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

The effect of sucrase-isomaltase deficiency on metabolism, food intake and preferences: protocol for a dietary intervention study

In Greenland, traditional marine foods are increasingly being replaced by sucrose- and starch-rich foods. A knock-out c.273_274delAG variant in the sucrase-isomaltase (SI) gene is relatively common in Greenland, with homozygous carriers being unable to digest sucrose and some starch. The variant is associated with a healthier metabolic phenotype in Greenlanders, which is confirmed by SI-knockout mice. We aim to assess if the healthy phenotype is explained by metabolic and microbial differences and if food and taste preferences differ between SI-genotypes. This paper describes the protocol for a randomised cross-over trial conducted in Greenland in 2022 with two dietary interventions of three days; a traditional meat- and fish-rich diet and a starch-rich Western diet with 11 energy% sucrose. The power calculation showed that 22 homozygous SI-carriers and 22 non-carriers were sufficient to detect a 0.5 mmol/L difference in glycaemic variability (80% power, α=0.05). We enrolled 18 carriers and 20 non-carriers. We examined food preferences at baseline and collected samples before and after each intervention for metabolic, metabolome, and microbiome profiling. Analyses of samples have not been completed yet. The Ethics Committee of Greenland approved the study. Results will be disseminated in international peer-reviewed journals and to the general Greenlandic population. NCT05375656.

Co-encapsulation of fish oil with essential oils and lutein/curcumin to increase the oxidative stability of fish oil powder

The oxidation-resistant and multi-functional fish oil powders were produced by co-encapsulating fish oil with essential oils, lutein, and curcumin. The ovalbumin/alginate complex was used as the wall, and the wall-to-oil ratio was fixed at 1:1 based on yield, oil recovery, and internalization efficiency (IE). Surface oil was removed to better understand the characteristics of the fish oil powders. Scanning electron microscopy (SEM) results indicated that the freeze-dried fish oil powders had irregular shapes with visible pores on the surface. Covalent bonds and electrostatic interactions within the ovalbumin/alginate complex were detected through FTIR. The garlic essential oil-added sample showed the strongest oxidative stability throughout the storage period (30 days). This work showed that fish oil had been encapsulated successfully and multi-functional fish oil powders could be produced by dissolving lipophilic bioactive compounds in fish oil before encapsulation.

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.

Anthropometric measures and blood pressure of Greenlandic preschool children

The study aims to describe anthropometric data of Greenlandic preschool children, blood pressure (BP) measures and effects of maternal smoking during pregnancy in a follow-up of the ACCEPT birth cohort. The study included 102 children (55 boys and 47 girls) aged 3.5–5.5 years. Anthropometric measures included weight, height, head circumference (HC), body mass index (BMI), waist and hip circumference, ratio for height/weight, waist/height, waist/hip and BP measurements. Overweight and obesity-prevalence was determined using the international obesity task force BMI references for children. Significant increases in anthropometrics from 3.5 to 5.5 years included weight, height, HC and hip circumference, whereas ratio for height/weight, waist/hip and waist/height decreased. Boys had significantly larger HC than girls. The prevalence of overweight and obesity was similar (35.1%) between genders. Mean systolic and diastolic BP were 104 and 68 mmHg, respectively. Children of mothers smoking during pregnancy had higher hip circumference, lower waist/hip ratio and higher diastolic BP. The study present updated anthropometric data and BP of Greenlandic preschool children and effects of maternal smoking during pregnancy. The prevalence of overweight and obesity was higher than previously reported and maternal smoking during pregnancy affected the child data.

Abbreviations ACCEPT: Adaptation to Climate Change, Environmental Pollution and dietary Transition; BMI: Body Mass Index; BP: Blood Pressure; Circ: Circumference; DBP: Diastolic Blood Pressure; FFH: Fisher-Freeman-Halton exact test; HC: Head Circumference; H: Height; HDL: high-density lipoprotein; HiC: Hip Circumference; IOTF International Obesity Task Force, Max: maximum, Min: minimum, P25: 25th percentile, P75: 75th percentile, SBP: Systolic Blood Pressure, SD: Standard Deviation; VDLD: very-low-density lipoprotein; WaC: Waist Circumference, W: Weight, WHO: World Health Organization.

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.

Toenail mercury levels positively correlate with obesity and abdominal obesity among Korean adults

BACKGROUND

Although previous studies have shown that short-term exposure to mercury is associated with obesity, it should be noted that mercury is not easily released and that it constantly accumulates in the body. However, few studies have explored the association between chronic mercury exposure and obesity. This study aimed to examine the association between chronic mercury exposure and obesity in Korean adults.

METHODS

The study used baseline data from the Trace Element Study of Korean Adults in Yeungnam area. A total of 495 participants aged 40-69 years who provided the required information (demographic, diet, lifestyle, toenail mercury levels, and health examination results) were included. Toenail mercury levels were measured using neutron-activation analysis. Body mass index and waist circumference were obtained from medical examination. Multivariable-adjusted logistic regression and restricted cubic spline regression were used in the analysis.

RESULTS

In the fully adjusted logistic regression models, participants with the highest toenail mercury levels had a higher prevalence of obesity (odds ratio [OR]: 3.26, 95 % confidence interval [CI]: 1.79-5.93) and abdominal obesity (OR: 2.30, 95 % CI: 1.15-4.59). In the cubic spline regression model, linear relationships were confirmed between increased toenail mercury levels and higher prevalence of obesity and abdominal obesity (all p > 0.05 for nonlinearity).

CONCLUSIONS

In summary, chronic mercury exposure was associated with higher prevalence of obesity and abdominal obesity in Korean adults. Therefore, the development of public health interventions against environmental exposure of foods is required to manage and prevent obesity.

Association of fine particulate matter with glucose and lipid metabolism: a longitudinal study in young adults

OBJECTIVES

This study aimed to evaluate whether PM2.5 exposure in a highly polluted area (>100 µg/m3) affects glucose and lipid metabolism in healthy adults.

METHODS

We recruited 110 healthy adults in Baoding city, Hebei, China, and followed them up between 2017 and 2018. Personal air samplers were used to monitor personal PM2.5 levels. Eight glucose and lipid metabolism parameters were quantified. We performed the linear mixed-effect models to investigate the relationships between PM2.5 and glucose and lipid metabolism parameters. Stratified analyses were further performed according to sex and body mass index (BMI).

RESULTS

The concentration of PM2.5 was the highest in spring, with a median of 232 μg/m3 and the lowest in autumn (139 μg/m3). After adjusting for potential confounders, we found that for each twofold increase in PM2.5, the median of insulin concentration decreased by 5.89% (95% CI -10.91% to -0.58%; p<0.05), and ox-LDL increased by 6.43% (95% CI 2.21% to 10.82%; p<0.05). Stratified analyses indicated that the associations were more pronounced in females, overweight and obese participants.

CONCLUSIONS

Exposure to high PM2.5 may have deleterious effects on glucose and lipid metabolism. Females, overweight and obese participants are more vulnerable.

