Malondialdehyde (MDA) and protein carbonyl (PCO) levels as biomarkers of oxidative stress in subjects with familial hypercholesterolemia

Familial hypercholesterolemia (FH) is clinically characterized by elevated total and low-density lipoprotein (LDL) cholesterol levels in plasma, which has high risk for developing atherosclerosis. Increased oxidative stress (OS) and FH have been related to atherosclerosis. The study aims to evaluate oxidative stress in patients with hypercholesterolemia by measuring lipid peroxidation and protein carbonyl (PCO) levels in these patients. PCO in these patients may provide a new diagnostic biomarker for oxidative damage in atherosclerosis. Total cholesterol (Tc), low-density lipoprotein-cholesterol (LDL-c), triglyceride (TG), high-density lipoprotein-cholesterol (HDL-c), lipoprotein(a) (Lp-a) levels and carotid intima-media thickness were measured to evaluate characteristics of patients (11 homozygous and 25 heterozygous) with FH. 25 age–gender–BMI matched healthy control subjects were included in the study for comparison. MDA and PCO levels were significantly higher in homozygous patients compared with those of heterozygous and controls and it was found that they are positively correlated with LDL-c, Tc, Lp-a and IMT while negatively correlated with HDL-c. The heterozygous group also had significantly higher MDA and PCO levels compared with controls. The data obtained could be important for understanding the alterations presented by FH and could be related to their increased risk of developing atherosclerosis. To our knowledge, measurements of PCO in patients with FH are not recorded before and this may be used as a biomarker for protein oxidation, which may play a role in the increased cardiovascular risk of patients with FH.