Apolipoprotein A-IV genetic polymorphism and its impact on quantitative traits in normoglycemic and non-insulin-dependent diabetic Hispanics from the San Luis Valley, Colorado.
Apolipoprotein A-IV exhibits a common two-allele polymorphism in several human populations studied to date. Using isoelectric focusing and immunoblotting, we have analyzed plasmas from 188 non-insulin-dependent diabetic and 238 normoglycemic Hispanic individuals from the San Luis Valley, Colorado, to determine APOA4 genotype frequencies and to estimate the impact of the genotypes on quantitative traits. The frequencies of the two common alleles, APOA4*1 and APOA4*2, were 0.929 and 0.069, respectively, in normal subjects and 0.901 and 0.096, respectively, in diabetics. The third rare allele, APOA4*3, was detected sporadically in both groups. We studied the impact of APOA4 polymorphism on the levels of total plasma cholesterol, HDL cholesterol and its subfractions (HDL3 and HDL2), LDL cholesterol, triglycerides, glucose, and insulin. We observed no significant effect of the APOA4 polymorphism on any trait in diabetics. However, we did note a significant sex-specific effect in normoglycemic females on the level of total HDL cholesterol (p = 0.001) and its subfractions HDL2 (p = 0.043) and HDL3 (p = 0.001). The effect of the APOA4*2 allele in normal Hispanic females was to lower the total HDL, HDL2, and HDL3 cholesterol by 8.75 mg/dl, 2.37 mg/dl, and 5.36 mg/dl, respectively, compared to the common APOA4*1 allele.
Kamboh
M I
MI
Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, PA 15261.
Iyengar
S
S
Aston
C E
CE
Hamman
R F
RF
Ferrell
R E
RE
D000328:Adult; D000368:Aged; D001054:Apolipoproteins A / Q000235:genetics*; D001786:Blood Glucose / Q000032:analysis; D003120:Colorado / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006630:Hispanic or Latino / Q000235:genetics*; D006801:Humans; D007328:Insulin / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic
D001054:Apolipoproteins A; D001786:Blood Glucose; D007328:Insulin; D008074:Lipoproteins; C022205:apolipoprotein A-IV