Sami dietary habits and the risk of cardiometabolic disease: a systematic review

This systematic literary review investigates if an association between Sami dietary habits and cardiometabolic outcomes exists, and examines the dietary characteristics and cardiometabolic status of the Sami population. Included were all articles assessing Sami dietary habits and cardiometabolic disease or risk factors. Embase, Medline and SweMed were searched on 26 September 2019 and articles were screened for eligibility in October 2019. Data were extracted according to Moose Guidelines and the Newcastle Ottawa Scale (NOS) was used to assess risk of bias. The initial search generated 4,195 articles in total. Nine articles met all inclusion criteria. Two were cohort studies and seven were cross-sectional. Rating by NOS ranked from 2/7 to 8/9 stars. The studies were largely descriptive and only few had results regarding a direct association between Sami dietary habits and cardiometabolic outcomes. The findings demonstrated no association between consumption of certain Sami food items and blood-lipids or mortality from CVD/CHD. A higher intake of fat, protein, reindeer-meat and coffee and a slightly lower blood pressure and mortality from CVD/CHD was seen among Sami compared with non-Sami. The limited amount and descriptive nature of the eligible articles indicate that resaerch within the fielt is limited. Thus, additional longitudinal studies are suggested.

Capturing a Complexity of Nutritional, Environmental, and Economic Impacts on Selected Health Parameters in the Russian High North

The rapid pace of economic exploration of the Arctic against the backdrop of progressing environmental change put a high priority on improving understanding of health impacts in the northern communities. Deficiencies in the capability to capture the complexity of health-influencing parameters along with a lack of observations in circumpolar territories present major challenges to establishing credible projections of disease incidence across varying northern environments. It is thus crucial to reveal the relative contributions of coacting factors to provide a basis for sustainable solutions in the sphere of public health. In order to better understand the adverse effects associated with public health, this study employed six-stage multiple regression analysis of incidence rates of fourteen diseases (International Classification of Diseases (ICD-11) codes most widespread in the Russian Arctic) against a set of environmental, nutritional, and economic variables. Variance inflationary factor and best-subsets regression methods were used to eliminate collinearity between the parameters of regression models. To address the diversity of health impacts across northern environments, territories of the Arctic zone of Russia were categorized as (1) industrial sites, (2) urban agglomerations, (3) rural inland, and (4) coastline territories. It was suggested that, in Type 1 territories, public health parameters were most negatively affected by air and water pollution, in Type 2 territories—by low-nutrient diets, in Type 3 and Type 4 territories—by economic factors. It was found that in the Western parts of the Russian Arctic, poor quality of running water along with low access to the quality-assured sources of water might increase the exposure to infectious and parasitic diseases and diseases of the circulatory, respiratory, and genitourinary systems. Low living standards across the Russian Arctic challenged the economic accessibility of adequate diets. In the cities, the nutritional transition to low-quality cheap market food correlated with a higher incidence of digestive system disorders, immune diseases, and neoplasms. In indigenous communities, the prevalence of low diversified diets based on traditional food correlated with the increase in the incidence rates of nutritional and metabolic diseases.

Dietary habits, metabolic health and vitamin D status in Greenlandic children

OBJECTIVE

To compare the dietary habits of children living in northern villages and in the capital of Greenland, given the reported transition from traditional to westernised diet in adults over recent decades, and to explore the association between consumption of marine mammals and fish (MMF) and the children's metabolic profile and vitamin D status.

DESIGN

Children answered an FFQ encompassing sixty-four individual food types pooled into six food categories. Their pubertal stage, body fat, fitness level, metabolic profile (non-HDL-cholesterol, glycated Hb, insulin, glucose, high-sensitivity C-reactive protein) as well as serum 25-hydroxyvitamin D (25(OH)D) concentration were evaluated.

SETTING

Siorapaluk and Qaanaaq (north of Greenland) and Nuuk (west).

PARTICIPANTS

Children aged 6-18 years (n 177).

RESULTS

MMF were most frequently eaten by children from Siorapaluk (mean (sd): 73·4 (14·1) times/month), followed by children from Qaanaaq (37·0 (25·0) times/month), and least often eaten by children from Nuuk (23·7 (24·6) times/month; P < 0·001). Children from Qaanaaq consumed 'junk food' more frequently (P < 0·001) and fruits and vegetables less frequently (P < 0·01) than children from Nuuk. MMF consumption was positively associated with serum 25(OH)D concentration (P < 0·05), but the overall prevalence of vitamin D deficiency was high (18 %). No association was found between MMF consumption and metabolic parameters.

CONCLUSIONS

The dietary transition and influence of western diets have spread to the north of Greenland and only the most remote place consumed a traditional diet highly based on MMF. We found no strong associations of MMF consumption with metabolic health, but a positive association with vitamin D status.

Effect of low-ratio n-6/n-3 PUFA on blood glucose: a meta-analysis

OBJECTIVE

The aim of this meta-analysis was to investigate the effect of increasing dietary low-ratio n-6/n-3 polyunsaturated fatty acid (PUFA) intake on blood glucose and other related indicators.

METHODS

We systematically searched randomized controlled trials of low-ratio n-6/n-3 PUFA intervention on PubMed, Embase, Cochrane library and related references up to August 2018. The change values were calculated as the weighted mean difference (WMD) by using a random-effect model.

RESULTS

Eleven randomized controlled trials were included. No significant effect of dietary low-ratio n-6/n-3 PUFA supplementation was observed on fasting blood glucose (WMD: 0.057 mmol L^-1; 95% CI: -0.090 to 0.204 mmol L^-1), insulin (WMD: -0.757 mIU L^-1; 95% CI: -2.419 to 0.904 mIU L^-1), insulin resistance index (WMD: -0.201; 95% CI: -0.566 to 0.165), and glycosylated hemoglobin (WMD: -0.063%; 95% CI: -0.061 to 0.186%). Subgroup analysis showed that the effect of low-ratio n-6/n-3 PUFA on the reduction of the plasma insulin level in North America (WMD: -3.473 mIU L^-1; 95% CI: -5.760 to -1.185 mIU L^-1) was more obvious than that in Asian countries (WMD: -0.797 mIU L^-1; 95% CI: -2.497 to 0.902 mIU L^-1) and European countries (WMD: -0.063 mIU L^-1; 95% CI: -0.061 to 0.186 mIU L^-1). In the subgroup of diabetic subjects, low-ratio n-6/n-3 PUFA supplementation can decrease the plasma insulin level (WMD: -3.010 mIU L^-1; 95% CI: -5.371 to -0.648 mIU L^-1) and insulin resistance index (WMD: -0.460; 95% CI: -0.908 to -0.012). When the intervention period was longer than 8 weeks, low-ratio n-6/n-3 PUFA supplementation could also decrease the plasma insulin level (WMD: -2.782 mIU L^-1; 95% CI: -4.946 to -0.618 mIU L^-1). No significant publication bias was observed for all blood glucose and other related indicators as suggested by Begg's test and Egger's test.

CONCLUSION

Our meta-analysis found that low-ratio n-6/n-3 PUFA supplementation could improve the glucose metabolism by reducing the insulin and insulin resistance in the diabetic patients. Low-ratio n-6/n-3 PUFA supplementation could reduce the plasma insulin level when the supplementation duration was longer than 8 weeks.

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.

Food security in Nunavut, Canada: barriers and recommendations

OBJECTIVES

The food supply of Inuit living in Nunavut, Canada, is characterized by market food of relatively low nutritional value and nutrient-dense traditional food. The objective of this study is to assess community perceptions about the availability and accessibility of traditional and market foods in Nunavut.

