoing a transition from a fisher-hunter to a westernized society and meanwhile the prevalence of type-2 diabetes (T2D) has increased dramatically. Studies have shown that a common nonsense p.Arg684Ter variant in TBC1D4, which is frequent in Greenland, confers genetic susceptibility towards high risk of T2D. The aim of the study is to investigate whether a traditional marine diet, with high fat and low carbohydrate, will improve glycemic control in Greenland Inuit compared to a western diet. Moreover, we want to examine if the response is more pronounced in carriers of the p.Arg684Ter variant.

MATERIALS AND METHODS

We will conduct a randomized, clinical cross-over trial with two dietary intervention periods of four weeks duration. The diet intervention comprise provision of >20E% and instruction for the remaining part of the diet. We expect to include 30 homozygous carriers and 30 homozygous non-carriers of the p.Arg684Ter variant, aged 18-80 years, across three Greenlandic towns. The primary outcome is plasma (p)-glucose 2 h post an oral glucose tolerance test and we aim to have 80% power, at α = 0.05, to detect a difference of 1.1 mmol/L. We will also include supporting measures of glucose homeostasis, assess other markers of the metabolic syndrome and perform metabolome and microbiome profiling. The statistical analysis will be performed as complete case analyses using linear mixed models.

ETHICS AND DISSEMINATION

The study received approval by the Ethics Committee of Greenland (KVUG 2018-26) and will be disseminated via international peer-reviewed journal articles and conferences.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov identifier no. NCT04011904.

Associations between birth weight and glucose intolerance in adulthood among Greenlandic Inuit

AIMS

To examine the association between birth weight and glucose intolerance in adult Greenlandic Inuit.

METHODS

We examined 1429 participants aged 18-56 years from two population-based, cross-sectional studies in Greenland with information on birth weight. Oral glucose tolerance tests, anthropometric measures and ultrasound of abdominal tissue were performed. Associations of birth weight with glucose markers were analysed using linear or logistic regressions. Spline analyses were conducted to examine u-shaped associations. Adjustments were done for age, sex, birth place, family history of diabetes, genetic admixture, TBC1D4 p.Arg684Ter carrier status, BMI and visceral adipose tissue.

RESULTS

The median birthweight was 3300 g and 3.9% had type 2 diabetes, T2DM. Spline analyses indicated overall linear associations. In fully adjusted analyses, an increase in birth weight of 1 kg was associated with a change in fasting plasma glucose of -0.06 mmol/L (95%CI: -0.11, -0.01), 2-h plasma glucose of -0.16 mmol/L (95%CI: -0.35, 0.02), HOMA-IR of -5.45% (95%CI: -10.34, -0.29), insulin sensitivity index of 7.04% (95%CI: 1.88, 12.45) and a trend towards a reduced risk of hyperglycaemia and T2DM, although statistically insignificant.

CONCLUSIONS

Birth weight was inversely associated with hepatic and peripheral insulin resistance independently of adult adiposity. Thus, the findings support low birth weight as a contributing factor for glucose intolerance in adult Inuit in Greenland.

Serum 25-hydroxyvitamin D, calcium and parathyroid hormone levels in Native and European populations in Greenland

Ca homoeostasis is important to human health and tightly controlled by powerful hormonal mechanisms that display ethnic variation. Ethnic variations could occur also in Arctic populations where the traditional Inuit diet is low in Ca and sun exposure is limited. We aimed to assess factors important to parathyroid hormone (PTH) and Ca in serum in Arctic populations. We included Inuit and Caucasians aged 50-69 years living in the capital city in West or in rural East Greenland. Lifestyle factors were assessed by questionnaires. The intake of Inuit diet was assessed from a FFQ. 25-Hydroxyvitamin D (25OHD2 and 25OHD3) levels were measured in serum as was albumin, Ca and PTH. The participation rate was 95 %, with 101 Caucasians and 434 Inuit. Median serum 25OHD (99·7 % was 25OHD3) in Caucasians/Inuit was 42/64 nmol/l (25, 75 percentiles 25, 54/51, 81) (P<0·001). Total Ca in serum was 2·33/2·29 mmol/l (25, 75 percentiles 2·26, 2·38/2·21, 2·36) (P=0·01) and PTH was 2·7/2·2 pmol/l (25, 75 percentiles 2·2, 4·1/1·7, 2·7) (P<0·001). The 69/97 Caucasians/Inuit with serum 25OHD <50 nmol/l differed in PTH (P=0·001) that rose with lower 25OHD levels in Caucasians, whereas this was not the case in Inuit. Ethnic origin influenced PTH (β=0·27, P<0·001) and Ca (β=0·22, P<0·001) in multivariate linear regression models after adjustment for age, sex, BMI, smoking, alcohol and diet. In conclusion, ethnic origin influenced PTH, PTH response to low vitamin D levels and Ca levels in populations in Greenland. Recommendations are to evaluate mechanisms underlying the ethnic influence on Ca homoeostasis and to assess the impact of transition in dietary habits on Ca homoeostasis and skeletal health in Arctic populations.

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.

Inuit Country Food Diet Pattern Is Associated with Lower Risk of Coronary Heart Disease

BACKGROUND

Inuit have experienced a rapid transition in diet and lifestyle over the past several decades, paralleled by the emergence of chronic diseases such as obesity, diabetes, and hypertension.

OBJECTIVE

To identify contemporary dietary patterns among Inuit and investigate their association with cardiovascular disease outcomes.

DESIGN

This was an association study in a cross-sectional population health and nutrition survey.

PARTICIPANTS

The participants included 1,570 adults (aged ≥18 years) from Nunavut in the International Polar Year Inuit Health Survey 2007-2008 who completed diet/health questionnaires and provided blood samples.

MAIN OUTCOME MEASURES

Outcomes measured included the prevalence of coronary heart disease, myocardial infarction, stroke, hyperlipidemia, and hypertension.

STATISTICAL ANALYSES PERFORMED

Principal component analysis was used to derive dietary patterns based on the consumption of nine market food groups and four country food groups reported in 24-hour dietary recalls. The associations between cardiovascular outcomes and identified dietary patterns were examined with logistic regression.

