Low bias in assayed values of lipoprotein antigens--lipoprotein(a) and apolipoproteins A-I and B--in midday postprandial blood specimens compared with morning fasting specimens.
Two-hour postprandial specimens have a -14% proportional bias for lipoprotein(a) [Lp(a)], a -0.035 g/L systematic bias for apolipoprotein (apo) A-I, and a -9% proportional bias for apo B, compared with values in 12-h fasting specimens. Although a physiological hemodilution appears to account for a portion of these biases, other major factors must be implicated for Lp(a) and apo B. Even after dilutional effects are controlled for, assayed values of Lp(a) are 11-13% lower, and assayed values of apo B are 8-9% lower, in postprandial specimens than in fasting specimens. Therefore, the time of collection of a blood sample relative to the last meal can significantly affect assayed values of lipoprotein antigens. Further studies are needed to determine whether these observations result from a physiological sequestering of lipoproteins in the postprandial state or from negative interferences affecting the assays of lipoprotein antigens.
Emancipator
K
K
Clinical Pathology Department, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD.
D016632:Apolipoprotein A-I / Q000378:metabolism*; D001055:Apolipoproteins B / Q000097:blood*; D005215:Fasting; D005502:Food; D006438:Hemodilution; D006801:Humans; D017270:Lipoprotein(a); D008074:Lipoproteins / Q000097:blood*; D012044:Regression Analysis
D016632:Apolipoprotein A-I; D001055:Apolipoproteins B; D017270:Lipoprotein(a); D008074:Lipoproteins