LDL Oxidation and Vitamin E and Vitamin a Contents of LDL in Male Patients with Early-Onset Coronary Heart Disease and in Their 1st-Degree Male Relatives

Objective: Coronary Heart Disease (CHD), of which the primary cause is atherosclerosis, is among the leading causes of mortality in the developed countries. Although many etiological agents have been considered responsible for the development of the disease, oxidized LDL (low-density lipoprotein) is the major risk factor. Formation of atherosclerotic lesion begins with the macrophages’ turning oxidized LDL’s into foam cells. Although many factors such as high LDL concentration, hypertension and low antioxidants in the system impair vascular structure and initiate this process, the present study is based on the genetic susceptibility and the risk groups. The present study comprised the male patients with angiography-based diagnosis of early-onset coronary heart disease, as well as their sons or 1st-degree relatives, who are considered as high-risk group. It was aimed to compare these groups in terms of susceptibility of LDL to oxidation and to measure and compare vitamin E and A contents of LDL between these groups. Homocysteine concentration, which is considered as an independent risk factor for CHD, was also compared between the groups. Materials and Methods: Susceptibility of LDL to oxidation was determined based on the formation of conjugated dienes observing for 200 minutes after being incubated with cupper (cu2+) ions. Vitamin E and A contents of LDL were measured by HPLC (High-performance Liquid Chromatography), which is considered as the reference method. Male patients with early-onset coronary heart disease (with >50% stenosis in at least two vessels on coronary angiography) and their 1st-degree relatives were compared in terms of above-mentioned three parameters. In addition, FPIA (Fluorescence Polarization Immuno-Assays) was used to measure homocysteine concentration. Results: Three study groups were created: Group 1 consisted of 20 patients aged 40-55 years, who had >50% stenosis in 2 and/or more vessels detected on coronary angiography; Group 2 consisted of 18 subjects aged 18-20 years, who are the 1st-degree relatives (sons or brothers) of Group 1; Group 3 (control group) consisted of healthy males aged 18-35 years. Susceptibility of LDL to oxidation showed significant difference between Group 2 and Group 3. No statistically significant difference was determined between the groups in terms of LDL content of Vitamin A and E. Homocysteine concentration was significantly higher in Group 1 and Group 2.

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