Heart rate is associated with red blood cell fatty acid concentration: the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study.

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.

Cardiovascular disease prevalence and its relation to risk factors in Alaska Eskimos.

BACKGROUND AND AIMS: Although Eskimos were thought to be protected from cardiovascular disease (CVD), state health data show a large proportion of deaths from CVD, despite traditional lifestyles and high omega-3 fatty acid intake. This article explores CVD prevalence and its relation to risk factors in Alaska Eskimos. METHODS AND RESULTS: A population-based cohort of 499 Alaska Eskimos > age 45 from the Norton Sound region was examined in 2000-2004 for CVD and associated risk factors as part of the Genetics of Coronary Artery Disease in Alaska Natives study. CVD and atherosclerosis were evaluated and adjudicated using standardized methods. Average age was 58 years; diabetes prevalence was low and high-density lipoprotein cholesterol (HDL-C) concentrations were high, but a large proportion smoked and had high pathogen burden. CVD was higher in men (12.6%) than in women (5.3%) (prevalence ratio 2.4, CI 1.3-4.4). Rates of stroke (6.1% in men, 1.8% in women) were similar to those for coronary heart disease (CHD) (6.1% men, 2.5% women). MI prevalence was low in both genders (1.9% and 0.7%). CVD was higher in men and in those >60 years. Hypertension, diabetes, high LDL-C, high apoB, and low HDL-C were all strong correlates (<.002) and albuminuria and CRP were also correlated with CVD (p<.05) after adjustment for age and gender. Carotid atherosclerosis was correlated with CVD (p=.0079) independent of other risk factors. CONCLUSION: These data show high CHD and stroke prevalence in Alaska Eskimos, despite low average LDL-C and high HDL-C. Hypertension and high LDL-C were independent correlates; identifying these risk factors early and treating to target is recommended.