RESULTS

Three dietary patterns were identified: market food, country food-fat, and country food-fish. The market food diet, characterized by high consumption of market-bought meat, cereals, vegetables, and added oil, was associated with elevated prevalence of coronary heart disease, myocardial infarction, and hypertension (odds ratio [OR] 1.44, 95% CI 0.82 to 2.51; OR 2.27, 95% CI 0.88 to 5.83; and OR 1.36, 95% CI 0.88 to 2.09). The country food-fish diet, characterized by high fish consumption and low sugar and sweets intake, was inversely associated with the prevalence of coronary heart disease, myocardial infarction, stroke, and hyperlipidemia (OR 0.78, 95% CI 0.43 to 1.37; OR 0.46, 95% CI 0.18 to 1.20; OR 0.34, 95% CI 0.07 to 2.13; and OR 0.69, 95% CI 0.39 to 1.22). The country food-fat diet, characterized by high marine mammal and added fat intake, was positively associated with the prevalence of coronary heart disease.

CONCLUSIONS

A diet featuring high food variety, high fish intake, and low sugar intake was negatively associated with the prevalence of cardiovascular outcomes among Inuit.

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.

The influence of persistent organic pollutants in the traditional Inuit diet on markers of inflammation

Concentrations of persistent organic pollutants (POPs) are high in Inuit living predominately on the traditional marine diet. Adverse effects of POPs include disruption of the immune system and cardiovascular diseases that are frequent in Greenland Inuit. We aimed to assess the association between exposure to POPs from the marine diet and inflammation, taking into account other factors such as vitamin D. We invited Inuit and non-Inuit living in settlements or the town in rural East Greenland or in the capital city Nuuk. Participants completed a food frequency questionnaire and donated a blood sample for measurement of the two markers of inflammation YKL-40 and hsCRP, 25-hydroxy-vitamin D, eleven organochlorine pesticides (OCPs), fourteen polychlorinated biphenyls (PCBs), one polybrominated biphenyl, and nine polybrominated diphenyl ethers (PBDEs) adjusted to the serum lipid content. Participants were 50 through 69 years old, living in settlements, town or city (n = 151/173/211; 95% participation rate). ΣOCP, ΣPCB and ΣPBDE serum levels were higher in Inuit than in non-Inuit (p<0.001/ p<0.001/ p<0.001), in older individuals (p<0.001/p<0.001/p = 0.002) and in participants with the highest intake of Greenlandic food items (p<0.001/p<0.001/p<0.001). Both YKL-40 and hsCRP serum levels were higher in Inuit compared to non-Inuit (p<0.001/p = 0.001), and increased with age (p<0.001/p = 0.001) and with the intake of Greenlandic food items (p<0.001/p = 0.002). Multivariate analysis conformed to a marked influence on both YKL-40 and hsCRP by ΣOCP (p<0.001/p<0.001) and ΣPCBs (p<0.001/p = 0.001) after adjusting for age, BMI, vitamin D, alcohol and smoking. POP levels were associated with the intake of the traditional Inuit diet and with markers of inflammation. This supports a pro-inflammatory role of POPs to promote chronic diseases common to populations in Greenland. These data inform guidelines on 'the Arctic dilemma' and encourage follow-up on the ageing Arctic populations.

Mercury diminishes the cardiovascular protective effect of omega-3 polyunsaturated fatty acids in the modern diet of Inuit in Canada

BACKGROUND

Inuit in Canada have low reported incidence of myocardial infarction (MI) because of their traditional rich n-3 fatty acids marine diet. They are experiencing rapid nutrition transition and ischemic heart disease is now becoming a health concern.

OBJECTIVES

Our goal was to describe the modern Inuit diet, the eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and methyl mercury (MeHg) intake and estimate their contributions to the risk of MI. We also estimated the effect of promoting the consumption of more traditional food on Inuit's MI risk.

METHODS

We estimated the effect of Inuit diet on MI risk with modelling. Model formulas and assumptions were extracted from various epidemiology studies and literatures. International Polar Year Inuit Health Survey (IHS) was a comprehensive health and nutrition survey conducted in 2007-8 with 2072 participants (aged 18-79) in Canada. Traditional food intake, blood biomarkers values from the IHS served as the baseline parameters of model input.

RESULTS

Inuit traditional diet contained both high level of EPA, DHA and MeHg and their combined net effect was estimated to reduce the relative risk of MI by 1% for men and 2% for women. Arctic char meat provided the largest amount of EPA and DHA. Ringed seal liver was the main source for MeHg. Increase intake of selected fish, like salmon, herring and Arctic char by 75g per day can reduce the relative risk of MI (RR 0.70, 0.78 and 0.90 respectively).

CONCLUSIONS

In the Inuit diet, the beneficial effect on MI of EPA and DHA is diminished by the adverse effect of MeHg. Promoting the increase consumption of fish species with high EPA+DHA and low MeHg may help to prevent MI among Inuit.

Omega-3 polyunsaturated fatty acid supplementation in the prevention of cardiovascular disease

INTRODUCTION

Omega-3 polyunsaturated fatty acids (PUFAs) have purported protective cardiovascular (CV) effects. We sought to assess the evidence available for the use of omega-3 PUFAs for the prevention of cardiovascular disease (CVD).

METHODS

A systematic literature search was conducted using MEDLINE and EMBASE from 1999 to 2015. Placebo-controlled, randomized controlled trials (RCTs) that enrolled over 1000 patients with follow-up greater than 1 year and meta-analyses of RCTs were included.

RESULTS

Eight RCTs and 2 meta-analyses were included. In patients with preexisting CVD, only 1 of 5 included RCTs demonstrated a reduction in CV events with omega-3 PUFAs; however, the effect size was minimal, and the study was limited by an open-label design and lack of placebo control. Two meta-analyses concluded omega-3 PUFAs do not reduce CV events in addition to standard, evidence-based therapy in patients after myocardial infarction. Of the 3 predominantly primary prevention RCTs, only 1 demonstrated a minor reduction in major coronary events; however, it was also an open-label study. Furthermore, the safety of omega-3 PUFAs should be considered. While data from RCTs have not demonstrated serious safety concerns, omega-3 PUFAs can increase the risk of bleeding and may interact with other medications that affect hemostasis, such as antiplatelet agents and warfarin.

