Effects of Losartan on the Urinary Angiotensinogen Excretion in Chronic Non-diabetic Proteinuric Renal Disease

Do, Yeon Sil; Choi, So Yeon; Jang, Eun Hee; Kim, Yong Kyun; Baek, Hyunjeong; Lee, Jung Eun; Huh, Wooseong; Kim, Dae Jung; Oh, Ha Young; Kim, Yoon Goo

Abstract

PURPOSE
There were experimental evidences supporting that intrarenal activation of the renin-angiotensin system contributes to increase BP, proteinuria and urinary angiotensinogen (UAGT) excretion. The purpose of this prospective, open label, controlled study was to investigate the effect of losartan on proteinuria and UAGT excretion in chronic non-diabetic proteinuric (0.4 to 2.0 g/day) renal disease with normal renal function (glomerular filtration rate, GFR>60 mL/min/1.73m2).
METHODS
Thirty two patients were randomly allocated to the losartan group (100 mg/day; n=17) or the control group (n=15). Systolic BP, diastolic BP, estimated GFR, urinary protein to creatinine ratio (UP/Cr), UAGT and plasma angiotensinogen (PAGT) level were compared between two groups at baseline, 6 months and 12 months.
RESULTS
UP/Cr (1.13+/-0.36 g/g vs. 1.07+/-0.34 g/g) was similar in two groups at baseline. Target BP (<140/90 mmHg) was maintained in both groups. After 6 months, UP/Cr (0.63+/-0.35 g/g vs. 0.97+/-0.41 g/g, p<0.01) was significantly decreased in the losartan group compared to the control group. In addition, UAGT (baseline 1.0) was noticeably suppressed in the losartan group (0.72+/-0.42 vs. 1.07+/-0.81, p=0.13). However, PAGT was not changed in both groups. Moreover, our study at 12 months period has demonstrated continuous suppression of UP/Cr (0.79+/-0.53 g/g vs. 1.00+/-0.50 g/g, p=0.06) and UAGT (0.60+/-0.51 vs. 1.51+/-1.36, p<0.05) in the losartan group. UP/Cr was highly correlated with UAGT (Correlation Coefficient=0.74, p<0.01), but not with PAGT.
CONCLUSION
Losartan not only induced a remarkable decrease in proteinuria but also contributed a reduction in UAGT in patients with chronic non-diabetic proteinuric renal disease.