THE RELATION OF ZONULIN LEVEL TO INFLAMMATION AND METABOLIC CONDITIONS IN PATIENTS WITH CHRONIC KIDNEY DISEASE

Abstract

Introduction and purpose: Chronic Kidney Disease (CKD) is a syndrome characterized by chronic, progressive and irreversible nephron loss, and it is a highly costing public health problem which is becoming increasingly common in society. Inflammation is one of the pathological mechanisms responsible for progressive deterioration of kidney function. Zonulin is identified as pre-haptoglobin 2 and is considered to be a potential inflammatory marker, and a moderate increase in circulating inflammatory biomarkers (CRP, IL-6, LPS and TNF-alpha) is typical for CKD patients. In our study, we aimed to investigate the relationship between zonulin level and disease progression in all stages of CKD (pre-dialysis and hemodialysis patients) and to evaluate its relationship with other inflammatory biomarkers.

Materials and methods: 87 cases were included in our study and it was planned as a prospective cohort study. 37 patients with pre-dialysis, 30 patients with hemodialysis and 20 healthy participants were included in the study. The demographic data of the cases were recorded. Cases were evaluated in 3 groups (healthy participants, pre-dialysis group and hemodialysis group). Serum zonulin, IL-6, LPS, TNF-alpha and IMA levels were observed in all cases. In addition, MDRD, albumin, BMI, Hb, Fe, cholesterol, uric acid, CRP and HbA1C levels of all the cases were also evaluated.

Results: A difference of median values of zonulin is determined among the groups and is statistically significant (p<0.001). The median value was 2,8 in the healthy group, 2,5 in the pre-dialysis group and 17,4 in the hemodialysis group (p<0.001). We found a moderate positive correlation between zonulin levels and all inflammatory biomarkers except IL-6. We found a negative correlation between IL-6 level and zonulin levels. When all the cases were examined, a moderate negative correlation was found between zonu-lin and MDRD, Albumin and Hb. In healthy individuals, no significant correlation was found between zonulin and any biochemical metabolic parameters. No significant correlation was found between zonulin levels and HbA1C, CRP, BMI, age, all cholesterol and triglyceride levels.

Conclusion: Zonulin is a valuable biomarker in diagnosing CKD and monitoring disease progression. We are of the opinion that it will shed light on studies with wider populations examining the zonulin-CKD relationship in the future.