CORRELATIONS BETWEEN INTRAVENOUS FAT TOLERANCE AND SERUM-LIPOPROTEINS IN NORMAL AND ATHEROSCLEROTIC SUBJECTS

Triglyceride (TG) and cholesterol concentrations in the major lipoprotein fractions and the i.v. fat tolerance test (IVFTT) k2 [fractional removal rate of exogenous TG] value were determined in healthy controls (n = 35), in survivors of myocardial infarction (MI, n = 43) and in patients with peripheral vascular disease (PVD, n = 33). MI patients had the highest lipid concentrations in the lipoproteins except for HDL[high density lipoprotein]-cholesterol, which was 26% lower in both MI and PVD patients compared to controls. For the other lipid concentrations, PVD patients had values between MI patients and control values. The mean k2 values for MI patients were 2.8%/min, for PVD patients 3.3%/min and for controls 4.4%/min. Data were pooled from all 111 individuals and correlations between lipids in the lipoprotein fractions and the k2 value were calculated. The highest r [correlation coefficients] value was found for log k2 versus log VLDL[very low density lipoprotein]-TG (r = -0.65, P < 0.001), but significant negative correlations between k2 and LDL[low density lipoprotein]- and HDL-TG were seen. A strong positive correlation was found between k2 and HDL-cholesterol. When partial regression analysis was carried out, this relationship prevailed and when the effects of both VLDL-TG and total TG were eliminated (r = 0.32, P < 0.001). Apparently the IVFTT k2 value independently gives an estimate of TG removal processes from plasma and reflects HDL activity on TG catabolism.