Endothelins and Markers of Renal Damage in Recently Diagnosed Hypertensive Patients

Endothelin has been identified as a potent vasoconstrictor. The aim of this study was to evaluate urinary endothelins and their relation to other markers of renal damage, such as microalbuminuria, creatinine, and N-acetyl-beta-glucosaminidase (NAG), in a group of recently diagnosed (less than 1 year) hypertensive subjects and a control group. We selected 50 subjects and divided them into two groups: 27 hypertensive patients (15 females and 12 males) without previous pharmacologic therapy, and 23 healthy, normotensive subjects (12 females and 11 males). All patients underwent a history and physical examination, chest x-ray, electrocardiography, funduscopy, and hematologic and biochemical analyses. Endothelins, microalbuminuria, creatinine, and NAG values were also determined in 24-hour urine samples. Creatinine, microalbuminuria, and NAG values were found to be higher in hypertensive than in normotensive subjects. The hypertensive group showed a nonsignificant elevation of total endothelin. In conclusion, the determination of elevated urinary endothelin does not appear to be an early marker of organ damage in hypertensive subjects. The urinary excretion of protein, creatinine, and NAG was higher in hypertensive subjects. A positive correlation was found between the urinary excretion of endothelins and markers of renal damage, microalbuminuria and NAG values. The relationship between endothelins and hypertension was without statistical significance.