Background: Diabetic nephropathy is one of the major causes of chronic kidney disease (CKD), consequently progression to end stage renal disease. The previous studies demonstrated that the inhibition on renin-angiotensin-aldosterone system (RAAS) such as by angiotensin converting enzyme inhibitor (ACEI) and angiotensin type I receptor blocker (ARB) reduced proteinuria and slow progression of CKD. Direct renin inhibitor (DRI) theoretical complete block RAAS by reducing plama renin activity, angiotensin I and angiotensin II. The present study aimed to determine the efficacy of aliskiren (DRI) monotherapy on blood pressure control and proteinuria reduction.
Material and Method: Diabetic mellitus patients with estimated glomerular filtration rate (eGFR) > 30 ml/min who had proteinuria > 300 mg/day were enrolled to receive aliskiren 150 mg/day for 2 weeks then 300 mg/day until 24 weeks.
Results: The SBP were significantly decreased form 137.8 to 123.7 (p = 0.01) at 2 weeks, 137.8 to 126.26 (p = 0.04) at 4 weeks and 137.8 to 121 mmHg (p = 0.002) at 24 weeks after treatment, respectively. Similar to SBP, the DBP was significantly decreased from 84.08 to 73.66 (p = 0.04) at 4 weeks and 84.08 to 75.85 mmHg (p = 0.002) at the end of study. Reduction of UPCR showed significantly reduced for 32.65% (p = 0.007) and 45% (p = 0.004) from baseline at 2 weeks and 24 weeks after DRI treatment respectively. Serum creatinine, eGFR and serum potassium were no significant changed from the baseline. There were no harmful adverse reaction in patients who receiving aliskirin.
Conclusion: Aliskiren monotherapy showed significantly reduced proteinuria, good blood pressure control without harmful side effect in overt diabetic nephropathy patients.

Keywords: Direct rennin inhibitor, RAAS system, Diabetic nephropathy, Proteinurea