Introduction: The insertion/deletion (I/D) polymorphism of the angiotensin‑converting enzyme (ACE) gene is associated with younger age at coronary artery disease (CAD) onset. Some data indicate the relationship between the DD genotype and the fibrinogen level. At the same time, the regulation of the renin-angiotensin system differs in women and men.
Objectives: The objective of the study was to evaluate the sex‑dependentassociation of the ACE I/D polymorphism with the plasma fibrinogen level in patients with premature CAD.
Patients and methods: The study included 407 participants with premature CAD: 257 women not older than 55 years and 150 men not older than 45 years. Study participants had at least 1 stenosis ≥50% in a major epicardial coronary artery. The ACE I/D polymorphism (rs4343) was genotyped using polymerase chain reaction. Fibrinogen levels were measured with a modified Clauss method. We found a significant interaction indicating that sex modifies the influence of the I/D polymorphism of the ACE gene on fibrinogen levels (P = 0.02). The highest mean fibrinogen level, adjusted for age and smoking status, was observed in women with the DD genotype (575.7 mg/dl) and it was significantly higher than in men with the DD genotype (367.1 mg/dl; P <0.001) or in women with the ID genotype (491.7 mg/dl; P = 0.04). In men, there was no significant difference in mean adjusted fibrinogen levels across genotypes.
Conclusions: The DD genotype of the ACE gene was associated with higher plasma fibrinogen levels in women with premature CAD yet not in men.