Lifestyle changes in Alaskan Natives have been related to the increase of cardiovascular disease and metabolic syndrome in the last decades. Variation of the apolipoprotein E (Apo E) genotype may contribute to the diverse response to diet in lipid metabolism and influence the association between fatty acids in plasma and risk factors for cardiovascular disease. The aim of this investigation was to analyze the interaction between Apo E isoforms and plasma fatty acids, influencing phenotypes related to metabolic diseases in Alaskan Natives. A sample of 427 adult Siberian Yupik Alaskan Natives was included. Fasting glucose, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, Apo A1, and Apo B plasma concentrations were measured using reference methods. Concentrations of 13 fatty acids in fasting plasma were analyzed by gas chromatography, and Apo E variants were identified. Analyses of covariance were conducted to identify Apo E isoform and fatty acid main effects and multiplicative interactions. The means for body mass index and age were 26 ? 5.2 and 47 ? 1.5, respectively. Significant main effects were observed for variation in Apo E and different fatty acids influencing Apo B levels, triglycerides, and total cholesterol. Significant interactions were found between Apo E isoform and selected fatty acids influencing total cholesterol, triglycerides, and Apo B concentrations. In summary, Apo E3/3 and 3/4 isoforms had significant interactions with circulating levels of stearic, palmitic, oleic fatty acids, and phenotypes of lipid metabolism in Alaskan Natives.
OBJECTIVES: To determine the prevalence of CVD and to identify and characterize associated risk factors in three distinct Eskimo populations. STUDY DESIGN: Cross-sectional. METHODS: A slightly modified Strong Heart Study protocol was followed to examine 454 participants, aged 25-91, from four villages. RESULTS: Overall, 6% of the participants under 55 years of age and 26% of those > or = 55 years of age showed evidence of CHD by ECG, or in patient records. The prevalence of "definite coronary heart disease" (CHD) in women with glucose intolerance (GI) was 21.0%, compared to 2.4% in those with normal glucose tolerance (NGT). Men had comparable values of 26.7% and 6.3%. In addition, comparable values for "possible CHD" were 29.7% vs 6.0% for women and 21.4% vs 8.0% for men. GI was associated with relatively higher prevalences of CHD in women than in men (prevalence ratio = 8.5 vs 4.3). CHD was significantly related to age, glucose intolerance and insulin. Hypertension and obesity were significantly associated with CHD only in some ethnic groups. The prevalence of current smokers was 56%. CONCLUSIONS: Recent changes in lifestyle and diet of Alaskan Eskimos, leading to obesity, hypertension, insulin resistance and DM, contribute to an increased risk for cardiovascular disease.
OBJECTIVES: The thirty-year-old hypothesis that omega-3 fatty acid (FA) may "reduce the development of thrombosis and atherosclerosis in the Western World" still needs to be tested. Dyerberg-Bang based their supposition on casual observations that coronary atherosclerosis in Greenlandic Inuit was 'almost unknown' and that they consumed large amounts of omega-3 FAs. However, no association was demonstrated with data. STUDY DESIGN: Cross-sectional study. METHODS: 454 Alaskan Eskimos were screened for coronary heart disease (CHD), using a protocol that included ECG, medical history, Rose questionnaire, blood chemistries, including plasma FA concentrations, and a 24-hour recall and a food frequency questionnaire assessment of omega-3 FA consumption. RESULTS: CHD was found in 6% of the cohort under 55 years of age and in 26% of those > or = 55 years of age. Eskimos with CHD consume as much omega-3 FAs as those without CHD, and the plasma concentrations confirm that dietary assessment. CONCLUSIONS: Average daily consumption of omega-3 FAs among Eskimos was high, with about 3-4 g/d reported, compared with 1-2 g/d used in intervention studies and the average consumption of 0.2 g/d by the American population. There was no association between current omega-3 FA consumption/blood concentrations and the presence of CHD.
To determine if heart rate (HR) is associated with desaturation indexes as HR is associated with arrhythmia and sudden death.
A community based cross-sectional study of 1214 Alaskan Inuit.
Data of FA concentrations from plasma and red blood cell membranes from those =35 years of age (n =?819) were compared to basal HR at the time of examination. Multiple linear regression with backward stepwise selection was employed to analyze the effect of the desaturase indexes on HR, after adjustment for relevant covariates.
The ?(5) desaturase index (?(5)-DI) measured in serum has recently been associated with a protective role for cardiovascular disease. This index measured here in plasma and red blood cells showed a negative correlation with HR. The plasma stearoyl-CoA-desaturase (SCD) index, previously determined to be related to cardiovascular disease (CVD) mortality, on the other hand, was positively associated with HR, while the ?(6) desaturase index (?(6)-DI) had no significant effect on HR.
Endogenous FA desaturation is associated with HR and thereby, in the case of SCD, possibly with arrhythmia and sudden death, which would at least partially explain the previously observed association between cardiovascular mortality and desaturase activity.