STUDY DESIGN

A qualitative study using focus group methodology.

METHODS

Focus groups were conducted in 6 communities in Nunavut in 2004 and collected information was analyzed.

RESULTS

Barriers to increased traditional food consumption included high costs of hunting and changes in lifestyle and cultural practices. Participants suggested that food security could be gained through increased economic support for local community hunts, freezers and education programs, as well as better access to cheaper and higher quality market food.

CONCLUSIONS

Interventions to improve the dietary quality of Nunavut residents are discussed.

Research with Arctic peoples: Unique research opportunities in heart, lung, blood and sleep disorders

Arctic peoples are spread over eight countries and comprise 3.74 million residents, of whom 9% are indigenous. The Arctic countries include Canada, Finland, Greenland (Denmark), Iceland, Norway, Russia, Sweden and the United States. Although Arctic peoples are very diverse, there are a variety of environmental and health issues that are unique to the Arctic regions, and research exploring these issues offers significant opportunities, as well as challenges. On July 28-29, 2004, the National Heart, Lung, and Blood Institute and the Canadian Institutes of Health Research co-sponsored a working group entitled "Research with Arctic Peoples: Unique Research Opportunities in Heart, Lung, Blood and Sleep Disorders". The meeting was international in scope with investigators from Greenland, Iceland and Russia, as well as Canada and the United States. Multiple health agencies from Canada and the United States sent representatives. Also attending were representatives from the International Union for Circumpolar Health (IUCH) and the National Indian Health Board. The working group developed a set of ten recommendations related to research opportunities in heart, lung, blood and sleep disorders; obstacles and solutions to research implementation; and ways to facilitate international comparisons. These recommendations are expected to serve as an agenda for future research.

Review Article: Indigenous health in the Arctic: an overview of the circumpolar Inuit population

The health of the Inuit has undergone substantial changes over the past five centuries, as a result of social, cultural, and economic changes brought about by interactions with Europeans. This process was accelerated considerably in the second half of the twentieth century. The incidence of infectious diseases has declined considerably but is still high compared with Western societies. Chronic diseases such as diabetes and cardiovascular disease are on the increase, while accidents, suicides, violence, and substance abuse are of major importance for the pattern of ill health in most Inuit communities. Lifestyle changes, social change, and changes in society and the environment are major determinants of health among the Inuit.

Omega-3 polyunsaturated fatty acid profiles and relationship with cardiometabolic risk factors in Cree (Eeyouch) of Northern Québec

Background

n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) from fish are known modulators of cardiometabolic risk factors.

Objective

To examine fatty acids (FAs) status and the relationship between n-3 LC-PUFA and cardiometabolic risk factors in Cree participants.

Design

We analyzed data from a cross-sectional study (n=829) conducted in Cree adults (aged 18–74 years) from 7 communities of the James Bay territory of Quebec (Canada) in 2005–2009. Sociodemographic, lifestyle, clinical and anthropometric data were collected. FAs were quantified in red blood cells (RBCs) under fasting conditions.

Results

A total of 89% of the participants were overweight (with 69% obesity), 33% had hypertriglyceridemia, 44% had low plasma HDL-c and 77% had fasting plasma insulin ≥90 pmol/l. Total n-3 PUFAs accounted for 6% of total FAs and were higher among older participants, while n-6 PUFAs accounted for 31% of total FAs and were higher among younger participants. According to the adjusted multiple linear regression models, n-3 LC-PUFA was associated (p<0.05) with higher total cholesterol, LDL-c and apo B-100, and was also associated (p<0.05) with lower blood glucose.

Conclusion

Overall, this study showed that n-3 LC-PUFA levels measured in the RBCs of the Cree adults are relatively low and tend towards lower levels among youth. These levels might be insufficient to offset the prevalence of cardiometabolic risk factors.

Identification of Novel Genetic Determinants of Erythrocyte Membrane Fatty Acid Composition among Greenlanders

Fatty acids (FAs) are involved in cellular processes important for normal body function, and perturbation of FA balance has been linked to metabolic disturbances, including type 2 diabetes. An individual’s level of FAs is affected by diet, lifestyle, and genetic variation. We aimed to improve the understanding of the mechanisms and pathways involved in regulation of FA tissue levels, by identifying genetic loci associated with inter-individual differences in erythrocyte membrane FA levels. We assessed the levels of 22 FAs in the phospholipid fraction of erythrocyte membranes from 2,626 Greenlanders in relation to single nucleotide polymorphisms genotyped on the MetaboChip or imputed. We identified six independent association signals. Novel loci were identified on chromosomes 5 and 11 showing strongest association with oleic acid (rs76430747 in ACSL6, beta (SE): -0.386% (0.034), p = 1.8x10^-28) and docosahexaenoic acid (rs6035106 in DTD1, 0.137% (0.025), p = 6.4x10^-8), respectively. For a missense variant (rs80356779) in CPT1A, we identified a number of novel FA associations, the strongest with 11-eicosenoic acid (0.473% (0.035), p = 2.6x10^-38), and for variants in FADS2 (rs174570), LPCAT3 (rs2110073), and CERS4 (rs11881630) we replicated known FA associations. Moreover, we observed metabolic implications of the ACSL6 (rs76430747) and CPT1A (rs80356779) variants, which both were associated with altered HbA1c (0.051% (0.013), p = 5.6x10^-6 and -0.034% (0.016), p = 3.1x10^-4, respectively). The latter variant was also associated with reduced insulin resistance (HOMA-IR, -0.193 (0.050), p = 3.8x10^-6), as well as measures of smaller body size, including weight (-2.676 kg (0.523), p = 2.4x10^-7), lean mass (-1.200 kg (0.271), p = 1.7x10^-6), height (-0.966 cm (0.230), p = 2.0x10^-5), and BMI (-0.638 kg/m² (0.181), p = 2.8x10^-4). In conclusion, we have identified novel genetic determinants of FA composition in phospholipids in erythrocyte membranes, and have shown examples of links between genetic variants associated with altered FA membrane levels and changes in metabolic traits.

Disruption of fatty-acid balance has in several previous studies been linked to human health conditions, including the metabolic syndrome, type 2 diabetes, and insulin resistance. Composition of fatty acids in lipid membranes is influenced, not only by diet and lifestyle, but also by genetic variation. By identifying genes linked to changes in the level of specific fatty acids, it may be possible to identify biological mechanisms and pathways central to regulation of fatty-acid composition in lipid membranes. We therefore aimed at finding such genes by studying Greenlanders. We identified six genomic regions harboring variants, which were associated with the level of at least one of 22 assessed erythrocyte membrane fatty acids, including two novel regions not previously linked to fatty acid levels. Moreover, we showed that two of the identified variants were associated with altered levels of glycosylated hemoglobin, and one of these variants was associated with reduced insulin resistance and decreased measures of body size. These results contribute to our understanding of fatty acid metabolism, and support a link between fatty acid balance and metabolic health.

