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Individuals with type 2 diabetes mellitus (DM) characteristically have elevated fasting and postprandial (PP) plasma triglycerides (TG). Previous case-control studies indicated that PPTG levels predict the presence of coronary artery disease (CAD) in people without DM; however, the data for patients with DM are conflicting. Therefore, we conducted a case-control study in DM individuals, 84 with (+) and 80 without (−) CAD. Our hypothesis was that DM individuals with or without CAD would have similar PPTG levels, but CAD+ individuals would have more small d<1.006 g/L lipoprotein particles. Several markers of PP lipid metabolism were measured over 10 h after a fat load. PP lipoprotein size and particle number were also determined. There was no significant difference in any measure of PP lipid metabolism between CAD+ and CAD−, except for apoB48, which was actually higher in CAD−. We followed 69 CAD− participants for a mean 8.7 years; 33 remained free of any cardiovascular event. There were no PP differences at baseline between these 33 who remained CAD− and either the 36 original CAD− who subsequently developed CAD or the original CAD+ group.PP measurements of TG-rich lipoproteins do not predict the presence of CAD in individuals with DM.

Individuals with type 2 diabetes mellitus (DM) characteristically have elevated fasting and postprandial (PP) plasma triglycerides (TG). Previous case-control studies indicated that PPTG levels predict the presence of coronary artery disease (CAD) in people without DM; however, the data for patients with DM are conflicting. Therefore, we conducted a case-control study in DM individuals, 84 with (+) and 80 without (–) CAD. Our hypothesis was that DM individuals with or without CAD would have similar PPTG levels, but CAD+ individuals would have more small d<1.006 g/L lipoprotein particles. Several markers of PP lipid metabolism were measured over 10 h after a fat load. PP lipoprotein size and particle number were also determined. There was no significant difference in any measure of PP lipid metabolism between CAD+ and CAD–, except for apoB48, which was actually higher in CAD–. We followed 69 CAD– participants for a mean 8.7 years; 33 remained free of any cardiovascular event. There were no PP differences at baseline between these 33 who remained CAD– and either the 36 original CAD– who subsequently developed CAD or the original CAD+ group.PP measurements of TG-rich lipoproteins do not predict the presence of CAD in individuals with DM.

Plasma lipoprotein [a] (Lp[a]) concentrations are inversely associated with, and largely determined by, apolipoprotein [a] (apo[a]) gene size, a highly polymorphic trait. We studied if, within an individual, the smaller apo[a] isoform always dominated, whether there was interaction between the two alleles, and whether these features differed between Caucasians and African Americans. We determined apo[a] gene sizes, apo[a] protein sizes and relative amounts, and plasma Lp[a] levels in 430 individuals (263 Caucasians and 167 African Americans). Of the 397 heterozygotes with at least one detectable apo[a] isoform (238 Caucasians and 159 African Americans), the larger allele dominated in 28% of Caucasians and 23% of African Americans, while the smaller allele dominated in 56% of Caucasians and 45% of African Americans. In Caucasians, dominance of the smaller allele increased with Lp[a] levels, from 44% at Lp[a] < or = 30 nM to 81% at Lp[a] >100 nM (P < 0.0001). Dominance by the smaller allele increased with increasing size of the larger allele in both groups but with the smaller allele only in African Americans. There was no interaction between apo[a] alleles within genotypes; one apo[a] isoform level was not associated with the other isoform level, and isoform levels were not affected by the difference in size. More of the dominance pattern was explained by Lp[a] level and apo[a] genotype in African Americans than in Caucasians (29% vs. 13%). Thus, genotype influences isoform-specific Lp[a] levels and dominance patterns differently in African Americans and in Caucasians.