Ehab Abdelatti¹, Tarek E. Korah¹, Alaa Dawood^1,, Ahmed Ragheb¹, Waleed M. Fathy², Waleed Mousa³, Ashraf Anas Zytoon³

Objectives: To evaluate serum relaxin and renal vascular resistance in diabetic and non-diabetic patients with different grades of chronic kidney disease and to correlate serum relaxin to various clinical and Doppler renal hemodynamic parameters. Materials and methods: Sixty patients with chronic kidney disease were divided into two groups: group 1 (30 patients with creatinine clearance of less than 30 ml/minute), and group 2 (30 patients with creatinine clearance of more than 30 ml/minute). Twelve patients (40%) had diabetes mellitus type 2 in group 1 and 18 (60%) in group 2. In addition, group 3 (20 healthy controls), compatible for age and gender, was included. Resistive index and pulsatility index were measured by Doppler ultrasonography of renal arteries. Serum relaxin was measured with ELISA method, and correlated with clinical and Doppler parameters. Results: Serum relaxin levels of groups 1 and 2 were significantly lower than group 3 and that of group 1 were significantly lower than group 2. Resistive index and pulsatility index of groups 1 and 2 were significantly higher than group 3, but there was no significant difference between group 1 and 2. There was an inverse correlation between serum relaxin levels, and serum creatinine in groups 1 and 2. In contrast, there was a positive correlation between serum relaxin and creatinine clearance in groups 1 and 2. There was an inverse correlation between serum relaxin levels, and both resistive index and pulsatility index, in group 2 but not in group 1. Finally, serum relaxin was significantly lower in diabetic compared to non-diabetic patients. Conclusions: We found that serum relaxin levels are significantly lower in patients with advanced stages of chronic kidney disease, as well as, in diabetic compared to non-diabetic patients. Also, serum relaxin is negatively correlated with patients’ age, resistive index and pulsatility index in patients with chronic kidney disease.

relaxin, diabetes mellitus, renal vascular resistance, diabetic nephropathy