Increased asthma and adipose tissue inflammatory gene expression with obesity and Inuit migration to a western country

BACKGROUND

An overlap between obesity and asthma exists, and inflammatory cells in adipose tissue could drive the development of asthma. Comparison of adipose tissue gene expression among Inuit living in Greenland to those in Denmark provides an opportunity to assess how changes in adipose tissue inflammation can be modified by migration and diet.

OBJECTIVE

To examine mast cell and inflammatory markers in adipose tissue and the association with asthma.

METHODS

Two Inuit populations were recruited, one living in Greenland and another in Denmark. All underwent adipose subcutaneous biopsy, followed by clinical assessment of asthma, and measurement of AHR. Adipose tissue biopsies were homogenised, RNA extracted, and PCR was performed to determine the relative gene expression of mast cell (tryptase, chymase, CPA3) and inflammatory markers (IL-6, IL-1β, and CD163).

RESULTS

Of the 1059 Greenlandic Inuit participants, 556 were living in Greenland and 6.4% had asthma. Asthma was increased in Denmark (9%) compared to Greenland (3.6%, p < 0.0001) and associated with increased adipose tissue IL-6 gene expression and increased BMI. There was no association between asthma and adipose tissue mast cell gene expression. Pro-inflammatory gene expression (IL-6, IL-1β) was higher in those living in Denmark, and with increasing BMI and dietary changes. The anti-inflammatory (M2) macrophage marker, CD163, was higher in Greenland-dwelling Inuit (p < 0.01).

CONCLUSIONS

No association was found between gene expression of mast cell markers in adipose tissue and asthma. Among Greenlandic Inuit, adipose tissue inflammation is also increased in those who migrate to Denmark, possibly as a result of dietary changes.

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.

Investigating the effects of arctic dietary intake on lung health

BACKGROUND/OBJECTIVE

Preservation of lung health requires understanding the modifiable risk factors of airflow limitation. This study investigates the association between diet and lung function in a population of Greenland Inuit residing in the Arctic (Greenland) or Western Europe (Denmark).

SUBJECTS/METHODS

Two unselected Inuit populations were recruited, one living in Greenland (Urban (Nuuk) n=358; Rural (Uummannaq) n=207) and the other in Denmark (n=539). Lung function was measured using spirometry and diet by a food frequency questionnaire. Factors associated with airflow limitation were assessed using multiple linear regression models.

RESULTS

The dietary composition differed significantly in the two regions, with higher whale, seal and wild meat intake and lower fruit and vegetable intake in the Arctic regions compared with Denmark. Consumption of vegetables (P=0.004) and whale and/or seal (P<0.0001) was significantly and positively associated with FEV1, as well as with FVC (vegetables: P=0.001, whale and/or seal: P=0.002). Regular fruit intake was included in the statistical models; however, it did not reach statistical significance (FEV1: P=0.053; FVC: P=0.055).

CONCLUSIONS

High dietary intake of vegetables as well as intake of arctic marine mammals had independent positive associations with lung function in this cohort of Greenlandic Inuit. These findings suggest an additive role of dietary intake of antioxidants and unsaturated fatty acids in lung health, which warrants prospective evaluation.

Effect of caloric restriction with or without n-3 polyunsaturated fatty acids on insulin sensitivity in obese subjects: A randomized placebo controlled trial

Background

Caloric restriction and n-3 polyunsaturated fatty acid (PUFA) supplementation protect from some of the metabolic complications. The aim of this study was to assess the influence of a low calorie diet with or without n-3 PUFA supplementation on glucose dependent insulinotropic polypeptide (GIP) output and insulin sensitivity markers in obese subjects.

Methods

Obese, non-diabetic subjects (BMI 30–40 kg/m²) and aged 25–65 yr. were put on low calorie diet (1200–1500 kcal/day) supplemented with either 1.8 g/day n-3 PUFA (DHA/EPA, 5:1) (n = 24) or placebo capsules (n = 24) for three months in a randomized placebo controlled trial. Insulin resistance markers and GIP levels were analysed from samples obtained at fasting and during an oral glucose tolerance test (OGTT).

Results

Caloric restriction with n-3 PUFA led to a decrease of insulin resistance index (HOMA-IR) and a significant reduction of insulin output as well as decreased GIP secretion during the OGTT. These effects were not seen with caloric restriction alone. Changes in GIP output were inversely associated with changes in red blood cell EPA content whereas fasting GIP level positively correlated with HOMA-IR index. Blood triglyceride level was lowered by caloric restriction with a greater effect when n-3 PUFA were included and correlated positively with fasting GIP level.

Conclusions

Three months of caloric restriction with DHA + EPA supplementation exerts beneficial effects on insulin resistance, GIP and triglycerides.

General significance

Combining caloric restriction and n-3 PUFA improves insulin sensitivity, which may be related to a decrease of GIP levels.

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Caloric restricted diet with n-3 PUFA improves insulin sensitivity in obese subjects

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n-3 PUFA supplementation combined with low calorie diet decrease GIP output

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Blood triglycerides level reduces after caloric restriction diet combined with n-3 PUFA

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GIP level positively correlates with HOMA-IR index and triglycerides

Frequency of Food Consumption and Self-reported Diabetes among Adult Men and Women in India: A Large Scale Nationally Representative Cross-sectional Study

BACKGROUND

Recent studies have shown that the choice of foods and frequency of intake plays a role in diabetes prevention. We examined the association between frequency of consumption of specific food items and the occurrence of diabetes in adult Indian population.

METHODS

Cross sectional data of 99,574 women and 61,361 men aged 20-49 years who participated in India's third National Family Health Survey conducted during 2005-06 was used for this study. Association between frequency of food intake such as daily, weekly, occasionally and never, and prevalence of diabetes were estimated using multivariable logistic regression models after adjusting for body mass index, tobacco smoking, alcohol drinking, television watching and socio-economic and demographic characteristics, stratified by sex.

RESULTS

In men, weekly (OR:0.64; 95%CI:0.47-0.88) and occasional (OR:0.60; 95%CI:0.44-0.81) consumption of milk/curd, weekly (OR:0.48; 95%CI:0.27-0.87) and occasional (OR:0.52; 95%CI:0.28-0.99) consumption of pulses/beans and consumption of fruits (OR ranges from 0.33 to 0.39) was associated with a significantly lower likelihood of diabetes whereas daily (OR:0.55; 95%CI:0.34-0.88) or weekly (OR:0.56; 95%CI:0.35-0.90) pulses/beans consumption and fruits intake (OR ranges from 0.36 to 0.46) was associated with a lower likelihood of diabetes in women.

CONCLUSION

This study has confirmed findings from high income countries that diabetes among adult Indians, which is large and increasing, might be contained by regular consumption of vegetarian foods including pulses, beans, fruits and dairy products. However, this is an observational finding and uncontrolled confounding cannot be excluded as an explanation for the association. More epidemiological research with better measures of food intake and clinical measures of diabetes is needed in a developing country setting to validate the findings.

Novel therapeutic strategies for adult obese asthmatics

Asthma is a complex syndrome that affects an estimated 26 million people in the United States but gaps exist in the recognition and management of asthmatic subgroups. This article proposes alternative approaches for future treatments of adult obese asthmatics who do not respond to standard controller therapies, drawing parallels between seemingly disparate therapeutics through their common signaling pathways. How metformin and statins can potentially improve airway inflammation is described and supplements are suggested. A move toward more targeted therapies for asthma subgroups is needed. These therapies address asthma and the comorbidities that accompany obesity and metabolic syndrome to provide the greatest therapeutic potential.

