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| Author(s): |
Fernanda Alexandre
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas |
| Defense date: | 2013-07-30 |
| Examining board members: |
Eliana Cotta de Faria;
Nelson Eduardo Duran Caballero;
Lázaro Alessandro Soares Nunes
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| Advisor: | Eliana Cotta de Faria |
| Abstract | |
Low concentrations of high-density lipoprotein-cholesterol (HDL-C) constitute one of the factors in the development of atherosclerotic disease, the main cause of death in developed and emerging countries. Previous studies demonstrated that the size of the HDL particle has been considered a new and potentially important marker of cardiovascular disease risk. Literature data demonstrate that HDL’s size and its cholesterol plasma concentrations are correlated, and subject to the influence of gender and proatherogenic factors. Recent data has demonstrated that the number of HDL particles can be better than HDL-C in the evaluation of cardiovascular risk. Besides, other physico-chemical analyses of HDL, such as volume, chemical composition and surface charge and aggregation, may provide relevant information about the particle. Therefore, this work aimed at establishing reference values of HDL size and volume, by gender and age, using the Dynamic Light Scattering (DLS) technique, which was similar to the NMR, in a sample of the Brazilian population; and evaluating HDL’s size, volume, chemical composition, particle number, surface charge and aggregate formation in human models of normo, hyper and hypoalphalipoproteinemia, verifying the relationship of these measurements with plasma HDL-C concentrations or with the chemical composition of the HDL particle, anthropometric and metabolic data and early atherosclerosis, in order to verify if the diameter of this lipoprotein is related to cardiovascular disease and dyslipidemia in humans. Based on the results obtained in this study, we demonstrated that HDL size, equal to 7,89nm ± 0.72 nm, and the volume, equal to 196.60 ± 69.21nm3, were higher in women, increased with age in both genders and can be explained by differences in ethnicity, dietary pattern and lack of physical activity in this population. Furthermore, we demonstrated that hyperalphalipoproteinemic subjects present higher values of particle size, volume and number, increased aggregate formation and lower surface charge when compared to normo and hypoalphalipoproteinemic. We found positive significant correlations with lipases and lipid transfer proteins, which suggest the metabolic influence of these variables on the studied parameters, and inverse correlations with carotid intima-media thickness indicating the potential atheroprotective effect of these variables. In conclusion, for the first time in the Brazilian population, we established reference values of HDL size and volume by gender and age using DLS technique, and the correlations found in our study with early atherosclerosis suggest that plasma concentrations of HDL-C are not the only negative risk factor for cardiovascular disease (AU) | |
| FAPESP's process: | 11/16476-9 - Physico-chemical and biochemical studies of high density lipoprotein in states of hypo and hyperalphalipoproteinemia: association with carotid artery intima-media thickness |
| Grantee: | Fernanda Alexandre |
| Support Opportunities: | Scholarships in Brazil - Master |