DISCUSSION AND CONCLUSION

There is currently a lack of evidence to support the routine use of omega-3 PUFAs in the primary and secondary prevention of CVD. Pharmacists are ideally situated to engage patients in the discussion of the lack of benefit and possible risk of omega-3 PUFA supplements.

Vitamin D-rich marine Inuit diet and markers of inflammation - a population-based survey in Greenland

The traditional Inuit diet in Greenland consists mainly of fish and marine mammals, rich in vitamin D. Vitamin D has anti-inflammatory capacity but markers of inflammation have been found to be high in Inuit living on a marine diet. Yet, the effect of vitamin D on inflammation in Inuit remains unsettled. This led us to investigate the association between vitamin D and markers of inflammation in a population with a high intake of a marine diet. We studied 535 Inuit and non-Inuit living in West and East Greenland. Information concerning dietary habits was obtained by interview-based FFQ. Blood samples were drawn for analysis of 25-hydroxyvitamin D, high-sensitivity C-reactive protein (hsCRP) and chitinase-3-like protein 1(YKL-40). Participants were divided into three groups based on degree of intake of the traditional Inuit diet. The diet groups (Inuit diet/mixed diet/imported foods) were associated with vitamin D levels in serum (74·2, 69·8 and 52·9 nm; P < 0·001), hsCRP (1·6, 1·4 and 1·3 mg/l; P = 0·002) and YKL-40 (130, 95 and 61 ng/ml; P < 0·001), respectively. YKL-40 level decreased with rising vitamin D level in Inuit (Inuit diet P = 0·002; mixed diet P = 0·011). YKL-40 was lower in groups with higher vitamin D levels after adjusting for other factors known to influence inflammation (P < 0·001). This was not seen for hsCRP. In conclusion, vitamin D and markers of inflammation vary in parallel with the intake of the marine Inuit diet. Vitamin D levels were inversely associated with YKL-40 levels, but no association with hsCRP was found. The hypothesised anti-inflammatory effect of vitamin D was not supported. Other factors in the marine diet may be speculated to influence inflammation.

Cardiovascular Disease Susceptibility and Resistance in Circumpolar Inuit Populations

Cardiovascular disease (CVD) is a major public health issue in indigenous populations in the Arctic. These diseases have emerged concomitantly with profound social changes over the past 60 years. The aim of this study was to summarize the literature on CVD risk among Arctic Inuit. Literature on prevalence, incidence, and time trends for CVD and its risk factors in Arctic Inuit populations was reviewed. Most evidence supports a similar incidence of coronary heart disease and a higher incidence of cerebrovascular disease among Arctic Inuit than seen in western populations. Factors that may increase CVD risk include aging of the population, genetic susceptibility, and a rapid increase in obesity, diabetes, and hypertension in parallel with decreasing physical activity and deterioration of the lipid profile. In contrast, and of great importance, there has been a decrease in smoking and alcohol intake (at least documented in Greenland), and contaminant levels are declining. Although there have been marked socioeconomic and dietary changes, it remains unsolved and to some extent controversial how this may have influenced cardiovascular risk among Arctic Inuit. The increase in life expectancy, in combination with improved prognosis for patients with manifest CVD, will inevitably lead to a large increase in absolute numbers of individuals affected by CVD in Arctic Inuit populations, exacerbated by the rise in most CVD risk factors over the past decades. For preventive purposes and for health care planning, it is crucial to carefully monitor disease incidence and trends in risk factors in these vulnerable Arctic populations.

National prevalence of coronary heart disease and its relationship with human development index: A systematic review

BACKGROUND

Coronary heart disease has become a major health concern over the past several decades. Several reviews have assessed the effects of socioeconomic status on the coronary heart disease epidemic in communities and countries, but only a few reviews have been performed at a global level. This study was to explore the relationship between the prevalence of coronary heart disease and socioeconomic development worldwide using the Human Development Index.

DESIGN

Systematic review.

METHODS

The data in this study were collected from the MEDLINE database. Cross-sectional studies reporting the prevalence of coronary heart disease until November 2014 were collected. The Human Development Index was sourced from the United Nations Development Programme Database and was used to measure the socioeconomic achievements of countries. Each country was classified as a developing or developed country based on its level of development according to the Human Development Index value.

RESULTS

Based on the data analysis on the global level, coronary heart disease prevalence had no association with the national Human Development Index (rho = 0.07). However, there was a positive association between coronary heart disease prevalence and the national Human Development Index in developing countries, although a negative association existed in developed countries (rho = 0.47 and -0.34, respectively). In addition, the past decades have witnessed a growing coronary heart disease epidemic in developing countries, with reverse trends observed in developed countries (P = 0.021 and 0.002, respectively).

CONCLUSIONS

With the development of socioeconomic status, as measured by the Human Development Index, the prevalence of coronary heart disease is growing in developing countries, while declining in developed countries. Future research needs to pay more attention to the reasonable allocation of medical resources and control of coronary heart disease risk factors.

Prevalence of self-reported myocardial infarction in Sami and non-Sami populations: the SAMINOR study

Objective

Measure the prevalence of self-reported myocardial infarction (SMI) in Sami and non-Sami populations in rural areas of Norway, and explore whether possible ethnic differences could be explained by established cardiovascular risk factors.

Design

Cross-sectional population-based study.

Methods

A health survey was conducted in 2003–2004 in areas with Sami and non-Sami populations (SAMINOR). The response rate was 60.9%. Information concerning lifestyle was collected by 2 self-administrated questionnaires, and clinical examinations provided anthropometric measurements, and data on blood pressure and lipid levels.

