Risk Factors and Protective Role of Section Vitamin C in Coronary Artery Disease: Insights from a Case-control Study

Introduction: Coronary Artery Disease (CAD) is a major global health burden, with oxidative stress playing a critical role in its pathogenesis. Vitamin C, a potent antioxidant, may offer protective effects against CAD; however, evidence from rural Indian populations remains limited. Aim: To investigate the association between plasma vitamin C levels and CAD, and to assess cardiovascular risk factors contributing to CAD among patients attending a tertiary care hospital in rural Southern India. Materials and Methods: A hospital-based prospective case-control study was conducted at the Department of Cardiology, Narayana Medical College, Nellore, Andhra Pradesh, India, between July 2023 and December 2024. The study included 200 participants aged ≥30 years, diagnosed with CAD via Coronary Angiography (CAG). Age- and sexmatched healthy controls were also recruited. Plasma vitamin C levels were measured using ultra-High-Performance Liquid Chromatography (u-HPLC). Statistical analysis was performed using IBM Statistical Package for the Social Sciences (SPSS) version 27.0 and R Studio Version 2024.12.0. Chi-square tests, paired t-tests, Odds Ratios (OR) with 95% Confidence Intervals (CIs), and logistic regression analyses were employed. Results: Of the 200 participants, 100 had CAD (cases) and the remaining 100 were non CAD (controls). The overall mean age of participants was 56.94±11.70 years, with ages ranging from 30 to 83 years. The mean serum vitamin C level was significantly lower among cases (65.53±8.75 μmol/L) than in healthy controls (71.63±7.67 μmol/L; p-value<0.001). Hypertension (OR=1.84; 95% CI: 1.05–3.23; p-value=0.033) and diabetes (OR=2.01; 95% CI: 1.14–3.55; p-value=0.015) were significantly associated with CAD, while dyslipidaemia was not (OR=1.99; 95% CI: 0.95–4.22; p-value=0.066). A significant negative correlation was observed between plasma vitamin C levels and CAD severity (r-value=–0.348; p-value<0.01). In multivariate analysis, increasing age and lower vitamin C levels were found to be significant independent predictors of CAD. Conclusion: Lower plasma vitamin C levels were significantly associated with CAD, supporting its potential protective role. Hypertension and diabetes emerged as major risk factors. These findings highlight the need for preventive strategies focusing on dietary antioxidants and the control of modifiable risk factors to reduce the burden of CAD.