Aim: Prevalence rates of coronary artery disease (CAD) are reported to be very high in Asian Indians. Conventional risk factors do not explain the high rates of CAD among Indians. Recently, several newer risk factors have been reported to be associated with CAD. We measured tissue plasminogen activator (tPA) antigen, plasminogen activator inhibitor-1 (PAI-1) and fibrinogen levels in South Indian diabetic and non-diabetic subjects with and without CAD.
Methods: Four groups of subjects were studied (all males); Group 1 comprised of non-diabetic subjects without CAD (n=50). Non-diabetic subjects with CAD formed group 2 (n=50); group 3 comprised of type 2 diabetic patients without CAD (n=50) and group 4 consisted of type 2 diabetic patients with CAD (n=50). CAD was diagnosed based on coronary angiographic evidence of severe double or triple vessel disease.
Results: Both diabetic and non-diabetic patients with CAD had significantly higher levels of tPA, PAI-1 and fibrinogen compared to non-diabetic without CAD (p < 0.05). Patients with CAD were distributed more in the upper tertiles of these risk factors compared to those without CAD. A strong association between tPA and PAI-1 was noted in the Pearson's correlation analysis (p < 0.001). Univariate regression analysis showed tPA (Odds ratio--1.12, p = 0.03), PAI-1 (Odds ratio--1.03, p = 0.008), fibrinogen (Odds ratio--1.01, p < 0.0001), serum cholesterol (Odds ratio--1.008, p = 0.04) and hypertension (Odds ratio--3.7, p = 0.0001) to be associated with CAD. Multiple logistic regression analysis revealed hypertension (Odds ratio--4.6, 95% confidence interval--2.113-9.950, p = 0.0001) and fibrinogen (Odds ratio--1.012, 95% confidence interval--1.007-1.018, p = 0.0001) as risk factors for CAD.
Conclusion: Our study suggests that prothrombogenic risk factors particularly fibrinogen may be associated with CAD in South Indians.