Abstract
BACKGROUND: Coronary artery disease (CAD) is one of the major contributors to death around the globe. This study aimed to investigate the relationship between serum vitamin D levels and the severity of CAD in patients with myocardial infarction (MI). METHODS: This cross-sectional analysis was carried out on 285 patients with MI at the Cardiology Unit of Jinnah Hospital, Lahore, Pakistan, from September 2022 to September 2023. All patients were enrolled through consecutive sampling and predetermined inclusion and exclusion criteria. A self-designed proforma was used for data collection. The patients were divided into two categories according to their CAD severity, using the Gensini score system: non-severe CAD and severe CAD. A comparative analysis between patients with non-severe CAD and severe CAD was performed via independent t-tests and chi-square tests. Pearson's correlation coefficient measured the relationship between serum vitamin D levels and CAD severity. Linear regression analysis evaluated the predictive value of serum vitamin D level for CAD severity. A p-value below 0.05 was set as statistically significant. This data analysis was conducted using IBM SPSS Statistics for Windows, Version 25 (Released 2017; IBM Corp., Armonk, New York, United States). RESULTS: Among the 285 patients, 65.95% (n=188) had non-severe CAD, while 34.05% (n=97) had severe CAD. Patients with severe CAD showed significantly lower mean serum vitamin D levels (14.60 ± 4.91) compared to those with non-severe CAD (28.85 ± 7.98). Statistically significant variations were noted in Gensini scores (p=0.001) and serum vitamin D levels (p=0.002) between the two study cohorts. A strong negative correlation was found between serum vitamin D levels and CAD severity (-r=0.79, 95% CI=-0.75 to -0.85, p<0.001). Moreover, regression analysis validated the use of serum vitamin D level as a significant determinant of CAD severity, with negative values of unstandardized coefficient (-3.50), standardized coefficient (-0.79), and a 95% CI of -1.92 to -5.40 (p<0.001), and an R-squared value of 0.86. CONCLUSIONS: This study observed a significant inverse relationship between vitamin D levels and CAD severity in patients with MI. Lower vitamin D levels were associated with more severe CAD, suggesting its potential as a risk factor and clinical tool for identifying high-risk patients and facilitating timely interventions, including vitamin D supplementation and other cardiovascular risk-reducing strategies.