Serum N-acetyl-beta-D-gulucosaminidase activity increases in association with insulin resistance in patients with coronary artery disease

Association between pulse wave velocity and a marker of renal tubular damage (N-acetyl-β-D-glucosaminidase) in patients without diabetes

The authors assessed the association between the ratio of urinary activity of N-acetyl-β-D-glucosaminidase (NAG) to creatinine and the brachial-ankle pulse wave velocity (baPWV) in patients without overt diabetes mellitus (DM). This was a cross-sectional study of 233 patients who had an estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m(2) and no history of kidney disease. Patients were divided into two groups: high NAG group (>5.8 U/g creatinine) and low NAG group (≤5.8 U/g creatinine). Mean baPWVs of the high NAG group were significantly higher than those of the low NAG group in both the eGFR ≥30 and <60 tertiles and the eGFR ≥60 and <90 tertiles. The baPWV was positively correlated with NAG in all patients (r=0.341, P<.001). Stepwise multivariate regression analysis showed that the baPWV was significantly related with NAG, age, and systolic blood pressure. Elevated NAG is related to elevated arterial stiffness in patients without DM.

Predictive Potential of Twenty-Two Biochemical Biomarkers for Coronary Artery Disease in Type 2 Diabetes Mellitus

We investigated the potential of a panel of 22 biomarkers to predict the presence of coronary artery disease (CAD) in type 2 diabetes mellitus (DM2) patients. The study enrolled 96 DM2 patients with (n = 75) and without (n = 21) evidence of CAD. We assessed a biochemical profile that included 22 biomarkers: total cholesterol, LDL, HDL, LDL/HDL, triglycerides, glucose, glycated hemoglobin, fructosamine, homocysteine, cysteine, methionine, reduced glutathione, oxidized glutathione, reduced glutathione/oxidized glutathione, L-arginine, asymmetric dimethyl-L-arginine, symmetric dimethyl-L-arginine, asymmetric dimethyl-L-arginine/L-arginine, nitrate plus nitrite, S-nitrosothiols, nitrotyrosine, and n-acetyl-β-glucosaminidase. Prediction models were built using logistic regression models. We found that eight biomarkers (methionine, nitratate plus nitrite, n-acetyl-β-glucosaminidase, BMI, LDL, HDL, reduced glutathione, and L-arginine/asymmetric dimethyl-L-arginine) along with gender and BMI were significantly associated with the odds of CAD in DM2. These preliminary findings support the notion that emerging biochemical markers might be used for CAD prediction in patients with DM2. Our findings warrant further investigation with large, well-designed studies.

Biomarkers of oxidative stress and endothelial dysfunction in glucose intolerance and diabetes mellitus

OBJECTIVES

To evaluate biomarkers of endothelial dysfunction and oxidative stress in glucose intolerance (GI) compared to overt diabetes (DM2).

DESIGN AND METHODS

140 volunteers including 96 with DM2, 32 with GI and 12 controls (C) were studied. (*)NO metabolites, (*)NO synthase inhibitors, thiols and N-acetyl-beta-glucosaminidase (NAGase) activity were analyzed by chemiluminescence, capillary electrophoresis, ELISA and colorimetric assay, respectively.

RESULTS

(*)NO metabolites were higher in GI (NOx: p=0.03; S-nitrosothiols: p=0.001) and DM2 (p=0.006; p=0.0006) groups in relation to group C, while nitrotyrosine was higher only in the DM2 group in comparison to the other groups. NAGase activity was elevated in GI (p=0.003) and DM2 (p=0.0004) groups in relation to group C, as well as, ADMA (p=0.01; p=0.003) and GSSG (p=0.01; p=0.002).

CONCLUSIONS

(*)NO metabolites, (*)NO synthase inhibitors, thiols and NAGase are biomarkers suitable to indicate endothelial dysfunction and oxidative stress in the early stages of impaired response to insulin.

Ascending aortic blood pressure-derived indices are not correlated with the extent of coronary artery disease in patients with impaired left ventricular function

BACKGROUND

Ascending aortic blood pressure-derived indices were shown to be related to coronary atherosclerosis. Unfortunately, most studies published so far included patients with preserved left ventricular function. Therefore, the aim of the present study was to investigate the relation between ascending aortic blood pressure-derived indices and the extent of coronary atherosclerosis in patients with impaired left ventricular function.

METHODS

The study group consisted of 375 patients (302 men and 73 women; mean age: 59.0+/-10.1 years) with angiographically confirmed coronary artery disease and ejection fraction < or =55%. Invasive ascending aortic blood pressure during catheterization and conventional sphygmomanometer measurements were taken.

RESULTS

None of the brachial or aortic blood pressure-derived indices differed between patients with one-, two- and three-vessel coronary artery disease. They were not independently related to the risk of having three-vessel coronary artery disease in none of the constructed models in logistic regression analysis. Moreover, none of the studied indices was correlated with Gensini or severity scores. We also did not find any significant correlation between blood pressure-derived indices and extent of coronary atherosclerosis in patients with ejection fraction < or =25%, 25-40% or >40%.

CONCLUSION

Ascending aortic blood pressure-derived indices are not correlated with the severity of coronary atherosclerosis in patients with coronary artery disease and impaired left ventricular function.