Frequency of fish intake and diabetes among adult Indians

OBJECTIVES

Recent studies have shown that the choice of foods plays a role in diabetes prevention. However, little empirical evidence on this association exists in developing countries. We aimed to examine the association between frequency of fish intake and self-reported diabetes status among adult men and women in India.

METHODS

Analysis of cross-sectional data from participants in India's third National Family Health Survey conducted during 2005-2006 was performed. Associations between fish intake, determined by frequency of consumption (daily, weekly, occasionally, and never), and self-reported diabetes were estimated using multivariable-adjusted models in 99,574 women, 56,742 men, and 39,257 couples aged 20-49 years after adjusting for frequency of consumption of other food items, body mass index (BMI) status, tobacco smoking, alcohol drinking, watching television, age, education, living standard of the household, and place of residence.

RESULTS

After adjustment for other dietary, lifestyle, and socioeconomic and demographic characteristics, odds of diabetes were 2 times higher (odds ratio [OR]: 2.02; 95% confidence interval [CI], 1.59-2.57; p < 0.0001) among those who reported consuming fish daily compared to those who never consumed fish. Weekly fish intake was also associated with a higher odds of having diabetes (OR: 1.55; 95% CI, 1.25-1.93; p < 0.0001). The adjusted effect of daily fish intake on diabetes was greater among men (OR: 2.46; 95% CI, 1.66-3.65) than among women (OR: 1.72; 95% CI, 1.26-2.33). In cross-spousal sensitivity analysis, the odds of a husband having diabetes was also associated with wife's daily/weekly consumption of fish (OR: 1.36; 95% CI, 0.92-2.01) and the odds of a wife having diabetes was also associated with husband's daily/weekly consumption of fish (OR: 1.21; 95% CI, 0.87-1.68).

CONCLUSIONS

In a large nationally representative sample of adult men and women in India, daily or weekly fish intake was positively associated with the presence of diabetes. However, this is an observational finding and uncontrolled confounding cannot be excluded as an explanation for the association. More epidemiological research with better measures of food intake and clinical measures of diabetes is needed in a developing country setting to validate the findings.

The Effect of n-3 Fatty Acids on Glucose Homeostasis and Insulin Sensitivity

Type 2 diabetes (T2D) as well as cardiovascular disease (CVD) represent major complications of obesity and associated metabolic disorders (metabolic syndrome). This review focuses on the effects of long-chain n-3 polyunsaturated fatty acids (omega-3) on insulin sensitivity and glucose homeostasis, which are improved by omega-3 in many animal models of metabolic syndrome, but remain frequently unaffected in humans. Here we focus on: (i) mechanistic aspects of omega-3 action, reflecting also our experiments in dietary obese mice; and (ii) recent studies analysing omega-3’s effects in various categories of human subjects. Most animal experiments document beneficial effects of omega-3 on insulin sensitivity and glucose metabolism even under conditions of established obesity and insulin resistance. Besides positive results obtained in both cross-sectional and prospective cohort studies on healthy human populations, also some intervention studies in prediabetic subjects document amelioration of impaired glucose homeostasis by omega-3. However, the use of omega-3 to reduce a risk of new-onset diabetes in prediabetic subjects still remains to be further characterized. The results of a majority of clinical trials performed in T2D patients suggest that omega-3 have none or marginal effects on metabolic control, while effectively reducing hypertriglyceridemia in these patients. Despite most of the recent randomized clinical trials do not support the role of omega-3 in secondary prevention of CVD, this issue remains still controversial. Combined interventions using omega-3 and antidiabetic or hypolipidemic drugs should be further explored and considered for treatment of patients with T2D and other diseases.

Dietary patterns in Greenland and their relationship with type 2 diabetes mellitus and glucose intolerance

OBJECTIVE

Traditional Inuit dietary patterns have been found to be beneficial for CVD but have not been investigated in relation to glucose intolerance. We examined the association between dietary patterns and type 2 diabetes mellitus (T2DM), impaired glucose tolerance (IGT) and impaired fasting glucose (IFG).

DESIGN

Cross-sectional design with a priori derived dietary patterns from an FFQ resulted in five patterns: imported meat (n 196), traditional food (n 601), balanced diet (n 126), unhealthy diet (n 652) and standard diet (n 799).

SETTING

Associations between dietary patterns and glucose-related outcomes were tested by linear and logistic regression analyses. Data included: dietary intake by FFQ, waist circumference, ethnicity, frequency of alcohol intake and smoking, physical activity, and oral glucose tolerance test results. Fasting participants and those without diagnosed T2DM were classified into normal glucose tolerance, IGT, IFG or T2DM. HOMA-IR (homeostatic model assessment-insulin resistance index) and HOMA-β (homeostatic model assessment of β-cell function) were calculated.

SUBJECTS

Data included 2374 Inuit, aged 18+ years.

RESULTS

Participants with a traditional dietary pattern had higher fasting plasma glucose (mean 5·73 (95% CI 5·68, 5·78) mmol/l, P < 0·0001) and lowest HOMA-β (48·66 (95% CI 46·86, 50·40), P < 0·0001). The traditional diet gave significantly higher odds for IFG and T2DM than the balanced diet, imported meat diet, standard diet and unhealthy diet.

CONCLUSIONS

Traditional food was positively associated with T2DM, IFG and fasting plasma glucose, and negatively associated with β-cell function, compared with a standard diet. The imported meat diet seemed the best in relation to glucose intolerance, with lowest fasting plasma glucose and lowest odds for IFG and T2DM.

Population groups in dietary transition

Background

Little is known about the effects of dietary acculturation in minority groups in the Nordic countries, including immigrants from non-Western societies.

Methods

A search was performed in Medlin33e/PubMed and SweMed+ for articles published in 1990–2011.

Results

A total of 840 articles were identified, with a final 32 articles used to tabulate results which were included in the primary analysis. High rates of vitamin D deficiency (23 articles) were found in immigrants of non-Western origin; deficiency rates were very high among both pregnant and non-pregnant women, and also among children, with young children of immigrant parents showing 50 times higher risk for rickets when compared to children of indigenous parents. The risk of iron deficiency (two articles) was high among immigrant women, while the results were inconclusive regarding children. High rates of dental caries (seven articles) were found among pre-school and younger school children of immigrant origin, while the risk of caries was not as evident among older children. In a secondary analysis, including 48 articles (results not tabulated), overweight and obesity (14 articles) were seen in many immigrant groups, resulting in a high prevalence of diabetes (2 review articles from a total of 14 original articles) and incidence of coronary heart disease (CHD; seven articles). For hypertension (three articles), dyslipidemia (four articles), and dietary patterns among immigrants (10 articles), the results were contradictory.

Conclusions

Risk of vitamin D deficiency is alarmingly high in the Nordic countries among immigrants of non-Western origin, especially among women. Dental caries is high among immigrant children aged 0–7 years due to a higher intake of sugary products. Overweight and obesity, associated with a higher risk of diabetes and CHD, are prevalent in many immigrant groups and need further attention.

