Serum cystatin C and neutrophil gelatinase-associated lipocalin in predicting the severity of coronary artery disease in diabetic patients.

OBJECTIVE: Cystatin C and neutrophil gelatinase-associated lipocalin (NGAL) are biomarkers of renal functions. We evaluated their roles in predicting the severity of coronary artery disease (CAD). METHODS: Fifty-two consecutive type 2 diabetic patients (32 males, 65.7±8.6 years) who underwent coronary angiography (CAG) for stable CAD were included in this single-center, prospective, cross-sectional study. Patients with an estimated glomerular filtration rate <60 mL/min/1.73 m2 and with a history of by-pass surgery and/or coronary stent implantation were excluded. The vessel score and Gensini score were calculated to assess the presence and severity of CAD. Mann-Whitney U test, Spearman test, and multiple linear regression analysis were used for the main statistical analyses. RESULTS: Serum cystatin C levels were higher in patients with multivessel disease than in those with single vessel disease [1260 ng/mL (953-1640) vs. 977 ng/mL (599-1114), p=0.017]. According to the median Gensini score, the higher score group also had higher cystatin C levels than the lower score group [1114 ng/mL (948-1567) vs. 929 ng/mL (569-1156), p=0.009]. However, serum NGAL levels were similar between these subgroups. There was a positive correlation between cystatin C and Gensini score (r=0.334, p=0.016). Multiple linear regression analysis revealed serum cystatin C as an independent predictor of the Gensini score (ß=0.360, t=2.311, p=0.026). These results may aid in defining cystatin C as a surrogate marker of the extent of CAD in further clinical trials. CONCLUSION: Serum Cystatin C, but not NGAL levels, could predict the severity of CAD in diabetic patients.

Use of alpha-lipoic acid in prevention of contrast-induced nephropathy in diabetic patients.

In this prospective study, we aimed to determine the protective antioxidant role of alpha-lipoic acid (ALA) on development of contrast-induced nephropathy (CIN) in diabetic patients undergoing coronary angiography. Seventy-eight diabetic patients undergoing coronary angiography were included. Thirty-nine patients were randomized to control group and 39 patients to ALA group. Both groups were hydrated on the day of angiography, and the ALA group had also received three doses of "Thioctacid 600 mg HR, MEDA Manufacturing GmbH" in pill form. Serum creatinine clearance, cystatin C, and urinary neutrophil gelatinase-associated lipocalin (NGAL) were studied before and after angiography. We defined CIN as either ≥25% or ≥0.5 mg/dL increase in serum creatinine at 48th hour after angiography. Baseline clinical characteristics were similar in both groups. Mehran risk score and creatinine clearance were comparable in control and therapy groups (5.59 ± 1.96 vs. 5.49 ± 1.73, p = 0.54 and 89 ± 21 vs. 96 ± 24, p = 0.13, respectively). The volumes of contrast media (median values of 80 mL vs. 75 mL) and hydration with saline (2862 ± 447 mL vs. 2637 ± 592 mL) were also similar (p > 0.05). The incidence of CIN was the same (8%) in both the groups. Alterations in serum creatinine, cystatin C, and urinary NGAL levels before and after the procedure were comparable between the ALA and control groups (group p-values were >0.05 in two-way repeated measures analysis of variance). We presented for the first time that ALA therapy added to hydration does not decrease the risk of CIN development in diabetic patients undergoing coronary angiography.

Glycoprotein IIIa gene polymorphism and coronary artery disease.

OBJECTIVE: Prevalence of glycoprotein IIIa gene polymorphisms (PIA2) has been reported to be elevated in persons who die of sudden death. PIA2 has been suggested as contributing to the development of atherosclerosis via coronary plaque rupture and thrombus formation. In this prospective study, we investigated the correlation between the PIA2 polymorphism, atherosclerotic plaque burden, and its prognostic significance. METHODS AND RESULTS: One hundred and seventy-eight patients (mean age 51 +/- 9.6 years) suspected to have atherosclerotic coronary artery disease underwent a coronary angiography and were evaluated for gene polymorphisms. Patients were followed up for 4 years for major adverse cardiac events (MACE). Thirty-eight patients (21%) had the PIA2 polymorphism.There was no statistically significant correlation between presence of atherosclerotic plaque burden, severity of coronary artery stenosis, and glycoprotein genotype. During the follow-up there were no significant differences between the 2 groups with regard to MACE. Any cause of death and cardiovascular death were higher in patients with PIA2 polymorphism but these differences were not significant. On univariate analysis, smoking, presence of severe coronary artery disease, and presence of myocardial infarction were correlated with elevated risk of MACE; presence of atypical angina was correlated with fewer MACE. On multivariate analysis, smoking was an independent risk factor for a MACE. On univariate or multivariate analysis, there was no relation between the PIA2 polymorphism and a MACE. CONCLUSIONS: The glycoprotein IIb/IIIa genotype was not shown to indicate the presence of atherosclerotic plaque. There was no correlation between the genotype and plaque vulnerability.