L. Djousse et al., Smoking influences the association between apolipoprotein E and lipids: The National Heart, Lung, and Blood Institute Family Heart Study, LIPIDS, 35(8), 2000, pp. 827-831
Apolipoprotein E allele 4 (apo epsilon(4)) and smoking each have been assoc
iated with an unfavorable lipid profile. We used data collected on 1,472 su
bjects in the National Heart, Lung, and Blood Institute family Heart Study
to assess whether smelting interacts with apo epsilon(4) to influence the l
evels of plasma lipids. We dichotomized smoking and apo epsilon(4) and used
analysis of covariance to estimate the means of lipids. Smokers had lower
body mass index, were younger, and consumed less fruits and vegetables. Amo
ng individuals without apo epsilon(4), comparing nonsmokers with smokers, m
ean low density lipoprotein cholesterol (LDL) was 129.3 and 134.4 mg/dL, re
spectively, for women and 126.1 and 127.6 mg/dL, respectively, for men. Amo
ng subjects with an apo epsilon(4) allele, corresponding means were 132.0,
and 152.9 mg/dL, respectively, for women and 131.3 and 137.3 mg/dL, respect
ively, for men (P for interaction <0.001 for women and 0.11 for men). A sim
ilar interaction was observed for total cholesterol among women (P = 0.02).
This study shows a statistically significant effect modification of the re
lation of apo epsilon(4) to LDL and total cholesterol by smoking among wome
n. Smoking may enhance genetic susceptibility to an unfavorable lipid profi
le among subjects with apo epsilon(4).