Results

The total number for the subsequent analysis was 15,206 men and women aged 36–79 years (born 1925–1968). Sex-specific analyses revealed no ethnic difference in SMI. In terms of the most important risk factors such as smoking, blood pressure, and lipid levels, no or only trivial ethnic differences were found in both women and men.

Conclusion

In this study, we found no difference in SMI between Sami and non-Sami in rural areas in Norway. The similar risk profile is the most plausible explanation; similar living conditions and close interaction between the ethnic groups may explain this.

Birth weight and risk of adiposity among adult Inuit in Greenland

Objective

The Inuit population in Greenland has undergone rapid socioeconomic and nutritional changes simultaneously with an increasing prevalence of obesity. Therefore, the objective was to examine fetal programming as part of the aetiology of obesity among Inuit in Greenland by investigating the association between birth weight and measures of body composition and fat distribution in adulthood.

Methods

The study was based on cross-sectional data from a total of 1,473 adults aged 18–61 years in two population-based surveys conducted in Greenland between 1999–2001 and 2005–2010. Information on birth weight was collected from birth records. Adiposity was assessed by anthropometry, fat mass index (FMI), fat-free mass index (FFMI), and visceral (VAT) and subcutaneous adipose tissue (SAT) estimated by ultrasound. The associations to birth weight were analyzed using linear regression models and quadratic splines. Analyses were stratified by sex, and adjusted for age, birthplace, ancestry and family history of obesity.

Results

Spline analyses showed linear relations between birth weight and adult adiposity. In multiple regression analyses, birth weight was positively associated with BMI, waist circumference, FMI, FFMI and SAT with generally weaker associations among women compared to men. Birth weight was only associated with VAT after additional adjustment for waist circumference and appeared to be specific and inverse for men only.

Conclusions

Higher birth weight among Inuit was associated with adiposity in adulthood. More studies are needed to explore a potential inverse association between birth size and VAT.

Decrease in vitamin D status in the Greenlandic adult population from 1987-2010

Background

Low vitamin D status may be pronounced in Arctic populations due to limited sun exposure and decreasing intake of traditional food.

Objective

To investigate serum 25(OH)D3 as a measure of vitamin D status among adult Inuit in Greenland, predictors of low serum 25(OH)D3 concentrations and the trend from 1987 to 2005–2010.

Design

A total of 2877 randomly selected Inuit (≥18 years) from the Inuit Health in Transition study were included. A sub-sample (n = 330) donated a blood sample in 1987 which allowed assessment of time trends in vitamin D status.

Results

The geometric mean serum 25(OH)D3 (25[OH]D2 concentrations were negligible and not reported) in 2005–2010 was lowest among the 18–29 year old individuals (30.7 nmol/L; 95% CI: 29.7; 31.7) and increased with age. In all age-groups it decreased from 1987 to 2005–2010 (32%–58%). Low 25(OH)D3 concentrations (<50 nmol/L) were present in 77% of the 18–29 year old and decreased with age. A characteristic seasonal variation in 25(OH)D3 concentrations was observed (range 33.2–57.1 nmol/L, p<0.001), with the highest concentrations in August to October. Age (2.0% per year increase; CI: 1.7, 2.2), female gender (7.1%; CI: 2.0; 12.5), alcohol intake (0.2% per increase in drinks/week; 0.0; 0.4), and traditional diet (10.0% per 100 g/d increase; CI: 7.9; 12.1) were associated with increased serum 25(OH)D3, whereas smoking (−11.6%; CI: −16.2; −6.9), BMI (−0.6%; CI: −1.1; −0.2) and latitude (−0.7% per degree increase; CI: −1.3; −0.2) were associated with decreased concentrations.

Conclusion

We identified a remarkable decrease in vitamin D status from 1987 to 2005–2010 and a presently low vitamin D status among Inuit in Greenland. A change away from a traditional diet may well explain the observed decline. The study argues for the need of increased dietary intake of vitamin D and supplementation might be considered.

Common low-density lipoprotein receptor p.G116S variant has a large effect on plasma low-density lipoprotein cholesterol in circumpolar inuit populations

BACKGROUND

Inuit are considered to be vulnerable to cardiovascular disease because their lifestyles are becoming more Westernized. During sequence analysis of Inuit individuals at extremes of lipid traits, we identified 2 nonsynonymous variants in low-density lipoprotein receptor (LDLR), namely p.G116S and p.R730W.

METHODS AND RESULTS

Genotyping these variants in 3324 Inuit from Alaska, Canada, and Greenland showed they were common, with allele frequencies 10% to 15%. Only p.G116S was associated with dyslipidemia: the increase in LDL cholesterol was 0.54 mmol/L (20.9 mg/dL) per allele (P=5.6×10(-49)), which was >3× larger than the largest effect sizes seen with other common variants in other populations. Carriers of p.G116S had a 3.02-fold increased risk of hypercholesterolemia (95% confidence interval, 2.34-3.90; P=1.7×10(-17)), but did not have classical familial hypercholesterolemia. In vitro, p.G116S showed 60% reduced ligand-binding activity compared with wild-type receptor. In contrast, p.R730W was associated with neither LDL cholesterol level nor altered in vitro activity.

CONCLUSIONS

LDLR p.G116S is thus unique: a common dysfunctional variant in Inuit whose large effect on LDL cholesterol may have public health implications.

Forty-five year trends in overweight and obesity in an indigenous arctic Inuit Society in transition and spatiotemporal trends

OBJECTIVES

Overweight and obesity associate with increased morbidity and premature death. Westernization of societies heralds rising obesity rates. A steep increase in body mass index (BMI) and overweight in Greenland from 1963 to 1998 led us to follow-up on height, weight, BMI, and rates of overweight among populations in Greenland and assess time trends between different stages of transition.

METHODS

BMI was calculated from height and weight measured on Inuit and non-Inuit aged 50 through 69 years surveyed in 1963, 1998, and 2008 in Ammassalik district in East Greenland and in 1998 and 2008 in the capital Nuuk in West Greenland.

