M. Dobiášová1, J.Frohlich2, A. Mydlilová3, J.Piťha4, M. Plášková4, R.Poledne4, K.Rašlová5, J.Stříbrná4, M.Šamánek6, Z. Urbanová7, M. Vrablík8
1 Institute of Physiology, Acad. Sci. CR, Prague, Czech Republic, 2St. Paul’s Hospital Healthy Heart Program/University of British Columbia, Vancouver, Canada, 3Institute for the care for mother and child, Prague, 4Institute for Clinical and Experimental Medicine, Prague, 5Institute of Preventive and Clinical Medicine, Bratislava, Slovak Republic, 6Center of Pediatric Cardiology and Cardiac Surgery, University Hospital Motol, Prague, 7Children’s Clinic of the First Faculty of Medicine, Charles University, Prague, 3rd Dept. of Medicíně, 81st school of Medicíně, Charles University, Prague, Czech Republic.
The plasma lipoprotein profile has the crucial effect on the development of atherosclerosis with resulting cardiovascular (CV) diseases. A number of demographic or clinic markers of CV risk such as sex, age, body mass, blood pressure , diabetes are projected in a specific plasma lipoprotein profile. An atherogenic profile is characterized by increased concentrations of small dense LDL particles and/or of small HDL particles and/or increased concentrations large VLDL particles. However, to evaluate the CV risk based on the complex of differently sized lipoprotein populations in practice is difficult. To the actual distribution of HDL and LDL particle size precisely corresponds the functional biomarker of lipoprotein quality – Fractional Esterification Rate of cholesterol (FERHDL) in apoB lipoproteins depleted plasma of [1,2]. The size of lipoprotein particles is prerequisite for the production of cholesteryl esters (CE) and their destination [3].
This functional biomarker highly correlates with the most simple algorithm (in different studies r = 0.7-0.9): Atherogenic Index of Plasma (AIP) as a logarithmically transformed ratio of molar concentrations of triglycerides (TG) to HDL-cholesterol (HDL-C) [4]. The association of AIP with lipoprotein particle size is intelligible as TGs participate in production of the population of small, dense LDLs, and have also been proposed to be a major determinant of cholesterol esterification/transfer and HDL remodeling in human plasma [5]. Both, FERHDL and AIP directly relate to other CV risk biochemical and clinical parameters. There is the highly significant correlation with apo B, apo CIII, apo E and inverse correlation with apo AI, while the correlation with serum total cholesterol and LDL-C is weak. In addition, there is a significant relation between sex, age, waist circumference, obesity, type II diabetes and insulin resistance [5,6]. Thus the FERHDL and AIP reflecting the distribution of particle sizes in lipoprotein subclasses have been shown to be the strongest predictor tests of positive findings on coronary angiography [6] and have a potential to predict the CV risk .
Particularly AIP may help to classify atherogenic or non-atherogenic lipid profiles without the need for a more complicated and costly laboratory determinations. In previously studied populations with widely different CV risk – altogether about 8000 subjects – the values of AIP differed dramatically [4,6]. The umbilical cord, young children, healthy pre-menopausal women have values below 0.1 while men and subjects with CV risk factors such as hypertension, diabetes type II, dyslipidemia have increasing values up to 0.4. Based on these data we suggest that AIP could be used in three risk categories: the lowest CV risk is represented by values below 0.11, the intermediate risk by values between +0.11 and +0.21 and high risk by values above 0.21. The AIP calculator is presented on www.biomed.cas.cz/fgu/aip
We present on the poster also the simple nomogram showing the individual’s atherogenic status.
References
[1] Dobiášová et al. Arterioscler. Thromb. 1991;11:64-70.
[2] Ohta et al. Atherosclerosis 1997;135:205-12.
[3] Dobiášová and. Frohlich. Clin.Chim Acta 1999, 286:257-271
[4] Dobiášová and Frohlich. Clin Biochem 2001;34:583–8.
[5] Dobiášová. Clin Chem 2004;50:113-115.
[6] Frohlich and Dobiášová. Clin Chem 2003;49:1873-1880.
Funding: Ministry of Health ČR, NR/8328, EGIS Praha, s.r.o.