[Comparative study of lipids, apoproteins and lipoproteins in patients with coronary disease and in a control population].

We carried out a comparative study of various lipid parameters (apo AI and B, LpAI, Lp(a) and LpBCIII) in coronary heart disease patients (19 males and 4 females, mean age 61 +/- 11 years) and in controls (18 males and 14 females, mean age 55 +/- 3 years) selected so that cholesterol and triglycerides levels be beneath 6 and 2.3 mmol/l in both populations. Apo AI and B were analysed by immunonephelometry and lipoparticles by electroimmunodiffusion. Nonparametric statistics tests were performed on account of the small numbers in both groups. Our study confirms the protective effect of Lp AI but did not show an obvious superiority of Lp AI quantification compared to apo AI. It highlights the interest of Lp(a) as an independent and additional risk factor for atherogenesis: no obvious correlation with any other lipidic parameter was demonstrated. An increase in Lp(a) beyond 0.30 g/l increases atherogenic risk 2.5 fold. We did not show any benefit of LpBCIII quantification in 'normolipemic' coronary patients. In conclusion, a discriminant analysis including the apo B/apo AI and apo B/LpAI ratios and Lp(a) allows an accurate classification of 67% of the patients.