RESULTS

A total of 1,186 were surveyed in 1963 (52 men/63 women), 1998 (309/226), and 2008 (297/239). BMI increased with time (P < 0.001; 1963/1998/2008 23.3/24.3/26.2 kg/m(2) ). In addition, BMI increased with urbanization in Inuit men (P = 0.001; settlements/town/city, in 1998, 23.9/24.9/25.5 kg/m(2) ; in 2008, 25.0/26.0/27.0 kg/m(2) ) while not in Inuit women (P = 0.18). The number of overweight Inuit (BMI >27 kg/m(2) ) increased with time in men (4.0/25.6/33.2% in 1963/1998/2008, P = 0.001) and in women (13.6/30.7/37.3%, P = 0.001). BMI was above 30 kg/m(2) in 2.0/10.8/17.5% of all Inuit men in 1963/1998/2008 (P = 0.003) and in 8.3%/23.0/24.5% of all Inuit women (P = 0.02) respectively.

CONCLUSIONS

Overweight and obesity rates rise with time and with societal transition in Greenland. Settlements and town are catching up with the city where the rate of increase is diminishing, although there were gender differences.

Ethnic difference in the prevalence of angina pectoris in Sami and non-Sami populations: the SAMINOR study

Objective

To assess the population burden of angina pectoris symptoms (APS), self-reported angina and a combination of these, and explore potential ethnic disparity in their patterns. If differences in APS were found between Sami and non-Sami populations, we aimed at evaluating the role of established cardiovascular risk factors as mediating factors.

Design

Cross-sectional population-based study.

Methods

A health survey was conducted in 2003–2004 in areas with Sami and non-Sami populations (SAMINOR). The response rate was 60.9%. The total number for the subsequent analysis was 15,206 men and women aged 36–79 years (born 1925–1968). Information concerning lifestyle was collected by 2 self-administrated questionnaires, and clinical examinations provided data on waist circumference, blood pressure and lipid levels.

Results

This study revealed an excess of APS, self-reported angina and a combination of these in Sami relative to non-Sami women and men. After controlling for age, the odds ratio (OR) for APS was 1.42 (p<0.001) in Sami women and 1.62 (p<0.001) for men. When including relevant biomarkers and conventional risk factors, little change was observed. When also controlling for moderate alcohol consumption and leisure-time physical activity, the OR in women was reduced to 1.24 (p=0.06). Little change was observed in men.

Conclusion

This study revealed an excess of APS, self-reported angina and a combination of these in Sami women and men relative to non-Sami women and men. Established risk factors explained little or none of the ethnic variation in APS. In women, however, less moderate alcohol consumption and leisure-time physical activity in Sami may explain the entire ethnic difference.

Use of glycosylated haemoglobin as diagnostic tool in Greenland: prevalence of diagnosed diabetes mellitus

BACKGROUND

The prevalence of undiagnosed diabetes mellitus (DM) in Greenland has been reported very high with only 30% of cases diagnosed. In 2010, glycosylated hemoglobin (A1C) was introduced as a diagnostic tool in Greenland. However, the current use of A1c is unknown as well as the current prevalence of diagnosed DM.The aim of this study was firstly to estimate the use of A1C as diagnostic tool within the first 27 months after introducing the method and secondly to estimate the age and gender specific prevalence of diagnosed DM in Greenland in 2012.

METHODS

This study was perfomed as a cross-sectional register study using data from electronic medical records (EMR). To analyse the use of A1C as diagnostic tool:A sample amongst all Greenlanders at or above age 35 old was used to determine the number of individuals screened with A1C within a 27 month period, excluding those already known to have DM.To estimate the prevalence of diagnosted DM: Patients with DM were identified electronically using a statistic module run on data in the EMR. Age and gender specific prevalence was estimated using the Greenlandic population as of 1 January 2012 as the background population.

RESULTS

The test sample resulted in a study group of 1008 individuals from which 2.3% (23) were excluded because they were already known to have DM. Among the remaining 985, 13.6% were tested with A1C at least once during the 27 months of observation. DM was diagnosed in 7.5% (10) of the tested persons and in 1.0% of the whole group.Regarding prevalence, a total of 920 patients with diagnosed DM were identified. The total prevalence among adults aged 20-79 years old was 2.20% (95% CI: 2.05-2.34) with no significant difference between genders.

CONCLUSION

Testing for DM using A1C as diagnostic tool is used in Greenland. The prevalence of diagnosed DM in Greenland remains low although increasing. Undiagnosed DM may still be an important issue in Greenland.

Fat distribution and glucose intolerance among Greenland Inuit

OBJECTIVE

A high amount of subcutaneous fat is suggested to explain the observation of lower obesity-associated metabolic risk among Inuit than among Europeans. We examined the association between measures of obesity (visceral adipose tissue [VAT], subcutaneous adipose tissue [SAT], BMI, waist circumference [WC], and percentage of body fat) and the indices of glucose metabolism (fasting and 2-h glucose levels, insulin resistance per homeostasis model assessment [HOMA-IR], and the insulin sensitivity index [ISI0,120]) among Greenland Inuit.

RESEARCH DESIGN AND METHODS

A total of 3,108 adult Inuit participated in a population-based study. The examination included a 75-g oral glucose tolerance test and anthropometric measurements. VAT and SAT were measured by ultrasound according to a validated protocol. Information on sociodemographic characteristics and health behaviors was obtained by interview.

RESULTS

Mean SATs were 1.8 and 3.5 cm in men and women, respectively. Mean VATs were 7.0 and 6.3 cm in men and women, respectively. The total prevalence of type 2 diabetes was 9%. Percentage of body fat generally was most strongly associated with all outcomes. Both SAT and VAT were significantly associated with glucose intolerance, fasting and 2-h plasma glucose levels, HOMA-IR, and ISI0,120. VAT was more strongly associated with all outcomes than was SAT. After further adjustment for BMI or WC, VAT was associated with glucose intolerance and insulin resistance, whereas there was a trend toward a negative or no association with SAT.

CONCLUSIONS

High mean values of SAT may to a large extent explain the high WC in Inuit populations, and this is suggested to contribute to the lower observed metabolic risk for a given level of obesity.

