Unravelling the Role of Apolipoprotein-B, Lipoprotein(a), and Homocysteine in Myocardial Infarction: A Tertiary Hospital Case-Control Analysis

OBJECTIVE Cardiovascular disease (CVD) causes approximately 17.9 million deaths globally each year, making it one of the leading causes of mortality. Around 15.00-20.00% of cardiovascular events occur without the presence of traditional risk factors. Some less commonly detected risk factors in CVD patients include hyperhomocysteinemia, metabolic syndrome, lipoprotein(a) (Lp(a)), apolipoprotein B (Apo-B), and elevated procoagulant levels. High levels of homocysteine (Hcy), Lp(a), and Apo-B are linked to an increased risk of myocardial infarction (MI). This study aimed to evaluate the prevalence of elevated Apo-B, Lp(a), and Hcy levels in MI patients from rural areas of Coimbatore District, Tamil Nadu, India. METHODS This case-control study was conducted at a tertiary care hospital from January to December 2021, following institutional ethics committee approval (IHEC/188/BIOCHEMISTRY/2020). Fifty MI patients (aged 30-80 years) and 50 age-sex matched healthy controls were recruited after obtaining informed written consent. Patients with previous MI, CAD, chronic kidney disease, or those on lipid-lowering therapy were excluded. Blood samples were collected under sterile conditions and analyzed for Apo-B, Lp(a) and Hcy using immunoturbidimetric methods. Statistical analysis was performed using SPSS version 24, with independent t-tests and Pearson correlation analysis. RESULTS The average levels of Apo-B, Lp(a) and Hcy in MI patients were 103.2 ± 5.9, 19.7 ± 1.6, and 29.5 ± 2.5, respectively, significantly higher than in the control group. A t-test confirmed a strong association between these risk markers and MI (p = 0.000), indicating their significant role in MI occurrence. ROC curve analysis demonstrated excellent discriminatory ability for Hcy (AUC = 0.868, sensitivity 85%, specificity 90%) with an optimal cut-off of 25 µmol/L. CONCLUSIONS Our findings confirm a strong association between elevated Apo-B, Hcy, and Lp(a) levels and the onset of first-episode MI, especially in patients without prior CVD or lipid-lowering treatment. This underscores the importance of screening for these risk factors, particularly in underserved rural populations, to enhance early detection and preventive care. KEYWORDS apolipoprotein B, cardiovascular risk factors, homo- cysteine, lipoprotein(a), myocardial infarction