The Role of Small Dense LDL Cholesterol and Ischemia Modified Albumin in Patients with Hyperlipidemia

Background: The analysis of lipid profiles is a crucial step for cardiovascular risk evaluation, prevention, and therapeutic management. Small dense LDL (sdLDL) is one of the distinct subfractions of LDL and is established to have pro-atherogenic properties. Ischemia-modified albumin (IMA) is an early biomarker arising as a result of oxidative stress and ischemia. Objective: This study aimed to determine serum levels of sdLDL and IMA in patients with hyperlipidemia. Methods: Seventy-four patients with hyperlipidemia and 35 healthy controls were included. sdLDL was determined by the heparin-magnesium precipitation method. IMA was measured quantified manually with the colorimetric method. The patient group was divided into three groups: HyperTG (n=11), HyperLDL (n=38), and combined hyperlipidemia (n=25). Results: Median serum sdLDL and IMA levels were higher in patients with hyperlipidemia than healthy participants (both, p<0.001). Elevated sdLDL levels were observed in the HyperLDL group compared to the HyperTG group and the combined hyperlipidemia group (p<0.001). Cut-off values for the detection of patients with hyperlipidemia were >70 mg/dL for sdLDL and >0.7 AU for IMA, and both parameters showed considerably high levels of sensitivity and specificity. Multiple logistic regression analysis revealed that high sdLDL (p=0.042) and high IMA (p<0.001) were independently associated with hyperlipidemia after adjusting for age and sex. Conclusion: Serum sdLDL and IMA levels could be used as biomarkers for dyslipidemia-associated diseases. Further studies with larger sample size are needed to validate the impact of sdLDL on the pathogenesis of atherogenesis, and its value in the diagnosis and prognosis hyperlipidemia. Keywords: Small dense LDL, Lipoprotein, Ischemia modified albumin, IMA, Atherosclerosis