Raised BMI cut-off for overweight in Greenland Inuit--a review

Background

Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI), a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population.

Objective

This led us to reconsider the cut-off point for overweight among Inuit in Greenland.

Design and findings

We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time.

Conclusion

Defining overweight according to the WHO cut-off of a BMI above 25 kg/m² in Greenland Inuit may overestimate the number of individuals with elevated BMI.

Marginalisation and cardiovascular disease among rural Sami in Northern Norway: a population-based cross-sectional study

BACKGROUND

Like other indigenous peoples, the Sami have been exposed to the huge pressures of colonisation, rapid modernisation and subsequent marginalisation. Previous studies among indigenous peoples show that colonialism, rapid modernisation and marginalisation is accompanied by increased stress, an unhealthy cardiovascular risk factor profile and disease burden. Updated data on the general burden of cardiovascular disease among the Sami is lacking. The primary objective of this study was to assess the relationship between marginalisation and self-reported lifetime cardiovascular disease (CVD) by minority/majority status in the rural Sami population of Norway.

METHODS

A cross-sectional population-based study (the SAMINOR study) was carried out in 2003-2004. The overall participation rate was 60.9% and a total of 4027 Sami individuals aged 36-79 years were included in the analyses. Data was collected by self-administrated questionnaires and a clinical examination.

RESULTS

The logistic regression showed that marginalised Sami living in Norwegian dominated areas were more than twice as likely to report CVD as non-marginalised Sami living in Sami majority areas (OR 2.10, 95% CI: 1.40-3.14). No sex difference was found in the effects of marginalisation on self-reported life-time cardiovascular disease. Moderate to no intermediate effects were seen after including established CVD risk factors.

CONCLUSIONS

This study showed that marginalised Sami living in Norwegian dominated areas were more than twice as likely as non-marginalised Sami from Sami majority areas to report lifetime cardiovascular disease (CVD). Moderate to no intermediate effects were seen after including established CVD risk factors, which suggest little difference in lifestyle related factors. Chronic stress exposure following marginalisation may however be a plausible explanation for some of the observed excess of CVD.

Intake of traditional Inuit diet vary in parallel with inflammation as estimated from YKL-40 and hsCRP in Inuit and non-Inuit in Greenland

BACKGROUND

Chronic low-grade inflammation is involved in the initiation and progression of atherosclerosis and ischemic heart disease. This was rare in pre-western Inuit who lived on a diet that consisted mainly of marine mammals rich in n-3 fatty acids.

OBJECTIVES

To assess the association between biomarkers of inflammation and the intake of traditional Inuit diet in addition to Inuit ethnicity.

METHODS

YKL-40 and hsCRP were measured in serum from 535 Inuit and non-Inuit living in the capital city Nuuk in West Greenland or in the main town or a settlement in rural East Greenland. Dietary habits were assessed by an interview-based food frequency questionnaire.

RESULTS

The participation rate was 95%. YKL-40 was higher in Inuit than in non-Inuit (p < 0.001), in Inuit with a higher intake of traditional Inuit diet (p < 0.001), and in Inuit from rural compared to urban areas (p < 0.001). It also rose with age (p < 0.001), alcohol intake (0.019) and smoking (p < 0.001). Inuit had higher hsCRP compared to non-Inuit (p = 0.003) and hsCRP increased in parallel with intake of traditional Inuit foods (p < 0.001). Alcohol associated with a decrease in hsCRP in Inuit (p = 0.004). YKL-40 and hsCRP increased with higher intakes of traditional Inuit diet after adjusting for ethnicity, gender, age, smoking, alcohol intake and BMI.

CONCLUSIONS

Biomarkers of inflammation vary in parallel with the intake of traditional Inuit diet. A diet based on marine mammals from the Arctic does not reduce inflammatory activity and it may be speculated that markers of inflammation reflect the disease rather than the cause of the disease.

Glycemic index and glycemic load in relation to glucose intolerance among Greenland's Inuit population

BACKGROUND

Intake of carbohydrates which elicit a large glycemic response is hypothesized to increase the risk of diabetes. However, studies assessing the relationship between glycemic index (GI) and glycemic load (GL) and diabetes are inconsistent. Only few studies have studied the relationship between GI and GL and markers of glucose metabolism, mostly in western populations.

OBJECTIVE

To determine the relationship between GI and GL and indices of glucose metabolism and prevalence of diabetes in Greenland's Inuit population.

DESIGN

The Inuit Health in Transition Study is a geographically representative cross-sectional study among aged ≥18years. Diet was assessed using a 67-item food frequency questionnaire. Logistic and linear regression was used to assess the association between GI and GL and diabetes, impaired fasting glucose, impaired glucose tolerance, HbA(1c), fasting plasma glucose, 2h plasma glucose, HOMA2-IR and HOMA2-%β.

RESULTS

No association was found between GI and GL and diabetes. GL was significantly inversely associated with IFG (OR: 0.91 (0.84-0.98)). While GI was positively associated with FPG, GL was positively associated with both HOMA2-IR and HOMA2-%β and inversely associated with IFG.

CONCLUSION

These findings do not support a link between dietary GI or GL and risk of type 2 diabetes among Greenland's Inuit population.

Frequent use of primary health care service in Greenland: an opportunity for undiagnosed disease case-finding

OBJECTIVES

To estimate the age- and gender-specific consultation rates of patients who availed primary health care service in Greenland and to analyse contact patterns among patients in Nuuk.

DESIGN

Observational and cross-sectional register study using data captured from the medical records.

MATERIALS AND METHODS

The number of patients specified by age and gender who had contacted the primary health care centres within the last year was identified using a statistic module applied to the electronic medical records system. The population as it was on the 1st of January 2011 was used as the background population. The age- and gender-specific consultation rates were calculated. Review of most recent contact was performed in a subsample of patients from Nuuk, and information of the type of contact and diagnoses was obtained.

