The relationship of APOE polymorphism and cholesterol levels in normoglycemic and diabetic subjects in a biethnic population from the San Luis Valley, Colorado.
We have determined apolipoprotein E (apoE = protein, APOE = gene) polymorphism and its relationship with total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and triglyceride levels in normoglycemic Hispanics (n = 446) and non-Hispanic whites (NHWs) (n = 659) as well as in diabetic Hispanics (n = 235) and NHWs (n = 116) from the San Luis Valley, Colorado. Effects were estimated separately for each group, and within each group men and women were analyzed separately; women were further categorized into pre- and post-menopausal status. The distribution of the APOE genotype pattern was comparable between the NHW normoglycemics and diabetics but it was significantly different among Hispanic normoglycemics and diabetics (P < 0.005). In the normoglycemic sample the APOE allele frequencies were significantly different between the two ethnic groups: the APOE*2 (0.09 vs. 0.05; P < 0.01) and APOE*4 (0.15 vs. 0.09; P < 0.002) allele frequencies were higher while the APOE*3 (0.76 vs. 0.86; P < 0.0001) allele frequency was lower in NHWs than in Hispanics. Significant variability among the three common APOE genotypes (3-2, 3-3, and 4-3) was observed for TC and LDL-C in normoglycemic Hispanic women (P = 0.09 and P = 0.03) but not in Hispanic men. In normoglycemic NHWs, however, significant mean differences among APOE genotypes were observed for TC and LDL-C in both women (P < 0.0001 and P < 0.0001) and men (P = 0.009 and P = 0.01). In Hispanic females, the APOE polymorphism accounted for 5.6% and 7.6% of the phenotypic variance for TC and LDL-C, respectively. In NHW females, the APOE polymorphism explained 10.2% of the phenotypic variance for TC and LDL-C, and in NHW males these values were 6.2% and 7.5%, respectively. There was no evidence of physiologic interaction between the APOE polymorphism and menopause status in affecting TC and LDL-C in NHW women (P = 0.65 and P = 0.55) but a suggestion of interaction was observed in Hispanic women for TC and LDL-C (P = 0.11 and 0.07). After the Hispanic women were stratified into pre- and postmenopausal groups, the effect of the APOE polymorphism on TC and LDL-C was significant only in the premenopausal group. Among diabetics, no significant effect of the APOE polymorphism was seen on cholesterol levels.(ABSTRACT TRUNCATED AT 400 WORDS)
Kamboh
M I
MI
Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, PA 15261, USA.
Aston
C E
CE
Hamman
R F
RF
D000328:Adult; D000483:Alleles; D001057:Apolipoproteins E / Q000235:genetics*; D001483:Base Sequence; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003120:Colorado; D003327:Coronary Disease / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000208:ethnology* / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006630:Hispanic or Latino / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D017698:Postmenopause; D017697:Premenopause; D014280:Triglycerides / Q000097:blood
D001057:Apolipoproteins E; D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides; D002784:Cholesterol