The Relationship between Inflammation-Oxidative Stress and Lipoprotein (a) Levels in Healthy Subjects

Lipoprotein (a) [Lp(a)] is a major carrier of pro-atherogenic oxidized phospholipids. It is widely recognized as an independent risk factor for cardiovascular diseases. Oxidative stress caused by oxidized phospholipids is a crucial trigger of chronic vascular inflammation, leading to atherosclerosis. Although various parameters provide information about oxidative stress, the relationship between oxidative stress and Lp(a) levels has not been thoroughly investigated. This study aimed to analyze this relationship and evaluate the diagnostic accuracy of these parameters in identifying high-risk patients.

Healthy subjects were grouped according to Lp(a) levels: those with Lp(a) ≥ 30 mg/dl were classified as high risk, and those with Lp(a) < 30 mg/dl as low risk. Monocyte to high-density lipoprotein ratio (MHR) and lymphocyte to monocyte ratio (LMR) were calculated and compared between groups.

MHR (23.61 ± 6.73 vs. 13.17 ± 4.56; p < 0.0001), LMR (5.17 ± 1.53 vs. 3.99 ± 1.11; p < 0.0001), lymphocyte count (3.15 ± 0.73 vs. 2.48 ± 0.62; p < 0.0001), and monocyte count (0.73 ± 0.23 vs. 0.58 ± 0.15; p < 0.0001) were significantly higher in the high-risk group. There were moderate positive correlations between Lp(a) level and monocyte count (r = 0.467; p < 0.0001), MHR (r = 0.598; p < 0.0001), and LMR (r = 0.464; p < 0.0001). A cut-off value of 14.73 for MHR was associated with 83.55% sensitivity and 83.03% specificity [area under the curve (AUC): 0.859; 95% confidence interval (CI): 0.802-0.925], and a cut-off value of 4.31 for LMR was associated with 81.68% sensitivity and 81.16% specificity (AUC: 0.853; 95% CI: 0.808-0.910) in predicting the high-risk group.

Oxidative stress-inflammation parameters were higher in the high-risk group and positively correlated with Lp(a) levels. Furthermore, MHR and LMR could be used to detect high-risk patients.