Acute in vivo chylomicron metabolism and postalimentary lipoprotein alterations in normolipidemic male smokers

Increased postprandial lipemia has been stated as one of the mechanisms res ponsible for atherogenesis in smokers. We measured the postalimentary lipid response and the in vivo intravascular delipidation index of an artificial chylomicron emulsion in healthy adult smokers and controls. The blood was collected in the fasting state immediately after the smokers smoked one cig arette. The lipemia was measured 2, 4, 6 and 8 h postalimentarily in smoker s (S, n=8) and in non-smoking controls (C, n=8) and the chylomicron metabol ism rate was measured 2, 4, 6, 8, 12, 16, 20, 24 and 30 min after the injec tion of an artificial emulsion to S (n= 10) and to C (n=10). The lipoprotei ns were isolated in the fasting period and 4 h after the fatty meal and the ir chemical composition in cholesterol, triglycerides, phospholipids and pr otein was determined. Smokers showed an increased lipolysis percentage valu e (mean +/-S.E.M) of the artificial chylomicron (39.1 +/-3.1) compared to c ontrols (26.5 +/-3.3) and higher levels of HDL2-PL: 28.4 +/-4.3 (S) versus 16.2 +/-2.0 (C) mg/dl (mean +/-S.E.M.). In conclusion, the oral fat toleran ce was not altered in smokers but an upregulation of the rate of metabolism of the TG-rich lipoproteins was elicited immediately after smoking one cig arette. (C) 2001 Elsevier Science B.V. All rights reserved.