Albuminuria and Endothelial Dysfunction in Patients with Non-Diabetic Chronic Kidney Disease

Abstract

BACKGROUND Albuminuria has been associated with cardiovascular events, but whether such an association can be explained by endothelial dysfunction is not fully understood. In this study, we examined the relationship between the urine albumin-to-creatinine ratio (UACR) and biomarkers of endothelial function in patients with chronic kidney disease (CKD). MATERIAL AND METHODS The cross-sectional associations of renal dysfunction and UACR with procoagulant and inflammatory factors were evaluated for 151 consecutive CKD (stage 3-5) patients. Subjects were grouped by UACR (≤300 mg/g or >300 mg/g) and estimated glomerular filtration rate (eGFR) (30≤ eGFR <60, 15≤ eGFR <30, or eGFR <15 ml/min per 1.73 m²). RESULTS A higher UACR level was associated with an increase in von Willebrand factor antigen (vWF: Ag) levels, vWF activity, factor VIII, interleukin-2, and log (interleukin-6), even after adjustment for risk factors. Linear regression analysis indicated that for every 88.5 mg/g increase in UACR, the vWF activity and factor VIII were elevated by 8.3% and 6.3%, respectively. The factorial design ANOVA data showed no statistically significant interaction between UACR and CKD stage with procoagulant and inflammatory factors. CONCLUSIONS Our study shows an eGFR-independent association of higher UACR with elevations in markers of endothelial dysfunction and inflammatory factors in CKD patients.

Figure 1

The flow chart of the study.

Figure 2

Main effect and interaction between 2 factors: CKD and UACR. (A) Effect of CKD and UACR on vWF activity. (B) Effect of CKD and UACR on vWF Ag. (C) Effect of CKD and UACR on factor VIII.

Figure 3

Inflammatory biomarkers associated with level of eGFR and UACR group. (A) Effect of CKD and UACR on Interleukin-2. (B) Effect of CKD and UACR on log (Interleukin-6). (C) Effect of CKD and UACR on superoxide dismutase.