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Predisposition to LDL oxidation in patients with and without angiographically established coronary artery disease
L Cominacini1, U Garbin, A M Pastorino
1Istituto di Semeiotica e Nefrologia Medica, Università di Verona, Italy.
Insights
Oxidative modification of low-density lipoprotein (LDL) is linked to atherosclerosis. Coronary artery disease patients showed increased LDL susceptibility to lipid peroxidation, unlike controls, suggesting a role in disease progression.
Area of Science:
- Cardiovascular Science
- Lipid Metabolism
- Oxidative Stress
Background:
- Oxidative modification of low-density lipoprotein (LDL) is implicated in atherosclerosis.
- Understanding LDL susceptibility to oxidation is crucial for cardiovascular disease research.
Purpose of the Study:
- To investigate differences in LDL oxidative modification susceptibility among coronary artery disease (CAD) patients, valvular heart disease (VHD) patients, type IIa hyperlipoproteinemia patients, and controls.
- To analyze the chemical composition and polyunsaturated fatty acid (PUFA) content of LDL in relation to oxidative modification.
Main Methods:
- Isolated LDL from patient groups and controls.
- Induced oxidative modification using copper ions.
- Measured lipid peroxidation by fluorescence intensity changes.
- Analyzed LDL chemical composition, including cholesterol, protein, and PUFA content.
Main Results:
- CAD patients exhibited significantly lower LDL lag phase (increased susceptibility to lipid peroxidation) compared to VHD patients and controls.
- Type IIa hyperlipoproteinemia patients showed a higher lag phase than CAD patients but lower than VHD and controls.
- CAD patients had altered LDL composition, including decreased free cholesterol, increased protein, higher PUFA concentration, and lower LDL size and cholesterol-to-protein ratio.
Conclusions:
- LDL isolated from CAD patients is more susceptible to oxidative modification.
- Specific alterations in LDL composition in CAD patients may contribute to increased oxidative stress and atherosclerotic damage.
- Findings highlight the role of LDL oxidation in the pathogenesis of coronary artery disease.
Abstract:
Oxidative modification of low density lipoprotein (LDL) may play an important role in the mechanism of atherosclerotic damage to blood vessels. In the present study the LDL isolated from the plasmas of 73 coronary artery disease (CAD) patients, 28 valvular heart disease (VHD) patients, 59 subjects affected by type IIa hyperlipoproteinemia and 71 controls was oxidatively modified by incubation with copper ions. In 15 CAD and 15 Type IIa patients and 15 controls the LDL chemical composition and polyunsaturated fatty acid (PUFA) content were also measured. Differences in the LDL susceptibilities to lipid peroxidation were studied by measuring the changes of fluorescence intensity. The lag phase in the CAD patients was found to be significantly lower than in the VHD and controls (P < 0.001). The lag phase in the type IIa patients was significantly higher than in the CAD patients (P < 0.01), and significantly lower than the VHD and controls (P < 0.01). The LDL isolated from the type IIa patients had an increase in the relative content of free and esterified cholesterol (P < 0.05), while the CAD patients had a decrease in the relative content of free cholesterol (P < 0.05), and an increase in the relative content of protein (P < 0.05). The lowest value of the LDL cholesterol to protein ratio and LDL size, was found in the CAD patients (P < 0.05). When expressed in micrograms/mg LDL cholesterol, the concentration of the LDL PUFAs was significantly higher in the CAD group than in the others (P < 0.05). The LDL alpha-tocopherol concentration was quite similar in the different groups.(ABSTRACT TRUNCATED AT 250 WORDS)