Smoking Sends Atherosclerosis Rates in Eskimos Soaring

By Crystal Phend
NEW YORK, 14 july 2008 -- High smoking rates among Alaskan Eskimos have wiped out the vascular benefits of their traditional fish-based diet heavy in omega-3 fatty acids, researchers found.
Rates of carotid atherosclerosis in these native Alaskans, while once lower than in the general population, have climbed above those reported in large national studies, reported Mary J. Roman, M.D., of Weill Cornell Medical College here, and colleagues online in Stroke: Journal of the American Heart Association.
The researchers attributed the shift to "astronomical" smoking rates -- 63% of Alaskan Eskimo men and 57% of women -- three times higher than the 21% U.S. average.
Ethnic Alaskan natives were thought to be protected from cardiovascular disease by their diet high in fish oils, but studies have documented increasing coronary artery disease in this population, the researchers said.
"Although omega-3 fatty acids have been shown in previous studies to have beneficial cardiovascular effects," the researchers concluded, "the data in this report suggest that Alaska Eskimos may have negated the protective effects of omega-3 fatty acids by increased rates of smoking and other lifestyle changes."
The researchers analyzed findings from the population-based Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study.
It included 1,214 men and women who had a physical examination, completed a questionnaire on atherosclerotic risk factors, provided blood samples, and were repeatedly scanned for carotid intima-media thickness.
Atherosclerotic plaque scores were 0.86 for men and 0.69 for women.
The average intima-media thickness was 0.61 mm for men and 0.59 for women. This was comparable to the 0.60 to 0.62 mm average for men and 0.54 to 0.56 average for women in the national population-based Atherosclerosis Risk in Communities Study, which had a similar average age as in the GOCADAN study (45 versus 42).
However, carotid atherosclerosis was more common in Alaska Eskimos at all ages for both genders than in national population-based samples despite similar risk factors as other ethnic and racial groups.
Compared with the Atherosclerosis Risk in Communities Study through age 64 and the Cardiovascular Health Study from age 65 to 74, the average prevalence was:
52% versus 27% at ages 45 to 49 among men and 33% versus 18% among women.
53% versus 35% at ages 50 to 54 among men and 62% versus 24% among women.
83% versus 46% at ages 55 to 59 among men and 56% versus 34% among women.
93% versus 53% at ages 60 to 64 among men and 81% versus 41% among women.
94% versus 68% at ages 65 to 69 among men and 92% versus 54% among women.
93% versus 75% at ages 70 to 74 among men and 90% versus 64% among women.
Carotid intima-media thickness and other more direct measures of atherosclerosis in Alaska Eskimos were primarily related to established risk factors, such as older age, hypertension, and diabetes.
Dietary intake of omega-3 fatty acids, in this population primarily from fish intake, was not correlated with carotid intima-media thickness.
The study was supported by a grant from the National Heart, Lung, and Blood Institute. The researchers reported no conflicts of interest.
Primary source: Stroke: Journal of the American Heart AssociationSource reference:Cutchins A, et al "Prevalence and correlates of subclinical atherosclerosis in Alaska Eskimos: The GOCADAN Study" Stroke 2008; 39.