RESULTS

Eighty-three percent of the population in Greenland had been in contact with the primary health care centre within the last year. Females were more frequent users than males. A subsample of 400 patients in Nuuk was identified. Personal contact was the most frequent type of consultation (75.8%), followed by telephone (14.8%) and e-mail (9.8%) consultations. Musculoskeletal symptoms accounted for the most frequent bases for diagnoses.

CONCLUSION

More than 80% of the whole population has been in contact with the primary health care system within the last year. This indicates that opportunistic case-finding of chronic diseases such as diabetes, hypertension, etc. providing a possible strategy for decreasing the number of undiagnosed cases.

Prevalence of the use of antihypertensive medications in Greenland: a study of quality of care amongst patients treated with antihypertensive drugs

OBJECTIVES

The primary objective was to estimate the prevalence of patients diagnosed with hypertension using the proxy marker of antihypertensive drug therapy in Greenland and to compare the prevalences within the 5 health regions in Greenland. The second objective was to review 2 quality indicators in antihypertensive care.

STUDY DESIGN

Observational and cross-sectional study reviewing electronic medical records.

METHODS

Information about age and gender was collected from all patients receiving antihypertensive drug prescriptions within a 2-year period prior to the data extraction in January 2011. Only patients aged 20 or above were included. The age- and gender-specific prevalence of patients in antihypertensive treatment was calculated using the population as it was 1 January 2010 in Greenland as background population. A subsample consisting of patients in antihypertensive treatment aged 20 or above born within the first 5 days of each month was identified. Review of electronic medical records 1 year back in time (1 January 2010 onwards) was carried out and information on blood pressure obtained. The quality of care was evaluated with respect to 2 indicators: follow-up management and blood pressure level, respectively.

RESULTS

The total number of patients in treatment with antihypertensive drugs was 4,462 (1,998 males and 2,464 females) corresponding to a prevalence of 11.4% (4,462/39,231). The prevalence was higher among females than among males. The prevalence increased with age and differed among the 5 health regions. The percentage of patients in antihypertensive treatment with minimum 1 follow-up visit within 1 year (blood pressure measured and registered in a health clinic) was only 77.7%. Some 45% of patients in antihypertensive treatment achieved blood pressure below 140/90 mmHg.

CONCLUSION

Hypertension is a common disorder in Greenland. The quality of antihypertensive care is suboptimal and leaves room for improvement. A national strategy based on guidelines, use of electronic drug prescriptions and recording of blood pressures combined with continuous monitoring the quality is recommended in order to prevent complications of untreated hypertension.

Serum apolipoproteins in relation to intakes of fish in population of Arkhangelsk County

Background

Diets rich in omega-3 fatty acids and low in saturated fat were found beneficially associated with blood lipids and cardio-vascular health. Lean reindeer meet and local cold water white-fish species high in omega-3 are among the main sources of nutrients in the rural area of the Nenets Autonomous Okrug (NAO) in Russia and are not normally consumed by the urban population from the same region. The aims of the study were firstly, to compare serum lipid profiles of residents of urban (Arkhangelsk city) and rural (NAO) regions of Arkhangelsk County, and secondly, to investigate the effects of fish consumption on the predictor of cardiovascular events apolipoprotein (Apo) B/ApoA-I ratio in these populations.

Methods

A cross-sectional study conducted in Arkhangelsk County, Russia. Sample size of 249 adults: 132 subjects from Arkhangelsk city, aged 21–70 and 117 subject (87% Ethnic Nenets) from NAO, aged 18–69.

Results

We observed more favorable lipid levels in NAO compared to Arkhangelsk participants. Age-adjusted geometric means of ApoB/ApoA-I ratio were 1.02 and 0.98 in men and women from Arkhangelsk; 0.84 and 0.91 in men and women from NAO respectively. Age and consumption of animal fat were positively associated with ApoB/ApoA-I ratio in women (pooled samples from Arkhangelsk and NAO). Body mass index and low levels of physical activity were positively associated with ApoB/ApoA-I ratio in men (pooled samples from Arkhangelsk and NAO). Reported oily fish consumption was not significantly correlated with ApoB/ApoA-I ratio.

Conclusion

The population sample from rural NAO, consisting largely of the indigenous Arctic population Nenets with healthier dietary sources, had a relatively less atherogenic lipid profile compared to the urban Arkhangelsk group. Fish consumption had no effect on apolipoproteins profile.

Dairy product intake and its association with body weight and cardiovascular disease risk factors in a population in dietary transition

OBJECTIVE

Higher dairy product intake has shown beneficial effects on body weight, blood pressure, type 2 diabetes, and cardiovascular disease (CVD) risk factors in Caucasian populations. This study evaluated dairy product intake and its association with body weight and CVD risk profile among a population undergoing a dietary transition in Canada, the Nunavik Inuit.

METHODS

Data were collected from August 27 to October 1, 2004, in the 14 villages of Nunavik on a Canadian research icebreaker (Canadian Coast Guard ship Amundsen). Dairy product intake and calcium intake were evaluated in 543 Inuit using a food frequency questionnaire. Physiological (lipid profile, fasting glucose, and insulin) and anthropometrical measurements were also obtained.

RESULTS

The range of median dairy product intake extended from 120 g/d in the lowest tertile to 290 g/d in the highest tertile. The median of calcium intake was 524 mg/d. Participants in the highest tertile of dairy product consumption had higher body weight, fat-free mass, waist circumference, waist-to-hip ratio, and fasting glucose concentrations than participants in the lowest tertile (all p < 0.01). After adjustments for potential cofactors, no significant association was observed. A higher prevalence of Inuit participants with metabolic syndrome was observed in the higher tertile compared with the first tertile (10.3% vs 1.6%; p < 0.001).

CONCLUSIONS

Higher dairy product intake in Nunavik Inuit is not related to protective effects on body weight and CVD. The consumption of dairy products in Nunavik Inuit is probably not sufficient to withdraw beneficial effects on body weight or CVD risk factors, as observed in North American populations.