The association of n-3 fatty acids with serum High Density Cholesterol (HDL) is modulated by sex but not by Inuit ancestry

OBJECTIVE

To explore the association between dietary n-3 fatty acids and serum lipids in a population with a high intake of marine food. Specifically to test interaction with sex and ethnicity.

METHODS

Information was obtained from 2280 Inuit who participated in a countrywide health survey in Greenland in 2005-2009. n-3 intake was estimated from an FFQ and analyses of Red Blood Cell (RBC) membranes. Serum total, HDL and LDL cholesterol and triglyceride were analysed. Obesity was measured. Information on ethnicity, smoking, alcohol consumption, and physical activity was obtained from an interview.

RESULTS

In linear regression models adjusted for age, sex, obesity, ethnicity, alcohol, and smoking serum HDL, LDL and triglyceride were associated with n-3 intake estimated as eicosapentaenoic acid (EPA) in RBC membranes. For HDL the interaction between EPA and sex was significant (p < 0.001). No significant interactions were observed for EPA and ethnicity.

CONCLUSION

A positive association of EPA with serum HDL and LDL and a negative association with triglyceride was observed among both men and women. For HDL, the association was stronger for men. The association of EPA with serum HDL was similar among Inuit with full Inuit ancestry and those with part Inuit ancestry. Diet and overweight are both realistic candidates for a population based intervention against dyslipidemia. Further studies of ethnic differences in the effect of n-3 fatty acids on cardiovascular risk factors are recommended.

Association of fish and n-3 fatty acid intake with the risk of type 2 diabetes: a meta-analysis of prospective studies

Results from observational studies on the association of fish and n-3 fatty acid consumption with type 2 diabetes mellitus (T2DM) risk are conflicting. Hence, a meta-analysis was performed to investigate this association from cohort studies. A comprehensive search was then conducted to identify cohort studies on the association of fish and/or n-3 fatty acid intake with T2DM risk. In the highest v. lowest categorical analyses, the fixed or random-effect model was selected based on the homogeneity test among studies. Linear and non-linear dose-response relationships were also assessed by univariate and bivariate random-effect meta-regression with restricted maximum likelihood estimation. In the highest v. lowest categorical analyses, the pooled relative risk (RR) of T2DM for intake of fish and n-3 fatty acid was 1·146 (95 % CI 0·975, 1·346) and 1·076 (95 % CI 0·955, 1·213), respectively. In the linear dose-response relationship, the pooled RR for an increment of one time (about 105 g)/week of fish intake (four times/month) and of 0·1 g/d of n-3 fatty acid intake was 1·042 (95 % CI 1·026, 1·058) and 1·057 (95 % CI 1·042, 1·073), respectively. The significant non-linear dose-response associations of fish and n-3 fatty acid intake with T2DM risk were not observed. The present evidence from observational studies suggests that the intake of both fish and n-3 fatty acids might be weakly positively associated with the T2DM risk. Further studies are needed to confirm these results.

The impact of long-chain n-3 polyunsaturated fatty acids on human health

A considerable literature has been published on the health benefits of fish, oil-rich fish and fish oils and their constituent long-chain (LC) n-3 PUFA. Evidence from epidemiological studies highlights the cardioprotective attributes of diets rich in fish, especially oil-rich fish. Data from intervention trials are consistent in suggesting that LC n-3 PUFA lower the risk of CVD, probably by the multiple mechanisms of lowering serum triacylglycerols, improving the LDL:HDL ratio, anti-arrhythmic effects on heart muscle, improved plaque stability, anti-thrombotic effects and reduced endothelial activation. Research indicates LC n-3 PUFA provision has an impact during development, and there is preliminary evidence that docosahexaenoic acid supplementation during pregnancy could optimise brain and retina development in the infant. LC n-3 PUFA are also postulated to ameliorate behavioural and mental health disturbances such as depression, schizophrenia, dementia and attention deficit hyperactivity disorder. However, despite some positive evidence in each of these areas, use of LC n-3 PUFA in these conditions remains at the experimental stage. In the case of immune function, there is little doubt that LC n-3 PUFA have a positive effect. Although intervention trials in rheumatoid arthritis show strong evidence of benefit, evidence for efficacy in other inflammatory conditions, including Crohn's disease, ulcerative colitis, psoriasis, lupus, multiple sclerosis, cystic fibrosis and asthma, is inconsistent or inadequate. More promising evidence in some conditions may come from studies which attempt to modify the fetal environment using LC n-3 PUFA supplementation during pregnancy.

The association between blood pressure and whole blood methylmercury in a cross-sectional study among Inuit in Greenland

BACKGROUND

The Inuit in Greenland have a high average consumption of marine species and are highly exposed to methylmercury, which in other studies has been related to hypertension. Data on the relation between methylmercury and hypertension is limited, especially in populations subjected to a high exposure of methylmercury. We examined the relation between whole blood mercury and blood pressure (BP) in Inuit in Greenland.

METHODS

A cross-sectional population-based study among adult Inuit in Greenland was performed in 2005-2009. Information on socio-demography, lifestyle, BP, blood samples and clinical measurements was obtained - the latter after overnight fasting. BP was measured according to standardized guidelines. Whole blood mercury concentration was used as a marker of exposure. The analyses were restricted to Inuit aged 30-69 years with four Greenlandic grandparents (N = 1,861). Multivariate regression analyses with inclusion of confounders were done separately for men and women with the omission of participants receiving anti-hypertensive drugs, except for logistic regression analyses of the relation between mercury and presence of hypertension (yes/no).

RESULTS

The mean whole blood mercury level was 20.5 μg/L among men and 14.7 μg/L among women. In multivariate analyses adjusted for confounders, diastolic BP decreased with increasing mercury concentration. In men diastolic BP decreased significantly for each four-fold increase in mercury concentration (Beta = -0.04, standard error = 0.01, p = 0.001), while no relation between mercury and diastolic BP was found among women. For systolic BP, a similar non-statistically significant result was seen only for men (Beta = -0.02, standard error = 0.01, p = 0.06). A relation between mercury and hypertension was only found in men; the odds ratio for hypertension was 0.99 (95% CI: 0.98-0.99). No relation between quintiles of mercury and hypertension was found. The relationship between mercury and BP parameters may be non-linear: In analyses of quintiles of mercury the overall effect of mercury on BP parameters was only statistically significant for diastolic BP among men (Wald test, p = 0.01), however pairwise comparisons showed that some quintiles were not statistically different. This result is supported by LOESS modelling.

CONCLUSIONS

No adverse associations between whole blood mercury and blood pressure were found. With increasing whole blood mercury concentrations, diastolic BP and the risk of hypertension decreased among men in the study: this may be explained by confounding by exercise or unknown factors.

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.

Prevalence and risk factors for self-reported diabetes among adult men and women in India: findings from a national cross-sectional survey

OBJECTIVE

We examined the distribution of diabetes and modifiable risk factors to provide data to aid diabetes prevention programmes in India.

DESIGN

Population-based cross-sectional survey of men and women included in India's third National Family Health Survey (NFHS-3, 2005-2006).

SETTING

The sample is a multistage cluster sample with an overall response rate of 98 %. All states of India are represented in the sample (except the small Union Territories), covering more than 99 % of the country's population.

