ABNORMAL-METABOLISM OF POSTPRANDIAL LIPOPROTEINS IN PATIENTS WITH NON-INSULIN-DEPENDENT DIABETES-MELLITUS IS NOT RELATED TO CORONARY-ARTERYDISEASE

To investigate whether abnormalities in alimentary lipemia explain the increased risk of coronary artery disease (CAD) in subjects with non- insulin-dependent diabetes mellitus (NIDDM), we performed an oral vita min A fat-load test in four groups of men (each n = 15): 1) NIDDM and angiographically verified CAD (DM+CAD-+): 2) CAD but no diabetes (DM-C AD+); 3) NIDDM but no CAD, excluded by an exercise thallium scan (DM+C AD-); and 4) healthy control subjects (DM-CAD-). The groups were match ed for age and body mass index. Plasma obtained after an overnight fas t and 2, 3, 4, 6, 9, 12, and 24 h after a fatty meal (78 g fat, 345,00 0 IU retinyl palmitate [RP]) was separated by density gradient ultrace ntrifugation into six fractions of triglyceride (TG)-rich lipoproteins : Svedberg flotation units (S-f) > 3200, S-f 1100-3200, S-f 400-1100, S-f 60-400, S-f 20-60, and S-f 12-20. TG, RP, and cholesterol concentr ations were measured in plasma and in each lipoprotein fraction. Postp randial plasma n: responses were significantly larger in both NIDDM gr oups than in the healthy control group. The most marked differences we re observed in the S-f 60-400 lipoproteins, whether measured as TG or RP responses. However, there were no differences between the DM+CAD+ a nd DM+CAD- groups. The between-group differences in alimentary lipemia were only partially explained by fasting TG levels. In contrast to th e healthy subjects, no significant negative correlation was observed i n the NIDDM patients between alimentary lipemia and lipoprotein lipase activity, implying an abnormality of the lipolysis of TG-rich particl es in NIDDM. Levels of atherogenic postprandial remnant lipoproteins a re increased in NIDDM. However, in this study the magnitude of aliment ary lipemia did not distinguish NIDDM patients with CAD from those wit hout CAD symptoms and normal exercise thallium scans.