Lipoprotein[a] concentrations and apolipoprotein[a] phenotypes in Caucasians and African Americans. The CARDIA study.
Little is known about racial differences in lipoprotein[a] (Lp[a]) concentrations and apolipoprotein[a] (apo[a]) phenotypes. Lp[a] protein concentrations were determined by a double monoclonal antibody enzyme-linked immunosorbent assay method in 4165 Caucasian and African American men and women from four US communities. Apo[a] phenotypes were determined by polyacrylamide gel electrophoresis and immunoblotting on a random subset of these participants (n = 690). The distribution of Lp[a] protein levels in Caucasians was highly skewed (mean, 6.9 mg/dL; median, 3.7 mg/dL). In contrast, the distribution in African Americans was less skewed (mean, 13.0 mg/dL; median, 11.6 mg/dL), and Lp[a] protein levels were approximately double those in Caucasians within most apo[a] phenotypes. The previously described inverse relationship between apo[a] size and Lp[a] concentration was generally confirmed in Caucasians, but the B phenotype had lower Lp[a] levels than the S1 or S2 phenotype. In African Americans, both the B and S1 phenotypes had lower Lp[a] levels than the S2 phenotype. The frequencies of the apo[a] phenotypes in African Americans differed from those in Caucasians (P < .001) and also differed from the frequencies reported in a Sudanese population (P < .002). African Americans had a lower frequency of the S2 phenotype than Caucasians (8% vs 18%; P < .01) and a higher frequency of S3 (36% vs 25%; P < .01). As compared with the data reported in Sudanese, African Americans also had a higher frequency of the S3 phenotype (36% vs 14%; P < .001) and a lower frequency of S4 (29% vs 44%; P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)
Marcovina
S M
SM
Department of Medicine, University of Washington, Seattle 98103.
Albers
J J
JJ
Jacobs
D R
DR
Perkins
L L
LL
Lewis
C E
CE
Howard
B V
BV
Savage
P
P
D000293:Adolescent; D000328:Adult; D001054:Apolipoproteins A / Q000235:genetics*; D044383:Black People / Q000235:genetics*; D003327:Coronary Disease / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood*; D008297:Male; D010641:Phenotype; D012307:Risk Factors; D013397:Sudan / Q000208:ethnology; D044465:White People / Q000235:genetics*; D001741:Black or African American
D001054:Apolipoproteins A; D017270:Lipoprotein(a)