|ISSN No. 1606-7754 Vol.17 No.1 April 2009|
Comparative effects of enarapril versus losartan on the prevention of diabetic nephropathy in type 2 diabetes patients with microalbuminuria
Masato Oguri, 1 Toshihiro Utsugi 1 Yoshio Ohyama,2 Tetsuya Nakamura, 3 Shoichi Tomono,4 and Masahiko Kurabayashi1
Department of Medicine and Biological Science, Gunma University Course of Medical Science, Graduate School of Medicine1, Department of General Medicine, Gunma University Hospital2, Clinical Investigation Unit, Gunma University Hospital,3 School of Health Science, Faculty of Medicine4, Gunma University, Maebashi, Gunma, Japan
A prospective randomized open-labeled study was performed to compare the renoprotective effects of enarapril and losartan on the development of microalbuminuria in type 2 diabetic patients with hypertension. Diabetic patients who have hypertension and microalbuminuria at base line (n=19) were recruited. Enarapril (n=11) or losartan (n=8) was randomly chosen by envelope methods and was prescribed for one year. At the end of this study, the blood pressure of patients in these two groups decreased significantly. Urine albumin-creatinine ratio (U-ACR) also decreased in these two groups, however, U-ACR of enarapril group was not significantly different from that of losartan group at any time of this study. Body mass index, HbA1c, blood pressure, and serum lipid profiles were not significantly different between the two groups. From these results, we conclude that the effects of enarapril and losartan on the development of microalbuminuria in type 2 diabetic patients along with hypertension seem to be equivalent in terms of clinical renoprotection.
Key words: Renoprotective effects; diabetic nephropathy; microalbuminuria; angiotensin-converting enzyme inhibitor, angiotensin II receptor blocker
Diabetic nephropathy is a major cause of premature morbidity and mortality in both type 1 and type 2 diabetes mellitus.1,2 A panel of reports have demonstrated that angiotensin converting enzyme inhibitor (ACEi) had renoproctive effects on the progression to overt proteinuria from microalbuminuria in type 1 diabetes patients3,4 and type 2 diabetes patients.5,6 Enarapril (ACEi) treatment has shown renoprotective effects in type 2 diabetes patients with normal blood pressure.7,8 Recently, a line of reports have shown that angiotensin II receptor blockers (ARB) have renoprotective effects on the development of diabetic nephropathy in type 2 diabetes patients suffering from hypertension.9 The results of RENAAL study involving the angiotensin II receptor blocker, losartan,10 and the Irbesartan Type 2 Diabetic Nephropathy Trial (IDNT)11 show that ARBs postpone the progression of type 2 diabetic renal disease at all stages, ranging from microalbuminuria to overt nephropathy and also End-stage renal disease (ESRD). The RENAAL study also showed that losartan improves renal outcomes in patients with type 2 diabetes mellitus and nephropathy over and above that attributable to blood pressure control alone.10 It is well documented that inhibition of the renin-angiotensin system has a renoprotective effect in diabetic patients suffering from hypertension, or even in those with normal blood pressure. However, it is unclear which agent, ACEi (enapranil) or ARB (losartan) has a more beneficial effect on the development and progression of diabetic nephropathy. Recent study showed that combined therapy of ACE inhibitor and angiotensin II receptor blocker has better effects on the development of non-diabetic renal disease compared with monotherapy.12 Thus, this study was initiated to compare the effects of an ACE inhibitor and an angiotensin II receptor blocker on the development of diabetic nephropathy in patients with type 2 diabetes with microalbuminuria. Type 2 diabetes patients suffering from hypertension were examined in a prospective randomized open-labeled study.