Cites: Am J Med. 2002 Dec 30;113 Suppl 9B:13S-24S12566134
BACKGROUND: Consumption of omega-3 fatty acids (FAs) is associated with a reduction in deaths from coronary heart disease, arrhythmia, and sudden death. Although these FAs were originally thought to be antiatherosclerotic, recent evidence suggests that their benefits are related to reducing risk for ventricular arrhythmia and that this may be mediated by a slowed heart rate (HR). METHODS: The study was conducted in Alaskan Eskimos participating in the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) Study, a population experiencing a dietary shift from unsaturated to saturated fats. We compared HR with red blood cell (RBC) FA content in 316 men and 391 women ages 35 to 74 years. RESULTS: Multivariate linear regression analyses of individual FAs with HR as the dependent variable and specific FAs as covariates revealed negative associations between HR and docosahexaenoic acid (22:6n-3; P = .004) and eicosapentaenoic acid (20:5n-3; P = .009) and positive associations between HR and palmitoleic acid (16:1n-7; P = .021), eicosanoic acid (20:1n9; P = .007), and dihomo-gamma-linolenic acid (DGLA; 20:3n-6; P = .021). Factor analysis revealed that the omega-3 FAs were negatively associated with HR (P = .003), whereas a cluster of other, non-omega-3 unsaturated FAs (16:1, 20:1, and 20:3) was positively associated. CONCLUSIONS: Marine omega-3 FAs are associated with lower HR, whereas palmitoleic and DGLA, previously identified as associated with saturated FA consumption and directly related to cardiovascular mortality, are associated with higher HR. These relations may at least partially explain the relations between omega-3 FAs, ventricular arrhythmia, and sudden death.
Objectives. Type 2 diabetes and the consumption of saturated fatty acids (FAs) are on the rise among Alaska Inuits. This analysis, based on a cross-sectional study, explores the possible associations of saturated FA content in red blood cells (RBCs) and parameters of glucose metabolism in a sample of Alaska Natives. Study design and methods. The sample included 343 women and 282 men aged 35-74. Statistical analyses explored the associations of selected RBC (myristic, palmitic and stearic acids) FAs with fasting glucose (plasma), fasting insulin (plasma), 2h glucose (2-hour glucose tolerance test), 2h insulin and homeostasis model assessment (HOMA) index. The models included sex and glucose metabolism status as fixed factors and age, body mass index (BMI), waist circumference, physical activity (METS) and FA content in RBCs as covariates. Measures of insulin, glucose and HOMA index were used as dependent variables. Results. Myristic acid was positively associated with fasting insulin (beta=0.47, p
OBJECTIVES: To test the hypothesis that the unusually low prevalences of insulin resistance (IR), metabolic syndrome (MS) and diabetes (DM) in Alaskan Eskimos, compared to American Indians, is related to the traditional Eskimo diet, high in C20-C22 omega-3 fatty acids (FAs). To determine if the relatively low blood pressures, low serum triglycerides and high HDL cholesterol levels in Eskimos result from high omega-3 FA consumption. STUDY DESIGN: Cross-sectional study. METHODS: We measured plasma FA concentrations in 447 Norton Sound Eskimos (35-74 years of age) and screened for DM, CHD and associated risk factors. A dietary assessment (24-hr recall) was obtained for comparison the day before the blood sampling. RESULTS: Plasma omega-3 FA concentrations were highly correlated with dietary omega-3 FAs and HDL levels and inversely correlated with plasma levels of insulin, 2-h insulin (OGTT), HOMI-IR, 2-h glucose (OGTT), triglyceride levels and diastolic blood pressure. CONCLUSIONS: High consumption of omega-3 FAs positively affects components of the MS, insulin sensitivity and glucose tolerance. This finding suggests that high consumption of C20-C22 omega-3 FAs protects against the development of the MS and glucose intolerance.
OBJECTIVES: To test the efficacy of a simple intervention method to reduce risk factors for type 2 diabetes (DM) and cardiovascular disease (CVD) in Alaskan Eskimos. STUDY DESIGN: The study consisted of 1) a comprehensive screening for risk factors of 454 individuals in 4 villages, 2) a 4-year intervention and 3) a repetition of the screening in year 5 to test the efficacy of the intervention. METHODS: Personal counseling (1hr/year) stressed the consumption of more traditional foods high in omega-3 fatty acids and less of certain specific store-bought foods high in palmitic acid, which was identified as being associated with glucose intolerance. RESULTS: The intervention resulted in significant reductions in plasma concentrations of total cholesterol (p = 0.0001), LDL cholesterol (p = 0.0001), fasting glucose (p = 0.0001), diastolic blood pressure (p = 0.0007) and improved glucose tolerance (p = 0.0006). This occurred without loss of body weight. Sixty percent of the participants had improved glucose tolerance; only one of the 44 originally identified with impaired glucose tolerance (IGT) developed DM during the study. CONCLUSIONS: Dramatic improvements of risk factors for DM and CVD were achieved in the intervention by primarily stressing the need for changes in the consumption of specific fats. The results suggest that fat consumption is an important risk factor for DM.