Plasma Lipid Peroxidation and Total Antioxidant Status among Dyslipidaemic and Hypertensive Nigerians with High Risk of Coronary Heart Disease

BACKGROUND: The oxidative modification hypothesis of atherosclerosis predicts that low density lipoprotein-cholesterol (LDL-C) oxidation is an early event in atherosclerosis and that oxidized LDL-C contributes to atherogenesis OBJECTIVE: To determine a link, if any, between the plasma lipid peroxidation and total antioxidant status (TAS) among dyslipidemic and hypertensive Nigerian patients with high risk of coronary heart disease. METHODS: The study groups comprised 58 hypertensive adult Nigerians whose fasting plasma total cholesterol (TC) levels were > 5.5mmol/L and with high risk coronary heart disease (CHD) lipid fraction i.e. ‘the ratio of high density lipoprotein cholesterol to total cholesterol’ (HDL-C/TC) < 0.13 were selected for the study. The control groups comprised 58 non hypertensive adult Nigerians with (HDL-C/TC) >0.30. RESULTS: The mean± SD TAS level(1.02 ± 0.15 mmol/L trolox) for males and (0.99 ± 0.17 mmol/L) for females were significantly reduced (p< 0.05) compared to the controls; however(MDA) level(5.15 ± 0.82 mmol/ml) for males and (5.06 ± 0.73mmol/ml) for females were significantly increased (p< 0.01) compared to the controls. The mean ± SD plasma TC and LDL-C malonyl level (5.87 ±0.23mmol/L and 4.65 ±0.34 mmol/L) were significantly increased (p< 0.01) in males hypertensive compared to the control. An inverse correlation between the TAS/TC(r= -0.53, p< 0.001) and TAS/LDL-C(r= -0.50, p< 0.001), however a direct correlation between the MDA/TC(r= 0.51, p< 0.001) and MDA/LDL-C(r= 0.48, p< 0.01) for males hypertensive were found. In female subjects the mean± SD plasma TC (5.95 ±0.13mmol/L) and LDL-C (4.45 ±1.04 mmol/L) were significantly increased (p< 0.05) and (p< 0.01) respectively compared to the controls. Also in hypertensive females inverse correlation between the TAS/TC(r= -0.59, p< 0.001) and TAS/LDL-C(r= –.41, p< 0.01), and a direct correlation between the MDA/TC(r= .48, p< 0.01) and MDA/LDL-C(r= 0.31, p< 0.05) were found.