Potential role of urinary angiotensinogen in predicting antiproteinuric effects of angiotensin receptor blocker in non-diabetic chronic kidney disease patients: a preliminary report.

OBJECTIVES: Many chronic kidney disease (CKD) patients have persistent overt proteinuria despite angiotensin receptor blocker (ARB) treatment. This study investigated whether the initial difference in intrarenal renin-angiotensin system activity measured with urinary angiotensinogen would affect the antiproteinuric effects of ARB.

METHODS: Between September 2005 and September 2008, in 50 non-diabetic proteinuric CKD patients not taking renin-angiotensin system inhibitors, the urinary protein/creatinine ratio (P/Cr), angiotensinogen/creatinine ratio (AGT/Cr), plasma renin and aldosterone were measured before starting valsartan, and were followed for 18 months.

RESULTS: Patients were divided into three groups according to their initial urinary AGT/Cr. The urinary P/Cr was lower in the low angiotensinogen group, but similar in the high and extremely high angiotensinogen groups (1.3±0.38 vs 2.0±0.92 vs 2.2±0.78). In all groups, the urinary P/Cr was decreased most for the first 6 months. The urinary P/Cr reduction at 6 months was greatest in the high angiotensinogen group (-24.2% vs -46.2% vs -16.4%). The urinary AGT/Cr was decreased most in the high angiotensinogen group. Renal functional deterioration was attenuated in the high angiotensinogen group compared with the extremely high angiotensinogen group.

CONCLUSIONS: The antiproteinuric effects of ARB were different according to the initial urinary angiotensinogen levels. These results suggest the potential value of the initial urinary AGT/Cr for predicting the therapeutic effect of ARB in proteinuric non-diabetic CKD patients.