SUBJECTS

Women (n 99 574) and men (n 56 742) aged 20-49 years residing in the sample households.

RESULTS

Prevalence of diabetes was 1598/100 000 (95 % CI 1462, 1735) among men and 1054/100 000 (95 % CI 974, 1134) among women in India. Rural-urban and marked geographic variation were found with higher rates in south and north-eastern India. Weekly and daily fish intake contributed to a significantly higher risk of diabetes among both women and men. Risks of diabetes increased with increased BMI, age and wealth status of both women and men, but no effects of the consumption of milk/curd, vegetables, eggs, television watching, alcohol consumption or smoking were found. Daily consumption of pulse/beans or fruits was associated with a significantly reduced risk of diabetes among women, whereas non-significant inverse associations were observed in the case of men.

CONCLUSIONS

Prevalence was underestimated using self-reports. The wide variation in self-reported diabetes is unlikely to be due entirely to reporting biases or access to health care, and indicates that modifiable risk factors exist. Prevention of diabetes should focus on obesity and target specific socio-economic groups in India.

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.

Effects of perfluorooctanesulfonate exposure on plasma lipid levels in the Inuit population of Nunavik (Northern Quebec)

BACKGROUND

Perfluorooctanesulfonate (PFOS) was used as a surfactant in various commercial products. In rodents, exposure to this compound induced various health effects, including hypolipidemia. In human populations, the potential toxicity of PFOS is not yet fully characterized, but indications of effects on lipids are reported. A recent study reported an increase in plasma cholesterol associated with exposure to perfluorinated compounds in humans exposed through drinking water, but similar effects were not reported in all exposed human populations. PFOS is widely distributed in the environment, including the arctic biota. The Inuit of Nunavik are exposed to environmental contaminants through the consumption of fish and game. This diet is also a source of omega3-polyunsaturated fatty acids (n-3 PUFAs) that are known to lower plasma triacylglycerols.

OBJECTIVE

This cross-sectional epidemiologic study aims at assessing the relationship between PFOS exposure and plasma lipids, while taking account of the concomitant hypolipidemic effect exerted by n-3 PUFAs.

METHODS

Plasma concentrations of PFOS and lipids were assessed in Nunavik Inuit adults (n=723) in the framework of a large-scale environmental health study. Associations of exposure levels to age, gender and selected wild food consumption associated with n-3 PUFAs intake, as well as the exposure on lipid levels were investigated by multivariate linear modeling.

RESULTS

In the Inuit population, PFOS exposure and n-3 PUFAs intake are related to traditional food consumption. Triacylglycerol and ratio of total cholesterol to high density lipoprotein cholesterol (HDL-C) levels were negatively associated with PFOS plasma levels, while HDL-C levels were positively associated, after adjustment for circulating levels of n-3 PUFAs and for the interaction between gender and PFOS plasma levels. Other plasma lipids, such as low density lipoprotein-cholesterol and non-HDL-C were not related to PFOS plasma concentrations.

CONCLUSION

The results of this study show a relationship between PFOS and plasma lipid levels in an environmentally exposed human population, and this effect appears distinct from that of n-3 PUFAs.

Eating fish and risk of type 2 diabetes: A population-based, prospective follow-up study

OBJECTIVE

To investigate the relation between total fish, type of fish (lean and fatty), and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake and risk of type 2 diabetes in a population-based cohort.

RESEARCH DESIGN AND METHODS

The analysis included 4,472 Dutch participants aged >or=55 years without diabetes at baseline. Dietary intake was assessed with a semiquantitative food frequency questionnaire. Hazard ratios (relative risk [RR]) with 95% CIs were used to examine risk associations adjusted for age, sex, lifestyle, and nutritional factors.

RESULTS

After 15 years of follow-up, 463 participants developed type 2 diabetes. Median fish intake, mainly lean fish (81%), was 10 g/day. Total fish intake was associated positively with risk of type 2 diabetes; the RR was 1.32 (95% CI 1.02-1.70) in the highest total fish group (>or=28 g/day) compared with that for non-fish eaters (P(trend) = 0.04). Correspondingly, lean fish intake tended to be associated positively with type 2 diabetes (RR highest group [>or=23 g/day] 1.30 [95% CI 1.01-1.68]; P(trend) = 0.06), but fatty fish was not. No association was observed between EPA and DHA intake and type 2 diabetes (RR highest group [>or=149.4 mg/day] 1.22 [0.97-1.53]). With additional adjustment for intake of selenium, cholesterol, and vitamin D, this RR decreased to 1.05 (0.80-1.38; P(trend) = 0.77).

CONCLUSIONS

The findings do not support a beneficial effect of total fish, type of fish, or EPA and DHA intake on the risk of type 2 diabetes. Alternatively, other dietary components, such as selenium, and unmeasured contaminants present in fish might explain our results.

Association between type of dietary fish and seafood intake and the risk of incident type 2 diabetes: the European prospective investigation of cancer (EPIC)-Norfolk cohort study

OBJECTIVE

To investigate the association between fish and seafood intake and new-onset type 2 diabetes.

RESEARCH DESIGN AND METHODS

This was a population-based prospective cohort (European Prospective Investigation of Cancer [EPIC]-Norfolk) study of men and women aged 40-79 years at baseline (1993-1997). Habitual fish and seafood intake (white fish, oily fish, fried fish, and shellfish) was assessed using a semiquantitative food frequency questionnaire and categorized as less than one or one or more portions/week. During a median (interquartile range) follow-up of 10.2 (9.1-11.2) years, there were 725 incident diabetes cases among 21,984 eligible participants.

RESULTS

Higher total fish intake (one or more versus less than one portions/week) was associated with a significantly lower risk of diabetes (odds ratio [OR] 0.75 [95% CI 0.58-0.96]), in analyses adjusted for age, sex, family history of diabetes, education, smoking, physical activity, dietary factors (total energy intake, alcohol intake, and plasma vitamin C) and obesity (BMI and waist circumference). White fish and oily fish intakes were similarly inversely associated with diabetes risk, but the associations were not significant after adjustment for dietary factors (oily fish) or obesity (white fish). Fried fish was not significantly associated with diabetes risk. Consuming one or more portions/week of shellfish was associated with an increased risk of diabetes (OR 1.36 [1.02-1.81]) in adjusted analyses.

CONCLUSIONS

Total, white, and oily fish consumption may be beneficial for reducing risk of diabetes, reinforcing the public health message to consume fish regularly. Greater shellfish intake seems to be associated with an increased risk of diabetes, warranting further investigation into cooking methods and mechanisms.

Influence of moderate energy restriction and seafood consumption on bone turnover in overweight young adults

BACKGROUND

Overweight and obesity are increasing in young adults. However, moderate energy restriction aimed at lowering body weight may promote bone turnover and bone loss. Inclusion of fish or fish oils in a weight-loss diet may attenuate these adverse skeletal effects.

OBJECTIVE

We examined the effects of incorporating fish or fish oil into an energy-restricted diet on bone turnover markers in young overweight adults.

