Association of gamma-glutamyl transferase activity with coronary risk factors

BACKGROUND: The association of gamma-glutamyl transferase (GGT) activity with oxidative processes, which play an important role in atherogenesis, has been demonstrated in clinical studies. OBJECTIVE: To investigate the connection betweeen serum GGT activity and conventional atherosclerotic risk factors in patients with coronary artery disease (CAD). METHOD: Patients who were clinically and angiographically diagnosed with CAD (n=235, 166 men, mean [+/- SD] age 60 +/- 10 years) were included in the present study. Parameters, such as serum GGT activity, biochemical measurements, and demographic and electrocardiographic features, were recorded. FINDINGS: The following risk factors for CAD were found: diabetes mellitus (n=72 [30%]), hypertension (n=117 [49.8%]) and smoking (n=116 49.3%]). Significant differences were noted regarding GGT activity between men and women (39.9 +/- 31.9 U/L versus 28.2 +/- 18.2 U/L; P<0.001), and smokers and nonsmokers (40.4 +/- 31.4 U/L versus 32.5 +/- 26.2 U/L; P=0.036). However, there was no significant difference in GGT activity between diabetic and nondiabetic patients, and hypertensive and normotensive patients. In the correlation analysis, a positive association was found between serum GGT activity and the following parameters: triglycerides (r=0.152, P=0.021), C-reactive protein (r=0.431, P<0.0001) and lipoprotein(a) (r=0.431, P=0.0.036). There was a negative correlation between serum GGT activity and high-density lipoprotein cholesterol (r=-0.146, P=0.027). A significant association was also demonstrated between serum GGT and P wave dispersion (P<0.0001). CONCLUSION: As an oxidative stress indicator, GGT activity is higher in CAD patients with risk factors such as atherogenic dyslipidemia, smoking and male sex.