Effect of Radio Contrast Agents on Release of Urinary Endothelin in Diabetic Patients with or Without Renal Impairment

Radiocontrast media (CM) is one of the most common causes of hospital-acquired acute renal failure. The proposed mechanisms include direct nephrotoxicity and renal ischemia. Endothelin-1 has potent vasoconstrictor effects on various vessels, including the renal vasculature. Patients with preexisting renal insufficiency, diabetes mellitus, congestive heart failure or dehydration are at high risk of radio contrast nephropathy. Aim of the Study: Was to examine the role of Endothelin in radiocontrast nephropathy in diabetic patients with or without renal impairment. Material and Methods: Forty patients who have been scheduled for examination using radiocontrast agents were enrolled in the present study. They were collected from cath lab and hemodialysis units in Kasr EL Aini hospitals. They were divided into 4 groups according to their renal function: Group A: 10 patients with DM but normal renal function. Group B: 10 patients with DM and impaired renal function. Group C: 10 patients with DM and advanced kidney disease. Group D: 10 healthy subjects of matched age and sex. Exclusion Criteria: Dehydration and pregnant women. All subjects were subjected to thorough clinical examination, All of them were scheduled for coronary angiography. All subjects undergone the following investigations before infusion of the contrast media (CM) and 48 h after infusion of contrast media: 1Measurement of serum creatinine and blood urea concentration 2Estimation of glomerular filtration rate (GFR). 3Measurement of plasma endothelin (ET) and urinary endothelin concentrations by radio immunoassay. Results: As regards urinary level of ET before radio contrast infusion in different subjects groups the highest levels Correspondence to: Dr. Eman Rushdy, The Department of Internal Medicine, Cairo Univerity, Cairo, Egypt. of ET before radio contrast was for groups B and C (ET levels were 3.64 and 3.76 respectively). Urinary ET was higher in control subjects (group D) than diabetic patients with normal kidney functions (group A). By comparing urinary ET before and after radio contrast infusion; there was no significant difference in groups A and C. While there was a significant rise in urinary ET in groups B and D. With the highest levels of urinary ET noted in group B. There was a positive correlation between urinary ET and blood urea and serum creatinine 48 hours after radiocontrast.