DESIGN

While following a strict hypoenergetic (-30% relative to estimated requirements) diet for 8 wk, 276 overweight men and women [body mass index (in kg/m(2)): 27.5-32.5; age: 20-40 y) were randomly assigned to 1 of 4 dietary groups: sunflower-oil capsules (3 g/d; control), cod (3 x 150 g/wk), salmon (3 x 150 g/wk), and fish-oil capsules (3 g/d). Body weight, bone biomarkers, and 25-hydroxyvitamin D were measured at baseline and endpoint. Data were analyzed with repeated-measures analysis of variance and general linear models.

RESULTS

The mean (+/-SD) weight loss was 5.14 +/- 3.0 kg (5.8% +/- 3.2% body weight) during the 8 wk in the 4 dietary groups combined. Urinary N-telopeptides of type I collagen and serum C-terminal telopeptide of type I collagen increased (P < 0.05), whereas serum osteocalcin (but not bone-specific alkaline phosphatase) decreased (P < 0.05) from baseline to endpoint. Increased fish or fish-oil consumption had no effect (P > 0.1) on the changes in bone markers induced by weight loss. In contrast, increased salmon consumption increased serum 25-hydroxyvitamin D (P < 0.01).

CONCLUSIONS

A nutritionally adequate but energy-restricted diet, with different contents of n-3 fatty acids, which resulted in modest weight loss, unfavorably altered bone turnover markers in young overweight adults. Such changes were not prevented by increased fish or fish-oil consumption.

Inflammation, obesity, and fatty acid metabolism: influence of n-3 polyunsaturated fatty acids on factors contributing to metabolic syndrome

Metabolic syndrome (MetS) comprises an array of metabolic risk factors including abdominal obesity, dyslipidemia, hypertension, and glucose intolerance. Individuals with MetS are at elevated risk for diabetes and cardiovascular disease. Central to the etiology of MetS is an interrelated triad comprising inflammation, abdominal obesity, and aberrations in fatty acid metabolism, coupled with the more recently recognized changes in metabolism during the postprandial period. We review herein preliminary evidence regarding the role of dietary n-3 polyunsaturated fatty acids in modulating each of the components of the triad of adiposity, inflammation, and fatty acid metabolism, with particular attention to the role of the postprandial period as a contributor to the pathophysiology of MetS.

Erythrocyte fatty acid composition and the metabolic syndrome: a National Heart, Lung, and Blood Institute GOLDN study

BACKGROUND

Different fatty acids may vary in their effect on the metabolic syndrome (MetS). We tested whether fatty acid classes measured in erythrocytes are associated with the MetS or its components.

METHODS

Included were men [n = 497; mean (SD) age, 49 (16) years] and women [n = 539; age, 48 (16) years] from 187 families in a National Heart, Lung, and Blood Institute (NHLBI) family study of the Genetics of Lipid-Lowering Drugs and Diet Network (GOLDN) conducted in Utah and Minnesota. We used gas chromatography to measure erythrocyte fatty acids and obtained data on potential confounding variables from interviewer-administered questionnaires.

RESULTS

The prevalence of the MetS as defined by the updated Adult Treatment Panel III criteria was 36.8% in Utah and 39.6% in Minnesota (P >0.05). In a multivariate model that included 4 fatty acid classes, covariates, and pedigree as a random effect, the odds ratios (95% confidence interval) for the MetS in the 1st, 2nd, 3rd, and 4th quartile of polyunsaturated fatty acids were 1.00, 0.72 (0.47-1.10), 0.67 (0.43-1.05), and 0.39 (0.24-0.64), respectively (P for trend = 0.0002). For the corresponding quartiles of saturated fatty acids, the odds ratios were 1.00, 1.19 (0.77-1.84), 1.48 (0.94-2.34), and 1.63 (1.01-2.63), respectively (P for trend = 0.03). Unlike n6 fatty acids, which showed an inverse association (P <0.05) with MetS, n3, trans, and monounsaturated fatty acids were not associated with the MetS (P >0.05). We observed significant correlations (P <0.05) between fatty acid classes, insulin, and components of the MetS.

CONCLUSIONS

Polyunsaturated fats are inversely associated with the MetS, whereas saturated fatty acids are positively associated with the MetS, probably through their effect on lipids, adiposity, insulin, and blood pressure.

Metabolic syndrome in Yup'ik Eskimos: the Center for Alaska Native Health Research (CANHR) Study

OBJECTIVE

This study investigated the prevalence of metabolic syndrome and its defining components among Yup'ik Eskimos.

RESEARCH METHODS AND PROCEDURES

A cross-sectional study design that included 710 adult Yup'ik Eskimos >or=18 years of age residing in 8 communities in Southwest Alaska. The prevalence of metabolic syndrome was determined using the recently updated Adult Treatment Panel III criteria.

RESULTS

The prevalence of metabolic syndrome in this study cohort was 14.7%, and varied by sex with 8.6% of the men and 19.8% of the women having metabolic syndrome. This is lower than the prevalence of 23.9% in the general U.S. adult population. The most common metabolic syndrome components/risk factors were increased waist circumference and elevated blood glucose. High-density lipoprotein (HDL) cholesterol levels in Yup'ik Eskimos were significantly higher, and triglycerides lower than levels reported in National Health and Nutritional Examination III.

DISCUSSION

Compared with other populations, metabolic syndrome is relatively uncommon in Yup'ik Eskimos. The higher prevalence among Yup'ik women is primarily explained by their large waist circumference, suggesting central body fat accumulation. Further increases in metabolic syndrome risk factors among Yup'ik Eskimos could lead to increases in the prevalence of type 2 diabetes and cardiovascular disease, once rare in this population.

The Pro12Ala polymorphism of the PPAR-gamma2 gene affects associations of fish intake and marine n-3 fatty acids with glucose metabolism

BACKGROUND/OBJECTIVES

Data on associations between marine n-3 fatty acids and glucose metabolism are inconsistent. Therefore, we explored effects of the Pro12Ala polymorphism in peroxisome proliferator-activated receptor (PPAR)-gamma2 gene on associations of fish intake and dietary and plasma eicosapentaenoic and docosahexaenoic acid with glucose metabolism. The design comprises of the cross-sectional analysis.

SUBJECTS/METHODS

The Pro12Ala variant in the PPAR-gamma2 (PPARG) gene was genotyped in 571 non-diabetic relatives of subjects with type II diabetes. The dietary intake was measured by a 3-day food record, and the plasma cholesterol ester fatty acid composition was analysed with gas chromatography. Associations of dietary and plasma variables with insulin resistance and fasting and 2-h glucose and free fatty acid concentrations were analysed with multiple linear regression analysis.

RESULTS

In men, there was a significant interaction between PPARG polymorphism and plasma docosahexaenoic acid on fasting free fatty acid concentration (P=0.036), and genotype-stratified models showed an inverse association in Pro homozygotes only (P=0.028). In women, the proportion of plasma eicosapentaenoic acid was higher in Ala-allele carriers compared to Pro homozygotes (1.67 vs 1.44% respectively, P=0.006). A significant interaction between PPARG polymorphism and fish intake on 2-h glucose was found in women (P=0.021), and genotype-stratified models suggested an inverse association in Ala-allele carriers only (P=0.039).

CONCLUSIONS

The findings suggest that PPARG polymorphism might affect the plasma proportion of eicosapentaenoic acid and modulate the associations of fish intake and marine n-3 fatty acids with glucose metabolism and fasting free fatty acids.