Relation between methylmercury exposure and plasma paraoxonase activity in inuit adults from Nunavik

BACKGROUND

Methylmercury (MeHg) exposure has been linked to an increased risk of coronary heart disease (CHD). Paraoxonase 1 (PON1), an enzyme located in the high-density-lipoprotein (HDL) fraction of blood lipids, may protect against CHD by metabolizing toxic oxidized lipids associated with low-density liproprotein and HDL. MeHg has been shown to inhibit PON1 activity in vitro, but this effect has not been studied in human populations.

OBJECTIVES

This study was conducted to determine whether blood mercury levels are linked to decreased plasma PON1 activities in Inuit people who are highly exposed to MeHg through their seafood-based diet.

METHODS

We measured plasma PON1 activity using a fluorogenic substrate and blood concentrations of mercury and selenium by inductively coupled plasma mass spectrometry in 896 Inuit adults. Sociodemographic, anthropometric, clinical, dietary, and lifestyle variables as well as PON1 gene variants (rs705379, rs662, rs854560) were considered as possible confounders or modifiers of the mercury-PON1 relation in multivariate analyses.

RESULTS

In a multiple regression model adjusted for age, HDL cholesterol levels, omega-3 fatty acid content of erythrocyte membranes, and PON1 variants, blood mercury concentrations were inversely associated with PON1 activities [β-coefficient = -0.063; 95% confidence interval (CI), -0.091 to -0.035; p < 0.001], whereas blood selenium concentrations were positively associated with PON1 activities (β-coefficient = 0.067; 95% CI, 0.045-0.088; p < 0.001). We found no interaction between blood mercury levels and PON1 genotypes.

CONCLUSIONS

Our results suggest that MeHg exposure exerts an inhibitory effect on PON1 activity, which seems to be offset by selenium intake.

Frequent left ventricular hypertrophy independent of blood pressure in 1851 pre-western Inuit

BACKGROUND

Elevated blood pressure is a risk factor for cardiovascular disease and may be detected by left ventricular hypertrophy (LVH) in electrocardiogram (ECG). Pre-western Inuit had frequent signs of LVH in ECG predominantly in the 3rd decade while a low occurrence of ischemic heart disease.

METHODS

We evaluated the association between blood pressures and ECG signs of LVH, cardiac auscultation, and symptoms related to heart disease in the recently recovered data from the survey of 1851 Inuit conducted in 1962-1964 in East Greenland.

RESULTS

The participation rate was 97%. Among the 812 Inuit aged 18 years or above blood pressure was unaltered until the age of 39 years (systolic, p=76; diastolic, p=0.36) and increased subsequently (both, p<0.001). Systolic blood pressure >140 mmHg was more frequent when aged >40 years (p<0.001) and diastolic blood pressure >90 mmHg was more common in men (p<0.001) and in men and women aged >40 years (p<0.001). ECG signs of LVH were more frequent in men (p<0.01) but the occurrence decreased from the age of 40 years (p<0.01), and were not influenced by systolic (p=0.97), diastolic (p=0.87) or pulse pressure (p=0.69).

CONCLUSIONS

Blood pressure rose only after the age of 40 years in pre-western Inuit. Left ventricular hypertrophy peaked among 30-year olds and was independent of elevated blood pressure. It may be speculated that the common left ventricular hypertrophy was due to marked physical activity that contributed to the low occurrence of ischemic heart disease among pre-western Inuit.

Omega-3 polyunsaturated acids and cardiovascular disease: notable ethnic differences or unfulfilled promise?

The consumption of long chain omega-3 polyunsaturated acids (PUFA) is considered to protect against cardiovascular disease and promote longevity following a heart attack. Historically, research in this area was fuelled by compelling reports of the cardiovascular benefits of omega-3 PUFA in select populations and cultures. More recent studies, in wider populations, suggest discordant findings: differences that are difficult to reconcile as the mechanism of action of omega-3 PUFA are poorly understood. As such, the use of this 'natural treatment' for cardiovascular disease is increasingly controversial, and potentially one of unfulfilled promise. To what extent does ethnicity influence the impact that omega-3 PUFA have on cardiovascular disease and its associated complications? We were interested to review the benefits of omega-3 PUFA in the management of cardiovascular risk amongst diverse ethnic groups. Using a systematic review of literature relating to omega-3 PUFA and cardiovascular disease, we found ethnicity to be a factor that accounts for inconsistency between studies. Some of the effects of omega-3 PUFA are limited to cultures with a very high omega-3 intake, and in turn, ethnicity moderates the efficiency with which PUFA are derived from the diet. Moreover, omega-3 PUFA are an important health care intervention in the current climate of globalization, where supplementation is likely to give protection to cultural groups undergoing dietary transition. Future epidemiological research into the efficacy of omega-3 PUFA in cardiovascular disease should consider the influence of ethnicity.

Low occurrence of ischemic heart disease among Inuit around 1963 suggested from ECG among 1851 East Greenland Inuit

BACKGROUND

The prevalence of coronary heart disease among Greenland Inuit today is similar to that of western populations. The cardiovascular risk profile among Inuit has changed over the past four decades with the introduction of a western life style. An unaltered prevalence of coronary heart disease has been proposed, but no pre-westernisation data exist.

AIM

To describe pre-westernisation prevalence of coronary heart disease among East Greenland Inuit.

DESIGN

A population study of 1851 Inuit living in East Greenland was conducted in 1962-1964. It included ECG, cardiac auscultation and recording of symptoms. ECGs were evaluated for ischemic signs, arrhythmia, hypertrophy, and conduction abnormalities.

RESULTS

The participation rate was 97%. A12-lead ECG was performed in 181 adults, including 65% of men aged 40 years and above. Hypertrophy was seen in 15% and peaked in 30-39 year olds. Pathological conduction disturbances were seen in 4% and 1% had ischemic signs. The age-standardised prevalence of ischemic ECG findings was 5.5%. Abnormal ECG findings did not correlate with pathologic findings on cardiac auscultation or symptoms related to heart disease.

CONCLUSIONS

Hypertrophy peaked among 30 years olds. Ischemic ECG findings were present in East Greenland Inuit before westernisation, the prevalence clearly lower than today.